From patchwork Sun Jun 7 18:18:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591831 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5DA8A618 for ; Sun, 7 Jun 2020 18:19:02 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B3A220663 for ; Sun, 7 Jun 2020 18:19:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LA2MnkDQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B3A220663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 83DCE6E174; Sun, 7 Jun 2020 18:18:57 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2A27C6E174 for ; Sun, 7 Jun 2020 18:18:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553935; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HFSbgw+jMLXkeGeVQko9oA8LjxZw2ty0U8jf3NzNvyw=; b=LA2MnkDQHYRjDasFwOn9GhumKxVjXCjK3MMvr1DTRIyM013FnO0EAW81OjVzl25N8yzyzP jacxbzMLLGCVEotDJPNcnGCez6/Az8lO3mvFA+an3MhHNNQeNddTUy5JpkJykwkOUMVTio cNTL/MmegZnM6HqpoabATuWjv0gRr4k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-200-NXJpie8tPKu-bZrlBUJo-w-1; Sun, 07 Jun 2020 14:18:51 -0400 X-MC-Unique: NXJpie8tPKu-bZrlBUJo-w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9ABFB7BAC; Sun, 7 Jun 2020 18:18:49 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 235DD5C1BD; Sun, 7 Jun 2020 18:18:46 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 01/15] ACPI / LPSS: Resume Cherry Trail PWM controller in no-irq phase Date: Sun, 7 Jun 2020 20:18:26 +0200 Message-Id: <20200607181840.13536-2-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The DSDTs on most Cherry Trail devices have an ugly clutch where the PWM controller gets poked from the _PS0 method of the graphics-card device: Local0 = PSAT /* \_SB_.PCI0.GFX0.PSAT */ If (((Local0 & 0x03) == 0x03)) { PSAT &= 0xFFFFFFFC Local1 = PSAT /* \_SB_.PCI0.GFX0.PSAT */ RSTA = Zero RSTF = Zero RSTA = One RSTF = One PWMB |= 0xC0000000 PWMC = PWMB /* \_SB_.PCI0.GFX0.PWMB */ } Where PSAT is the power-status register of the PWM controller, so if it is in D3 when the GFX0 device's PS0 method runs then it will turn it on and restore the PWM ctrl register value it saved from its PS3 handler. Note not only does it restore it, it ors it with 0xC0000000 turning it on at a time where we may not want it to get turned on at all. The pwm_get call which the i915 driver does to get a reference to the PWM controller, already adds a device-link making the GFX0 device a consumer of the PWM device. So it should already have been resumed when the above AML runs and the AML should thus not do its undesirable poking of the PWM controller register. But the PCI core powers on PCI devices in the no-irq resume phase and thus calls the troublesome PS0 method in the no-irq resume phase. Where as LPSS devices by default are resumed in the early resume phase. This commit sets the resume_from_noirq flag in the bsw_pwm_dev_desc struct, so that Cherry Trail PWM controllers will be resumed in the no-irq phase. Together with the device-link added by the pwm-get this ensures that the PWM controller will be on when the troublesome PS0 method runs, which stops it from poking the PWM controller. Signed-off-by: Hans de Goede --- drivers/acpi/acpi_lpss.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 5e2bfbcf526f..67892fc0b822 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -257,6 +257,7 @@ static const struct lpss_device_desc bsw_pwm_dev_desc = { .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, .prv_offset = 0x800, .setup = bsw_pwm_setup, + .resume_from_noirq = true, }; static const struct lpss_device_desc byt_uart_dev_desc = { From patchwork Sun Jun 7 18:18:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591837 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B931B618 for ; Sun, 7 Jun 2020 18:19:05 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 97355207F9 for ; Sun, 7 Jun 2020 18:19:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FmjY2zPp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97355207F9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2C9F66E17F; Sun, 7 Jun 2020 18:19:01 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 023C76E17F for ; Sun, 7 Jun 2020 18:18:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553938; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Z03aB3lpL2fP/UUzJpbbrqQ4nW5d9M/aiy+eur4dVlU=; b=FmjY2zPp6XJXSNQgLfy6F174vm/JE8ilDE3+C//qjkEg6ofEIAGgphdo8JAJJJ4rYwwgnG f/maIS8yPdSjNr9vF1T6/wprMxmPKICDpjlZNPodUSMeykM0Z3qeUWCmjX3+F+bcY3YpM2 DIzL5ApSiA/LCt6a/zO97jQ14/qFtjc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-191-k84aKQmNPX69czyOuBRvzw-1; Sun, 07 Jun 2020 14:18:54 -0400 X-MC-Unique: k84aKQmNPX69czyOuBRvzw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 64EED1005510; Sun, 7 Jun 2020 18:18:52 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id E2D1A5C1BD; Sun, 7 Jun 2020 18:18:49 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 02/15] ACPI / LPSS: Save Cherry Trail PWM ctx registers only once (at activation) Date: Sun, 7 Jun 2020 20:18:27 +0200 Message-Id: <20200607181840.13536-3-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The DSDTs on most Cherry Trail devices have an ugly clutch where the PWM controller gets turned off from the _PS3 method of the graphics-card dev: Method (_PS3, 0, Serialized) // _PS3: Power State 3 { ... PWMB = PWMC /* \_SB_.PCI0.GFX0.PWMC */ PSAT |= 0x03 Local0 = PSAT /* \_SB_.PCI0.GFX0.PSAT */ ... } Where PSAT is the power-status register of the PWM controller. Since the i915 driver will do a pwm_get on the pwm device as it uses it to control the LCD panel backlight, there is a device-link marking the i915 device as a consumer of the pwm device. So that the PWM controller will always be suspended after the i915 driver suspends (which is the right thing to do). This causes the above GFX0 PS3 AML code to run before acpi_lpss.c calls acpi_lpss_save_ctx(). So on these devices the PWM controller will already be off when acpi_lpss_save_ctx() runs. This causes it to read/save all 1-s (0xffffffff) as ctx register values. When these bogus values get restored on resume the PWM controller actually keeps working, since most bits are reserved, but this does set bit 3 of the LPSS General purpose register, which for the PWM controller has the following function: "This bit is re-used to support 32kHz slow mode. Default is 19.2MHz as PWM source clock". This causes the clock of the PWM controller to switch from 19.2MHz to 32KHz, which is a slow-down of a factor 600. Surprisingly enough so far there have been few bug reports about this. This is likely because the i915 driver was hardcoding the PWM frequency to 46 KHz, which divided by 600 would result in a PWM frequency of approx. 78 Hz, which mostly still works fine. There are some bug reports about the LCD backlight flickering after suspend/resume which are likely caused by this issue. But with the upcoming patch-series to finally switch the i915 drivers code for external PWM controllers to use the atomic API and to honor the PWM frequency specified in the video BIOS (VBT), this becomes a much bigger problem. On most cases the VBT specifies either 200 Hz or 20 KHz as PWM frequency, which with the mentioned issue ends up being either 1/3 Hz, where the backlight actually visible blinks on and off every 3s, or in 33 Hz and horrible flickering of the backlight. There are a number of possible solutions to this problem: 1. Make acpi_lpss_save_ctx() run before GFX0._PS3 Pro: Clean solution from pov of not medling with save/restore ctx code Con: As mentioned the current ordering is the right thing to do Con: Requires assymmetry in at what suspend/resume phase we do the save vs restore, requiring more suspend/resume ordering hacks in already convoluted acpi_lpss.c suspend/resume code. 2. Do some sort of save once mode for the LPSS ctx Pro: Reasonably clean Con: Needs a new LPSS flag + code changes to handle the flag 3. Detect we have failed to save the ctx registers and do not restore them Pro: Not PWM specific, might help with issues on other LPSS devices too Con: If we can get away with not restoring the ctx why bother with it at all? 4. Do not save the ctx for CHT PWM controllers Pro: Clean, as simple as dropping a flag? Con: Not so simple as dropping a flag, needs a new flag to ensure that we still do lpss_deassert_reset() on device activation. 5. Make the pwm-lpss code fixup the LPSS-context registers Pro: Keeps acpi_lpss.c code clean Con: Moves knowledge of LPSS-context into the pwm-lpss.c code 1 and 5 both do not seem to be a desirable way forward. 3 and 4 seem ok, but they both assume that restoring the LPSS-context registers is not necessary. I have done a couple of test and those do show that restoring the LPSS-context indeed does not seem to be necessary on devices using s2idle suspend (and successfully reaching S0i3). But I have no hardware to test deep / S3 suspend. So I'm not sure that not restoring the context is safe. That leaves solution 2, which is about as simple / clean as 3 and 4, so this commit fixes the described problem by implementing a new LPSS_SAVE_CTX_ONCE flag and setting that for the CHT PWM controllers. Signed-off-by: Hans de Goede --- Changes in v2: - Move #define LPSS_SAVE_CTX_ONCE define to group it with LPSS_SAVE_CTX --- drivers/acpi/acpi_lpss.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 67892fc0b822..a8d7d83ac761 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -67,7 +67,15 @@ ACPI_MODULE_NAME("acpi_lpss"); #define LPSS_CLK_DIVIDER BIT(2) #define LPSS_LTR BIT(3) #define LPSS_SAVE_CTX BIT(4) -#define LPSS_NO_D3_DELAY BIT(5) +/* + * For some devices the DSDT AML code for another device turns off the device + * before our suspend handler runs, causing us to read/save all 1-s (0xffffffff) + * as ctx register values. + * Luckily these devices always use the same ctx register values, so we can + * work around this by saving the ctx registers once on activation. + */ +#define LPSS_SAVE_CTX_ONCE BIT(5) +#define LPSS_NO_D3_DELAY BIT(6) struct lpss_private_data; @@ -254,7 +262,7 @@ static const struct lpss_device_desc byt_pwm_dev_desc = { }; static const struct lpss_device_desc bsw_pwm_dev_desc = { - .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, + .flags = LPSS_SAVE_CTX_ONCE | LPSS_NO_D3_DELAY, .prv_offset = 0x800, .setup = bsw_pwm_setup, .resume_from_noirq = true, @@ -885,9 +893,14 @@ static int acpi_lpss_activate(struct device *dev) * we have to deassert reset line to be sure that ->probe() will * recognize the device. */ - if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE)) lpss_deassert_reset(pdata); +#ifdef CONFIG_PM + if (pdata->dev_desc->flags & LPSS_SAVE_CTX_ONCE) + acpi_lpss_save_ctx(dev, pdata); +#endif + return 0; } @@ -1031,7 +1044,7 @@ static int acpi_lpss_resume(struct device *dev) acpi_lpss_d3_to_d0_delay(pdata); - if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + if (pdata->dev_desc->flags & (LPSS_SAVE_CTX | LPSS_SAVE_CTX_ONCE)) acpi_lpss_restore_ctx(dev, pdata); return 0; From patchwork Sun Jun 7 18:18:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591843 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F790138C for ; Sun, 7 Jun 2020 18:19:08 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5C8FB20663 for ; Sun, 7 Jun 2020 18:19:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dDjRB/Rv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C8FB20663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 85E0F6E18E; Sun, 7 Jun 2020 18:19:03 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 241296E18E for ; Sun, 7 Jun 2020 18:19:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553941; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cWk/To7CyUecrdM3R5nBGROQ1lUsEmkED3rqhu0hGtk=; b=dDjRB/RvQ+CK4xVKtvIv7EN+ScdwMAf4sOxoPg1yW53TqyOie7mM/aZpjLwufofEqYMhnB qXXSni955bDIKUuVCh9BuhLqz7jORZzymAW+6GO9FAwUdQNqC+5K2mZePRm5fJpNnipqPP xUeXwNUOGsAdOvqS5N/MdG9Qzu9FNzs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-129-13oHECoTMi6A5Xa-mPGvVQ-1; Sun, 07 Jun 2020 14:18:57 -0400 X-MC-Unique: 13oHECoTMi6A5Xa-mPGvVQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3419D107ACCA; Sun, 7 Jun 2020 18:18:55 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id ABDB75C1BD; Sun, 7 Jun 2020 18:18:52 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 03/15] pwm: lpss: Add range limit check for the base_unit register value Date: Sun, 7 Jun 2020 20:18:28 +0200 Message-Id: <20200607181840.13536-4-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" When the user requests a high enough period ns value, then the calculations in pwm_lpss_prepare() might result in a base_unit value of 0. But according to the data-sheet the way the PWM controller works is that each input clock-cycle the base_unit gets added to a N bit counter and that counter overflowing determines the PWM output frequency. Adding 0 to the counter is a no-op. The data-sheet even explicitly states that writing 0 to the base_unit bits will result in the PWM outputting a continuous 0 signal. base_unit values > (base_unit_range / 256), or iow base_unit values using the 8 most significant bits, cause loss of resolution of the duty-cycle. E.g. assuming a base_unit_range of 65536 steps, then a base_unit value of 768 (256 * 3), limits the duty-cycle resolution to 65536 / 768 = 85 steps. Clamp the max base_unit value to base_unit_range / 32 to ensure a duty-cycle resolution of at least 32 steps. This limits the maximum output frequency to 600 KHz / 780 KHz depending on the base clock. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-lpss.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index 9d965ffe66d1..cae74ce61654 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -97,6 +97,14 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, freq *= base_unit_range; base_unit = DIV_ROUND_CLOSEST_ULL(freq, c); + /* + * base_unit must not be 0 and for values > (base_unit_range / 256) + * (values using the 8 most significant bits) the duty-cycle resolution + * degrades. Clamp the maximum value to base_unit_range / 32 which + * leaves a duty-cycle resolution of 32 steps. + */ + base_unit = clamp_t(unsigned long long, base_unit, 1, + base_unit_range / 32); on_time_div = 255ULL * duty_ns; do_div(on_time_div, period_ns); @@ -105,7 +113,6 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, orig_ctrl = ctrl = pwm_lpss_read(pwm); ctrl &= ~PWM_ON_TIME_DIV_MASK; ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT); - base_unit &= base_unit_range; ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT; ctrl |= on_time_div; From patchwork Sun Jun 7 18:18:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591845 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 44397618 for ; Sun, 7 Jun 2020 18:19:10 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 21EDB20663 for ; Sun, 7 Jun 2020 18:19:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cVOIu3+l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 21EDB20663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 925526E195; Sun, 7 Jun 2020 18:19:05 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) by gabe.freedesktop.org (Postfix) with ESMTPS id 291226E193 for ; Sun, 7 Jun 2020 18:19:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553943; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+z9T5HyNDydCcPP8B4mlCiq74wNu8VINCuUykY7+WkQ=; b=cVOIu3+l9NfvtYtaSGMjvxplnVlX+nzZxzT/fJKCBDR7ukeHrI3CHl1rjdGutqFd2rUmv3 XUt9vCxOUXiiJH5iPgi/sBDAgtE4511VBh4QBBBuLfLhjKFfdhnUlpI2FDZdgSRu+sLvfb JD4QJA4jQyjY8I2hwZawekBJkyrgRJ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-227-vb8HK3sSOoeJFfxZyuHNwA-1; Sun, 07 Jun 2020 14:19:00 -0400 X-MC-Unique: vb8HK3sSOoeJFfxZyuHNwA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C98D81005510; Sun, 7 Jun 2020 18:18:58 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7BB0B5C1BD; Sun, 7 Jun 2020 18:18:55 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 04/15] pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare() Date: Sun, 7 Jun 2020 20:18:29 +0200 Message-Id: <20200607181840.13536-5-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" According to the data-sheet the way the PWM controller works is that each input clock-cycle the base_unit gets added to a N bit counter and that counter overflowing determines the PWM output frequency. So assuming e.g. a 16 bit counter this means that if base_unit is set to 1, after 65535 input clock-cycles the counter has been increased from 0 to 65535 and it will overflow on the next cycle, so it will overflow after every 65536 clock cycles and thus the calculations done in pwm_lpss_prepare() should use 65536 and not 65535. This commit fixes this. Note this also aligns the calculations in pwm_lpss_prepare() with those in pwm_lpss_get_state(). Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko --- drivers/pwm/pwm-lpss.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index cae74ce61654..a764e062103b 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -93,7 +93,7 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, * The equation is: * base_unit = round(base_unit_range * freq / c) */ - base_unit_range = BIT(lpwm->info->base_unit_bits) - 1; + base_unit_range = BIT(lpwm->info->base_unit_bits); freq *= base_unit_range; base_unit = DIV_ROUND_CLOSEST_ULL(freq, c); @@ -112,7 +112,7 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, orig_ctrl = ctrl = pwm_lpss_read(pwm); ctrl &= ~PWM_ON_TIME_DIV_MASK; - ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT); + ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT); ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT; ctrl |= on_time_div; From patchwork Sun Jun 7 18:18:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591853 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 257B6138C for ; Sun, 7 Jun 2020 18:19:13 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 036A720760 for ; Sun, 7 Jun 2020 18:19:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NRJ3eVbl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 036A720760 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D3FC26E1AA; Sun, 7 Jun 2020 18:19:09 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4A3B36E190 for ; Sun, 7 Jun 2020 18:19:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553947; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2T3eRMbyvrcLqFR6Ify+n4ofIKOt8s+1Ga6XZ53Ws0g=; b=NRJ3eVblCWQwJms90/vSrLgkLUFvgUHSajY6OP/rfFhd+uH2pFmtBFOeJ5OQjyAsoghdE2 xBLkEHQeiEAtTrHlwPDvER287GBcTiIzzooBxCHwp0N8xqIxKIDpp5R2qX+2oEkTakCGHq latz9cpgJf/LcjlMTfzpIyJnuxiPilA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-358-D8qt0zuLPa6G1IRqiXZPDQ-1; Sun, 07 Jun 2020 14:19:03 -0400 X-MC-Unique: D8qt0zuLPa6G1IRqiXZPDQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9CA7880B70A; Sun, 7 Jun 2020 18:19:01 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1DEA35C1BD; Sun, 7 Jun 2020 18:18:58 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 05/15] pwm: lpss: Set SW_UPDATE bit when enabling the PWM Date: Sun, 7 Jun 2020 20:18:30 +0200 Message-Id: <20200607181840.13536-6-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On the LPSS PWM controller found on Bay Trail (BYT) and Cherry Trail (CHT) platforms, the following sequence results in an output duty-cycle of 100% independent of what the duty-cycle requested in the ctrl-reg is: 1. Clear ENABLE bit in ctrl register 2. Let the machine reach a S0i3 low power state 3. Set the ENABLE bit in the ctrl register The LPSS PWM controller has a mechanism where the ctrl register value and the actual base-unit and on-time-div values used are latched. When software sets the SW_UPDATE bit then at the end of the current PWM cycle, the new values from the ctrl-register will be latched into the actual registers, and the SW_UPDATE bit will be cleared. Note on BYT and CHT the ENABLE bit must be set before waiting for the SW_UPDATE bit to clear, otherwise the SW_UPDATE bit will never clear (this is indicated in the pwm-lpss.c code by lpwm->info->bypass being false). My theory about why this is happening is that when we hit S0i3 the part which holds the latched values gets turned off and when its turned back on again at least the on-time-div value has been lost and gets reset to 0 which corresponds to an output duty-cycle of 100%. Testing has shown that setting the SW_UPDATE bit to request latching the ctrl-register values into the actual registers (again) fixes this, confirming this theory. In the past there have been issues where setting the SW_UPDATE bit when nothing has changed would lead to the next ctrl register changing being ignored, see commit 2153bbc12f77 ("pwm: lpss: Only set update bit if we are actually changing the settings"), so we should only set the SW_UPDATE bit when actually changing the ENABLE bit from 0 to 1. When looking into how to fix this I noticed that on platforms where lpwm->info->bypass == false we unnecessarily do 2 read-modify-write cycles of the ctrl register, one to set the base-unit and on-time-div, immediately followed by another to set the ENABLE bit. This commit fixes the 100% duty cycle issue by folding the setting of the ENABLE bit into pwm_lpss_prepare(), which already checks if any bits in the ctrl-register have actually changed and if that is the case then sets the SW_UPDATE bit. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-lpss.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index a764e062103b..2cb0e2a9c08c 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -80,7 +80,7 @@ static inline int pwm_lpss_is_updating(struct pwm_device *pwm) } static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, - int duty_ns, int period_ns) + int duty_ns, int period_ns, bool enable) { unsigned long long on_time_div; unsigned long c = lpwm->info->clk_rate, base_unit_range; @@ -115,6 +115,8 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm, ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT); ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT; ctrl |= on_time_div; + if (enable) + ctrl |= PWM_ENABLE; if (orig_ctrl != ctrl) { pwm_lpss_write(pwm, ctrl); @@ -142,8 +144,9 @@ static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm, pm_runtime_put(chip->dev); return ret; } - pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period); - pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false); + pwm_lpss_prepare(lpwm, pwm, + state->duty_cycle, state->period, + lpwm->info->bypass == false); ret = pwm_lpss_wait_for_update(pwm); if (ret) { pm_runtime_put(chip->dev); @@ -154,7 +157,8 @@ static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm, ret = pwm_lpss_is_updating(pwm); if (ret) return ret; - pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period); + pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, + state->period, false); return pwm_lpss_wait_for_update(pwm); } } else if (pwm_is_enabled(pwm)) { From patchwork Sun Jun 7 18:18:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591857 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C3B0E618 for ; Sun, 7 Jun 2020 18:19:14 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A1C242075A for ; Sun, 7 Jun 2020 18:19:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BlFlGxtV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1C242075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 71F826E190; Sun, 7 Jun 2020 18:19:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7C7D36E1A3 for ; Sun, 7 Jun 2020 18:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553949; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OyDeV0Z/UvojkUctUmW3EntL3TMpO41rrKpUP7M6VZg=; b=BlFlGxtVdYBxUc6GwjmPaZV5yc//ihSYZIuqWlfxSLNc+vCri7gZhcoKC9eSHrk41xNwvt bI7Kh2TSuKw0jWOrrG5L9rT/dscxlXy+C1lx7pd6C0uAB7PB+9TYVDMDRpoXfI56voxPIS PmHxB5lQJk8mIRAIPMEI7LtRR+U6VEw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-400-fVAAphEBPgm62TEAu2EzzQ-1; Sun, 07 Jun 2020 14:19:07 -0400 X-MC-Unique: fVAAphEBPgm62TEAu2EzzQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C15C7107ACCA; Sun, 7 Jun 2020 18:19:05 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5D455C1BD; Sun, 7 Jun 2020 18:19:01 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 06/15] pwm: crc: Fix period / duty_cycle times being off by a factor of 256 Date: Sun, 7 Jun 2020 20:18:31 +0200 Message-Id: <20200607181840.13536-7-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" While looking into adding atomic-pwm support to the pwm-crc driver I noticed something odd, there is a PWM_BASE_CLK define of 6 MHz and there is a clock-divider which divides this with a value between 1-128, and there are 256 duty-cycle steps. The pwm-crc code before this commit assumed that a clock-divider setting of 1 means that the PWM output is running at 6 MHZ, if that is true, where do these 256 duty-cycle steps come from? This would require an internal frequency of 256 * 6 MHz = 1.5 GHz, that seems unlikely for a PMIC which is using a silicon process optimized for power-switching transistors. It is way more likely that there is an 8 bit counter for the duty cycle which acts as an extra fixed divider wrt the PWM output frequency. The main user of the pwm-crc driver is the i915 GPU driver which uses it for backlight control. Lets compare the PWM register values set by the video-BIOS (the GOP), assuming the extra fixed divider is present versus the PWM frequency specified in the Video-BIOS-Tables: Device: PWM Hz set by BIOS PWM Hz specified in VBT Asus T100TA 200 200 Asus T100HA 200 200 Lenovo Miix 2 8 23437 20000 Toshiba WT8-A 23437 20000 So as we can see if we assume the extra division by 256 then the register values set by the GOP are an exact match for the VBT values, where as otherwise the values would be of by a factor of 256. This commit fixes the period / duty_cycle calculations to take the extra division by 256 into account. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-crc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 272eeb071147..43fc912c1fe9 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -21,8 +21,10 @@ #define PWM_MAX_LEVEL 0xFF -#define PWM_BASE_CLK 6000000 /* 6 MHz */ -#define PWM_MAX_PERIOD_NS 21333 /* 46.875KHz */ +#define PWM_BASE_CLK_MHZ 6 /* 6 MHz */ +#define PWM_MAX_PERIOD_NS 5461333 /* 183 Hz */ + +#define NSEC_PER_MHZ 1000 /** * struct crystalcove_pwm - Crystal Cove PWM controller @@ -72,7 +74,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, /* changing the clk divisor, need to disable fisrt */ crc_pwm_disable(c, pwm); - clk_div = PWM_BASE_CLK * period_ns / NSEC_PER_SEC; + clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, clk_div | PWM_OUTPUT_ENABLE); From patchwork Sun Jun 7 18:18:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591861 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14FB9138C for ; Sun, 7 Jun 2020 18:19:17 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E6AD22076C for ; Sun, 7 Jun 2020 18:19:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SBi+Ppwv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6AD22076C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0491A6E1B6; Sun, 7 Jun 2020 18:19:15 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 268E46E1B1 for ; Sun, 7 Jun 2020 18:19:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553952; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=enDmigKPZ6hGhbnIXLCk/1+mW1SDxZUvwf02x4z1WGI=; b=SBi+Ppwvn1GmOj5rahjbmRCUsN3OO+0K1777pF4Yzw4MHBWeOlUvLrzROY/7eH84dW+ISN oAwGJ0yO2/nPpcpjs61fk6857LIFFsHsyVjRcKtWxq9uhT0RHeq1EKJ849nu1TYTrQkoSY tsIcv+02UCimfSSJ2Ldliw4hHPSLMYE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-486-CJJhDXefOBaofatwiqt3zw-1; Sun, 07 Jun 2020 14:19:10 -0400 X-MC-Unique: CJJhDXefOBaofatwiqt3zw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 88C36464; Sun, 7 Jun 2020 18:19:08 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 168D45C1BD; Sun, 7 Jun 2020 18:19:05 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 07/15] pwm: crc: Fix off-by-one error in the clock-divider calculations Date: Sun, 7 Jun 2020 20:18:32 +0200 Message-Id: <20200607181840.13536-8-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The CRC PWM controller has a clock-divider which divides the clock with a value between 1-128. But as can seen from the PWM_DIV_CLK_xxx defines, this range maps to a register value of 0-127. So after calculating the clock-divider we must subtract 1 to get the register value, unless the requested frequency was so high that the calculation has already resulted in a (rounded) divider value of 0. Note that before this fix, setting a period of PWM_MAX_PERIOD_NS which corresponds to the max. divider value of 128 could have resulted in a bug where the code would use 128 as divider-register value which would have resulted in an actual divider value of 0 (and the enable bit being set). A rounding error stopped this bug from actually happen. This same rounding error means that after the subtraction of 1 it is impossible to set the divider to 128. Also bump PWM_MAX_PERIOD_NS by 1 ns to allow setting a divider of 128 (register-value 127). Signed-off-by: Hans de Goede --- drivers/pwm/pwm-crc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 43fc912c1fe9..5ba2a65c524c 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -22,7 +22,7 @@ #define PWM_MAX_LEVEL 0xFF #define PWM_BASE_CLK_MHZ 6 /* 6 MHz */ -#define PWM_MAX_PERIOD_NS 5461333 /* 183 Hz */ +#define PWM_MAX_PERIOD_NS 5461334 /* 183 Hz */ #define NSEC_PER_MHZ 1000 @@ -75,6 +75,9 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, /* changing the clk divisor, need to disable fisrt */ crc_pwm_disable(c, pwm); clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); + /* clk_div 1 - 128, maps to register values 0-127 */ + if (clk_div > 0) + clk_div--; regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, clk_div | PWM_OUTPUT_ENABLE); From patchwork Sun Jun 7 18:18:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591869 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFFB31391 for ; Sun, 7 Jun 2020 18:19:19 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AC67F2076C for ; Sun, 7 Jun 2020 18:19:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ACsoGBqV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC67F2076C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A3DFA6E1A3; Sun, 7 Jun 2020 18:19:18 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id E4C016E1A3 for ; Sun, 7 Jun 2020 18:19:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553956; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bzR5wJk9hqmAJndMjPuTZRIr7gmgMinW4Tv3VnbU63Q=; b=ACsoGBqVX7pEdPEZTEs2NM8bx+tv7kgpL6+dY2chmeWqdT7NI7Ck9O316bM1hYljOviODB BX2I8d7Qr4CG+VY3jAIkNyWwCoz8VoOMF2i4Jv0tmdtSbRWsPUD2e/jQ43oSJeqY0yQ7C/ PJg0Aim3d6jcLsJwG9ShfAeLh1KM8/g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-502-Dlo-8yqPM_S6Y7K1Z09CFA-1; Sun, 07 Jun 2020 14:19:13 -0400 X-MC-Unique: Dlo-8yqPM_S6Y7K1Z09CFA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4F0AD80B70A; Sun, 7 Jun 2020 18:19:11 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id D21115C1BD; Sun, 7 Jun 2020 18:19:08 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 08/15] pwm: crc: Fix period changes not having any effect Date: Sun, 7 Jun 2020 20:18:33 +0200 Message-Id: <20200607181840.13536-9-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The pwm-crc code is using 2 different enable bits: 1. bit 7 of the PWM0_CLK_DIV (PWM_OUTPUT_ENABLE) 2. bit 0 of the BACKLIGHT_EN register I strongly suspect that the BACKLIGHT_EN register at address 0x51 really controls a separate output-only GPIO which is connected to the LCD panels backlight-enable input. Like how the PANEL_EN register at address 0x52 controls an output-only GPIO which is earmarked for the LCD panel's enable pin. If this is correct then this GPIO should really be added to the gpio-crystalcove.c driver and the PWM driver should stop poking it. But I've been unable to come up with a definitive answer here, so I'm keeping this as is for now. As the comment in the old code already indicates we must disable the PWM before we can change the clock divider. But the crc_pwm_disable() and crc_pwm_enable() calls the old code make for this only change the BACKLIGHT_EN register; and the value of that register does not matter for changing the period / the divider. What does matter is that the PWM_OUTPUT_ENABLE bit must be cleared before a new value can be written. This commit modifies crc_pwm_config() to clear PWM_OUTPUT_ENABLE instead when changing the period, so that period changes actually work. Note this fix will cause a significant behavior change on some devices using the CRC PWM output to drive their backlight. Before the PWM would always run with the output frequency configured by the BIOS at boot, now the period time specified by the i915 driver will actually be honored. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-crc.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 5ba2a65c524c..ef49a6e3c4d6 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -72,8 +72,9 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, if (pwm_get_period(pwm) != period_ns) { int clk_div; - /* changing the clk divisor, need to disable fisrt */ - crc_pwm_disable(c, pwm); + /* changing the clk divisor, clear PWM_OUTPUT_ENABLE first */ + regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0); + clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); /* clk_div 1 - 128, maps to register values 0-127 */ if (clk_div > 0) @@ -81,9 +82,6 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, clk_div | PWM_OUTPUT_ENABLE); - - /* enable back */ - crc_pwm_enable(c, pwm); } /* change the pwm duty cycle */ From patchwork Sun Jun 7 18:18:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591877 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8A9D3138C for ; Sun, 7 Jun 2020 18:19:23 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 681082074B for ; Sun, 7 Jun 2020 18:19:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NOQm1aJB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 681082074B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 50D2F6E219; Sun, 7 Jun 2020 18:19:22 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 854136E219 for ; Sun, 7 Jun 2020 18:19:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553959; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VQY8iWdUxeaJSt6cQARP9fYgzH7R1SLcHzNz2kLwBS0=; b=NOQm1aJBbfqCQrm3SaUmpkqC2OBvS7E7SdRrEFdIXYbozpSKTpkPekKNPcdfzuzFGv0WJX 6gKnwCHeFWXwN7hlcVHt8wIJ4GKU2309OUIyInMAtYSrKoU5zbdGI1FaaQUZUBozKWH2l1 SyAaCsOTo5K5CzKz6OhB1pX9v3PhMnQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-234-97ED1xytN9CaHIlM8AERcg-1; Sun, 07 Jun 2020 14:19:15 -0400 X-MC-Unique: 97ED1xytN9CaHIlM8AERcg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1ADD8107ACCA; Sun, 7 Jun 2020 18:19:14 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9629C5C1BD; Sun, 7 Jun 2020 18:19:11 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 09/15] pwm: crc: Enable/disable PWM output on enable/disable Date: Sun, 7 Jun 2020 20:18:34 +0200 Message-Id: <20200607181840.13536-10-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The pwm-crc code is using 2 different enable bits: 1. bit 7 of the PWM0_CLK_DIV (PWM_OUTPUT_ENABLE) 2. bit 0 of the BACKLIGHT_EN register So far we've kept the PWM_OUTPUT_ENABLE bit set when disabling the PWM, this commit makes crc_pwm_disable() clear it on disable and makes crc_pwm_enable() set it again on re-enable. This should disable the internal (divided) PWM clock and tri-state the PWM output pin when disabled, saving some power. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-crc.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index ef49a6e3c4d6..53734bcf67e1 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -41,10 +41,24 @@ static inline struct crystalcove_pwm *to_crc_pwm(struct pwm_chip *pc) return container_of(pc, struct crystalcove_pwm, chip); } +static int crc_pwm_calc_clk_div(int period_ns) +{ + int clk_div; + + clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); + /* clk_div 1 - 128, maps to register values 0-127 */ + if (clk_div > 0) + clk_div--; + + return clk_div; +} + static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm) { struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + int div = crc_pwm_calc_clk_div(pwm_get_period(pwm)); + regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div | PWM_OUTPUT_ENABLE); regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1); return 0; @@ -53,8 +67,10 @@ static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm) static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm) { struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + int div = crc_pwm_calc_clk_div(pwm_get_period(pwm)); regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0); + regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div); } static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, @@ -70,16 +86,10 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, } if (pwm_get_period(pwm) != period_ns) { - int clk_div; + int clk_div = crc_pwm_calc_clk_div(period_ns); /* changing the clk divisor, clear PWM_OUTPUT_ENABLE first */ regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0); - - clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); - /* clk_div 1 - 128, maps to register values 0-127 */ - if (clk_div > 0) - clk_div--; - regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, clk_div | PWM_OUTPUT_ENABLE); } From patchwork Sun Jun 7 18:18:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591883 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 94005618 for ; Sun, 7 Jun 2020 18:19:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7172820760 for ; Sun, 7 Jun 2020 18:19:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fRLDDqCL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7172820760 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1A2176E25B; Sun, 7 Jun 2020 18:19:23 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 81FD46E219 for ; Sun, 7 Jun 2020 18:19:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553960; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R4xyCpsnyFP/IgmIE5mjiCG2zWFUJ/yjZ7Igp3ZZReY=; b=fRLDDqCLYdkH7HxxjpXcwBZ5a6zyU/CToKLd3vxd7UgcWdeViKpwEnxcPM0zf8/JPoVlJI ASzkLnui3rLXXB+yqUFfufSLCki6wAouiQuoz+YFwt2mQ0yO/TwvFt+GWDn/UFC1upukx2 Vi0ACrAOPwnY7SenIHI5h3QzSo6nmQo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-369-iGresnhmPZG6fGIgQ3OmqQ-1; Sun, 07 Jun 2020 14:19:18 -0400 X-MC-Unique: iGresnhmPZG6fGIgQ3OmqQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DF44E7BAC; Sun, 7 Jun 2020 18:19:16 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 61B4C5C1BD; Sun, 7 Jun 2020 18:19:14 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 10/15] pwm: crc: Implement apply() method to support the new atomic PWM API Date: Sun, 7 Jun 2020 20:18:35 +0200 Message-Id: <20200607181840.13536-11-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Replace the enable, disable and config pwm_ops with an apply op, to support the new atomic PWM API. Signed-off-by: Hans de Goede --- drivers/pwm/pwm-crc.c | 107 +++++++++++++++++++++++------------------- 1 file changed, 59 insertions(+), 48 deletions(-) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 53734bcf67e1..58c7e9ef7278 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -41,70 +41,81 @@ static inline struct crystalcove_pwm *to_crc_pwm(struct pwm_chip *pc) return container_of(pc, struct crystalcove_pwm, chip); } -static int crc_pwm_calc_clk_div(int period_ns) +static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { - int clk_div; - - clk_div = PWM_BASE_CLK_MHZ * period_ns / (256 * NSEC_PER_MHZ); - /* clk_div 1 - 128, maps to register values 0-127 */ - if (clk_div > 0) - clk_div--; - - return clk_div; -} - -static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm) -{ - struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); - int div = crc_pwm_calc_clk_div(pwm_get_period(pwm)); - - regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div | PWM_OUTPUT_ENABLE); - regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1); - - return 0; -} - -static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm) -{ - struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); - int div = crc_pwm_calc_clk_div(pwm_get_period(pwm)); - - regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0); - regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, div); -} - -static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, - int duty_ns, int period_ns) -{ - struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip); + int err, clk_div, level, pwm_output_enable; struct device *dev = crc_pwm->chip.dev; - int level; - if (period_ns > PWM_MAX_PERIOD_NS) { + if (state->period > PWM_MAX_PERIOD_NS) { dev_err(dev, "un-supported period_ns\n"); return -EINVAL; } - if (pwm_get_period(pwm) != period_ns) { - int clk_div = crc_pwm_calc_clk_div(period_ns); + if (state->polarity != PWM_POLARITY_NORMAL) + return -ENOTSUPP; + + if (pwm_is_enabled(pwm) && !state->enabled) { + err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0); + if (err) { + dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err); + return err; + } + } + + if (pwm_get_duty_cycle(pwm) != state->duty_cycle || + pwm_get_period(pwm) != state->period) { + level = state->duty_cycle * PWM_MAX_LEVEL / state->period; + err = regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level); + if (err) { + dev_err(dev, "Error writing PWM0_DUTY_CYCLE %d\n", err); + return err; + } + } + + if (pwm_is_enabled(pwm) && state->enabled && + pwm_get_period(pwm) != state->period) { /* changing the clk divisor, clear PWM_OUTPUT_ENABLE first */ - regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0); - regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, - clk_div | PWM_OUTPUT_ENABLE); + err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, 0); + if (err) { + dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err); + return err; + } } - /* change the pwm duty cycle */ - level = duty_ns * PWM_MAX_LEVEL / period_ns; - regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level); + if (pwm_get_period(pwm) != state->period || + pwm_is_enabled(pwm) != state->enabled) { + clk_div = PWM_BASE_CLK_MHZ * state->period / + (256 * NSEC_PER_MHZ); + /* clk_div 1 - 128, maps to register values 0-127 */ + if (clk_div > 0) + clk_div--; + + pwm_output_enable = state->enabled ? PWM_OUTPUT_ENABLE : 0; + + err = regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, + clk_div | pwm_output_enable); + if (err) { + dev_err(dev, "Error writing PWM0_CLK_DIV %d\n", err); + return err; + } + } + + if (!pwm_is_enabled(pwm) && state->enabled) { + err = regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1); + if (err) { + dev_err(dev, "Error writing BACKLIGHT_EN %d\n", err); + return err; + } + } return 0; } static const struct pwm_ops crc_pwm_ops = { - .config = crc_pwm_config, - .enable = crc_pwm_enable, - .disable = crc_pwm_disable, + .apply = crc_pwm_apply, }; static int crystalcove_pwm_probe(struct platform_device *pdev) From patchwork Sun Jun 7 18:18:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591885 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EA084618 for ; Sun, 7 Jun 2020 18:19:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C784A2074B for ; Sun, 7 Jun 2020 18:19:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HvHI/oRi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C784A2074B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 190206E1B3; Sun, 7 Jun 2020 18:19:27 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 75EEC6E378 for ; Sun, 7 Jun 2020 18:19:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553964; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lKSCk6QuQzVxgH872USZwWSK0gPTDPHYq3zfkekP8Dw=; b=HvHI/oRiGlBL1Ezwtg9Oc44OrGUkylE3PQpFBLWPJVoyCSKMFHqAoFIBy9V6+kZo0p1fos BPxG8IUvMDcTO5oHKUewrxJ7z5OTpT6XgPRx0jUiGNgEB59ifYRJO51D8tXp4xRHyyirrv AlkuHXZ2xJNKhr2Q3e9ciTDcWssBiFs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-348-h7VsWf2ZNR64kVcH94W-WA-1; Sun, 07 Jun 2020 14:19:22 -0400 X-MC-Unique: h7VsWf2ZNR64kVcH94W-WA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A793780B70A; Sun, 7 Jun 2020 18:19:20 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 32D7A5C1BD; Sun, 7 Jun 2020 18:19:17 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 11/15] pwm: crc: Implement get_state() method Date: Sun, 7 Jun 2020 20:18:36 +0200 Message-Id: <20200607181840.13536-12-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Implement the pwm_ops.get_state() method to complete the support for the new atomic PWM API. Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko --- drivers/pwm/pwm-crc.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 58c7e9ef7278..6c75a3470bc8 100644 --- a/drivers/pwm/pwm-crc.c +++ b/drivers/pwm/pwm-crc.c @@ -114,8 +114,37 @@ static int crc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } +static void crc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct crystalcove_pwm *crc_pwm = to_crc_pwm(chip); + struct device *dev = crc_pwm->chip.dev; + unsigned int clk_div, clk_div_reg, duty_cycle_reg; + int error; + + error = regmap_read(crc_pwm->regmap, PWM0_CLK_DIV, &clk_div_reg); + if (error) { + dev_err(dev, "Error reading PWM0_CLK_DIV %d\n", error); + return; + } + + error = regmap_read(crc_pwm->regmap, PWM0_DUTY_CYCLE, &duty_cycle_reg); + if (error) { + dev_err(dev, "Error reading PWM0_DUTY_CYCLE %d\n", error); + return; + } + + clk_div = (clk_div_reg & ~PWM_OUTPUT_ENABLE) + 1; + + state->period = clk_div * NSEC_PER_MHZ * 256 / PWM_BASE_CLK_MHZ; + state->duty_cycle = duty_cycle_reg * state->period / PWM_MAX_LEVEL; + state->polarity = PWM_POLARITY_NORMAL; + state->enabled = !!(clk_div_reg & PWM_OUTPUT_ENABLE); +} + static const struct pwm_ops crc_pwm_ops = { .apply = crc_pwm_apply, + .get_state = crc_pwm_get_state, }; static int crystalcove_pwm_probe(struct platform_device *pdev) From patchwork Sun Jun 7 18:18:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591895 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 82452138C for ; Sun, 7 Jun 2020 18:19:34 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5FEB52075A for ; Sun, 7 Jun 2020 18:19:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Zlc956vg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FEB52075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 88B136E223; Sun, 7 Jun 2020 18:19:33 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id A208C6E1ED for ; Sun, 7 Jun 2020 18:19:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553970; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9qR6rmdUeqQSUNGkLDHXMEUzE7CJ6YnDyFwyWLHoCx4=; b=Zlc956vgZdCZALEObnFyBLOp1zqFUWDPcYftlZ52UVEPZiokXd5pDGenIVTtzp6ybyTx26 TU3YrGSeimdXc7dC7pW9LmhcOnvoKEOS9miwO7SNyNf+79yPZQM4UTLEh4PgEPhYwA5w68 MPW/5D4Tg3FqBk3t5ROkvpIm6HmUBLI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-380-BcB30-saP0KnH6z9d0w4Jg-1; Sun, 07 Jun 2020 14:19:25 -0400 X-MC-Unique: BcB30-saP0KnH6z9d0w4Jg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7039418FE860; Sun, 7 Jun 2020 18:19:23 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF0E05C1BD; Sun, 7 Jun 2020 18:19:20 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 12/15] drm/i915: panel: Add get_vbt_pwm_freq() helper Date: Sun, 7 Jun 2020 20:18:37 +0200 Message-Id: <20200607181840.13536-13-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Factor the code which checks and drm_dbg_kms-s the VBT PWM frequency out of get_backlight_max_vbt(). This is a preparation patch for honering the VBT PWM frequency for devices which use an external PWM controller (devices using pwm_setup_backlight()). Signed-off-by: Hans de Goede --- drivers/gpu/drm/i915/display/intel_panel.c | 27 ++++++++++++++-------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 3c5056dbf607..8efdd9f08a08 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -1543,18 +1543,9 @@ static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz) return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul); } -static u32 get_backlight_max_vbt(struct intel_connector *connector) +static u16 get_vbt_pwm_freq(struct drm_i915_private *dev_priv) { - struct drm_i915_private *dev_priv = to_i915(connector->base.dev); - struct intel_panel *panel = &connector->panel; u16 pwm_freq_hz = dev_priv->vbt.backlight.pwm_freq_hz; - u32 pwm; - - if (!panel->backlight.hz_to_pwm) { - drm_dbg_kms(&dev_priv->drm, - "backlight frequency conversion not supported\n"); - return 0; - } if (pwm_freq_hz) { drm_dbg_kms(&dev_priv->drm, @@ -1567,6 +1558,22 @@ static u32 get_backlight_max_vbt(struct intel_connector *connector) pwm_freq_hz); } + return pwm_freq_hz; +} + +static u32 get_backlight_max_vbt(struct intel_connector *connector) +{ + struct drm_i915_private *dev_priv = to_i915(connector->base.dev); + struct intel_panel *panel = &connector->panel; + u16 pwm_freq_hz = get_vbt_pwm_freq(dev_priv); + u32 pwm; + + if (!panel->backlight.hz_to_pwm) { + drm_dbg_kms(&dev_priv->drm, + "backlight frequency conversion not supported\n"); + return 0; + } + pwm = panel->backlight.hz_to_pwm(connector, pwm_freq_hz); if (!pwm) { drm_dbg_kms(&dev_priv->drm, From patchwork Sun Jun 7 18:18:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591899 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 43A04618 for ; Sun, 7 Jun 2020 18:19:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 206B52075A for ; Sun, 7 Jun 2020 18:19:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NFoiWhTN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 206B52075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2C2CC6E25F; Sun, 7 Jun 2020 18:19:35 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7FF456E21A for ; Sun, 7 Jun 2020 18:19:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553972; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Bo+5Xc22DSQgHX94UHCTDC49JHx7yrbbanPFfLG3ock=; b=NFoiWhTN/6ZZyiU8OLEzWv+GUvcoAjrrX4Up4DeQPt6hD/HSD0cu/OUTl56s6PkKK8Lc+9 QU4MvsO15yegFb57idALSol3gZmeiDc0RiWlq9P/iNdPNKpszdl6xYWpJrysBTVfhNmC4B 6/v4DyIHaZKPLN+RollcPs9SBiUdvcY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-129-IZbhlf1nMbiqMAD3bT9I7w-1; Sun, 07 Jun 2020 14:19:28 -0400 X-MC-Unique: IZbhlf1nMbiqMAD3bT9I7w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4808C8014D4; Sun, 7 Jun 2020 18:19:26 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id B80765C1BD; Sun, 7 Jun 2020 18:19:23 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 13/15] drm/i915: panel: Honor the VBT PWM frequency for devs with an external PWM controller Date: Sun, 7 Jun 2020 20:18:38 +0200 Message-Id: <20200607181840.13536-14-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" So far for devices using an external PWM controller (devices using pwm_setup_backlight()), we have been hardcoding the period-time passed to pwm_config() to 21333 ns. I suspect this was done because many VBTs set the PWM frequency to 200 which corresponds to a period-time of 5000000 ns, which greatly exceeds the PWM_MAX_PERIOD_NS define in the Crystal Cove PMIC PWM driver, which used to be 21333. This PWM_MAX_PERIOD_NS define was actually based on a bug in the PWM driver where its period and duty-cycle times where off by a factor of 256. Due to this bug the hardcoded CRC_PMIC_PWM_PERIOD_NS value of 21333 would result in the PWM driver using its divider of 128, which would result in a PWM output frequency of 6000000 Hz / 256 / 128 = 183 Hz. So actually pretty close to the default VBT value of 200 Hz. Now that this bug in the pwm-crc driver is fixed, we can actually use the VBT defined frequency. This is important because: a) With the pwm-crc driver fixed it will now translate the hardcoded CRC_PMIC_PWM_PERIOD_NS value of 21333 ns / 46 Khz to a PWM output frequency of 23 KHz (the max it can do). b) The pwm-lpss driver used on many models has always honored the 21333 ns / 46 Khz request Some panels do not like such high output frequencies. E.g. on a Terra Pad 1061 tablet, using the LPSS PWM controller, the backlight would go from off to max, when changing the sysfs backlight brightness value from 90-100%, anything under aprox. 90% would turn the backlight fully off. Honoring the VBT specified PWM frequency will also hopefully fix the various bug reports which we have received about users perceiving the backlight to flicker after a suspend/resume cycle. Signed-off-by: Hans de Goede --- .../drm/i915/display/intel_display_types.h | 1 + drivers/gpu/drm/i915/display/intel_panel.c | 19 +++++++++++-------- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index b24266c624fa..24ea4a7b6dde 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -223,6 +223,7 @@ struct intel_panel { bool util_pin_active_low; /* bxt+ */ u8 controller; /* bxt+ only */ struct pwm_device *pwm; + int pwm_period_ns; /* DPCD backlight */ u8 pwmgen_bit_count; diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 8efdd9f08a08..14e611c92194 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -40,8 +40,6 @@ #include "intel_dsi_dcs_backlight.h" #include "intel_panel.h" -#define CRC_PMIC_PWM_PERIOD_NS 21333 - void intel_fixed_panel_mode(const struct drm_display_mode *fixed_mode, struct drm_display_mode *adjusted_mode) @@ -597,7 +595,7 @@ static u32 pwm_get_backlight(struct intel_connector *connector) int duty_ns; duty_ns = pwm_get_duty_cycle(panel->backlight.pwm); - return DIV_ROUND_UP(duty_ns * 100, CRC_PMIC_PWM_PERIOD_NS); + return DIV_ROUND_UP(duty_ns * 100, panel->backlight.pwm_period_ns); } static void lpt_set_backlight(const struct drm_connector_state *conn_state, u32 level) @@ -671,9 +669,10 @@ static void bxt_set_backlight(const struct drm_connector_state *conn_state, u32 static void pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level) { struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel; - int duty_ns = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100); + int duty_ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); - pwm_config(panel->backlight.pwm, duty_ns, CRC_PMIC_PWM_PERIOD_NS); + pwm_config(panel->backlight.pwm, duty_ns, + panel->backlight.pwm_period_ns); } static void @@ -1917,6 +1916,9 @@ static int pwm_setup_backlight(struct intel_connector *connector, return -ENODEV; } + panel->backlight.pwm_period_ns = NSEC_PER_SEC / + get_vbt_pwm_freq(dev_priv); + /* * FIXME: pwm_apply_args() should be removed when switching to * the atomic PWM API. @@ -1926,9 +1928,10 @@ static int pwm_setup_backlight(struct intel_connector *connector, panel->backlight.min = 0; /* 0% */ panel->backlight.max = 100; /* 100% */ level = intel_panel_compute_brightness(connector, 100); - ns = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100); + ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); - retval = pwm_config(panel->backlight.pwm, ns, CRC_PMIC_PWM_PERIOD_NS); + retval = pwm_config(panel->backlight.pwm, ns, + panel->backlight.pwm_period_ns); if (retval < 0) { drm_err(&dev_priv->drm, "Failed to configure the pwm chip\n"); pwm_put(panel->backlight.pwm); @@ -1937,7 +1940,7 @@ static int pwm_setup_backlight(struct intel_connector *connector, } level = DIV_ROUND_UP(pwm_get_duty_cycle(panel->backlight.pwm) * 100, - CRC_PMIC_PWM_PERIOD_NS); + panel->backlight.pwm_period_ns); panel->backlight.level = intel_panel_compute_brightness(connector, level); panel->backlight.enabled = panel->backlight.level != 0; From patchwork Sun Jun 7 18:18:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591907 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3A97A618 for ; Sun, 7 Jun 2020 18:19:40 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 186CE2076C for ; Sun, 7 Jun 2020 18:19:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UpxIkpid" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 186CE2076C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; 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Sun, 07 Jun 2020 14:19:31 -0400 X-MC-Unique: oNMRjCBeNee_IRdKuw0bZw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 180AE8015CE; Sun, 7 Jun 2020 18:19:29 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 914F75C1BD; Sun, 7 Jun 2020 18:19:26 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 14/15] drm/i915: panel: Honor the VBT PWM min setting for devs with an external PWM controller Date: Sun, 7 Jun 2020 20:18:39 +0200 Message-Id: <20200607181840.13536-15-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" So far for devices using an external PWM controller (devices using pwm_setup_backlight()), we have been hardcoding the minimum allowed PWM level to 0. But several of these devices specify a non 0 minimum setting in their VBT. Change pwm_setup_backlight() to use get_backlight_min_vbt() to get the minimum level. Signed-off-by: Hans de Goede --- drivers/gpu/drm/i915/display/intel_panel.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 14e611c92194..cb28b9908ca4 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -1925,8 +1925,8 @@ static int pwm_setup_backlight(struct intel_connector *connector, */ pwm_apply_args(panel->backlight.pwm); - panel->backlight.min = 0; /* 0% */ panel->backlight.max = 100; /* 100% */ + panel->backlight.min = get_backlight_min_vbt(connector); level = intel_panel_compute_brightness(connector, 100); ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); @@ -1941,8 +1941,9 @@ static int pwm_setup_backlight(struct intel_connector *connector, level = DIV_ROUND_UP(pwm_get_duty_cycle(panel->backlight.pwm) * 100, panel->backlight.pwm_period_ns); - panel->backlight.level = - intel_panel_compute_brightness(connector, level); + level = intel_panel_compute_brightness(connector, level); + panel->backlight.level = clamp(level, panel->backlight.min, + panel->backlight.max); panel->backlight.enabled = panel->backlight.level != 0; drm_info(&dev_priv->drm, "Using %s PWM for LCD backlight control\n", From patchwork Sun Jun 7 18:18:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11591911 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 32360618 for ; Sun, 7 Jun 2020 18:19:42 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0DE1520663 for ; Sun, 7 Jun 2020 18:19:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UUix8R/O" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DE1520663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D0D826E378; Sun, 7 Jun 2020 18:19:39 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5197A6E391 for ; Sun, 7 Jun 2020 18:19:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591553977; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jyZxXAN/50odynkuGcRyQRxDg+34tQTkyTc3TZVLI8I=; b=UUix8R/OD0+XG82quXBSU6n1jaNsbULtoOaSFPUMh0y4FizoJNIWIH22MRrV8kFHhR8b+g pXOQMJP2VMfYQx3itI0kEhQvLfBP4jP2h4p2QZ1qx8ws5zFgIGP/V+YbnDUp95VKK9hleQ 1U79IKE7OcYYCge5ZwV5sOUICSUwe20= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-327-ef9hfPkjMYqFvKNtUFi2FQ-1; Sun, 07 Jun 2020 14:19:33 -0400 X-MC-Unique: ef9hfPkjMYqFvKNtUFi2FQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CF5E81005510; Sun, 7 Jun 2020 18:19:31 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-92.ams2.redhat.com [10.36.112.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 610A15C1BD; Sun, 7 Jun 2020 18:19:29 +0000 (UTC) From: Hans de Goede To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Jani Nikula , Joonas Lahtinen , =?utf-8?b?VmlsbGUgU3ly?= =?utf-8?b?asOkbMOk?= , "Rafael J . Wysocki" , Len Brown Subject: [PATCH v2 15/15] drm/i915: panel: Use atomic PWM API for devs with an external PWM controller Date: Sun, 7 Jun 2020 20:18:40 +0200 Message-Id: <20200607181840.13536-16-hdegoede@redhat.com> In-Reply-To: <20200607181840.13536-1-hdegoede@redhat.com> References: <20200607181840.13536-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-acpi@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , Andy Shevchenko , Mika Westerberg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Now that the PWM drivers which we use have been converted to the atomic PWM API, we can move the i915 panel code over to using the atomic PWM API. The removes a long standing FIXME and this removes a flicker where the backlight brightness would jump to 100% when i915 loads even if using the fastset path. Signed-off-by: Hans de Goede --- .../drm/i915/display/intel_display_types.h | 3 +- drivers/gpu/drm/i915/display/intel_panel.c | 73 +++++++++---------- 2 files changed, 37 insertions(+), 39 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 24ea4a7b6dde..48afb2925271 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -28,6 +28,7 @@ #include #include +#include #include #include @@ -223,7 +224,7 @@ struct intel_panel { bool util_pin_active_low; /* bxt+ */ u8 controller; /* bxt+ only */ struct pwm_device *pwm; - int pwm_period_ns; + struct pwm_state pwm_state; /* DPCD backlight */ u8 pwmgen_bit_count; diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index cb28b9908ca4..a0f76343f381 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -592,10 +592,11 @@ static u32 bxt_get_backlight(struct intel_connector *connector) static u32 pwm_get_backlight(struct intel_connector *connector) { struct intel_panel *panel = &connector->panel; - int duty_ns; + int duty_ns, period_ns; duty_ns = pwm_get_duty_cycle(panel->backlight.pwm); - return DIV_ROUND_UP(duty_ns * 100, panel->backlight.pwm_period_ns); + period_ns = pwm_get_period(panel->backlight.pwm); + return DIV_ROUND_UP(duty_ns * 100, period_ns); } static void lpt_set_backlight(const struct drm_connector_state *conn_state, u32 level) @@ -669,10 +670,10 @@ static void bxt_set_backlight(const struct drm_connector_state *conn_state, u32 static void pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level) { struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel; - int duty_ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); - pwm_config(panel->backlight.pwm, duty_ns, - panel->backlight.pwm_period_ns); + panel->backlight.pwm_state.duty_cycle = + DIV_ROUND_UP(level * panel->backlight.pwm_state.period, 100); + pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); } static void @@ -841,10 +842,8 @@ static void pwm_disable_backlight(const struct drm_connector_state *old_conn_sta struct intel_connector *connector = to_intel_connector(old_conn_state->connector); struct intel_panel *panel = &connector->panel; - /* Disable the backlight */ - intel_panel_actually_set_backlight(old_conn_state, 0); - usleep_range(2000, 3000); - pwm_disable(panel->backlight.pwm); + panel->backlight.pwm_state.enabled = false; + pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); } void intel_panel_disable_backlight(const struct drm_connector_state *old_conn_state) @@ -1176,9 +1175,14 @@ static void pwm_enable_backlight(const struct intel_crtc_state *crtc_state, { struct intel_connector *connector = to_intel_connector(conn_state->connector); struct intel_panel *panel = &connector->panel; + int level = panel->backlight.level; - pwm_enable(panel->backlight.pwm); - intel_panel_actually_set_backlight(conn_state, panel->backlight.level); + level = intel_panel_compute_brightness(connector, level); + + panel->backlight.pwm_state.duty_cycle = + DIV_ROUND_UP(level * panel->backlight.pwm_state.period, 100); + panel->backlight.pwm_state.enabled = true; + pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); } static void __intel_panel_enable_backlight(const struct intel_crtc_state *crtc_state, @@ -1897,8 +1901,7 @@ static int pwm_setup_backlight(struct intel_connector *connector, struct drm_i915_private *dev_priv = to_i915(dev); struct intel_panel *panel = &connector->panel; const char *desc; - u32 level, ns; - int retval; + u32 level; /* Get the right PWM chip for DSI backlight according to VBT */ if (dev_priv->vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) { @@ -1916,36 +1919,30 @@ static int pwm_setup_backlight(struct intel_connector *connector, return -ENODEV; } - panel->backlight.pwm_period_ns = NSEC_PER_SEC / - get_vbt_pwm_freq(dev_priv); - - /* - * FIXME: pwm_apply_args() should be removed when switching to - * the atomic PWM API. - */ - pwm_apply_args(panel->backlight.pwm); - panel->backlight.max = 100; /* 100% */ panel->backlight.min = get_backlight_min_vbt(connector); - level = intel_panel_compute_brightness(connector, 100); - ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); - retval = pwm_config(panel->backlight.pwm, ns, - panel->backlight.pwm_period_ns); - if (retval < 0) { - drm_err(&dev_priv->drm, "Failed to configure the pwm chip\n"); - pwm_put(panel->backlight.pwm); - panel->backlight.pwm = NULL; - return retval; + if (pwm_is_enabled(panel->backlight.pwm) && + pwm_get_period(panel->backlight.pwm)) { + /* PWM is already enabled, use existing settings */ + pwm_get_state(panel->backlight.pwm, &panel->backlight.pwm_state); + + level = DIV_ROUND_UP(panel->backlight.pwm_state.duty_cycle * + 100, panel->backlight.pwm_state.period); + level = intel_panel_compute_brightness(connector, level); + panel->backlight.level = clamp(level, panel->backlight.min, + panel->backlight.max); + panel->backlight.enabled = true; + + drm_dbg_kms(&dev_priv->drm, "PWM already enabled at freq %ld, VBT freq %d, level %d\n", + NSEC_PER_SEC / panel->backlight.pwm_state.period, + get_vbt_pwm_freq(dev_priv), level); + } else { + /* Set period from VBT frequency, leave other setting at 0. */ + panel->backlight.pwm_state.period = + NSEC_PER_SEC / get_vbt_pwm_freq(dev_priv); } - level = DIV_ROUND_UP(pwm_get_duty_cycle(panel->backlight.pwm) * 100, - panel->backlight.pwm_period_ns); - level = intel_panel_compute_brightness(connector, level); - panel->backlight.level = clamp(level, panel->backlight.min, - panel->backlight.max); - panel->backlight.enabled = panel->backlight.level != 0; - drm_info(&dev_priv->drm, "Using %s PWM for LCD backlight control\n", desc); return 0;