From patchwork Sat Dec 7 13:03:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nick Chan X-Patchwork-Id: 13898267 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DD3DE7717B for ; Sat, 7 Dec 2024 13:08:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:To:From:Reply-To: Cc:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=qHIXzgbPPD4fstMUw0DICfprbDFs+kDoHZiZBpx82hE=; b=C7dkMY7QI3XP5QwcLAtN9g1cq3 FhUHvpvJxXZ3/4hBersGpssuvas7XUWjQhujWolJ4kApT0f7nsIm+JSjksjW9fIhYBndkSxcGzjil 3HtZYw5u7j6ab1iSO6I4k31ArWruZPu2AQWx+qpjjAh5bc04tvH3c5JndkTWbSGZa5CiQA8fbYJVz dUQ/C+i+zVZHCrCmjF79ANk3s/gdivAaXNMDoonRYBiYbWVEfNzBsB9VR4/oOxdhNWRFKqOAgwfcc +FJIPRmxToe5zUXEBHjEG10pvj+9hbqtXS1+CmSy3YAa3+uTdIG/aYK5wwr4dBuxZ2/MUdk8PBVZ5 VhR8tfJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tJuXT-00000003yBX-1iO6; Sat, 07 Dec 2024 13:08:03 +0000 Received: from mail-pg1-x52e.google.com ([2607:f8b0:4864:20::52e]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tJuUW-00000003xeS-3MmE for linux-arm-kernel@lists.infradead.org; Sat, 07 Dec 2024 13:05:02 +0000 Received: by mail-pg1-x52e.google.com with SMTP id 41be03b00d2f7-7fd17f2312bso2307354a12.0 for ; Sat, 07 Dec 2024 05:05:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733576699; x=1734181499; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=qHIXzgbPPD4fstMUw0DICfprbDFs+kDoHZiZBpx82hE=; b=hKEEeIxIe3eRT+4wRYMlMOPXqLQFNN/8mhYUkRezJamx2KCvVLU3Ph9yosYXKTDB9U a94Om7Y/W+HWkOzJc0Rp01WcLoRgFgq/tKfl13FhtveTba0INL/0fo9vevBYjJaR8giN beXDfT2UFgUlyO94q+PzPZ568RowyV6bPygWFh306cXk1a/QkvitCLuInvLaHCQqLkoc MGoGTGjsSg2+0iCxC4MtLPcOZoMH5S5IH/L4p5lx3tRJg3OiuAaSdKItfisE5RXushFm c3JqLvZ6HBhWkTnlloNxjtIU3A4aho/UMFbwK7DXmpY4SSTUixEq/jQKg5MFYBWQ+10G issw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733576699; x=1734181499; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qHIXzgbPPD4fstMUw0DICfprbDFs+kDoHZiZBpx82hE=; b=pAjxuTMH4UhfLHfedaghWTEAaqGDarTheaCriTiukjWCww9CCr3R7GUWcf236EOfcR miDyIyES/5GqaqPBVFwAKg0caD1wfj24l8/GRpwtHolR0ValU8JuQUg280RZ6XfGdcmD 1ow9uAjV8pprlMEFQ91D5NGRzgaG82HzHbFyDJy5CtQKOqXEp3o1d6p7VUf2qXn3uQVh 6q6Tcx5/pJ2RhQwEYeFj0pDhNz9uKq3PpQQdcdrIsAP5itIVtvauNIchpydJ7d7zU5Nb dKO5XpCdH/olB9vshcaTTgzF2VxH6VikCnD+UEmU6HleYwDHwvRqX2FTtSLG4PQ8Ki59 dqAQ== X-Forwarded-Encrypted: i=1; AJvYcCUDk7ffIgB5WxVLlWcy+GZ4647Z9Nz9eFvxiTdOIfEMIc3YS+jQdil/BdwXAmKjfe+2p3EvE78puDYGzc4Lghvd@lists.infradead.org X-Gm-Message-State: AOJu0YzjpTYgbMZF03b82Fca4y83jgwGoaeko+WWINvsqVapCl9STX6j JtS3knk41kKpYNtY2tMjyH4EN9VafsH3TWc8p7AXwy0h4PRqksim X-Gm-Gg: ASbGnct+aJS+knPp5NeYXSZ0v+bzaVpuH7hhqnDIIhAf8f8ghwAlpB4TUtZlK9RnfuE 0CNeyN0IyIwG3lYRL4Q/IMhPTzeSL+CieFOE4v1nGf5RZ/XgesVJwcOsqExWdiJLz6U7c/TtH6V uqW22pPsKO76A4ab/fCUPgLogjVNNImh0TkSWn7UHrG4k2moeXWZ05tlxhUZsaP8zim6edggf3h X6x7kTWVGV1x573bKHfEIxJMG6Jx5AXYXvlSgjgqfLg7707zuz/bGCUPbDsqi49oA== X-Google-Smtp-Source: AGHT+IEDQeoGt4Ew7k231hhERT2d9WsKRLc2X38liJ7cpCgF7Y2V2yw87HksK3OB6TyrAZV3ss+7hw== X-Received: by 2002:a17:902:dacd:b0:216:1b4c:7396 with SMTP id d9443c01a7336-2161b4c7520mr77087385ad.3.1733576699637; Sat, 07 Dec 2024 05:04:59 -0800 (PST) Received: from localhost.localdomain ([59.188.211.160]) by smtp.googlemail.com with ESMTPSA id d9443c01a7336-21628c59730sm12779715ad.105.2024.12.07.05.04.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Dec 2024 05:04:59 -0800 (PST) From: Nick Chan To: Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Helge Deller , Hector Martin , Sven Peter , Alyssa Rosenzweig , Nick Chan , dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/3] backlight: dwi_bl: Add Apple DWI backlight driver Date: Sat, 7 Dec 2024 21:03:15 +0800 Message-ID: <20241207130433.30351-3-towinchenmi@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241207130433.30351-1-towinchenmi@gmail.com> References: <20241207130433.30351-1-towinchenmi@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241207_050500_865217_B290F932 X-CRM114-Status: GOOD ( 23.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add driver for backlight controllers attached via Apple DWI 2-wire interface, which is found on some Apple iPhones, iPads and iPod touches with a LCD display. Signed-off-by: Nick Chan --- drivers/video/backlight/Kconfig | 12 +++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/dwi_bl.c | 124 +++++++++++++++++++++++++++++++ 3 files changed, 137 insertions(+) create mode 100644 drivers/video/backlight/dwi_bl.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 3614a5d29c71..e64cc3d51ac5 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -166,6 +166,18 @@ config BACKLIGHT_EP93XX To compile this driver as a module, choose M here: the module will be called ep93xx_bl. +config BACKLIGHT_APPLE_DWI + tristate "Apple DWI 2-Wire Interface Backlight Driver" + depends on ARCH_APPLE || COMPILE_TEST + default y + help + Say Y to enable the backlight driver for backlight controllers + attached via the Apple DWI 2-wire interface which is found in some + Apple iPhones, iPads and iPod touches. + + To compile this driver as a module, choose M here: the module will + be called dwi_bl. + config BACKLIGHT_IPAQ_MICRO tristate "iPAQ microcontroller backlight driver" depends on MFD_IPAQ_MICRO diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 8fc98f760a8a..0a569d7f0210 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_BACKLIGHT_BD6107) += bd6107.o obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o obj-$(CONFIG_BACKLIGHT_DA903X) += da903x_bl.o obj-$(CONFIG_BACKLIGHT_DA9052) += da9052_bl.o +obj-$(CONFIG_BACKLIGHT_APPLE_DWI) += dwi_bl.o obj-$(CONFIG_BACKLIGHT_EP93XX) += ep93xx_bl.o obj-$(CONFIG_BACKLIGHT_GPIO) += gpio_backlight.o obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o diff --git a/drivers/video/backlight/dwi_bl.c b/drivers/video/backlight/dwi_bl.c new file mode 100644 index 000000000000..d4bfd74b3129 --- /dev/null +++ b/drivers/video/backlight/dwi_bl.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Driver for backlight controllers attached via Apple DWI 2-wire interface + * + * Copyright (c) 2024 Nick Chan + */ + +#include +#include +#include +#include + +#define DWI_BL_CTL 0x0 +#define DWI_BL_CTL_SEND1 BIT(0) +#define DWI_BL_CTL_SEND2 BIT(4) +#define DWI_BL_CTL_SEND3 BIT(5) +#define DWI_BL_CTL_LE_DATA BIT(6) +/* Only used on Apple A9 and later */ +#define DWI_BL_CTL_SEND4 BIT(12) + +#define DWI_BL_CMD 0x4 +#define DWI_BL_CMD_TYPE GENMASK(31, 28) +#define DWI_BL_CMD_TYPE_SET_BRIGHTNESS 0xa +#define DWI_BL_CMD_DATA GENMASK(10, 0) + +#define DWI_BL_CTL_SEND (DWI_BL_CTL_SEND1 | \ + DWI_BL_CTL_SEND2 | \ + DWI_BL_CTL_SEND3 | \ + DWI_BL_CTL_LE_DATA | \ + DWI_BL_CTL_SEND4) + +#define DWI_BL_MAX_BRIGHTNESS 2047 + +struct apple_dwi_bl { + void __iomem *base; +}; + +static int dwi_bl_update_status(struct backlight_device *bl) +{ + struct apple_dwi_bl *dwi_bl = bl_get_data(bl); + + int brightness = backlight_get_brightness(bl); + + u32 cmd = 0; + + cmd |= FIELD_PREP(DWI_BL_CMD_DATA, brightness); + cmd |= FIELD_PREP(DWI_BL_CMD_TYPE, DWI_BL_CMD_TYPE_SET_BRIGHTNESS); + + writel(cmd, dwi_bl->base + DWI_BL_CMD); + writel(DWI_BL_CTL_SEND, dwi_bl->base + DWI_BL_CTL); + + return 0; +} + +static int dwi_bl_get_brightness(struct backlight_device *bl) +{ + struct apple_dwi_bl *dwi_bl = bl_get_data(bl); + + u32 cmd = readl(dwi_bl->base + DWI_BL_CMD); + + return FIELD_GET(DWI_BL_CMD_DATA, cmd); +} + +static const struct backlight_ops dwi_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .get_brightness = dwi_bl_get_brightness, + .update_status = dwi_bl_update_status +}; + +static int dwi_bl_probe(struct platform_device *dev) +{ + struct apple_dwi_bl *dwi_bl; + struct backlight_device *bl; + struct backlight_properties props; + struct resource *res; + + dwi_bl = devm_kzalloc(&dev->dev, sizeof(struct apple_dwi_bl), GFP_KERNEL); + if (!dwi_bl) + return -ENOMEM; + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + return -ENXIO; + + dwi_bl->base = devm_ioremap_resource(&dev->dev, res); + if (IS_ERR(dwi_bl->base)) + return PTR_ERR(dwi_bl->base); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = DWI_BL_MAX_BRIGHTNESS; + + bl = devm_backlight_device_register(&dev->dev, dev->name, &dev->dev, + dwi_bl, &dwi_bl_ops, &props); + if (IS_ERR(bl)) + return PTR_ERR(bl); + + platform_set_drvdata(dev, dwi_bl); + + bl->props.brightness = dwi_bl_get_brightness(bl); + + return 0; +} + +static const struct of_device_id dwi_bl_of_match[] = { + { .compatible = "apple,dwi-bl" }, + {}, +}; + +MODULE_DEVICE_TABLE(of, dwi_bl_of_match); + +static struct platform_driver dwi_bl_driver = { + .driver = { + .name = "dwi-bl", + .of_match_table = dwi_bl_of_match + }, + .probe = dwi_bl_probe, +}; + +module_platform_driver(dwi_bl_driver); + +MODULE_DESCRIPTION("Apple DWI Backlight Driver"); +MODULE_AUTHOR("Nick Chan "); +MODULE_LICENSE("Dual MIT/GPL");