From patchwork Fri Feb 14 04:02:13 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nick Chan X-Patchwork-Id: 13974431 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B673AC02198 for ; Fri, 14 Feb 2025 04:04:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 364C510E466; Fri, 14 Feb 2025 04:04:15 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="RxO+LRua"; dkim-atps=neutral Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) by gabe.freedesktop.org (Postfix) with ESMTPS id C772B10E466 for ; Fri, 14 Feb 2025 04:04:13 +0000 (UTC) Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-220c8eb195aso30819235ad.0 for ; Thu, 13 Feb 2025 20:04:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1739505853; x=1740110653; darn=lists.freedesktop.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=THGbXf//SrScK+32A3BUuAqCods80KxGwHDBckzXHsI=; b=RxO+LRuaPUHOQ6SNJUMNDt+PDAvacWZfx9UWa5F/uksFHEDiGufJKL0rbBg7Sz4pI+ faKdvn+BwdLx5KPrmOozRlwqJV/eqxRnv0WBeM5N/0fzG5p5CjwgLAHaHcOPQT7q9n5o OUPuHhZ51dSUk6ID/1WlswGkVB7cdZcKWde1QmHzw8Zs4KUOKmNSdw/gv+Fbz+eS2wyQ an7QNkaaiDrNO74lyFkPQ/Hfsu4haePUlBlPp17r5n1SocqBFjVOAugm/MwXEMRYQbcp 2Cd8dzGR6IrdS2wz2WFf4qeDUaqw6B7F/HOj/876PrEuQwoRTDHxCAkj/InTQcJj24Hj mCCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739505853; x=1740110653; 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=THGbXf//SrScK+32A3BUuAqCods80KxGwHDBckzXHsI=; b=mb3WCh6lKqRQq9oet0OGs/aQTVlwUW5pbFNGUPdmY+EO7YcBLc6yIV8qTnEiPDzXLW Wyv3NKtzJ3JhmDtTpo5OZH/dDwkzPa7AyIVp/g5M1IANZA5q/oqKdsd8uVz0pgVJSGDF NK3r4azdSN5x3vsvYA0cBRvfw3rPPn0lesnRdk0osSwS19b3HMVz9t9qGgwLZmQtOfSw Yf2F4T139PtBVnvTy48enCbZbLalpK7kSJAd3eyqycvG4uVcKWJ9GdOZYL9Y4vHY7E5C qP+HwT8xyZL7BTSbReoX789208V8HK1vNxvks9qW5DOvkYnHdrC1RPzJMQoZXZ/bnxJm ATPg== X-Forwarded-Encrypted: i=1; AJvYcCXC1S4QJOAxFlwGHVsoGOj8/2dlXbNYUQuK3FZ9bXIeMCQIH0yIj1LWsd9simLyz9EARj9mS+jBCQs=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzXK7qaootRJLPHk08D3xJ+7tfot3/CwnhrLUNNPEuSzhR2DVaQ oOM5Skk8c2Wc998yQiZmUltEpslRGsp8UI/fYAWgptc8rMvDiPAo X-Gm-Gg: ASbGnctt37F7vMpLeNM7injRGO2sK+eKZFxmC2gANubK2RhYbTdftHU80JNrvyjKcT1 3fMWF3VIwEUXkFy77edJ1xCaJQQoC2BsOgN6ziZwddeXpkCMbkIYTN8a3HOMOesD2oLVgA8AXdX AOcZ7Dzl+dYhpzh3SBmooTy8POu5kbQmUaPZqvseuT95f3v0RFaolJh4e8nWcmDoW0zJpZ2sk2T efVZME5oxLN0yNOLAcYSs/5avj/mcbh6w29zOml/HznLO1q1ZLF7BX36BSwsf0luSEZ0A7HbtqF XmtKJUJcu2TozGw= X-Google-Smtp-Source: AGHT+IGxivn76yELBYxib0w0BFCjx4VgWlcePDuyKrKPnZS1ISzc7Gxg04wRI/FeWDE8mSYuN0bpnA== X-Received: by 2002:a05:6a20:2585:b0:1ed:a812:8860 with SMTP id adf61e73a8af0-1ee5c796e7fmr16856578637.25.1739505853270; Thu, 13 Feb 2025 20:04:13 -0800 (PST) Received: from nick-mbp.. ([49.130.17.220]) by smtp.googlemail.com with ESMTPSA id d2e1a72fcca58-7324273e3e7sm2181227b3a.91.2025.02.13.20.04.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Feb 2025 20:04:12 -0800 (PST) From: Nick Chan To: Janne Grunau , Sven Peter , Alyssa Rosenzweig , Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Helge Deller , Nick Chan , asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org Subject: [PATCH v6 2/3] backlight: apple_dwi_bl: Add Apple DWI backlight driver Date: Fri, 14 Feb 2025 12:02:13 +0800 Message-ID: <20250214040306.16312-3-towinchenmi@gmail.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250214040306.16312-1-towinchenmi@gmail.com> References: <20250214040306.16312-1-towinchenmi@gmail.com> MIME-Version: 1.0 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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. Although there is an existing apple_bl driver, it is for backlight controllers on Intel Macs attached via PCI, which is completely different from the Samsung-derived DWI block. Reviewed-by: Daniel Thompson (RISCstar) Signed-off-by: Nick Chan --- drivers/video/backlight/Kconfig | 11 +++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/apple_dwi_bl.c | 123 +++++++++++++++++++++++++ 3 files changed, 135 insertions(+) create mode 100644 drivers/video/backlight/apple_dwi_bl.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 3614a5d29c71..cee113bba30f 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -290,6 +290,17 @@ config BACKLIGHT_APPLE If you have an Intel-based Apple say Y to enable a driver for its backlight. +config BACKLIGHT_APPLE_DWI + tristate "Apple DWI 2-Wire Interface Backlight Driver" + depends on ARCH_APPLE || COMPILE_TEST + 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 apple_dwi_bl. + config BACKLIGHT_QCOM_WLED tristate "Qualcomm PMIC WLED Driver" select REGMAP diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 8fc98f760a8a..156ff9461fb3 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_BACKLIGHT_ADP5520) += adp5520_bl.o obj-$(CONFIG_BACKLIGHT_ADP8860) += adp8860_bl.o obj-$(CONFIG_BACKLIGHT_ADP8870) += adp8870_bl.o obj-$(CONFIG_BACKLIGHT_APPLE) += apple_bl.o +obj-$(CONFIG_BACKLIGHT_APPLE_DWI) += apple_dwi_bl.o obj-$(CONFIG_BACKLIGHT_AS3711) += as3711_bl.o obj-$(CONFIG_BACKLIGHT_BD6107) += bd6107.o obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o diff --git a/drivers/video/backlight/apple_dwi_bl.c b/drivers/video/backlight/apple_dwi_bl.c new file mode 100644 index 000000000000..93bd744972d6 --- /dev/null +++ b/drivers/video/backlight/apple_dwi_bl.c @@ -0,0 +1,123 @@ +// 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 +#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(*dwi_bl), GFP_KERNEL); + if (!dwi_bl) + return -ENOMEM; + + dwi_bl->base = devm_platform_get_and_ioremap_resource(dev, 0, &res); + if (IS_ERR(dwi_bl->base)) + return PTR_ERR(dwi_bl->base); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = DWI_BL_MAX_BRIGHTNESS; + props.scale = BACKLIGHT_SCALE_LINEAR; + + 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 = "apple-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");