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: 13898434 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 12F07E7717D for ; Sat, 7 Dec 2024 23:46:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 95C9D10E424; Sat, 7 Dec 2024 23:46:49 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="PlSwjHmq"; dkim-atps=neutral Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2162410E231 for ; Sat, 7 Dec 2024 13:05:00 +0000 (UTC) Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-2161eb94cceso8294405ad.2 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.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=qHIXzgbPPD4fstMUw0DICfprbDFs+kDoHZiZBpx82hE=; b=PlSwjHmqmzt64/3DjyORqhs82z0A4u++Z5tYQNkEoQz44TLoRWe+6E8kUtsWs9pUk0 AR1yGCEmsv11tzMCy63OMLSby/fquz0h8QL7lRHKPcePnRv2dh4PGMfKBn/+wpjhwXot 7H/RUvFe6jXSyoMUE4Pxn8KEFjNzA5L5n1FFR3RUfo9GxO28T8J15M3u1nlxFUNeLuTa FpdOzS+WEdS4x4ifhQv3qeja2FzqCso4mgTdwPAGGuiVJE4twPFYXIgjNRypO9zsqTgo VmZdQmQiYcLIVcQhLLbr0CWCe7AUbGs8Bnb3dC0MHz4d8puMXZfnyrn3cVnvpwvmQcsu cgqA== 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=bvAwEcSxkeqMcWH1RDRTxWtlhoNIQz6li0b/YFz4prpbowVzESwGMRupvfHQb9J6AF NOYawHLGFgdoMjLpMgKLZCA9FXaing3+f57Q4VtKtjTOPun7DkFPk+KUHKAM36SVSuqW 5gj2KeL5I7ntZOr+Tu6cqTifPojExPbemUGxVAra6aTLoyCkpUdIGFPn/YYPNvMk18Bu tmBlnQjIr9Ml25XrJkaj/6EsgHr7KYv2vRc/jhMfrzgbqM2GPfbEiSKm72xJAv7VaLxn Snwd4Ek/0O7BzqNj/09XLCJP+hwEmxBDmZaDynHxKQX+6yrqp5e7CcdGnl31fXkU0aXy 57AQ== X-Forwarded-Encrypted: i=1; AJvYcCX7OUByl+kR3VuD2MIFk/HkmhDD1zU8Rmmibbbtx5snkYC28Xv2JXif5Kilc/o+o1yYDXQCFJpbLuc=@lists.freedesktop.org X-Gm-Message-State: AOJu0YxxCYQHy8N38nksdqelTNUU1Yx1hPg/IJeQhcJQmLqmQPNCFPaq VWS4dCVlv/N6KSbJ16QgUmtI7pgyAp15LgC46q+e6BIoj1VKMEe9 X-Gm-Gg: ASbGncu0gYGWHLtdoJqmnXPOPpsO/8M9K7eFRquXm7GZQ6SrBsSie8kd7c+q1AJIG4f CZd345tWvAzh9/7mMz7+ViSjGy5YlByaOiacTD7R34+ymG5eWsWtSceW7OBpR112lpwKng/xqbS M+AB55t7Y3iSwKi2u9U+fCFgjAFcMbe0SkzQS82C6XV3mrd5gEpsX2+NOV3Xm39x2vhKrURO1T1 BYFgEdK2DkqVrycDX7tmjj9eMhHLR45ZyPSXno2sf3v7E6Z5rxy5adBFFk4kJeNiQ== 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-Mailman-Approved-At: Sat, 07 Dec 2024 23:46:21 +0000 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. 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");