From patchwork Fri Dec 6 17:24:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nick Chan X-Patchwork-Id: 13897665 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 C5AEBE7717E for ; Fri, 6 Dec 2024 19:45:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7461E10F199; Fri, 6 Dec 2024 19:45:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="V1Q6ukGI"; dkim-atps=neutral Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) by gabe.freedesktop.org (Postfix) with ESMTPS id 89A0D10F143 for ; Fri, 6 Dec 2024 17:28:15 +0000 (UTC) Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-725b93a59feso958146b3a.2 for ; Fri, 06 Dec 2024 09:28:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733506095; x=1734110895; 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=Mhx+3SpE0HhgGnWW6FB4h1qjMppjxy5kVkibP++35Cs=; b=V1Q6ukGI8sbY+Ive/w8ADcGUPXt7chUIngwHhY4eP8yJs5M9N10IY433hZmpKFBPnc S0O1d6HtXLYNe8SeSfTZyruckhKYPDhIaOFOCOSAaIT87qFVPY88LOG4L9611F3Webiw lkRuLd9Tk59hjOLNbB0TioCKRJSz2sLPcdzP1Su0h7etbumVtup2GDN16jfUQjOUMg34 fFcdUqHZiCxuUZHEhSAJFDeDPfoaoKZS6q94MT0Zg1rh93d+1c8iZFVFmvaHsE40u8w9 +rzAXX0jpPJg2c+EYKQhCjfvH5xenRd665zIlq7LlkAu2kHaxPj7VQoSq010Uy4UGb1m 7GUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733506095; x=1734110895; 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=Mhx+3SpE0HhgGnWW6FB4h1qjMppjxy5kVkibP++35Cs=; b=h1/PKuitSNcVEKZ1xV3jSKMJKjdZ43bhaHGsNTUICcTFCp7SVq5T6+/BevYG5oJRgn chE9GUJPCEku8e4GTxC53mmU51Ioih1xH7sYXv4h9TIMXI6hL7cDEKEVjWWMDww+wrkX lP8WNGSg/RGHSp8K67Iz5maNzYhv7Vc6scztdmqaQEQON9Hw4M7bR1skWUKoKadu/2ZV 0lpx+0bH0Z92vObM9jn+54S4pzkdJw7J8y7BVCjrSg4jY6RiCuLeDP7d8Xg09gdmCSVV 3E3sOJvF9xuWL/ug2t3xIcjS70d08sbi2VWKocwi86ulc4q2AM028T7wC0jdndyIdo3n W21Q== X-Forwarded-Encrypted: i=1; AJvYcCU0QZvpjh83M3Vh7cyse53ULJhmhZfivdsmBYYzIpRY/Zf0HUFayVqfRhqXnbqZX6rG0yHHvU+KXSg=@lists.freedesktop.org X-Gm-Message-State: AOJu0YzmkDSgHAa5zXhjio3GyDOK92d7JrOgZETWcdRuq1OROKHKc5cw P1++YzysS18hPNF/uvUyZg8y+HrmX5maXdFNLJDBEgbXo1JZ4Y68 X-Gm-Gg: ASbGncv+0QpdUIA/SA6R5M/V6dYK2rtlXjaLJ9vDHqmMq+VAjsz2egZ/kS0c2ZIbsmG XgO4a+OjJy2yifcWIDu5zbAtYosf2boLMfuIA+YKhnxp7spN8Ew2JXoDRm+Ih25ct6Gqoc+Jw0r isHtveVS002jVPY/RpB7RygxmnIZBn4QTKDyOIYs2Hv5YbCtwzX91Wh28tNoG468BVInEmbEp90 LbhNgqoyNkZOCxJadJBonW6Z55pG7X0mMNkmzSRD0j42Jys7gyEfbbEt6zbQX7A X-Google-Smtp-Source: AGHT+IHmRnmelG8M99ofNXhJAhbZ1joLqatv/c5LTXmUbLyOedvxPVbkzChlDj9sArumdzcvk7YaUg== X-Received: by 2002:a17:90a:c105:b0:2ee:db8a:29d0 with SMTP id 98e67ed59e1d1-2ef6ab07f61mr5535784a91.26.1733506094955; Fri, 06 Dec 2024 09:28:14 -0800 (PST) Received: from localhost.localdomain ([49.130.54.203]) by smtp.googlemail.com with ESMTPSA id d2e1a72fcca58-725a2cc6950sm3204512b3a.173.2024.12.06.09.28.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Dec 2024 09:28:14 -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 2/3] backlight: dwi_bl: Add Apple DWI backlight driver Date: Sat, 7 Dec 2024 01:24:34 +0800 Message-ID: <20241206172735.4310-3-towinchenmi@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206172735.4310-1-towinchenmi@gmail.com> References: <20241206172735.4310-1-towinchenmi@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 06 Dec 2024 19:45:35 +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 | 123 +++++++++++++++++++++++++++++++ 3 files changed, 136 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..6dd7edf661fd --- /dev/null +++ b/drivers/video/backlight/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 + +#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); + + 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");