From patchwork Mon Dec 9 07:58:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nick Chan X-Patchwork-Id: 13899048 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 D022BE77173 for ; Mon, 9 Dec 2024 07:59:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4F98D10E2BB; Mon, 9 Dec 2024 07:59:39 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="G+/WXIg6"; dkim-atps=neutral Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9812310E2BB for ; Mon, 9 Dec 2024 07:59:38 +0000 (UTC) Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-216585cbe1eso4056615ad.3 for ; Sun, 08 Dec 2024 23:59:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733731178; x=1734335978; 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=vQREW8pkvf9d8FBI+//lDw3xZKcfVT8Bj/1BVrjl3sc=; b=G+/WXIg6I1k3tclf5Dtw2rwZP4zczXhnH30hpABHYMv2VkeoBNoYTDwW//N55RJ/fR WuuO4KS8VZCIh9qTOcfzM6lqySYfVfFkWuQxjEeEHNqce5bzQJ5Sqlug1nNfhTzaf5Jj XRymxNvwvLgk1chcZqVtSiKw7HGD5tnCSPDwOBnLgwoxT6og/G1bv2PF8UDv66DvugXQ JzlH1w3g9iSkgIhsjoNc1jpNi0ck13Cw6/nynFUeecBlbIiWkCJc8d+VFgYXubpr15Mr NM9rjEOM9RCINIM7/sLBniYm837nCQzg+3pixE82t8w1QSthw5mnICN6F9i05xXaUZYq Yh8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733731178; x=1734335978; 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=vQREW8pkvf9d8FBI+//lDw3xZKcfVT8Bj/1BVrjl3sc=; b=uCRR4fC2EkE/kv43uq429HnMOFXY0TcWToD8m7rpyAqSzLxt/H8RlryR8QTUh9lpZO gbPBNdkFusuMSV/tBi7/J4HWLl5TSk76IxyDpnnxJv33a6SM4qsenjT7WprzUhyusbB7 b3a7wsuoeWRNapJZ/kEmPS3a4EHLnyXhl/TlqbIvm43Z++KGgCCA44DL5SUozo4oaxiW AAWvncweJc9M+JUBQzzBLgYinn2IYMWSwJ449P5gzJltuGv3zS9bXljbAXP+rJ7Rf9nQ yvZEa0OK4pClYUknSeECRxL7o0RLEU28JWOPe8BSbKRXYeh00HGwlo+TFPt4Ft+Nc8Ww OmHw== X-Forwarded-Encrypted: i=1; AJvYcCX+93hwLUe5s4TqbBL2D8XUxqSAoPuo/dwYyh1qxJmEsJfg+G1ahyWZDuGPeNgovLsuwbdZs+EglU8=@lists.freedesktop.org X-Gm-Message-State: AOJu0YxLjOf6YwM2EoBTPfmxJUe+BKY+o9gHnRrnhA4asP8aTyW9G+n1 fdv7LaVCZtH3NNH8r4YxpdyVto3QrtRqFcc+scO2VH3ZbWXWwOkA X-Gm-Gg: ASbGncsKSNOfyf/i+EZDxHKWqYabAjFfr2soj41GHylhA46/UcE5KWf8b52RYgHn/+u vIMuCxA1QOcr8il+4RRolH48A03zAXuyjJgZjMbYVIAxFztLr+ODUanuUKjC+XdmlUEYfz2wGmm RWxuFTizeHyQvlz1V6g1LwcLz3e+OUvmVs21JRPBUN+Vlolmc/KsFASxNJt4tg4b1dKBt1TF0tu +3ZPqePo2jMpy3D01lXrYyXFgnVPpAe/7l4aV/YnMZdxfQ4Yq2TfUeAGRwpPZD1JQ== X-Google-Smtp-Source: AGHT+IEJ6aeTSfdHSwUg/1x4m3Ob8o0V0LmoiLC6iCHD0eKmgDPprihMoSkpmUMGcXKVy/JGiuvYmQ== X-Received: by 2002:a17:902:ec87:b0:215:8dd3:536a with SMTP id d9443c01a7336-21614d2efdcmr161736885ad.4.1733731177985; Sun, 08 Dec 2024 23:59:37 -0800 (PST) Received: from localhost.localdomain ([59.188.211.160]) by smtp.googlemail.com with ESMTPSA id d9443c01a7336-21628b6588csm36508025ad.235.2024.12.08.23.59.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 08 Dec 2024 23:59:37 -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 v3 2/3] backlight: dwi_bl: Add Apple DWI backlight driver Date: Mon, 9 Dec 2024 15:58:34 +0800 Message-ID: <20241209075908.140014-3-towinchenmi@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241209075908.140014-1-towinchenmi@gmail.com> References: <20241209075908.140014-1-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. Signed-off-by: Nick Chan --- drivers/video/backlight/Kconfig | 12 +++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/dwi_bl.c | 126 +++++++++++++++++++++++++++++++ 3 files changed, 139 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..501c36bed8f3 --- /dev/null +++ b/drivers/video/backlight/dwi_bl.c @@ -0,0 +1,126 @@ +// 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(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");