From patchwork Wed Sep 18 14:57:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Jacques Hiblot X-Patchwork-Id: 173980 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp2570124ill; Wed, 18 Sep 2019 07:57:52 -0700 (PDT) X-Google-Smtp-Source: APXvYqyiEUSuwf2eMRlYJ359SLRP4sSQ8Kem814yMiGMPLMwIAguiOf9XxcbrHaLenvaWwqwccqy X-Received: by 2002:a63:db57:: with SMTP id x23mr4365283pgi.224.1568818672712; Wed, 18 Sep 2019 07:57:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568818672; cv=none; d=google.com; s=arc-20160816; b=EVvHTGH5/sS+C7zX55k2emwIIjWyWP+NnWtpOtuiUrIkRbG6RZZqOut38DATDKbKGR MUaLx8TUo8HgL7nFgYLX9ZNFWGY3FxrdlJmebAjqMKnpqWnaUc8pEQ+BT1wl6cyBseh2 3Rq2hAJWt9mJxJOTCxgHMQcZro+FLKj7K7DCmokJ0RbHZjmWRBBt8MRwVc5wsiUzrLFC vWinVSAqQJl3OgvsnJ0KeIIy2P8ff0Q166dqkn33AWBQIcpzYU3VgLogUsB9mOVLMrJq 9kYWconqil6n3ippg6VrLn7o94vOPjH4bT2Tog1yMLfDnvkq72xYrtYVqxK4dwMbg11/ N96g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:cc:list-subscribe :list-help:list-post:list-archive:list-unsubscribe:list-id :precedence:mime-version:references:in-reply-to:message-id:date :subject:to:from:delivered-to; bh=1Zdom2Nr2A16NikSU2jReQS7wb/3i97pK6NiNTQ/Q8k=; b=RvZ9RI6nGzWbY/2qAt0UFeYkxKxKJvzyx9L+xs9iYW1l4+jelxDKorwYBE8QFwJerp i6Z6u1OOe3u2VboL/cAvGZSOhCThYDL06gBaejwJxIeZJ2crsA3m0/VQzhnVPO1TVkON iAS1F2cJ4F974+YaJ8Q4g1gjbbp68QuAqC0ZLHjP71GPMj5z6fmuBBgPtEevMtnikZt1 Qhs+vrgv2j6/jagJOC7fudCz1aPzPDNSHh4dQ05jyWX8QExyQfQ4DDFP4O8SNRUeHFI+ e2gFdaf5Ly+VQJYtkI6DQYbAXjitOj84yEaO/LDP3pu5+/jJGnt1rCkZGMfs5RfqOVh6 wfcQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTPS id g24si4351100pgh.416.2019.09.18.07.57.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 18 Sep 2019 07:57:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) client-ip=131.252.210.177; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C6C106F3D3; Wed, 18 Sep 2019 14:57:50 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by gabe.freedesktop.org (Postfix) with ESMTPS id BF51E6F3D3 for ; Wed, 18 Sep 2019 14:57:48 +0000 (UTC) Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvhG7030891; Wed, 18 Sep 2019 09:57:43 -0500 Received: from DLEE101.ent.ti.com (dlee101.ent.ti.com [157.170.170.31]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvhPf034516; Wed, 18 Sep 2019 09:57:43 -0500 Received: from DLEE110.ent.ti.com (157.170.170.21) by DLEE101.ent.ti.com (157.170.170.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 18 Sep 2019 09:57:39 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE110.ent.ti.com (157.170.170.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 18 Sep 2019 09:57:43 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvg21012827; Wed, 18 Sep 2019 09:57:42 -0500 From: Jean-Jacques Hiblot To: , , , , , Subject: [PATCH v7 2/5] leds: Add of_led_get() and led_put() Date: Wed, 18 Sep 2019 16:57:27 +0200 Message-ID: <20190918145730.22805-3-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190918145730.22805-1-jjhiblot@ti.com> References: <20190918145730.22805-1-jjhiblot@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1568818664; bh=FW2OvH18itsvE6UAtDakYRqQG2wDJZRYT9jmsjwMxCQ=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=ISNJEmG1QANm/MzdWIWF0ndFcJQPjmCDXbuBj17aL5fxcDXNtPCHdUVis9ykGtIC8 V9w4AbtLrtbZy8pI6qBTzlMiXQf5iUhDiMVV/3GbaSdpP7iDCTe03pYrp0oGp9BLQ6 8IbBF9VK72/TAY6Xm6rTEgSow/QXN7Gz5j3IjAYg= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, dmurphy@ti.com, jjhiblot@ti.com, linux-leds@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Tomi Valkeinen This patch adds basic support for a kernel driver to get a LED device. This will be used by the led-backlight driver. Only OF version is implemented for now, and the behavior is similar to PWM's of_pwm_get() and pwm_put(). Signed-off-by: Tomi Valkeinen Signed-off-by: Jean-Jacques Hiblot Acked-by: Pavel Machek --- drivers/leds/led-class.c | 50 ++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 4 ++++ 2 files changed, 54 insertions(+) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index c2167b66b61f..2b8f20f94128 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "leds.h" static struct class *leds_class; @@ -214,6 +215,55 @@ static int led_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); +static int led_match_led_of_node(struct device *led_dev, const void *data) +{ + return led_dev->of_node == data; +} + +/** + * of_led_get() - request a LED device via the LED framework + * @np: device node to get the LED device from + * @index: the index of the LED + * + * Returns the LED device parsed from the phandle specified in the "leds" + * property of a device tree node or a negative error-code on failure. + */ +struct led_classdev *of_led_get(struct device_node *np, int index) +{ + struct device *led_dev; + struct led_classdev *led_cdev; + struct device_node *led_node; + + led_node = of_parse_phandle(np, "leds", index); + if (!led_node) + return ERR_PTR(-ENOENT); + + led_dev = class_find_device(leds_class, NULL, led_node, + led_match_led_of_node); + of_node_put(led_node); + + if (!led_dev) + return ERR_PTR(-EPROBE_DEFER); + + led_cdev = dev_get_drvdata(led_dev); + + if (!try_module_get(led_cdev->dev->parent->driver->owner)) + return ERR_PTR(-ENODEV); + + return led_cdev; +} +EXPORT_SYMBOL_GPL(of_led_get); + +/** + * led_put() - release a LED device + * @led_cdev: LED device + */ +void led_put(struct led_classdev *led_cdev) +{ + module_put(led_cdev->dev->parent->driver->owner); +} +EXPORT_SYMBOL_GPL(led_put); + static int led_classdev_next_name(const char *init_name, char *name, size_t len) { diff --git a/include/linux/leds.h b/include/linux/leds.h index b8df71193329..6f7371bc7757 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -20,6 +20,7 @@ struct device; struct led_pattern; +struct device_node; /* * LED Core */ @@ -196,6 +197,9 @@ extern void devm_led_classdev_unregister(struct device *parent, extern void led_classdev_suspend(struct led_classdev *led_cdev); extern void led_classdev_resume(struct led_classdev *led_cdev); +extern struct led_classdev *of_led_get(struct device_node *np, int index); +extern void led_put(struct led_classdev *led_cdev); + /** * led_blink_set - set blinking with software fallback * @led_cdev: the LED to start blinking From patchwork Wed Sep 18 14:57:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Jacques Hiblot X-Patchwork-Id: 173981 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp2570212ill; Wed, 18 Sep 2019 07:57:57 -0700 (PDT) X-Google-Smtp-Source: APXvYqxnNTUURyy1dv5gCYIvPI5sJXLmH/epKlvrQrAxXbyelvr8xqFv5V7eDTCrXVZ8xPRsaOl+ X-Received: by 2002:a17:902:758a:: with SMTP id j10mr4651967pll.233.1568818677428; Wed, 18 Sep 2019 07:57:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568818677; cv=none; d=google.com; s=arc-20160816; b=ydeUPlJ21LtLUnCIqgjniPJyJb28QcUyH7+NsQukhvNNPo3uO5mYattTeZhDv/BpJc cWcRwq//b64QX2XhA1Yh4qBaeWnDMRdfxMgGCzC5/LPZ+U8MNG5hocAUSjFfjtVE9GuR xrE5ssD50LFqzEhF0eHP7QkH/kP4xH8BFuA6CsfQwiVXi+V1125YuiafwMS1OQ0S+LlN DVKn3qcKyNmXbYMinp2dwreqKjkF6ByH47i1aGFSeJ/cmrymURtuev6XLS+DMYZTRghJ 4cA/zyoeOFE1YMMElvT4CLAMygTLDmvMbh51Av+X4YlegHuDcAgh2mQv6P26BJ8b9N67 zwPw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:cc:list-subscribe :list-help:list-post:list-archive:list-unsubscribe:list-id :precedence:mime-version:references:in-reply-to:message-id:date :subject:to:from:delivered-to; bh=/NNYg4BBiknTEa/lp4TnGpNDJSNSSc6iBlDUxvBHqKY=; b=Mc+wlgX8GsEuqyYSu5SGQXVCCZvi7fq8Qn5+rFrbgyIXOTW+Uby2QeR0txJ9xSl/NV ArXqpXOv8T5or0G+mBvC67VqbirGezeQ8saD5gxw/XKd+W4Yn0T0ugZSdR6dLtqSvILW ImqadR6i+ohryWsvfh4LjuxEnfqf3pT4J6QKMyVPiF0tKGZ2m58jdHzlmHNIUFow4eGI FE+eqT/4dRCAf6QpC3ggnmVvodeI6GB9ckNG7CIpf4Q3JnMBKfEUeg3VswyG5RQPBt+z OoE8TSfRUETVMOJitS1RpsLG1ecx7AselW/a/M2dpw+FTnFJT+YEdko6t+JGXyDaO509 ns/Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTPS id y6si2009403pjp.41.2019.09.18.07.57.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 18 Sep 2019 07:57:57 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) client-ip=131.252.210.177; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org; dmarc=fail (p=QUARANTINE sp=NONE dis=QUARANTINE) header.from=ti.com Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 762B06F51C; Wed, 18 Sep 2019 14:57:53 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by gabe.freedesktop.org (Postfix) with ESMTPS id C58E76F52A for ; Wed, 18 Sep 2019 14:57:51 +0000 (UTC) Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvlED030897; Wed, 18 Sep 2019 09:57:47 -0500 Received: from DLEE101.ent.ti.com (dlee101.ent.ti.com [157.170.170.31]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvlPT034554; Wed, 18 Sep 2019 09:57:47 -0500 Received: from DLEE111.ent.ti.com (157.170.170.22) by DLEE101.ent.ti.com (157.170.170.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 18 Sep 2019 09:57:43 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE111.ent.ti.com (157.170.170.22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 18 Sep 2019 09:57:43 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8IEvkSK012924; Wed, 18 Sep 2019 09:57:46 -0500 From: Jean-Jacques Hiblot To: , , , , , Subject: [PATCH v7 5/5] backlight: add led-backlight driver Date: Wed, 18 Sep 2019 16:57:30 +0200 Message-ID: <20190918145730.22805-6-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190918145730.22805-1-jjhiblot@ti.com> References: <20190918145730.22805-1-jjhiblot@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1568818667; bh=6S3JyHHSxZ1lgxM/3c8fAQaB4nGGyxmQrSnj9yuVQGg=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=RvQp65o6qAKRQ8lmWEwdmXStdmC0q9OMe13aLNY7fgiru/QqOqEiRJwfUV75UD3D9 LCHrdG3ctyZeK0KHTAcv5nvY+BB3BfrTYBMoNHbOKvMaldfjjapLo5qIXbIAsdRkrC QHs/trmTPRSA0rRQODKZM0hhhnUpYPjczEoOao+4= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, dmurphy@ti.com, jjhiblot@ti.com, linux-leds@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Tomi Valkeinen This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight. Signed-off-by: Tomi Valkeinen Signed-off-by: Jean-Jacques Hiblot Acked-by: Pavel Machek Reviewed-by: Daniel Thompson --- drivers/video/backlight/Kconfig | 7 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 8b081d61773e..585a1787618c 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -458,6 +458,13 @@ config BACKLIGHT_RAVE_SP help Support for backlight control on RAVE SP device. +config BACKLIGHT_LED + tristate "Generic LED based Backlight Driver" + depends on LEDS_CLASS && OF + help + If you have a LCD backlight adjustable by LED class driver, say Y + to enable this driver. + endif # BACKLIGHT_CLASS_DEVICE endmenu diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 63c507c07437..2a67642966a5 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o +obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c new file mode 100644 index 000000000000..6044390d8b88 --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,260 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/ + * Author: Tomi Valkeinen + * + * Based on pwm_bl.c + */ + +#include +#include +#include +#include + +struct led_bl_data { + struct device *dev; + struct backlight_device *bl_dev; + struct led_classdev **leds; + bool enabled; + int nb_leds; + unsigned int *levels; + unsigned int default_brightness; + unsigned int max_brightness; +}; + +static void led_bl_set_brightness(struct led_bl_data *priv, int level) +{ + int i; + int bkl_brightness; + + if (priv->levels) + bkl_brightness = priv->levels[level]; + else + bkl_brightness = level; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], bkl_brightness); + + priv->enabled = true; +} + +static void led_bl_power_off(struct led_bl_data *priv) +{ + int i; + + if (!priv->enabled) + return; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], LED_OFF); + + priv->enabled = false; +} + +static int led_bl_update_status(struct backlight_device *bl) +{ + struct led_bl_data *priv = bl_get_data(bl); + int brightness = bl->props.brightness; + + if (bl->props.power != FB_BLANK_UNBLANK || + bl->props.fb_blank != FB_BLANK_UNBLANK || + bl->props.state & BL_CORE_FBBLANK) + brightness = 0; + + if (brightness > 0) + led_bl_set_brightness(priv, brightness); + else + led_bl_power_off(priv); + + return 0; +} + +static const struct backlight_ops led_bl_ops = { + .update_status = led_bl_update_status, +}; + +static int led_bl_get_leds(struct device *dev, + struct led_bl_data *priv) +{ + int i, nb_leds, ret; + struct device_node *node = dev->of_node; + struct led_classdev **leds; + unsigned int max_brightness; + unsigned int default_brightness; + + ret = of_count_phandle_with_args(node, "leds", NULL); + if (ret < 0) { + dev_err(dev, "Unable to get led count\n"); + return -EINVAL; + } + + nb_leds = ret; + if (nb_leds < 1) { + dev_err(dev, "At least one LED must be specified!\n"); + return -EINVAL; + } + + leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds, + GFP_KERNEL); + if (!leds) + return -ENOMEM; + + for (i = 0; i < nb_leds; i++) { + leds[i] = devm_led_get(dev, i); + if (IS_ERR(leds[i])) + return PTR_ERR(leds[i]); + } + + /* check that the LEDs all have the same brightness range */ + max_brightness = leds[0]->max_brightness; + for (i = 1; i < nb_leds; i++) { + if (max_brightness != leds[i]->max_brightness) { + dev_err(dev, "LEDs must have identical ranges\n"); + return -EINVAL; + } + } + + /* get the default brightness from the first LED from the list */ + default_brightness = leds[0]->brightness; + + priv->nb_leds = nb_leds; + priv->leds = leds; + priv->max_brightness = max_brightness; + priv->default_brightness = default_brightness; + + return 0; +} + +static int led_bl_parse_levels(struct device *dev, + struct led_bl_data *priv) +{ + struct device_node *node = dev->of_node; + int num_levels; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + num_levels = of_property_count_u32_elems(node, "brightness-levels"); + if (num_levels > 1) { + int i; + unsigned int db; + u32 *levels = NULL; + + levels = devm_kzalloc(dev, sizeof(u32) * num_levels, + GFP_KERNEL); + if (!levels) + return -ENOMEM; + + ret = of_property_read_u32_array(node, "brightness-levels", + levels, + num_levels); + if (ret < 0) + return ret; + + /* + * Try to map actual LED brightness to backlight brightness + * level + */ + db = priv->default_brightness; + for (i = 0 ; i < num_levels; i++) { + if ((i && db > levels[i-1]) && db <= levels[i]) + break; + } + priv->default_brightness = i; + priv->max_brightness = num_levels - 1; + priv->levels = levels; + } else if (num_levels >= 0) + dev_warn(dev, "Not enough levels defined\n"); + + ret = of_property_read_u32(node, "default-brightness-level", &value); + if (!ret && value <= priv->max_brightness) + priv->default_brightness = value; + else if (!ret && value > priv->max_brightness) + dev_warn(dev, "Invalid default brightness. Ignoring it\n"); + + return 0; +} + +static int led_bl_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct led_bl_data *priv; + int ret, i; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + priv->dev = &pdev->dev; + + ret = led_bl_get_leds(&pdev->dev, priv); + if (ret) + return ret; + + ret = led_bl_parse_levels(&pdev->dev, priv); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to parse DT data\n"); + return ret; + } + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = priv->max_brightness; + props.brightness = priv->default_brightness; + props.power = (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN : + FB_BLANK_UNBLANK; + priv->bl_dev = backlight_device_register(dev_name(&pdev->dev), + &pdev->dev, priv, &led_bl_ops, &props); + if (IS_ERR(priv->bl_dev)) { + dev_err(&pdev->dev, "Failed to register backlight\n"); + return PTR_ERR(priv->bl_dev); + } + + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_disable(priv->leds[i]); + + backlight_update_status(priv->bl_dev); + + return 0; +} + +static int led_bl_remove(struct platform_device *pdev) +{ + struct led_bl_data *priv = platform_get_drvdata(pdev); + struct backlight_device *bl = priv->bl_dev; + int i; + + backlight_device_unregister(bl); + + led_bl_power_off(priv); + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_enable(priv->leds[i]); + + return 0; +} + +static const struct of_device_id led_bl_of_match[] = { + { .compatible = "led-backlight" }, + { } +}; + +MODULE_DEVICE_TABLE(of, led_bl_of_match); + +static struct platform_driver led_bl_driver = { + .driver = { + .name = "led-backlight", + .of_match_table = of_match_ptr(led_bl_of_match), + }, + .probe = led_bl_probe, + .remove = led_bl_remove, +}; + +module_platform_driver(led_bl_driver); + +MODULE_DESCRIPTION("LED based Backlight Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:led-backlight");