From patchwork Tue Sep 10 10:59:43 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: 173509 Delivered-To: patch@linaro.org Received: by 2002:a05:6e02:ce:0:0:0:0 with SMTP id r14csp5628744ilq; Tue, 10 Sep 2019 04:00:06 -0700 (PDT) X-Google-Smtp-Source: APXvYqyFwmrvac96CRmKvscqtpnd5cvf3S5gTJ2w4foWtashd71z/tjeMlNa72e+qn7KNk4nMK8Q X-Received: by 2002:aa7:dccb:: with SMTP id w11mr29302750edu.235.1568113206779; Tue, 10 Sep 2019 04:00:06 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568113206; cv=none; d=google.com; s=arc-20160816; b=i3XOaZ9Nbr/hb/2X326oHg+aVJudqpJZAzpiAXQfUKjfxfK/dcMCl42AOWcy+Lh2pK nekhrv1XSXm9iarKelan/P/ym+mpxOwIrFq9AVvY47KdVj07KvA8AoWsAlvtAZpOOWsB dNt8jWlZ87xWu8DxwH+XhpaHLwtA+y2fq6Sf28036XF3NbEuK777z+5fNCgy3Rh0mhr1 uYn88THYMclzgf+d4ddIH/+s8622ig4aNFqVoQimYxMUXpK04T5rQ/J/sumiSzcXay0Q YeERfsr/pMGxH6gOoEWQHEytGQk/SDHJd7hWhkSc/CPPqZDTriHmzE1lq8BsmHB8TFg7 Y3tQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=GmpKwYhuK5X7dWJRaRkcMJXDbBVLOuX+foIqgPcfYaQ=; b=rDZ+1REVuX3kntDzZYQwQosNwgrWWsA5VmwlXKx7laJCXa+E7oB6UwOLHX8wTIv+lr hdxAM51Gk4xEVXMwxSk8NjFdrpt1xckAv5XiFlNr2MQdQJgc7JVJD+dLGef3pyhsbZiD 2bc1sFUOEkOytpyqkKK8rqDiJCu/U8DL8Q2zcXiX3QHX0eaTCHVhTiUJxHUzVCvv4Mi7 jNbJcRPxvSBGOAQCf9cchoZp+KzkNnUdACtKzc/YSgzwJ5Q6ugmefjz+GjbtxnlJdlWN 8xz3uOSiloNnApekZE7K/qb+oS0kkFg5MjG8hilsEIPMRltJNNWASwpMbwBCnXvguje8 2z4Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@ti.com header.s=ti-com-17Q1 header.b=GTl7tqKB; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=NONE dis=NONE) header.from=ti.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id k53si10818593edb.303.2019.09.10.04.00.06; Tue, 10 Sep 2019 04:00:06 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@ti.com header.s=ti-com-17Q1 header.b=GTl7tqKB; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=NONE dis=NONE) header.from=ti.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390672AbfIJLAD (ORCPT + 27 others); Tue, 10 Sep 2019 07:00:03 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:55952 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729140AbfIJLAD (ORCPT ); Tue, 10 Sep 2019 07:00:03 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id x8AAxrvY071827; Tue, 10 Sep 2019 05:59:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1568113193; bh=GmpKwYhuK5X7dWJRaRkcMJXDbBVLOuX+foIqgPcfYaQ=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=GTl7tqKBWUTt/YMmhUHbDPNfVGgYS7mGYfMM+DE0S3PsXq9qfwKVMrxMwq9i49UKZ 19oc8mgpKk/f2a03GJlISL75+udY5Vp6/69mVxjZvbAEQR60wfV6RkH6kyNfGnSJJk +rFzJswDlUis/KWsidcSRqVyiMocB3rbGTtm2VHY= Received: from DFLE106.ent.ti.com (dfle106.ent.ti.com [10.64.6.27]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8AAxr9Z034403; Tue, 10 Sep 2019 05:59:53 -0500 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE106.ent.ti.com (10.64.6.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Tue, 10 Sep 2019 05:59:53 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE108.ent.ti.com (10.64.6.29) 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; Tue, 10 Sep 2019 05:59:53 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8AAxqrJ054728; Tue, 10 Sep 2019 05:59:52 -0500 From: Jean-Jacques Hiblot To: , , , , , CC: , , , , , Jean-Jacques Hiblot Subject: [PATCH v5 1/4] leds: Add of_led_get() and led_put() Date: Tue, 10 Sep 2019 12:59:43 +0200 Message-ID: <20190910105946.23057-2-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190910105946.23057-1-jjhiblot@ti.com> References: <20190910105946.23057-1-jjhiblot@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(+) -- 2.17.1 diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 4e2af8df5aa8..eb98bf13e53b 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "leds.h" static struct class *leds_class; @@ -213,6 +214,55 @@ 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_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_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 match_name(struct device *dev, const void *data) { if (!dev_name(dev)) diff --git a/include/linux/leds.h b/include/linux/leds.h index bee8e3f8dddd..0a71c7cdd191 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -19,6 +19,7 @@ struct device; struct led_pattern; +struct device_node; /* * LED Core */ @@ -145,6 +146,9 @@ 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 Tue Sep 10 10:59:46 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: 173510 Delivered-To: patch@linaro.org Received: by 2002:a05:6e02:ce:0:0:0:0 with SMTP id r14csp5628828ilq; Tue, 10 Sep 2019 04:00:12 -0700 (PDT) X-Google-Smtp-Source: APXvYqwM31yTQSJx4pmHox28nhPJYvNNPLwxixE5gcxVViCqYvn0n1faKgyAVPBiUUGxlE6L9v0s X-Received: by 2002:a17:906:2458:: with SMTP id a24mr24175321ejb.69.1568113211989; Tue, 10 Sep 2019 04:00:11 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568113211; cv=none; d=google.com; s=arc-20160816; b=1B7YRzQFv2gyL+smb/MOVEOrfX3KhcLpjYQ32JFlfG/FjY8N1PVF6iNkvKLiN8yCcj YuyXFC1jDke9kuOd2I5FVY04ZRD8oNzQYw9OO3PJFHjnpDOp4IDz/hag65RXu1DGWkD9 lf1qPtzNaco9VarUCl0QJziTStHGCqDW+uX7IxsZArWvnlU/ZiE/iRAAiN0FIcSSrWqX hAm8Mr2kNc45O41IvklfBNMCtNitpikEte+vGle9+W7Qs6+IYHcD/1CD6zFYinChEuQV 7AmIO2TiwE3uIWbyBo91LZXx00JvEZsA3MISccrzj1Sv/kazY3bOFcKdETVJwCi9QxT3 MvRg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=qIs5dMJbfaGqvzhLeRH8knJ6IbeNkNZctw+PcBiFsXM=; b=zi8dctu+O0E3sjdoBP2xkuAuKrxHZM6uf5b3QZAk5JFpe6OMnHbIA1Aj8bagqlw5le uXmy7q+1KAfBkjp1abN29NsOyDc1RMaFPMRC2mm5T8P3oNZ4kSPZeWvG2xuzulIhj8Q5 XD6HeE5BdrG/jKZXN4QvelAeBYPG8mGc2FIEqRz7HEQQ7Bm/ECAXGGTwfyaMM/BIqj9m BrGR4rxYLfLf9yPuwBp72IT/EoPlbR65gmCq9aYqiID49A1nKYGajX1rOWvOxmT+Immv QF4gFX8WvDfDrF2Fwd2g3Ed2d6RKmmnc9qRhwt+sCOtOyRYeqM5ND7K/cM/z0l94uzL0 6x3Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@ti.com header.s=ti-com-17Q1 header.b=bwWjIG7w; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=NONE dis=NONE) header.from=ti.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. 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Multiple LEDs can be used for a single backlight. Signed-off-by: Tomi Valkeinen Signed-off-by: Jean-Jacques Hiblot Acked-by: Pavel Machek --- drivers/video/backlight/Kconfig | 7 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 264 +++++++++++++++++++++++++++++++ 3 files changed, 272 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c -- 2.17.1 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..a72456e11fb9 --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,264 @@ +// 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 +#include +#include + +#define BKL_FULL_BRIGHTNESS 255 + +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");