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[209.132.180.67]) by mx.google.com with ESMTP id g195si11522093pfb.158.2019.07.01.08.14.55; Mon, 01 Jul 2019 08:14:55 -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="Ydn/br+g"; 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 S1730247AbfGAPOu (ORCPT + 30 others); Mon, 1 Jul 2019 11:14:50 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:53868 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730208AbfGAPOm (ORCPT ); Mon, 1 Jul 2019 11:14:42 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x61FEVL0084346; Mon, 1 Jul 2019 10:14:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1561994071; bh=UPVLwiiF/QJ52gzM7BCswJcz/5sU+K2QOlt4pm8nu90=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=Ydn/br+g3vvC58ptwJVlrKLQ4WdkfTKLowky0DdRdtIdxq3kunMcv/qjzXS0qDyMZ Qj/iury9uxyy1MD0RqBq1qPwuwSMKnmv7W44z/2Om0M3rEu1H2vkKhq5GFUbNGmqcm fyh3Zv/ZQi3s8Cy1FuefFi/xiD1ptpwl1AnD8C/M= Received: from DLEE113.ent.ti.com (dlee113.ent.ti.com [157.170.170.24]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x61FEUG1106616 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 1 Jul 2019 10:14:31 -0500 Received: from DLEE105.ent.ti.com (157.170.170.35) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Mon, 1 Jul 2019 10:14:30 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE105.ent.ti.com (157.170.170.35) 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; Mon, 1 Jul 2019 10:14:30 -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 x61FETjF067739; Mon, 1 Jul 2019 10:14:30 -0500 From: Jean-Jacques Hiblot To: , , , , , , CC: , , , , , Jean-Jacques Hiblot Subject: [PATCH 3/4] backlight: add led-backlight driver Date: Mon, 1 Jul 2019 17:14:22 +0200 Message-ID: <20190701151423.30768-4-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190701151423.30768-1-jjhiblot@ti.com> References: <20190701151423.30768-1-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 a led-backlight driver (led_bl), which is mostly similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Signed-off-by: Tomi Valkeinen Signed-off-by: Jean-Jacques Hiblot --- drivers/video/backlight/Kconfig | 7 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 217 +++++++++++++++++++++++++++++++ 3 files changed, 225 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..e699924cc2bc --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2015-2018 Texas Instruments Incorporated - http://www.ti.com/ + * Author: Tomi Valkeinen + * + * Based on pwm_bl.c + */ + +#include +#include +#include +#include +#include +#include +#include + +struct led_bl_data { + struct device *dev; + struct backlight_device *bl_dev; + + unsigned int *levels; + bool enabled; + struct regulator *power_supply; + struct gpio_desc *enable_gpio; + + struct led_classdev *led_cdev; + + unsigned int max_brightness; + unsigned int default_brightness; +}; + +static void led_bl_set_brightness(struct led_bl_data *priv, int brightness) +{ + int err; + + if (!priv->enabled) { + err = regulator_enable(priv->power_supply); + if (err < 0) + dev_err(priv->dev, "failed to enable power supply\n"); + + if (priv->enable_gpio) + gpiod_set_value_cansleep(priv->enable_gpio, 1); + } + + led_set_brightness(priv->led_cdev, priv->levels[brightness]); + + priv->enabled = true; +} + +static void led_bl_power_off(struct led_bl_data *priv) +{ + if (!priv->enabled) + return; + + led_set_brightness(priv->led_cdev, LED_OFF); + + if (priv->enable_gpio) + gpiod_set_value_cansleep(priv->enable_gpio, 0); + + regulator_disable(priv->power_supply); + + 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_parse_dt(struct device *dev, + struct led_bl_data *priv) +{ + struct device_node *node = dev->of_node; + int num_levels; + u32 *levels; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + num_levels = of_property_count_u32_elems(node, "brightness-levels"); + if (num_levels < 0) + return num_levels; + + 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; + + ret = of_property_read_u32(node, "default-brightness-level", &value); + if (ret < 0) + return ret; + + if (value >= num_levels) { + dev_err(dev, "invalid default-brightness-level\n"); + return -EINVAL; + } + + priv->levels = levels; + priv->max_brightness = num_levels - 1; + priv->default_brightness = value; + + return 0; +} + +static int led_bl_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct led_bl_data *priv; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + priv->dev = &pdev->dev; + priv->led_cdev = to_led_classdev(pdev->dev.parent); + + ret = led_bl_parse_dt(&pdev->dev, priv); + if (ret < 0) { + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "failed to parse DT data\n"); + return ret; + } + + priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_LOW); + if (IS_ERR(priv->enable_gpio)) { + ret = PTR_ERR(priv->enable_gpio); + goto err; + } + + priv->power_supply = devm_regulator_get(&pdev->dev, "power"); + if (IS_ERR(priv->power_supply)) { + ret = PTR_ERR(priv->power_supply); + goto err; + } + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = priv->max_brightness; + 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"); + ret = PTR_ERR(priv->bl_dev); + goto err; + } + + priv->bl_dev->props.brightness = priv->default_brightness; + backlight_update_status(priv->bl_dev); + + return 0; + +err: + + return ret; +} + +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; + + backlight_device_unregister(bl); + + led_bl_power_off(priv); + + 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");