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[2610:10:20:722:a800:ff:fe36:1795]) by mx.google.com with ESMTPS id e25si19259325pff.30.2019.07.08.03.27.24 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 08 Jul 2019 03:27:24 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 2610:10:20:722:a800:ff:fe36:1795 as permitted sender) client-ip=2610:10:20:722:a800:ff:fe36:1795; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of dri-devel-bounces@lists.freedesktop.org designates 2610:10:20:722:a800:ff:fe36:1795 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 AF66089C6A; Mon, 8 Jul 2019 10:27:18 +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 7624D89C63 for ; Mon, 8 Jul 2019 10:27:17 +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 x68ARCKE001167; Mon, 8 Jul 2019 05:27:12 -0500 Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x68ARCXK067712 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 8 Jul 2019 05:27:12 -0500 Received: from DLEE103.ent.ti.com (157.170.170.33) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Mon, 8 Jul 2019 05:27:12 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE103.ent.ti.com (157.170.170.33) 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, 8 Jul 2019 05:27:12 -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 x68ARBBD074756; Mon, 8 Jul 2019 05:27:11 -0500 From: Jean-Jacques Hiblot To: , , , , , , Subject: [PATCH v2 4/4] backlight: add led-backlight driver Date: Mon, 8 Jul 2019 12:27:00 +0200 Message-ID: <20190708102700.23138-5-jjhiblot@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190708102700.23138-1-jjhiblot@ti.com> References: <20190708102700.23138-1-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=1562581632; bh=rsEOI56jQUV/QiIXLNiFABw3GYyB7YCOM03aYJBNebY=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=IwE43AKX9lENFZKxTVI+asaWNv6oN5tvkv2zblXfDyurPb5Tzh3BpD8bm72fZGhTA b7TCwgR/y86wDVYE5di5om/pudSqGB+SaA+JteRViAeFwpCWlW2Z70SBVy26MJmpo4 osKDYo9MlhIMMDpeEOJ+g5zEt0nn1hNjHfjvKCbQ= 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, Jean-Jacques Hiblot , 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 --- drivers/video/backlight/Kconfig | 7 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 235 +++++++++++++++++++++++++++++++ 3 files changed, 243 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..7644277cfdbb --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,235 @@ +// 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 int to_led_brightness(struct led_classdev *led, int value) +{ + return (value * led->max_brightness) / BKL_FULL_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++) { + int led_brightness; + struct led_classdev *led = priv->leds[i]; + + led_brightness = to_led_brightness(led, bkl_brightness); + led_set_brightness(led, led_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_parse_dt(struct device *dev, + struct led_bl_data *priv) +{ + struct device_node *node = dev->of_node; + int num_levels; + u32 *levels = NULL; + u32 value; + int ret; + bool use_default_levels = false; + + if (!node) + return -ENODEV; + + num_levels = of_property_count_u32_elems(node, "brightness-levels"); + if (num_levels < 0) { + dev_warn(dev, "can't get brightness-levels. using default levels\n"); + use_default_levels = true; + num_levels = BKL_FULL_BRIGHTNESS + 1; + } + + if (!use_default_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) + value = num_levels / 2; + + if (value >= num_levels) { + dev_warn(dev, "invalid default-brightness-level. using default\n"); + value = num_levels / 2; + } + + ret = of_count_phandle_with_args(node, "leds", NULL); + if (ret < 0) { + dev_err(dev, "unable to get led count\n"); + return -EINVAL; + } + + priv->nb_leds = ret; + if (priv->nb_leds < 1) { + dev_err(dev, "At least one LED must be specified!\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; + int 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_parse_dt(&pdev->dev, priv); + if (ret < 0) { + dev_err(&pdev->dev, "failed to parse DT data\n"); + return ret; + } + priv->leds = devm_kzalloc(&pdev->dev, + sizeof(struct led_classdev *) * priv->nb_leds, + GFP_KERNEL); + if (!priv->leds) + return -ENOMEM; + + for (i = 0; i < priv->nb_leds; i++) { + priv->leds[i] = devm_led_get(&pdev->dev, i); + if (IS_ERR(priv->leds[i])) + return PTR_ERR(priv->leds[i]); + } + + 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");