From patchwork Sat Jan 19 10:30:18 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Courbot X-Patchwork-Id: 213817 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 514A92C007C for ; Sat, 19 Jan 2013 21:29:14 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751979Ab3ASK2m (ORCPT ); Sat, 19 Jan 2013 05:28:42 -0500 Received: from mail-pb0-f52.google.com ([209.85.160.52]:57826 "EHLO mail-pb0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723Ab3ASK2j (ORCPT ); Sat, 19 Jan 2013 05:28:39 -0500 Received: by mail-pb0-f52.google.com with SMTP id ro2so2509997pbb.39 for ; Sat, 19 Jan 2013 02:28:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=OWq5T/cSNIvLbwFafzELxIeHh3QyOurFWnViAXFx24c=; b=pgUvEBKkhouEPYTdH74JR1ArsrnzAsByD1Bc02vFQ6QLlWlYvk/0+7JkPZ2J/x+rY4 gdu0RUtc4h5rMgbjlpZLX7GqVXmpddoqmB0swBUAH3N+Qm2tg3LAtKfGh0PhloYrQdKx eMI269qM0aBLD4OnyeBNJQIRaU+2eLiddD4nQ8M5tQ66K1Dx+v/1/o8BOQ+bzwTF+ic9 VJV55M241QpG/C8wI+xx7Owgvn3vIOSasqBuTGpWV7FkuXynRrNKtYVPEk14Pozlmcdt bk8sdqTIGOXIiSsE9jiRD7P916GldsTntANJMsbaCNCXC2iP+wMv7PW+48AKM+CBxyHg 9hsQ== X-Received: by 10.66.73.68 with SMTP id j4mr31238528pav.84.1358591318517; Sat, 19 Jan 2013 02:28:38 -0800 (PST) Received: from roland.nvidia.com ([203.18.50.4]) by mx.google.com with ESMTPS id nw9sm4796145pbb.42.2013.01.19.02.28.35 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 19 Jan 2013 02:28:37 -0800 (PST) From: Alexandre Courbot To: Thierry Reding , Stephen Warren Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Mark Zhang , gnurou@gmail.com, Alexandre Courbot Subject: [PATCH 1/3] pwm-backlight: add subdriver mechanism Date: Sat, 19 Jan 2013 19:30:18 +0900 Message-Id: <1358591420-7790-2-git-send-email-acourbot@nvidia.com> X-Mailer: git-send-email 1.8.1.1 In-Reply-To: <1358591420-7790-1-git-send-email-acourbot@nvidia.com> References: <1358591420-7790-1-git-send-email-acourbot@nvidia.com> Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org PWM-controlled backlights often need additional power control prior to activating the PWM, typically switching regulators or GPIOs. This has been done so far through hooks defined in board files, but this mechanism cannot be used on platforms that rely on the device tree. This patch introduces a "subdriver" mechanism to the pwm-backlight driver that allows such hooks to be defined in optionally-compiled sub-drivers. Every subdriver has its own device tree properties, which sets the correct hooks to the pwm-backlight driver. Signed-off-by: Alexandre Courbot --- drivers/video/backlight/Makefile | 4 +++ drivers/video/backlight/pwm_bl.c | 67 +++++++++++++++++++++++++++++++++++++++- include/linux/pwm_backlight.h | 15 +++++++++ 3 files changed, 85 insertions(+), 1 deletion(-) diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index e7ce729..df97ab1 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -29,6 +29,10 @@ obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o +# pwm-backlight subdrivers must be listed *before* pwm_bl.o. +# Link order is important as subdrivers must register themselves +# before pwm-backlight's probe function can be called. +obj-$(CONFIG_BACKLIGHT_PWM_TEGRA) += pwm_bl_tegra.o obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o obj-$(CONFIG_BACKLIGHT_DA903X) += da903x_bl.o obj-$(CONFIG_BACKLIGHT_DA9052) += da9052_bl.o diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 069983c..b65a797 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -22,6 +22,7 @@ #include struct pwm_bl_data { + void *subdriver_data; struct pwm_device *pwm; struct device *dev; unsigned int period; @@ -35,6 +36,54 @@ struct pwm_bl_data { void (*exit)(struct device *); }; +static DEFINE_MUTEX(pwm_backlight_subdrivers_mutex); +static LIST_HEAD(pwm_backlight_subdrivers); + +void pwm_backlight_add_subdriver(struct pwm_backlight_subdriver *driver) +{ + mutex_lock(&pwm_backlight_subdrivers_mutex); + list_add(&driver->list, &pwm_backlight_subdrivers); + mutex_unlock(&pwm_backlight_subdrivers_mutex); +} +EXPORT_SYMBOL(pwm_backlight_add_subdriver); + +void pwm_backlight_remove_subdriver(struct pwm_backlight_subdriver *driver) +{ + mutex_lock(&pwm_backlight_subdrivers_mutex); + list_del(&driver->list); + mutex_unlock(&pwm_backlight_subdrivers_mutex); +} +EXPORT_SYMBOL(pwm_backlight_remove_subdriver); + +/** + * pwm_backlight_set_subdriver_data - set subdriver data + * @dev: backlight device which data is to be set + * @data: subdriver data + * + * This function can be called *only* in the init() hook of the subdriver. The + * data will be temporarily set as driver data before being retrieved by + * the probe() function and moved to its final place. + */ +void pwm_backlight_set_subdriver_data(struct device *dev, void *data) +{ + dev_set_drvdata(dev, data); +} +EXPORT_SYMBOL(pwm_backlight_set_subdriver_data); + +/** + * pwm_backlight_get_subdriver_data - retrieve subdriver data + * @dev: backlight device to get subdriver data of + * + * This function can be called in any subdriver hook, excepted init(). + */ +void *pwm_backlight_get_subdriver_data(struct device *dev) +{ + struct backlight_device *bl = dev_get_drvdata(dev); + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); + return pb->subdriver_data; +} +EXPORT_SYMBOL(pwm_backlight_get_subdriver_data); + static int pwm_backlight_update_status(struct backlight_device *bl) { struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); @@ -98,6 +147,7 @@ static const struct backlight_ops pwm_backlight_ops = { static int pwm_backlight_parse_dt(struct device *dev, struct platform_pwm_backlight_data *data) { + struct pwm_backlight_subdriver *subdriver; struct device_node *node = dev->of_node; struct property *prop; int length; @@ -150,6 +200,17 @@ static int pwm_backlight_parse_dt(struct device *dev, * backlight power. Support for specifying these needs to be * added. */ + mutex_lock(&pwm_backlight_subdrivers_mutex); + list_for_each_entry(subdriver, &pwm_backlight_subdrivers, list) + if (of_device_is_compatible(node, subdriver->name)) { + data->init = subdriver->init; + data->exit = subdriver->exit; + data->notify = subdriver->notify; + data->notify_after = subdriver->notify_after; + data->check_fb = subdriver->check_fb; + break; + } + mutex_unlock(&pwm_backlight_subdrivers_mutex); return 0; } @@ -201,6 +262,9 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } + /* if the init function set subdriver data, move it to correct place */ + pb->subdriver_data = dev_get_drvdata(&pdev->dev); + if (data->levels) { max = data->levels[data->max_brightness]; pb->levels = data->levels; @@ -249,10 +313,11 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } + platform_set_drvdata(pdev, bl); + bl->props.brightness = data->dft_brightness; backlight_update_status(bl); - platform_set_drvdata(pdev, bl); return 0; err_alloc: diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index 56f4a86..6abe1ef 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -20,4 +20,19 @@ struct platform_pwm_backlight_data { int (*check_fb)(struct device *dev, struct fb_info *info); }; +struct pwm_backlight_subdriver { + struct list_head list; + const char *name; + int (*init)(struct device *dev); + int (*notify)(struct device *dev, int brightness); + void (*notify_after)(struct device *dev, int brightness); + void (*exit)(struct device *dev); + int (*check_fb)(struct device *dev, struct fb_info *info); +}; + +void pwm_backlight_add_subdriver(struct pwm_backlight_subdriver *driver); +void pwm_backlight_remove_subdriver(struct pwm_backlight_subdriver *driver); + +void pwm_backlight_set_subdriver_data(struct device *dev, void *data); +void *pwm_backlight_get_subdriver_data(struct device *dev); #endif