Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933404Ab3CGVQP (ORCPT ); Thu, 7 Mar 2013 16:16:15 -0500 Received: from hqemgate04.nvidia.com ([216.228.121.35]:15228 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751787Ab3CGVQN (ORCPT ); Thu, 7 Mar 2013 16:16:13 -0500 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 07 Mar 2013 13:10:05 -0800 From: Andrew Chew To: , CC: , Subject: [PATCH 1/1 v5] pwm_bl: Add support for backlight enable regulator Date: Thu, 7 Mar 2013 13:16:08 -0800 Message-ID: <1362690968-24854-1-git-send-email-achew@nvidia.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5886 Lines: 184 The backlight enable regulator is specified in the device tree node for backlight. Signed-off-by: Andrew Chew --- Renamed en_supply to enable_supply to match the corresponding device tree property. Removed unnecessary check for pb->enable_supply validity. This supply is mandatory, and probe will fail if it is not provided. Renamed the tracking bool from en_supply_enabled to enabled so that it's more generic. Encapsulated pwm_enable() and pwm_disable() calls into the enabled check so that we never unnecessarily turn on or off the pwm if it's already been turned on or off. .../bindings/video/backlight/pwm-backlight.txt | 14 +++++ drivers/video/backlight/pwm_bl.c | 56 ++++++++++++++++---- 2 files changed, 60 insertions(+), 10 deletions(-) diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt index 1e4fc72..7e2e089 100644 --- a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -10,6 +10,11 @@ Required properties: last value in the array represents a 100% duty cycle (brightest). - default-brightness-level: the default brightness level (index into the array defined by the "brightness-levels" property) + - enable-supply: A phandle to the regulator device tree node. This + regulator will be turned on and off as the pwm is enabled and disabled. + Many backlights are enabled via a GPIO. In this case, we instantiate + a fixed regulator and give that to enable-supply. If a regulator + is not needed, then provide a dummy fixed regulator. Optional properties: - pwm-names: a list of names for the PWM devices specified in the @@ -19,10 +24,19 @@ Optional properties: Example: + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + regulator-boot-on; + gpio = <&some_gpio>; + enable-active-high; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 0 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 069983c..c517d4a 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -20,10 +20,13 @@ #include #include #include +#include struct pwm_bl_data { struct pwm_device *pwm; struct device *dev; + bool enabled; + struct regulator *enable_supply; unsigned int period; unsigned int lth_brightness; unsigned int *levels; @@ -35,6 +38,38 @@ struct pwm_bl_data { void (*exit)(struct device *); }; +static void pwm_backlight_enable(struct backlight_device *bl) +{ + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); + + /* Bail if we are already enabled. */ + if (pb->enabled) + return; + + pwm_enable(pb->pwm); + + if (regulator_enable(pb->enable_supply) != 0) + dev_warn(&bl->dev, "Failed to enable regulator"); + + pb->enabled = true; +} + +static void pwm_backlight_disable(struct backlight_device *bl) +{ + struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); + + /* Bail if we are already disabled. */ + if (!pb->enabled) + return; + + if (regulator_disable(pb->enable_supply) != 0) + dev_warn(&bl->dev, "Failed to disable regulator"); + + pwm_disable(pb->pwm); + + pb->enabled = false; +} + static int pwm_backlight_update_status(struct backlight_device *bl) { struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev); @@ -52,7 +87,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) if (brightness == 0) { pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_disable(bl); } else { int duty_cycle; @@ -66,7 +101,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) duty_cycle = pb->lth_brightness + (duty_cycle * (pb->period - pb->lth_brightness) / max); pwm_config(pb->pwm, duty_cycle, pb->period); - pwm_enable(pb->pwm); + pwm_backlight_enable(bl); } if (pb->notify_after) @@ -145,12 +180,6 @@ static int pwm_backlight_parse_dt(struct device *dev, data->max_brightness--; } - /* - * TODO: Most users of this driver use a number of GPIOs to control - * backlight power. Support for specifying these needs to be - * added. - */ - return 0; } @@ -213,6 +242,13 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->exit = data->exit; pb->dev = &pdev->dev; + pb->enable_supply = devm_regulator_get(&pdev->dev, "enable"); + if (IS_ERR(pb->enable_supply)) { + ret = PTR_ERR(pb->enable_supply); + pb->enable_supply = NULL; + goto err_alloc; + } + pb->pwm = devm_pwm_get(&pdev->dev, NULL); if (IS_ERR(pb->pwm)) { dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); @@ -268,7 +304,7 @@ static int pwm_backlight_remove(struct platform_device *pdev) backlight_device_unregister(bl); pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_disable(bl); if (pb->exit) pb->exit(&pdev->dev); return 0; @@ -283,7 +319,7 @@ static int pwm_backlight_suspend(struct device *dev) if (pb->notify) pb->notify(pb->dev, 0); pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_backlight_disable(bl); if (pb->notify_after) pb->notify_after(pb->dev, 0); return 0; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/