From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757156AbZBPNOS (ORCPT ); Mon, 16 Feb 2009 08:14:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755182AbZBPNN5 (ORCPT ); Mon, 16 Feb 2009 08:13:57 -0500 Received: from smtp.nokia.com ([192.100.122.230]:38944 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754897AbZBPNNz (ORCPT ); Mon, 16 Feb 2009 08:13:55 -0500 Date: Mon, 16 Feb 2009 14:57:46 +0200 From: Felipe Balbi To: "Balbi Felipe (Nokia-D/Helsinki)" Cc: "linux-kernel@vger.kernel.org" , Felipe Balbi , Richard Purdie Subject: Re: [PATCH] leds: triggers: introduce gpio led trigger Message-ID: <20090216125746.GR21181@scadufax.research.nokia.com> Reply-To: felipe.balbi@nokia.com References: <1234786651-4433-1-git-send-email-felipe.balbi@nokia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234786651-4433-1-git-send-email-felipe.balbi@nokia.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-OriginalArrivalTime: 16 Feb 2009 13:12:29.0527 (UTC) FILETIME=[3861C670:01C99038] X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 16, 2009 at 01:17:31PM +0100, Balbi Felipe (Nokia-D/Helsinki) wrote: > From: Felipe Balbi > > The gpio led trigger will allow leds to be triggered by > gpio events. > > There's a timer function that keeps checking the gpio > value in order to know when we need to turn leds on/off. > > It's useful for usecases as n810's keypad leds that could > be triggered by the gpio event generated when user slides > up to show the keypad. > > We also provide means for userland to tell us what is the > desired brightness for that special led when it goes on > so userland could use information from ambient light sensors > and not set led brightness too high if it's not necessary. > > This trigger was tested with n810. > > Cc: Richard Purdie > Signed-off-by: Felipe Balbi > --- > drivers/leds/Kconfig | 13 +++ > drivers/leds/Makefile | 1 + > drivers/leds/ledtrig-gpio.c | 229 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 243 insertions(+), 0 deletions(-) > create mode 100644 drivers/leds/ledtrig-gpio.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 7427136..2bd77d5 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -216,6 +216,19 @@ config LEDS_TRIGGER_BACKLIGHT > > If unsure, say N. > > +config LEDS_TRIGGER_GPIO > + tristate "LED GPIO Trigger" > + depends on LEDS_TRIGGERS > + depends on GPIOLIB > + help > + This allows LEDs to be controlled by gpio events. It's good > + when using gpios as switches and triggering the needed LEDs > + from there. One use case is n810's keypad LEDs that could > + be triggered by this trigger when user slides up to show > + keypad. > + > + If unsure, say N. > + > config LEDS_TRIGGER_DEFAULT_ON > tristate "LED Default ON Trigger" > depends on LEDS_TRIGGERS > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index 9d76f0f..c9e5d31 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -30,4 +30,5 @@ obj-$(CONFIG_LEDS_TRIGGER_TIMER) += ledtrig-timer.o > obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK) += ledtrig-ide-disk.o > obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT) += ledtrig-heartbeat.o > obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT) += ledtrig-backlight.o > +obj-$(CONFIG_LEDS_TRIGGER_GPIO) += ledtrig-gpio.o > obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o > diff --git a/drivers/leds/ledtrig-gpio.c b/drivers/leds/ledtrig-gpio.c > new file mode 100644 > index 0000000..af24dcf > --- /dev/null > +++ b/drivers/leds/ledtrig-gpio.c > @@ -0,0 +1,229 @@ > +/* > + * ledtrig-gio.c - LED Trigger Based on GPIO events > + * > + * Copyright 2009 Felipe Balbi > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include "leds.h" > + > +struct gpio_trig_data { > + struct delayed_work work; > + struct led_classdev *led; > + > + unsigned desired_brightness; /* desired brightness when led is on */ > + unsigned inverted; /* true when gpio is inverted */ > + unsigned gpio; /* gpio that triggers the leds */ > +}; > + > +static ssize_t gpio_trig_brightness_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + > + return sprintf(buf, "%u\n", gpio_data->desired_brightness); > +} > + > +static ssize_t gpio_trig_brightness_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t n) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + unsigned desired_brightness; > + int ret; > + > + ret = sscanf(buf, "%u", &desired_brightness); > + if (ret < 1 || desired_brightness > 255) { > + dev_err(dev, "invalid value\n"); > + return -EINVAL; > + } > + > + gpio_data->desired_brightness = desired_brightness; > + > + return n; > +} > +static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show, > + gpio_trig_brightness_store); > + > +static ssize_t gpio_trig_inverted_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + > + return sprintf(buf, "%s\n", gpio_data->inverted ? "yes" : "no"); > +} > + > +static ssize_t gpio_trig_inverted_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t n) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + unsigned inverted; > + int ret; > + > + ret = sscanf(buf, "%u", &inverted); > + if (ret < 1) { > + dev_err(dev, "invalid value\n"); > + return -EINVAL; > + } > + > + gpio_data->inverted = !!inverted; > + > + return n; > +} > +static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show, > + gpio_trig_inverted_store); > + > +static ssize_t gpio_trig_gpio_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + > + return sprintf(buf, "%u\n", gpio_data->gpio); > +} > + > +static ssize_t gpio_trig_gpio_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t n) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct gpio_trig_data *gpio_data = led->trigger_data; > + unsigned gpio; > + int ret; > + > + ret = sscanf(buf, "%u", &gpio); > + if (ret < 1) { > + dev_err(dev, "couldn't read gpio number\n"); > + cancel_delayed_work(&gpio_data->work); > + return -EINVAL; > + } > + > + gpio_data->gpio = gpio; > + schedule_delayed_work(&gpio_data->work, msecs_to_jiffies(50)); > + > + return n; > +} > +static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store); > + > +static void gpio_trig_work(struct work_struct *work) > +{ > + struct gpio_trig_data *gpio_data = container_of(work, > + struct gpio_trig_data, work.work); > + > + if (!gpio_data->gpio) > + goto out; > + > + if (!gpio_data->inverted) { > + if (gpio_get_value(gpio_data->gpio)) { > + if (gpio_data->desired_brightness) > + led_set_brightness(gpio_data->led, > + gpio_data->desired_brightness); > + else > + led_set_brightness(gpio_data->led, LED_FULL); > + } else { > + led_set_brightness(gpio_data->led, LED_OFF); > + } > + } else { > + if (!gpio_get_value(gpio_data->gpio)) { > + if (gpio_data->desired_brightness) > + led_set_brightness(gpio_data->led, > + gpio_data->desired_brightness); > + else > + led_set_brightness(gpio_data->led, LED_FULL); > + } else { > + led_set_brightness(gpio_data->led, LED_OFF); > + } > + } > + > +out: > + /* Completely arbitrary constant. I'm guessing user won't be able > + * to trigger gpio event twice in less then 50ms and in case of > + * having to trigger several leds, we won't notice the delay between > + * them. > + */ > + schedule_delayed_work(&gpio_data->work, msecs_to_jiffies(50)); > +} > + > +static void gpio_trig_activate(struct led_classdev *led) > +{ > + struct gpio_trig_data *gpio_data; > + int ret; > + > + gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL); > + if (!gpio_data) > + return; > + > + ret = device_create_file(led->dev, &dev_attr_gpio); > + if (ret) > + goto err_gpio; > + > + ret = device_create_file(led->dev, &dev_attr_inverted); > + if (ret) > + goto err_inverted; > + > + ret = device_create_file(led->dev, &dev_attr_desired_brightness); > + if (ret) > + goto err_brightness; > + > + gpio_data->led = led; > + led->trigger_data = gpio_data; > + INIT_DELAYED_WORK(&gpio_data->work, gpio_trig_work); > + > + return; > + > +err_brightness: > + device_remove_file(led->dev, &dev_attr_inverted); > + > +err_inverted: > + device_remove_file(led->dev, &dev_attr_gpio); > + > +err_gpio: > + kfree(gpio_data); > +} > + > +static void gpio_trig_deactivate(struct led_classdev *led) > +{ > + struct gpio_trig_data *gpio_data = led->trigger_data; > + > + if (gpio_data) { > + device_remove_file(led->dev, &dev_attr_gpio); > + device_remove_file(led->dev, &dev_attr_inverted); > + device_remove_file(led->dev, &dev_attr_desired_brightness); > + cancel_delayed_work(&gpio_data->work); Just a question. Should I flush_scheduled_work() here ?? Here goes a patch adding it: diff --git a/drivers/leds/ledtrig-gpio.c b/drivers/leds/ledtrig-gpio.c index af24dcf..d532812 100644 --- a/drivers/leds/ledtrig-gpio.c +++ b/drivers/leds/ledtrig-gpio.c @@ -202,6 +202,7 @@ static void gpio_trig_deactivate(struct led_classdev *led) device_remove_file(led->dev, &dev_attr_inverted); device_remove_file(led->dev, &dev_attr_desired_brightness); cancel_delayed_work(&gpio_data->work); + flush_scheduled_work(); kfree(gpio_data); } } -- balbi