Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754692AbZA0Kyi (ORCPT ); Tue, 27 Jan 2009 05:54:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754803AbZA0Kx6 (ORCPT ); Tue, 27 Jan 2009 05:53:58 -0500 Received: from metis.ext.pengutronix.de ([92.198.50.35]:54226 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754661AbZA0Kx5 (ORCPT ); Tue, 27 Jan 2009 05:53:57 -0500 From: Luotao Fu To: rpurdie@rpsys.net Cc: linux-kernel@vger.kernel.org, Luotao Fu Subject: [PATCH] leds: Simple driver for pwm driven LEDs Date: Tue, 27 Jan 2009 11:53:54 +0100 Message-Id: <1233053634-25052-1-git-send-email-l.fu@pengutronix.de> X-Mailer: git-send-email 1.5.6.5 X-SA-Exim-Connect-IP: 2001:6f8:1178:2:215:17ff:fe12:23b0 X-SA-Exim-Mail-From: l.fu@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6218 Lines: 237 This one adds a simple driver for pwm driver LEDs. pwm_id and period can be defined in board file. It is developed for pxa, however it is probably generic enough to be used on other platforms with pwm. Signed-off-by: Luotao Fu --- drivers/leds/Kconfig | 6 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-pwm.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/leds_pwm.h | 21 ++++++ 4 files changed, 181 insertions(+), 0 deletions(-) create mode 100644 drivers/leds/leds-pwm.c create mode 100644 include/linux/leds_pwm.h diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 7427136..4dcd58d 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -171,6 +171,12 @@ config LEDS_DA903X This option enables support for on-chip LED drivers found on Dialog Semiconductor DA9030/DA9034 PMICs. +config LEDS_PWM + tristate "PWM driven LED Support" + depends on LEDS_CLASS && HAVE_PWM + help + This option enables support for pwm driven LEDs + comment "LED Triggers" config LEDS_TRIGGERS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 9d76f0f..8a8c22a 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_LEDS_FSG) += leds-fsg.o obj-$(CONFIG_LEDS_PCA955X) += leds-pca955x.o obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o +obj-$(CONFIG_LEDS_PWM) += leds-pwm.o # LED Triggers obj-$(CONFIG_LEDS_TRIGGER_TIMER) += ledtrig-timer.o diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c new file mode 100644 index 0000000..cdfdc87 --- /dev/null +++ b/drivers/leds/leds-pwm.c @@ -0,0 +1,153 @@ +/* + * linux/drivers/leds-pwm.c + * + * simple PWM based LED control + * + * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de) + * + * based on leds-gpio.c by Raphael Assenat + * + * 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 +#include +#include + +struct led_pwm_data { + struct led_classdev cdev; + struct pwm_device *pwm; + unsigned int active_low; + unsigned int period; + unsigned int max_brightness; +}; + +static void led_pwm_set(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + struct led_pwm_data *led_dat = + container_of(led_cdev, struct led_pwm_data, cdev); + unsigned int max = led_dat->max_brightness; + unsigned int period = led_dat->period; + + if (brightness == 0) { + pwm_config(led_dat->pwm, 0, period); + pwm_disable(led_dat->pwm); + } else { + pwm_config(led_dat->pwm, brightness * period / max, period); + pwm_enable(led_dat->pwm); + } +} + +static int led_pwm_probe(struct platform_device *pdev) +{ + struct led_pwm_platform_data *pdata = pdev->dev.platform_data; + struct led_pwm *cur_led; + struct led_pwm_data *leds_data, *led_dat; + int i, ret = 0; + + if (!pdata) + return -EBUSY; + + leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds, + GFP_KERNEL); + if (!leds_data) + return -ENOMEM; + + for (i = 0; i < pdata->num_leds; i++) { + cur_led = &pdata->leds[i]; + led_dat = &leds_data[i]; + + led_dat->pwm = pwm_request(cur_led->pwm_id, + cur_led->name); + if (IS_ERR(led_dat->pwm)) { + dev_err(&pdev->dev, "unable to request PWM %d\n", + cur_led->pwm_id); + goto err; + } + + led_dat->cdev.name = cur_led->name; + led_dat->cdev.default_trigger = cur_led->default_trigger; + led_dat->active_low = cur_led->active_low; + led_dat->max_brightness = cur_led->max_brightness; + led_dat->period = cur_led->pwm_period_ns; + led_dat->cdev.brightness_set = led_pwm_set; + led_dat->cdev.brightness = LED_OFF; + led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; + + ret = led_classdev_register(&pdev->dev, &led_dat->cdev); + if (ret < 0) { + pwm_free(led_dat->pwm); + goto err; + } + } + + platform_set_drvdata(pdev, leds_data); + + return 0; + +err: + if (i > 0) { + for (i = i - 1; i >= 0; i--) { + led_classdev_unregister(&leds_data[i].cdev); + pwm_free(leds_data[i].pwm); + } + } + + kfree(leds_data); + + return ret; +} + +static int __devexit led_pwm_remove(struct platform_device *pdev) +{ + int i; + struct led_pwm_platform_data *pdata = pdev->dev.platform_data; + struct led_pwm_data *leds_data; + + leds_data = platform_get_drvdata(pdev); + + for (i = 0; i < pdata->num_leds; i++) { + led_classdev_unregister(&leds_data[i].cdev); + pwm_free(leds_data[i].pwm); + } + + kfree(leds_data); + + return 0; +} + +static struct platform_driver led_pwm_driver = { + .probe = led_pwm_probe, + .remove = __devexit_p(led_pwm_remove), + .driver = { + .name = "leds_pwm", + .owner = THIS_MODULE, + }, +}; + +static int __init led_pwm_init(void) +{ + return platform_driver_register(&led_pwm_driver); +} + +static void __exit led_pwm_exit(void) +{ + platform_driver_unregister(&led_pwm_driver); +} + +module_init(led_pwm_init); +module_exit(led_pwm_exit); + +MODULE_AUTHOR("Luotao Fu "); +MODULE_DESCRIPTION("PWM LED driver for PXA"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:leds-pwm"); diff --git a/include/linux/leds_pwm.h b/include/linux/leds_pwm.h new file mode 100644 index 0000000..33a0711 --- /dev/null +++ b/include/linux/leds_pwm.h @@ -0,0 +1,21 @@ +/* + * PWM LED driver data - see drivers/leds/leds-pwm.c + */ +#ifndef __LINUX_LEDS_PWM_H +#define __LINUX_LEDS_PWM_H + +struct led_pwm { + const char *name; + const char *default_trigger; + unsigned pwm_id; + u8 active_low; + unsigned max_brightness; + unsigned pwm_period_ns; +}; + +struct led_pwm_platform_data { + int num_leds; + struct led_pwm *leds; +}; + +#endif -- 1.5.6.5 -- 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/