| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1233053634-25052-1-git-send-email-l.fu@pengutronix.de>
Date: Tue, 27 Jan 2009 11:53:54 +0100
From: Luotao Fu <l.fu@...gutronix.de>
To: rpurdie@...ys.net
Cc: linux-kernel@...r.kernel.org, Luotao Fu <l.fu@...gutronix.de>
Subject: [PATCH] leds: Simple driver for pwm driven LEDs
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 <l.fu@...gutronix.de>
---
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@...gutronix.de)
+ *
+ * based on leds-gpio.c by Raphael Assenat <raph@...com>
+ *
+ * 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 <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/leds.h>
+#include <linux/err.h>
+#include <linux/pwm.h>
+#include <linux/leds_pwm.h>
+
+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 <l.fu@...gutronix.de>");
+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@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists