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path: root/target/linux/generic/files/drivers/pwm/gpio-pwm.c
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Diffstat (limited to 'target/linux/generic/files/drivers/pwm/gpio-pwm.c')
-rw-r--r--target/linux/generic/files/drivers/pwm/gpio-pwm.c298
1 files changed, 0 insertions, 298 deletions
diff --git a/target/linux/generic/files/drivers/pwm/gpio-pwm.c b/target/linux/generic/files/drivers/pwm/gpio-pwm.c
deleted file mode 100644
index 58e518f..0000000
--- a/target/linux/generic/files/drivers/pwm/gpio-pwm.c
+++ /dev/null
@@ -1,298 +0,0 @@
-/*
- * drivers/pwm/gpio.c
- *
- * Models a single-channel PWM device using a timer and a GPIO pin.
- *
- * Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
- *
- * This program is free software; you may redistribute and/or modify
- * it under the terms of the GNU General Public License Version 2, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
- * USA
- */
-
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/hrtimer.h>
-#include <linux/err.h>
-#include <linux/platform_device.h>
-#include <linux/workqueue.h>
-#include <linux/gpio.h>
-#include <linux/slab.h>
-#include <linux/pwm/pwm.h>
-
-struct gpio_pwm {
- struct pwm_device pwm;
- struct hrtimer timer;
- struct work_struct work;
- pwm_callback_t callback;
- int gpio;
- unsigned long polarity : 1;
- unsigned long active : 1;
-};
-
-static inline struct gpio_pwm *to_gpio_pwm(const struct pwm_channel *p)
-{
- return container_of(p->pwm, struct gpio_pwm, pwm);
-}
-
-static void
-gpio_pwm_work (struct work_struct *work)
-{
- struct gpio_pwm *gp = container_of(work, struct gpio_pwm, work);
-
- if (gp->active)
- gpio_direction_output(gp->gpio, gp->polarity ? 1 : 0);
- else
- gpio_direction_output(gp->gpio, gp->polarity ? 0 : 1);
-}
-
-static enum hrtimer_restart
-gpio_pwm_timeout(struct hrtimer *t)
-{
- struct gpio_pwm *gp = container_of(t, struct gpio_pwm, timer);
- ktime_t tnew;
-
- if (unlikely(gp->pwm.channels[0].duty_ticks == 0))
- gp->active = 0;
- else if (unlikely(gp->pwm.channels[0].duty_ticks
- == gp->pwm.channels[0].period_ticks))
- gp->active = 1;
- else
- gp->active ^= 1;
-
- if (gpio_cansleep(gp->gpio))
- schedule_work(&gp->work);
- else
- gpio_pwm_work(&gp->work);
-
- if (!gp->active && gp->pwm.channels[0].callback)
- gp->pwm.channels[0].callback(&gp->pwm.channels[0]);
-
- if (unlikely(!gp->active &&
- (gp->pwm.channels[0].flags & BIT(FLAG_STOP)))) {
- clear_bit(FLAG_STOP, &gp->pwm.channels[0].flags);
- complete_all(&gp->pwm.channels[0].complete);
- return HRTIMER_NORESTART;
- }
-
- if (gp->active)
- tnew = ktime_set(0, gp->pwm.channels[0].duty_ticks);
- else
- tnew = ktime_set(0, gp->pwm.channels[0].period_ticks
- - gp->pwm.channels[0].duty_ticks);
- hrtimer_start(&gp->timer, tnew, HRTIMER_MODE_REL);
-
- return HRTIMER_NORESTART;
-}
-
-static void gpio_pwm_start(struct pwm_channel *p)
-{
- struct gpio_pwm *gp = to_gpio_pwm(p);
-
- gp->active = 0;
- gpio_pwm_timeout(&gp->timer);
-}
-
-static int
-gpio_pwm_config_nosleep(struct pwm_channel *p,
- struct pwm_channel_config *c)
-{
- struct gpio_pwm *gp = to_gpio_pwm(p);
- int ret = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&p->lock, flags);
-
- switch (c->config_mask) {
-
- case PWM_CONFIG_DUTY_TICKS:
- p->duty_ticks = c->duty_ticks;
- break;
-
- case PWM_CONFIG_START:
- if (!hrtimer_active(&gp->timer)) {
- gpio_pwm_start(p);
- }
- break;
- default:
- ret = -EINVAL;
- break;
- }
-
- spin_unlock_irqrestore(&p->lock, flags);
- return ret;
-}
-
-static int
-gpio_pwm_stop_sync(struct pwm_channel *p)
-{
- struct gpio_pwm *gp = to_gpio_pwm(p);
- int ret;
- int was_on = hrtimer_active(&gp->timer);
-
- if (was_on) {
- do {
- init_completion(&p->complete);
- set_bit(FLAG_STOP, &p->flags);
- ret = wait_for_completion_interruptible(&p->complete);
- if (ret)
- return ret;
- } while (p->flags & BIT(FLAG_STOP));
- }
-
- return was_on;
-}
-
-static int
-gpio_pwm_config(struct pwm_channel *p,
- struct pwm_channel_config *c)
-{
- struct gpio_pwm *gp = to_gpio_pwm(p);
- int was_on = 0;
-
- if (p->pwm->config_nosleep) {
- if (!p->pwm->config_nosleep(p, c))
- return 0;
- }
-
- might_sleep();
-
- was_on = gpio_pwm_stop_sync(p);
- if (was_on < 0)
- return was_on;
-
- if (c->config_mask & PWM_CONFIG_PERIOD_TICKS)
- p->period_ticks = c->period_ticks;
-
- if (c->config_mask & PWM_CONFIG_DUTY_TICKS)
- p->duty_ticks = c->duty_ticks;
-
- if (c->config_mask & PWM_CONFIG_POLARITY) {
- gp->polarity = c->polarity ? 1 : 0;
- p->active_high = gp->polarity;
- }
-
- if ((c->config_mask & PWM_CONFIG_START)
- || (was_on && !(c->config_mask & PWM_CONFIG_STOP)))
- gpio_pwm_start(p);
-
- return 0;
-}
-
-static int
-gpio_pwm_set_callback(struct pwm_channel *p,
- pwm_callback_t callback)
-{
- struct gpio_pwm *gp = to_gpio_pwm(p);
- gp->callback = callback;
- return 0;
-}
-
-static int
-gpio_pwm_request(struct pwm_channel *p)
-{
- p->tick_hz = 1000000000UL;
- return 0;
-}
-
-static int
-gpio_pwm_probe(struct platform_device *pdev)
-{
- struct gpio_pwm *gp;
- struct gpio_pwm_platform_data *gpd = pdev->dev.platform_data;
- int ret = 0;
-
- /* TODO: create configfs entries, so users can assign GPIOs to
- * PWMs at runtime instead of creating a platform_device
- * specification and rebuilding their kernel */
-
- if (!gpd || gpio_request(gpd->gpio, dev_name(&pdev->dev)))
- return -EINVAL;
-
- gp = kzalloc(sizeof(*gp), GFP_KERNEL);
- if (!gp) {
- ret = -ENOMEM;
- goto err_alloc;
- }
-
- platform_set_drvdata(pdev, gp);
-
- gp->pwm.dev = &pdev->dev;
- gp->pwm.bus_id = dev_name(&pdev->dev);
- gp->pwm.nchan = 1;
- gp->gpio = gpd->gpio;
-
- INIT_WORK(&gp->work, gpio_pwm_work);
-
- hrtimer_init(&gp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- gp->timer.function = gpio_pwm_timeout;
-
- gp->pwm.owner = THIS_MODULE;
- gp->pwm.config_nosleep = gpio_pwm_config_nosleep;
- gp->pwm.config = gpio_pwm_config;
- gp->pwm.request = gpio_pwm_request;
- gp->pwm.set_callback = gpio_pwm_set_callback;
-
- ret = pwm_register(&gp->pwm);
- if (ret)
- goto err_pwm_register;
-
- return 0;
-
-err_pwm_register:
- platform_set_drvdata(pdev, 0);
- kfree(gp);
-err_alloc:
- return ret;
-}
-
-static int
-gpio_pwm_remove(struct platform_device *pdev)
-{
- struct gpio_pwm *gp = platform_get_drvdata(pdev);
- int ret;
-
- ret = pwm_unregister(&gp->pwm);
- hrtimer_cancel(&gp->timer);
- cancel_work_sync(&gp->work);
- platform_set_drvdata(pdev, 0);
- kfree(gp);
-
- return 0;
-}
-
-static struct platform_driver gpio_pwm_driver = {
- .driver = {
- .name = "gpio_pwm",
- .owner = THIS_MODULE,
- },
- .probe = gpio_pwm_probe,
- .remove = gpio_pwm_remove,
-};
-
-static int __init gpio_pwm_init(void)
-{
- return platform_driver_register(&gpio_pwm_driver);
-}
-module_init(gpio_pwm_init);
-
-static void __exit gpio_pwm_exit(void)
-{
- platform_driver_unregister(&gpio_pwm_driver);
-}
-module_exit(gpio_pwm_exit);
-
-MODULE_AUTHOR("Bill Gatliff <bgat@billgatliff.com>");
-MODULE_DESCRIPTION("PWM output using GPIO and a high-resolution timer");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:gpio_pwm");
generated by cgit v1.1 at 2024-12-25 22:19:23 +0000