--- /dev/null
+/* drivers/android/timed_gpio.c
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/hrtimer.h>
+#include <linux/err.h>
+#include <asm/arch/gpio.h>
+
+#include "android_timed_gpio.h"
+
+
+static struct class *timed_gpio_class;
+
+struct timed_gpio_data {
+ struct device *dev;
+ struct hrtimer timer;
+ spinlock_t lock;
+ unsigned gpio;
+ int max_timeout;
+ u8 active_low;
+};
+
+static enum hrtimer_restart gpio_timer_func(struct hrtimer *timer)
+{
+ struct timed_gpio_data *gpio_data = container_of(timer, struct timed_gpio_data, timer);
+
+ gpio_direction_output(gpio_data->gpio, gpio_data->active_low ? 1 : 0);
+ return HRTIMER_NORESTART;
+}
+
+static ssize_t gpio_enable_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct timed_gpio_data *gpio_data = dev_get_drvdata(dev);
+ int remaining;
+
+ if (hrtimer_active(&gpio_data->timer)) {
+ ktime_t r = hrtimer_get_remaining(&gpio_data->timer);
+ remaining = r.tv.sec * 1000 + r.tv.nsec / 1000000;
+ } else
+ remaining = 0;
+
+ return sprintf(buf, "%d\n", remaining);
+}
+
+static ssize_t gpio_enable_store(
+ struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct timed_gpio_data *gpio_data = dev_get_drvdata(dev);
+ int value;
+ unsigned long flags;
+
+ sscanf(buf, "%d", &value);
+
+ spin_lock_irqsave(&gpio_data->lock, flags);
+
+ /* cancel previous timer and set GPIO according to value */
+ hrtimer_cancel(&gpio_data->timer);
+ gpio_direction_output(gpio_data->gpio, gpio_data->active_low ? !value : !!value);
+
+ if (value > 0) {
+ if (value > gpio_data->max_timeout)
+ value = gpio_data->max_timeout;
+
+ hrtimer_start(&gpio_data->timer,
+ ktime_set(value / 1000, (value % 1000) * 1000000),
+ HRTIMER_MODE_REL);
+ }
+
+ spin_unlock_irqrestore(&gpio_data->lock, flags);
+
+ return size;
+}
+
+static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, gpio_enable_show, gpio_enable_store);
+
+static int android_timed_gpio_probe(struct platform_device *pdev)
+{
+ struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct timed_gpio *cur_gpio;
+ struct timed_gpio_data *gpio_data, *gpio_dat;
+ int i, ret = 0;
+
+ if (!pdata)
+ return -EBUSY;
+
+ gpio_data = kzalloc(sizeof(struct timed_gpio_data) * pdata->num_gpios, GFP_KERNEL);
+ if (!gpio_data)
+ return -ENOMEM;
+
+ for (i = 0; i < pdata->num_gpios; i++) {
+ cur_gpio = &pdata->gpios[i];
+ gpio_dat = &gpio_data[i];
+
+ hrtimer_init(&gpio_dat->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ gpio_dat->timer.function = gpio_timer_func;
+ spin_lock_init(&gpio_dat->lock);
+
+ gpio_dat->gpio = cur_gpio->gpio;
+ gpio_dat->max_timeout = cur_gpio->max_timeout;
+ gpio_dat->active_low = cur_gpio->active_low;
+ gpio_direction_output(gpio_dat->gpio, gpio_dat->active_low);
+
+ gpio_dat->dev = device_create(timed_gpio_class, &pdev->dev, 0, "%s", cur_gpio->name);
+ if (unlikely(IS_ERR(gpio_dat->dev)))
+ return PTR_ERR(gpio_dat->dev);
+
+ dev_set_drvdata(gpio_dat->dev, gpio_dat);
+ ret = device_create_file(gpio_dat->dev, &dev_attr_enable);
+ if (ret)
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, gpio_data);
+
+ return 0;
+}
+
+static int android_timed_gpio_remove(struct platform_device *pdev)
+{
+ struct timed_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct timed_gpio_data *gpio_data = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < pdata->num_gpios; i++) {
+ device_remove_file(gpio_data[i].dev, &dev_attr_enable);
+ device_unregister(gpio_data[i].dev);
+ }
+
+ kfree(gpio_data);
+
+ return 0;
+}
+
+static struct platform_driver android_timed_gpio_driver = {
+ .probe = android_timed_gpio_probe,
+ .remove = android_timed_gpio_remove,
+ .driver = {
+ .name = "android-timed-gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init android_timed_gpio_init(void)
+{
+ timed_gpio_class = class_create(THIS_MODULE, "timed_output");
+ if (IS_ERR(timed_gpio_class))
+ return PTR_ERR(timed_gpio_class);
+ return platform_driver_register(&android_timed_gpio_driver);
+}
+
+static void __exit android_timed_gpio_exit(void)
+{
+ class_destroy(timed_gpio_class);
+ platform_driver_unregister(&android_timed_gpio_driver);
+}
+
+module_init(android_timed_gpio_init);
+module_exit(android_timed_gpio_exit);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("Android timed gpio driver");
+MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / commitdiff