1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/switch/switch_gpio.c b/drivers/switch/switch_gpio.c
new file mode 100644
index 00000000000..7e9faa211e4
--- /dev/null
+++ b/drivers/switch/switch_gpio.c
@@ -0,0 +1,172 @@
+/*
+ *  drivers/switch/switch_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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/switch.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+
+struct gpio_switch_data {
+        struct switch_dev sdev;
+        unsigned gpio;
+        const char *name_on;
+        const char *name_off;
+        const char *state_on;
+        const char *state_off;
+        int irq;
+        struct work_struct work;
+};
+
+static void gpio_switch_work(struct work_struct *work)
+{
+        int state;
+        struct gpio_switch_data *data =
+                container_of(work, struct gpio_switch_data, work);
+
+        state = gpio_get_value(data->gpio);
+        switch_set_state(&data->sdev, state);
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+        struct gpio_switch_data *switch_data =
+            (struct gpio_switch_data *)dev_id;
+
+        schedule_work(&switch_data->work);
+        return IRQ_HANDLED;
+}
+
+static ssize_t switch_gpio_print_state(struct switch_dev *sdev, char *buf)
+{
+        struct gpio_switch_data *switch_data =
+                container_of(sdev, struct gpio_switch_data, sdev);
+        const char *state;
+        if (switch_get_state(sdev))
+                state = switch_data->state_on;
+        else
+                state = switch_data->state_off;
+
+        if (state)
+                return sprintf(buf, "%s\n", state);
+        return -1;
+}
+
+static int gpio_switch_probe(struct platform_device *pdev)
+{
+        struct gpio_switch_platform_data *pdata = pdev->dev.platform_data;
+        struct gpio_switch_data *switch_data;
+        int ret = 0;
+
+        if (!pdata)
+                return -EBUSY;
+
+        switch_data = kzalloc(sizeof(struct gpio_switch_data), GFP_KERNEL);
+        if (!switch_data)
+                return -ENOMEM;
+
+        switch_data->sdev.name = pdata->name;
+        switch_data->gpio = pdata->gpio;
+        switch_data->name_on = pdata->name_on;
+        switch_data->name_off = pdata->name_off;
+        switch_data->state_on = pdata->state_on;
+        switch_data->state_off = pdata->state_off;
+        switch_data->sdev.print_state = switch_gpio_print_state;
+
+    ret = switch_dev_register(&switch_data->sdev);
+        if (ret < 0)
+                goto err_switch_dev_register;
+
+        ret = gpio_request(switch_data->gpio, pdev->name);
+        if (ret < 0)
+                goto err_request_gpio;
+
+        ret = gpio_direction_input(switch_data->gpio);
+        if (ret < 0)
+                goto err_set_gpio_input;
+
+        INIT_WORK(&switch_data->work, gpio_switch_work);
+
+        switch_data->irq = gpio_to_irq(switch_data->gpio);
+        if (switch_data->irq < 0) {
+                ret = switch_data->irq;
+                goto err_detect_irq_num_failed;
+        }
+
+        ret = request_irq(switch_data->irq, gpio_irq_handler,
+                          IRQF_TRIGGER_LOW, pdev->name, switch_data);
+        if (ret < 0)
+                goto err_request_irq;
+
+        /* Perform initial detection */
+        gpio_switch_work(&switch_data->work);
+
+        return 0;
+
+err_request_irq:
+err_detect_irq_num_failed:
+err_set_gpio_input:
+        gpio_free(switch_data->gpio);
+err_request_gpio:
+    switch_dev_unregister(&switch_data->sdev);
+err_switch_dev_register:
+        kfree(switch_data);
+
+        return ret;
+}
+
+static int __devexit gpio_switch_remove(struct platform_device *pdev)
+{
+        struct gpio_switch_data *switch_data = platform_get_drvdata(pdev);
+
+        cancel_work_sync(&switch_data->work);
+        gpio_free(switch_data->gpio);
+    switch_dev_unregister(&switch_data->sdev);
+        kfree(switch_data);
+
+        return 0;
+}
+
+static struct platform_driver gpio_switch_driver = {
+        .probe          = gpio_switch_probe,
+        .remove         = __devexit_p(gpio_switch_remove),
+        .driver         = {
+                .name   = "switch-gpio",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init gpio_switch_init(void)
+{
+        return platform_driver_register(&gpio_switch_driver);
+}
+
+static void __exit gpio_switch_exit(void)
+{
+        platform_driver_unregister(&gpio_switch_driver);
+}
+
+module_init(gpio_switch_init);
+module_exit(gpio_switch_exit);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("GPIO Switch driver");
+MODULE_LICENSE("GPL");