gpio-button-hotplug: add volume button handling
[openwrt/openwrt.git] / package / kernel / gpio-button-hotplug / src / gpio-button-hotplug.c
index d81898f932a1a6f82169dad20fc8746e172ef26f..3e8e0ea26846d054bf878343a01005210f9e3d34 100644 (file)
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/gpio_keys.h>
+#include <linux/gpio/consumer.h>
 
 #define BH_SKB_SIZE    2048
 
 #define DRV_NAME       "gpio-keys"
 #define PFX    DRV_NAME ": "
 
-struct bh_priv {
-       unsigned long           seen;
-};
-
 struct bh_event {
        const char              *name;
        unsigned int            type;
@@ -55,7 +52,8 @@ struct bh_map {
 
 struct gpio_keys_button_data {
        struct delayed_work work;
-       struct bh_priv bh;
+       unsigned long seen;
+       int map_entry;
        int last_state;
        int count;
        int threshold;
@@ -97,6 +95,8 @@ static struct bh_map button_map[] = {
        BH_MAP(KEY_RESTART,             "reset"),
        BH_MAP(KEY_RFKILL,              "rfkill"),
        BH_MAP(KEY_VIDEO,               "video"),
+       BH_MAP(KEY_VOLUMEDOWN,          "volume_down"),
+       BH_MAP(KEY_VOLUMEUP,            "volume_up"),
        BH_MAP(KEY_WIMAX,               "wwan"),
        BH_MAP(KEY_WLAN,                "wlan"),
        BH_MAP(KEY_WPS_BUTTON,          "wps"),
@@ -237,36 +237,6 @@ static int button_get_index(unsigned int code)
        return -1;
 }
 
-static void button_hotplug_event(struct gpio_keys_button_data *data,
-                          unsigned int type, int value)
-{
-       struct bh_priv *priv = &data->bh;
-       unsigned long seen = jiffies;
-       int btn;
-
-       pr_debug(PFX "event type=%u, code=%u, value=%d\n", type, data->b->code, value);
-
-       if ((type != EV_KEY) && (type != EV_SW))
-               return;
-
-       btn = button_get_index(data->b->code);
-       if (btn < 0)
-               return;
-
-       button_hotplug_create_event(button_map[btn].name, type,
-                       (seen - priv->seen) / HZ, value);
-       priv->seen = seen;
-}
-
-struct gpio_keys_button_dev {
-       int polled;
-       struct delayed_work work;
-
-       struct device *dev;
-       struct gpio_keys_platform_data *pdata;
-       struct gpio_keys_button_data data[0];
-};
-
 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
 {
        int val;
@@ -279,27 +249,61 @@ static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
        return val ^ bdata->b->active_low;
 }
 
-static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
+static void gpio_keys_handle_button(struct gpio_keys_button_data *bdata)
 {
+       unsigned int type = bdata->b->type ?: EV_KEY;
        int state = gpio_button_get_value(bdata);
+       unsigned long seen = jiffies;
 
-       if (state != bdata->last_state) {
-               unsigned int type = bdata->b->type ?: EV_KEY;
+       pr_debug(PFX "event type=%u, code=%u, pressed=%d\n",
+                type, bdata->b->code, state);
+
+       /* is this the initialization state? */
+       if (bdata->last_state == -1) {
+               /*
+                * Don't advertise unpressed buttons on initialization.
+                * Just save their state and continue otherwise this
+                * can cause OpenWrt to enter failsafe.
+                */
+               if (type == EV_KEY && state == 0)
+                       goto set_state;
+               /*
+                * But we are very interested in pressed buttons and
+                * initial switch state. These will be reported to
+                * userland.
+                */
+       } else if (bdata->last_state == state) {
+               /* reset asserted counter (only relevant for polled keys) */
+               bdata->count = 0;
+               return;
+       }
 
-               if (bdata->count < bdata->threshold) {
-                       bdata->count++;
-                       return;
-               }
+       if (bdata->count < bdata->threshold) {
+               bdata->count++;
+               return;
+       }
 
-               if (bdata->last_state != -1 || type == EV_SW)
-                       button_hotplug_event(bdata, type, state);
+       if (bdata->seen == 0)
+               bdata->seen = seen;
 
-               bdata->last_state = state;
-       }
+       button_hotplug_create_event(button_map[bdata->map_entry].name, type,
+                                   (seen - bdata->seen) / HZ, state);
+       bdata->seen = seen;
 
+set_state:
+       bdata->last_state = state;
        bdata->count = 0;
 }
 
+struct gpio_keys_button_dev {
+       int polled;
+       struct delayed_work work;
+
+       struct device *dev;
+       struct gpio_keys_platform_data *pdata;
+       struct gpio_keys_button_data data[0];
+};
+
 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
 {
        struct gpio_keys_platform_data *pdata = bdev->pdata;
@@ -318,7 +322,9 @@ static void gpio_keys_polled_poll(struct work_struct *work)
 
        for (i = 0; i < bdev->pdata->nbuttons; i++) {
                struct gpio_keys_button_data *bdata = &bdev->data[i];
-               gpio_keys_polled_check_state(bdata);
+
+               if (bdata->gpiod)
+                       gpio_keys_handle_button(bdata);
        }
        gpio_keys_polled_queue_work(bdev);
 }
@@ -337,16 +343,8 @@ static void gpio_keys_irq_work_func(struct work_struct *work)
 {
        struct gpio_keys_button_data *bdata = container_of(work,
                struct gpio_keys_button_data, work.work);
-       int state = gpio_button_get_value(bdata);
-
-       if (state != bdata->last_state) {
-               unsigned int type = bdata->b->type ?: EV_KEY;
 
-               if (bdata->last_state != -1 || type == EV_SW)
-                       button_hotplug_event(bdata, type, state);
-
-               bdata->last_state = state;
-       }
+       gpio_keys_handle_button(bdata);
 }
 
 static irqreturn_t button_handle_irq(int irq, void *_bdata)
@@ -354,8 +352,8 @@ static irqreturn_t button_handle_irq(int irq, void *_bdata)
        struct gpio_keys_button_data *bdata =
                (struct gpio_keys_button_data *) _bdata;
 
-       schedule_delayed_work(&bdata->work,
-                             msecs_to_jiffies(bdata->software_debounce));
+       mod_delayed_work(system_wq, &bdata->work,
+                        msecs_to_jiffies(bdata->software_debounce));
 
        return IRQ_HANDLED;
 }
@@ -416,7 +414,7 @@ gpio_keys_get_devtree_pdata(struct device *dev)
                                return ERR_PTR(error);
                        }
                } else {
-                       button->active_low = flags & OF_GPIO_ACTIVE_LOW;
+                       button->active_low = !!(flags & OF_GPIO_ACTIVE_LOW);
                }
 
                if (of_property_read_u32(pp, "linux,code", &button->code)) {
@@ -523,6 +521,19 @@ static int gpio_keys_button_probe(struct platform_device *pdev,
                        return -EINVAL;
                }
 
+               bdata->map_entry = button_get_index(button->code);
+               if (bdata->map_entry < 0) {
+                       dev_warn(dev, DRV_NAME "does not support key code:%u\n",
+                               button->code);
+                       continue;
+               }
+
+               if (!(button->type == 0 || button->type == EV_KEY ||
+                     button->type == EV_SW)) {
+                       dev_warn(dev, DRV_NAME "only supports buttons or switches\n");
+                       continue;
+               }
+
                error = devm_gpio_request(dev, gpio,
                                     button->desc ? button->desc : DRV_NAME);
                if (error) {
@@ -543,13 +554,13 @@ static int gpio_keys_button_probe(struct platform_device *pdev,
                }
 
                bdata->can_sleep = gpio_cansleep(gpio);
-               bdata->last_state = -1;
+               bdata->last_state = -1; /* Unknown state on boot */
 
                if (bdev->polled) {
                        bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
                                                        pdata->poll_interval);
                } else {
-                       bdata->threshold = 1;
+                       /* bdata->threshold = 0; already initialized */
 
                        if (button->debounce_interval) {
                                error = gpiod_set_debounce(bdata->gpiod,
@@ -595,6 +606,11 @@ static int gpio_keys_probe(struct platform_device *pdev)
                struct gpio_keys_button_data *bdata = &bdev->data[i];
                unsigned long irqflags = IRQF_ONESHOT;
 
+               INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func);
+
+               if (!bdata->gpiod)
+                       continue;
+
                if (!button->irq) {
                        bdata->irq = gpio_to_irq(button->gpio);
 
@@ -609,7 +625,8 @@ static int gpio_keys_probe(struct platform_device *pdev)
                        bdata->irq = button->irq;
                }
 
-               INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func);
+               schedule_delayed_work(&bdata->work,
+                                     msecs_to_jiffies(bdata->software_debounce));
 
                ret = devm_request_threaded_irq(&pdev->dev,
                        bdata->irq, NULL, button_handle_irq,
@@ -624,9 +641,6 @@ static int gpio_keys_probe(struct platform_device *pdev)
                        dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n",
                                button->gpio, bdata->irq);
                }
-
-               if (bdata->b->type == EV_SW)
-                       button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
        }
 
        return 0;
@@ -637,7 +651,6 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
        struct gpio_keys_platform_data *pdata;
        struct gpio_keys_button_dev *bdev;
        int ret;
-       int i;
 
        ret = gpio_keys_button_probe(pdev, &bdev, 1);
 
@@ -651,9 +664,6 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
        if (pdata->enable)
                pdata->enable(bdev->dev);
 
-       for (i = 0; i < pdata->nbuttons; i++)
-               gpio_keys_polled_check_state(&bdev->data[i]);
-
        gpio_keys_polled_queue_work(bdev);
 
        return ret;