struct input_dev *input;
struct timer_list timer;
struct work_struct work;
+ bool disabled;
};
struct gpio_keys_drvdata {
struct input_dev *input;
+ struct mutex disable_lock;
+ unsigned int n_buttons;
struct gpio_button_data data[0];
};
+/*
+ * SYSFS interface for enabling/disabling keys and switches:
+ *
+ * There are 4 attributes under /sys/devices/platform/gpio-keys/
+ * keys [ro] - bitmap of keys (EV_KEY) which can be
+ * disabled
+ * switches [ro] - bitmap of switches (EV_SW) which can be
+ * disabled
+ * disabled_keys [rw] - bitmap of keys currently disabled
+ * disabled_switches [rw] - bitmap of switches currently disabled
+ *
+ * Userland can change these values and hence disable event generation
+ * for each key (or switch). Disabling a key means its interrupt line
+ * is disabled.
+ *
+ * For example, if we have following switches set up as gpio-keys:
+ * SW_DOCK = 5
+ * SW_CAMERA_LENS_COVER = 9
+ * SW_KEYPAD_SLIDE = 10
+ * SW_FRONT_PROXIMITY = 11
+ * This is read from switches:
+ * 11-9,5
+ * Next we want to disable proximity (11) and dock (5), we write:
+ * 11,5
+ * to file disabled_switches. Now proximity and dock IRQs are disabled.
+ * This can be verified by reading the file disabled_switches:
+ * 11,5
+ * If we now want to enable proximity (11) switch we write:
+ * 5
+ * to disabled_switches.
+ *
+ * We can disable only those keys which don't allow sharing the irq.
+ */
+
+/**
+ * get_n_events_by_type() - returns maximum number of events per @type
+ * @type: type of button (%EV_KEY, %EV_SW)
+ *
+ * Return value of this function can be used to allocate bitmap
+ * large enough to hold all bits for given type.
+ */
+static inline int get_n_events_by_type(int type)
+{
+ BUG_ON(type != EV_SW && type != EV_KEY);
+
+ return (type == EV_KEY) ? KEY_CNT : SW_CNT;
+}
+
+/**
+ * gpio_keys_disable_button() - disables given GPIO button
+ * @bdata: button data for button to be disabled
+ *
+ * Disables button pointed by @bdata. This is done by masking
+ * IRQ line. After this function is called, button won't generate
+ * input events anymore. Note that one can only disable buttons
+ * that don't share IRQs.
+ *
+ * Make sure that @bdata->disable_lock is locked when entering
+ * this function to avoid races when concurrent threads are
+ * disabling buttons at the same time.
+ */
+static void gpio_keys_disable_button(struct gpio_button_data *bdata)
+{
+ if (!bdata->disabled) {
+ /*
+ * Disable IRQ and possible debouncing timer.
+ */
+ disable_irq(gpio_to_irq(bdata->button->gpio));
+ if (bdata->button->debounce_interval)
+ del_timer_sync(&bdata->timer);
+
+ bdata->disabled = true;
+ }
+}
+
+/**
+ * gpio_keys_enable_button() - enables given GPIO button
+ * @bdata: button data for button to be disabled
+ *
+ * Enables given button pointed by @bdata.
+ *
+ * Make sure that @bdata->disable_lock is locked when entering
+ * this function to avoid races with concurrent threads trying
+ * to enable the same button at the same time.
+ */
+static void gpio_keys_enable_button(struct gpio_button_data *bdata)
+{
+ if (bdata->disabled) {
+ enable_irq(gpio_to_irq(bdata->button->gpio));
+ bdata->disabled = false;
+ }
+}
+
+/**
+ * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
+ * @ddata: pointer to drvdata
+ * @buf: buffer where stringified bitmap is written
+ * @type: button type (%EV_KEY, %EV_SW)
+ * @only_disabled: does caller want only those buttons that are
+ * currently disabled or all buttons that can be
+ * disabled
+ *
+ * This function writes buttons that can be disabled to @buf. If
+ * @only_disabled is true, then @buf contains only those buttons
+ * that are currently disabled. Returns 0 on success or negative
+ * errno on failure.
+ */
+static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
+ char *buf, unsigned int type,
+ bool only_disabled)
+{
+ int n_events = get_n_events_by_type(type);
+ unsigned long *bits;
+ ssize_t ret;
+ int i;
+
+ bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
+ if (!bits)
+ return -ENOMEM;
+
+ for (i = 0; i < ddata->n_buttons; i++) {
+ struct gpio_button_data *bdata = &ddata->data[i];
+
+ if (bdata->button->type != type)
+ continue;
+
+ if (only_disabled && !bdata->disabled)
+ continue;
+
+ __set_bit(bdata->button->code, bits);
+ }
+
+ ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
+ buf[ret++] = '\n';
+ buf[ret] = '\0';
+
+ kfree(bits);
+
+ return ret;
+}
+
+/**
+ * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
+ * @ddata: pointer to drvdata
+ * @buf: buffer from userspace that contains stringified bitmap
+ * @type: button type (%EV_KEY, %EV_SW)
+ *
+ * This function parses stringified bitmap from @buf and disables/enables
+ * GPIO buttons accordinly. Returns 0 on success and negative error
+ * on failure.
+ */
+static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
+ const char *buf, unsigned int type)
+{
+ int n_events = get_n_events_by_type(type);
+ unsigned long *bits;
+ ssize_t error;
+ int i;
+
+ bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
+ if (!bits)
+ return -ENOMEM;
+
+ error = bitmap_parselist(buf, bits, n_events);
+ if (error)
+ goto out;
+
+ /* First validate */
+ for (i = 0; i < ddata->n_buttons; i++) {
+ struct gpio_button_data *bdata = &ddata->data[i];
+
+ if (bdata->button->type != type)
+ continue;
+
+ if (test_bit(bdata->button->code, bits) &&
+ !bdata->button->can_disable) {
+ error = -EINVAL;
+ goto out;
+ }
+ }
+
+ mutex_lock(&ddata->disable_lock);
+
+ for (i = 0; i < ddata->n_buttons; i++) {
+ struct gpio_button_data *bdata = &ddata->data[i];
+
+ if (bdata->button->type != type)
+ continue;
+
+ if (test_bit(bdata->button->code, bits))
+ gpio_keys_disable_button(bdata);
+ else
+ gpio_keys_enable_button(bdata);
+ }
+
+ mutex_unlock(&ddata->disable_lock);
+
+out:
+ kfree(bits);
+ return error;
+}
+
+#define ATTR_SHOW_FN(name, type, only_disabled) \
+static ssize_t gpio_keys_show_##name(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct platform_device *pdev = to_platform_device(dev); \
+ struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
+ \
+ return gpio_keys_attr_show_helper(ddata, buf, \
+ type, only_disabled); \
+}
+
+ATTR_SHOW_FN(keys, EV_KEY, false);
+ATTR_SHOW_FN(switches, EV_SW, false);
+ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
+ATTR_SHOW_FN(disabled_switches, EV_SW, true);
+
+/*
+ * ATTRIBUTES:
+ *
+ * /sys/devices/platform/gpio-keys/keys [ro]
+ * /sys/devices/platform/gpio-keys/switches [ro]
+ */
+static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
+static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
+
+#define ATTR_STORE_FN(name, type) \
+static ssize_t gpio_keys_store_##name(struct device *dev, \
+ struct device_attribute *attr, \
+ const char *buf, \
+ size_t count) \
+{ \
+ struct platform_device *pdev = to_platform_device(dev); \
+ struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
+ ssize_t error; \
+ \
+ error = gpio_keys_attr_store_helper(ddata, buf, type); \
+ if (error) \
+ return error; \
+ \
+ return count; \
+}
+
+ATTR_STORE_FN(disabled_keys, EV_KEY);
+ATTR_STORE_FN(disabled_switches, EV_SW);
+
+/*
+ * ATTRIBUTES:
+ *
+ * /sys/devices/platform/gpio-keys/disabled_keys [rw]
+ * /sys/devices/platform/gpio-keys/disables_switches [rw]
+ */
+static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
+ gpio_keys_show_disabled_keys,
+ gpio_keys_store_disabled_keys);
+static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
+ gpio_keys_show_disabled_switches,
+ gpio_keys_store_disabled_switches);
+
+static struct attribute *gpio_keys_attrs[] = {
+ &dev_attr_keys.attr,
+ &dev_attr_switches.attr,
+ &dev_attr_disabled_keys.attr,
+ &dev_attr_disabled_switches.attr,
+ NULL,
+};
+
+static struct attribute_group gpio_keys_attr_group = {
+ .attrs = gpio_keys_attrs,
+};
+
static void gpio_keys_report_event(struct gpio_button_data *bdata)
{
struct gpio_keys_button *button = bdata->button;
return IRQ_HANDLED;
}
-static int __devinit gpio_keys_setup_key(struct device *dev,
+static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
struct gpio_button_data *bdata,
struct gpio_keys_button *button)
{
char *desc = button->desc ? button->desc : "gpio_keys";
+ struct device *dev = &pdev->dev;
+ unsigned long irqflags;
int irq, error;
setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
goto fail3;
}
- error = request_irq(irq, gpio_keys_isr,
- IRQF_SHARED |
- IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
- desc, bdata);
+ irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+ /*
+ * If platform has specified that the button can be disabled,
+ * we don't want it to share the interrupt line.
+ */
+ if (!button->can_disable)
+ irqflags |= IRQF_SHARED;
+
+ error = request_irq(irq, gpio_keys_isr, irqflags, desc, bdata);
if (error) {
dev_err(dev, "Unable to claim irq %d; error %d\n",
irq, error);
goto fail1;
}
+ ddata->input = input;
+ ddata->n_buttons = pdata->nbuttons;
+ mutex_init(&ddata->disable_lock);
+
platform_set_drvdata(pdev, ddata);
input->name = pdev->name;
if (pdata->rep)
__set_bit(EV_REP, input->evbit);
- ddata->input = input;
-
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
struct gpio_button_data *bdata = &ddata->data[i];
bdata->input = input;
bdata->button = button;
- error = gpio_keys_setup_key(dev, bdata, button);
+ error = gpio_keys_setup_key(pdev, bdata, button);
if (error)
goto fail2;
input_set_capability(input, type, button->code);
}
- error = input_register_device(input);
+ error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
if (error) {
- dev_err(dev, "Unable to register input device, "
- "error: %d\n", error);
+ dev_err(dev, "Unable to export keys/switches, error: %d\n",
+ error);
goto fail2;
}
+ error = input_register_device(input);
+ if (error) {
+ dev_err(dev, "Unable to register input device, error: %d\n",
+ error);
+ goto fail3;
+ }
+
/* get current state of buttons */
for (i = 0; i < pdata->nbuttons; i++)
gpio_keys_report_event(&ddata->data[i]);
return 0;
+ fail3:
+ sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
fail2:
while (--i >= 0) {
free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
struct input_dev *input = ddata->input;
int i;
+ sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
+
device_init_wakeup(&pdev->dev, 0);
for (i = 0; i < pdata->nbuttons; i++) {
projects / platform / kernel / linux-rpi.git / commitdiff