* @value: value of the event
*
* This function should be used by drivers implementing various input
- * devices. See also input_inject_event().
+ * devices to report input events. See also input_inject_event().
+ *
+ * NOTE: input_event() may be safely used right after input device was
+ * allocated with input_allocate_device(), even before it is registered
+ * with input_register_device(), but the event will not reach any of the
+ * input handlers. Such early invocation of input_event() may be used
+ * to 'seed' initial state of a switch or initial position of absolute
+ * axis, etc.
*/
-
void input_event(struct input_dev *dev,
unsigned int type, unsigned int code, int value)
{
return 0;
}
+union input_seq_state {
+ struct {
+ unsigned short pos;
+ bool mutex_acquired;
+ };
+ void *p;
+};
+
static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
{
- if (mutex_lock_interruptible(&input_mutex))
- return NULL;
+ union input_seq_state *state = (union input_seq_state *)&seq->private;
+ int error;
+
+ /* We need to fit into seq->private pointer */
+ BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
+
+ error = mutex_lock_interruptible(&input_mutex);
+ if (error) {
+ state->mutex_acquired = false;
+ return ERR_PTR(error);
+ }
+
+ state->mutex_acquired = true;
return seq_list_start(&input_dev_list, *pos);
}
return seq_list_next(v, &input_dev_list, pos);
}
-static void input_devices_seq_stop(struct seq_file *seq, void *v)
+static void input_seq_stop(struct seq_file *seq, void *v)
{
- mutex_unlock(&input_mutex);
+ union input_seq_state *state = (union input_seq_state *)&seq->private;
+
+ if (state->mutex_acquired)
+ mutex_unlock(&input_mutex);
}
static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
static const struct seq_operations input_devices_seq_ops = {
.start = input_devices_seq_start,
.next = input_devices_seq_next,
- .stop = input_devices_seq_stop,
+ .stop = input_seq_stop,
.show = input_devices_seq_show,
};
static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
{
- if (mutex_lock_interruptible(&input_mutex))
- return NULL;
+ union input_seq_state *state = (union input_seq_state *)&seq->private;
+ int error;
+
+ /* We need to fit into seq->private pointer */
+ BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
+
+ error = mutex_lock_interruptible(&input_mutex);
+ if (error) {
+ state->mutex_acquired = false;
+ return ERR_PTR(error);
+ }
+
+ state->mutex_acquired = true;
+ state->pos = *pos;
- seq->private = (void *)(unsigned long)*pos;
return seq_list_start(&input_handler_list, *pos);
}
static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- seq->private = (void *)(unsigned long)(*pos + 1);
- return seq_list_next(v, &input_handler_list, pos);
-}
+ union input_seq_state *state = (union input_seq_state *)&seq->private;
-static void input_handlers_seq_stop(struct seq_file *seq, void *v)
-{
- mutex_unlock(&input_mutex);
+ state->pos = *pos + 1;
+ return seq_list_next(v, &input_handler_list, pos);
}
static int input_handlers_seq_show(struct seq_file *seq, void *v)
{
struct input_handler *handler = container_of(v, struct input_handler, node);
+ union input_seq_state *state = (union input_seq_state *)&seq->private;
- seq_printf(seq, "N: Number=%ld Name=%s",
- (unsigned long)seq->private, handler->name);
+ seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
if (handler->fops)
seq_printf(seq, " Minor=%d", handler->minor);
seq_putc(seq, '\n');
return 0;
}
+
static const struct seq_operations input_handlers_seq_ops = {
.start = input_handlers_seq_start,
.next = input_handlers_seq_next,
- .stop = input_handlers_seq_stop,
+ .stop = input_seq_stop,
.show = input_handlers_seq_show,
};
return 0;
}
-#define INPUT_DO_TOGGLE(dev, type, bits, on) \
- do { \
- int i; \
- if (!test_bit(EV_##type, dev->evbit)) \
- break; \
- for (i = 0; i < type##_MAX; i++) { \
- if (!test_bit(i, dev->bits##bit) || \
- !test_bit(i, dev->bits)) \
- continue; \
- dev->event(dev, EV_##type, i, on); \
- } \
+#define INPUT_DO_TOGGLE(dev, type, bits, on) \
+ do { \
+ int i; \
+ bool active; \
+ \
+ if (!test_bit(EV_##type, dev->evbit)) \
+ break; \
+ \
+ for (i = 0; i < type##_MAX; i++) { \
+ if (!test_bit(i, dev->bits##bit)) \
+ continue; \
+ \
+ active = test_bit(i, dev->bits); \
+ if (!active && !on) \
+ continue; \
+ \
+ dev->event(dev, EV_##type, i, on ? active : 0); \
+ } \
} while (0)
#ifdef CONFIG_PM
EXPORT_SYMBOL(input_unregister_handler);
/**
+ * input_handler_for_each_handle - handle iterator
+ * @handler: input handler to iterate
+ * @data: data for the callback
+ * @fn: function to be called for each handle
+ *
+ * Iterate over @bus's list of devices, and call @fn for each, passing
+ * it @data and stop when @fn returns a non-zero value. The function is
+ * using RCU to traverse the list and therefore may be usind in atonic
+ * contexts. The @fn callback is invoked from RCU critical section and
+ * thus must not sleep.
+ */
+int input_handler_for_each_handle(struct input_handler *handler, void *data,
+ int (*fn)(struct input_handle *, void *))
+{
+ struct input_handle *handle;
+ int retval = 0;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
+ retval = fn(handle, data);
+ if (retval)
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return retval;
+}
+EXPORT_SYMBOL(input_handler_for_each_handle);
+
+/**
* input_register_handle - register a new input handle
* @handle: handle to register
*
* we can't be racing with input_unregister_handle()
* and so separate lock is not needed here.
*/
- list_add_tail(&handle->h_node, &handler->h_list);
+ list_add_tail_rcu(&handle->h_node, &handler->h_list);
if (handler->start)
handler->start(handle);
{
struct input_dev *dev = handle->dev;
- list_del_init(&handle->h_node);
+ list_del_rcu(&handle->h_node);
/*
* Take dev->mutex to prevent race with input_release_device().
mutex_lock(&dev->mutex);
list_del_rcu(&handle->d_node);
mutex_unlock(&dev->mutex);
+
synchronize_rcu();
}
EXPORT_SYMBOL(input_unregister_handle);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff