diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/hid/hid-core.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 04cee65531d7..f93dd6f48a79 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1750,6 +1750,94 @@ void hid_disconnect(struct hid_device *hdev) } EXPORT_SYMBOL_GPL(hid_disconnect); +/** + * hid_hw_start - start underlying HW + * @hdev: hid device + * @connect_mask: which outputs to connect, see HID_CONNECT_* + * + * Call this in probe function *after* hid_parse. This will setup HW + * buffers and start the device (if not defeirred to device open). + * hid_hw_stop must be called if this was successful. + */ +int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask) +{ + int error; + + error = hdev->ll_driver->start(hdev); + if (error) + return error; + + if (connect_mask) { + error = hid_connect(hdev, connect_mask); + if (error) { + hdev->ll_driver->stop(hdev); + return error; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(hid_hw_start); + +/** + * hid_hw_stop - stop underlying HW + * @hdev: hid device + * + * This is usually called from remove function or from probe when something + * failed and hid_hw_start was called already. + */ +void hid_hw_stop(struct hid_device *hdev) +{ + hid_disconnect(hdev); + hdev->ll_driver->stop(hdev); +} +EXPORT_SYMBOL_GPL(hid_hw_stop); + +/** + * hid_hw_open - signal underlying HW to start delivering events + * @hdev: hid device + * + * Tell underlying HW to start delivering events from the device. + * This function should be called sometime after successful call + * to hid_hiw_start(). + */ +int hid_hw_open(struct hid_device *hdev) +{ + int ret; + + ret = mutex_lock_killable(&hdev->ll_open_lock); + if (ret) + return ret; + + if (!hdev->ll_open_count++) { + ret = hdev->ll_driver->open(hdev); + if (ret) + hdev->ll_open_count--; + } + + mutex_unlock(&hdev->ll_open_lock); + return ret; +} +EXPORT_SYMBOL_GPL(hid_hw_open); + +/** + * hid_hw_close - signal underlaying HW to stop delivering events + * + * @hdev: hid device + * + * This function indicates that we are not interested in the events + * from this device anymore. Delivery of events may or may not stop, + * depending on the number of users still outstanding. + */ +void hid_hw_close(struct hid_device *hdev) +{ + mutex_lock(&hdev->ll_open_lock); + if (!--hdev->ll_open_count) + hdev->ll_driver->close(hdev); + mutex_unlock(&hdev->ll_open_lock); +} +EXPORT_SYMBOL_GPL(hid_hw_close); + /* * A list of devices for which there is a specialized driver on HID bus. * @@ -2747,6 +2835,7 @@ struct hid_device *hid_allocate_device(void) spin_lock_init(&hdev->debug_list_lock); sema_init(&hdev->driver_lock, 1); sema_init(&hdev->driver_input_lock, 1); + mutex_init(&hdev->ll_open_lock); return hdev; } |