diff options
Diffstat (limited to 'include/linux/hid.h')
| -rw-r--r-- | include/linux/hid.h | 46 |
1 files changed, 45 insertions, 1 deletions
diff --git a/include/linux/hid.h b/include/linux/hid.h index e14b465b114..895b85639de 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -456,7 +456,8 @@ struct hid_device { /* device report descriptor */ unsigned country; /* HID country */ struct hid_report_enum report_enum[HID_REPORT_TYPES]; - struct semaphore driver_lock; /* protects the current driver */ + struct semaphore driver_lock; /* protects the current driver, except during input */ + struct semaphore driver_input_lock; /* protects the current driver */ struct device dev; /* device */ struct hid_driver *driver; struct hid_ll_driver *ll_driver; @@ -477,6 +478,7 @@ struct hid_device { /* device report descriptor */ unsigned int status; /* see STAT flags above */ unsigned claimed; /* Claimed by hidinput, hiddev? */ unsigned quirks; /* Various quirks the device can pull on us */ + bool io_started; /* Protected by driver_lock. If IO has started */ struct list_head inputs; /* The list of inputs */ void *hiddev; /* The hiddev structure */ @@ -599,6 +601,10 @@ struct hid_usage_id { * @resume: invoked on resume if device was not reset (NULL means nop) * @reset_resume: invoked on resume if device was reset (NULL means nop) * + * probe should return -errno on error, or 0 on success. During probe, + * input will not be passed to raw_event unless hid_device_io_start is + * called. + * * raw_event and event should return 0 on no action performed, 1 when no * further processing should be done and negative on error * @@ -738,6 +744,44 @@ const struct hid_device_id *hid_match_id(struct hid_device *hdev, s32 hid_snto32(__u32 value, unsigned n); /** + * hid_device_io_start - enable HID input during probe, remove + * + * @hid - the device + * + * This should only be called during probe or remove and only be + * called by the thread calling probe or remove. It will allow + * incoming packets to be delivered to the driver. + */ +static inline void hid_device_io_start(struct hid_device *hid) { + if (hid->io_started) { + dev_warn(&hid->dev, "io already started"); + return; + } + hid->io_started = true; + up(&hid->driver_input_lock); +} + +/** + * hid_device_io_stop - disable HID input during probe, remove + * + * @hid - the device + * + * Should only be called after hid_device_io_start. It will prevent + * incoming packets from going to the driver for the duration of + * probe, remove. If called during probe, packets will still go to the + * driver after probe is complete. This function should only be called + * by the thread calling probe or remove. + */ +static inline void hid_device_io_stop(struct hid_device *hid) { + if (!hid->io_started) { + dev_warn(&hid->dev, "io already stopped"); + return; + } + hid->io_started = false; + down(&hid->driver_input_lock); +} + +/** * hid_map_usage - map usage input bits * * @hidinput: hidinput which we are interested in |