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media: uvcvideo: Send a control event when a Control Change interrupt arrives

Browse source 
UVC defines a method of handling asynchronous controls, which sends a
USB packet over the interrupt pipe. This patch implements support for
such packets by sending a control event to the user. Since this can
involve USB traffic and, therefore, scheduling, this has to be done
in a work queue.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Guennadi Liakhovetski 2018-07-26 04:17:53 -04:00 committed by Mauro Carvalho Chehab
parent 8e7a1dbc7b
commit e5225c820c
5 changed files with 288 additions and 69 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

211
drivers/media/usb/uvc/uvc_ctrl.c
View file

@ -20,6 +20,7 @@
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
#include <media/v4l2-ctrls.h>
@ -971,12 +972,30 @@ static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain,
return 0;
}
static s32 __uvc_ctrl_get_value(struct uvc_control_mapping *mapping,
const u8 *data)
{
s32 value = mapping->get(mapping, UVC_GET_CUR, data);
if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
struct uvc_menu_info *menu = mapping->menu_info;
unsigned int i;
for (i = 0; i < mapping->menu_count; ++i, ++menu) {
if (menu->value == value) {
value = i;
break;
}
}
}
return value;
}
static int __uvc_ctrl_get(struct uvc_video_chain *chain,
struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
s32 *value)
{
struct uvc_menu_info *menu;
unsigned int i;
int ret;
if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
@ -993,18 +1012,8 @@ static int __uvc_ctrl_get(struct uvc_video_chain *chain,
ctrl->loaded = 1;
}
*value = mapping->get(mapping, UVC_GET_CUR,
uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
menu = mapping->menu_info;
for (i = 0; i < mapping->menu_count; ++i, ++menu) {
if (menu->value == *value) {
*value = i;
break;
}
}
}
*value = __uvc_ctrl_get_value(mapping,
uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
return 0;
}
@ -1216,53 +1225,135 @@ static void uvc_ctrl_fill_event(struct uvc_video_chain *chain,
ev->u.ctrl.default_value = v4l2_ctrl.default_value;
}
static void uvc_ctrl_send_event(struct uvc_fh *handle,
struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
s32 value, u32 changes)
/*
* Send control change events to all subscribers for the @ctrl control. By
* default the subscriber that generated the event, as identified by @handle,
* is not notified unless it has set the V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK flag.
* @handle can be NULL for asynchronous events related to auto-update controls,
* in which case all subscribers are notified.
*/
static void uvc_ctrl_send_event(struct uvc_video_chain *chain,
struct uvc_fh *handle, struct uvc_control *ctrl,
struct uvc_control_mapping *mapping, s32 value, u32 changes)
{
struct v4l2_fh *originator = handle ? &handle->vfh : NULL;
struct v4l2_subscribed_event *sev;
struct v4l2_event ev;
if (list_empty(&mapping->ev_subs))
return;
uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, value, changes);
uvc_ctrl_fill_event(chain, &ev, ctrl, mapping, value, changes);
list_for_each_entry(sev, &mapping->ev_subs, node) {
if (sev->fh != &handle->vfh ||
if (sev->fh != originator ||
(sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK) ||
(changes & V4L2_EVENT_CTRL_CH_FLAGS))
v4l2_event_queue_fh(sev->fh, &ev);
}
}
static void uvc_ctrl_send_slave_event(struct uvc_fh *handle,
struct uvc_control *master, u32 slave_id,
const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
/*
* Send control change events for the slave of the @master control identified
* by the V4L2 ID @slave_id. The @handle identifies the event subscriber that
* generated the event and may be NULL for auto-update events.
*/
static void uvc_ctrl_send_slave_event(struct uvc_video_chain *chain,
struct uvc_fh *handle, struct uvc_control *master, u32 slave_id)
{
struct uvc_control_mapping *mapping = NULL;
struct uvc_control *ctrl = NULL;
u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
unsigned int i;
s32 val = 0;
/*
* We can skip sending an event for the slave if the slave
* is being modified in the same transaction.
*/
for (i = 0; i < xctrls_count; i++) {
if (xctrls[i].id == slave_id)
return;
}
__uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0);
if (ctrl == NULL)
return;
if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
if (__uvc_ctrl_get(chain, ctrl, mapping, &val) == 0)
changes |= V4L2_EVENT_CTRL_CH_VALUE;
uvc_ctrl_send_event(handle, ctrl, mapping, val, changes);
uvc_ctrl_send_event(chain, handle, ctrl, mapping, val, changes);
}
static void uvc_ctrl_status_event_work(struct work_struct *work)
{
struct uvc_device *dev = container_of(work, struct uvc_device,
async_ctrl.work);
struct uvc_ctrl_work *w = &dev->async_ctrl;
struct uvc_video_chain *chain = w->chain;
struct uvc_control_mapping *mapping;
struct uvc_control *ctrl = w->ctrl;
struct uvc_fh *handle;
unsigned int i;
int ret;
mutex_lock(&chain->ctrl_mutex);
handle = ctrl->handle;
ctrl->handle = NULL;
list_for_each_entry(mapping, &ctrl->info.mappings, list) {
s32 value = __uvc_ctrl_get_value(mapping, w->data);
/*
* handle may be NULL here if the device sends auto-update
* events without a prior related control set from userspace.
*/
for (i = 0; i < ARRAY_SIZE(mapping->slave_ids); ++i) {
if (!mapping->slave_ids[i])
break;
uvc_ctrl_send_slave_event(chain, handle, ctrl,
mapping->slave_ids[i]);
}
uvc_ctrl_send_event(chain, handle, ctrl, mapping, value,
V4L2_EVENT_CTRL_CH_VALUE);
}
mutex_unlock(&chain->ctrl_mutex);
/* Resubmit the URB. */
w->urb->interval = dev->int_ep->desc.bInterval;
ret = usb_submit_urb(w->urb, GFP_KERNEL);
if (ret < 0)
uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
ret);
}
bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
struct uvc_control *ctrl, const u8 *data)
{
struct uvc_device *dev = chain->dev;
struct uvc_ctrl_work *w = &dev->async_ctrl;
if (list_empty(&ctrl->info.mappings)) {
ctrl->handle = NULL;
return false;
}
w->data = data;
w->urb = urb;
w->chain = chain;
w->ctrl = ctrl;
schedule_work(&w->work);
return true;
}
static bool uvc_ctrl_xctrls_has_control(const struct v4l2_ext_control *xctrls,
unsigned int xctrls_count, u32 id)
{
unsigned int i;
for (i = 0; i < xctrls_count; ++i) {
if (xctrls[i].id == id)
return true;
}
return false;
}
static void uvc_ctrl_send_events(struct uvc_fh *handle,
@ -1277,29 +1368,39 @@ static void uvc_ctrl_send_events(struct uvc_fh *handle,
for (i = 0; i < xctrls_count; ++i) {
ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
/* Notification will be sent from an Interrupt event. */
continue;
for (j = 0; j < ARRAY_SIZE(mapping->slave_ids); ++j) {
if (!mapping->slave_ids[j])
u32 slave_id = mapping->slave_ids[j];
if (!slave_id)
break;
uvc_ctrl_send_slave_event(handle, ctrl,
mapping->slave_ids[j],
xctrls, xctrls_count);
/*
* We can skip sending an event for the slave if the
* slave is being modified in the same transaction.
*/
if (uvc_ctrl_xctrls_has_control(xctrls, xctrls_count,
slave_id))
continue;
uvc_ctrl_send_slave_event(handle->chain, handle, ctrl,
slave_id);
}
/*
* If the master is being modified in the same transaction
* flags may change too.
*/
if (mapping->master_id) {
for (j = 0; j < xctrls_count; j++) {
if (xctrls[j].id == mapping->master_id) {
changes |= V4L2_EVENT_CTRL_CH_FLAGS;
break;
}
}
}
if (mapping->master_id &&
uvc_ctrl_xctrls_has_control(xctrls, xctrls_count,
mapping->master_id))
changes |= V4L2_EVENT_CTRL_CH_FLAGS;
uvc_ctrl_send_event(handle, ctrl, mapping, xctrls[i].value,
changes);
uvc_ctrl_send_event(handle->chain, handle, ctrl, mapping,
xctrls[i].value, changes);
}
}
@ -1472,9 +1573,10 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value);
}
int uvc_ctrl_set(struct uvc_video_chain *chain,
int uvc_ctrl_set(struct uvc_fh *handle,
struct v4l2_ext_control *xctrl)
{
struct uvc_video_chain *chain = handle->chain;
struct uvc_control *ctrl;
struct uvc_control_mapping *mapping;
s32 value;
@ -1581,6 +1683,9 @@ int uvc_ctrl_set(struct uvc_video_chain *chain,
mapping->set(mapping, value,
uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
ctrl->handle = handle;
ctrl->dirty = 1;
ctrl->modified = 1;
return 0;
@ -1612,7 +1717,9 @@ static int uvc_ctrl_get_flags(struct uvc_device *dev,
| (data[0] & UVC_CONTROL_CAP_SET ?
UVC_CTRL_FLAG_SET_CUR : 0)
| (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ?
UVC_CTRL_FLAG_AUTO_UPDATE : 0);
UVC_CTRL_FLAG_AUTO_UPDATE : 0)
| (data[0] & UVC_CONTROL_CAP_ASYNCHRONOUS ?
UVC_CTRL_FLAG_ASYNCHRONOUS : 0);
kfree(data);
return ret;
@ -2173,6 +2280,8 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
struct uvc_entity *entity;
unsigned int i;
INIT_WORK(&dev->async_ctrl.work, uvc_ctrl_status_event_work);
/* Walk the entities list and instantiate controls */
list_for_each_entry(entity, &dev->entities, list) {
struct uvc_control *ctrl;
@ -2241,6 +2350,8 @@ void uvc_ctrl_cleanup_device(struct uvc_device *dev)
struct uvc_entity *entity;
unsigned int i;
cancel_work_sync(&dev->async_ctrl.work);
/* Free controls and control mappings for all entities. */
list_for_each_entry(entity, &dev->entities, list) {
for (i = 0; i < entity->ncontrols; ++i) {

125
drivers/media/usb/uvc/uvc_status.c
View file

@ -78,7 +78,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
/* --------------------------------------------------------------------------
* Status interrupt endpoint
*/
static void uvc_event_streaming(struct uvc_device *dev, u8 *data, int len)
struct uvc_streaming_status {
u8 bStatusType;
u8 bOriginator;
u8 bEvent;
u8 bValue[];
} __packed;
struct uvc_control_status {
u8 bStatusType;
u8 bOriginator;
u8 bEvent;
u8 bSelector;
u8 bAttribute;
u8 bValue[];
} __packed;
static void uvc_event_streaming(struct uvc_device *dev,
struct uvc_streaming_status *status, int len)
{
if (len < 3) {
uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
@ -86,31 +103,97 @@ static void uvc_event_streaming(struct uvc_device *dev, u8 *data, int len)
return;
}
if (data[2] == 0) {
if (status->bEvent == 0) {
if (len < 4)
return;
uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
data[1], data[3] ? "pressed" : "released", len);
uvc_input_report_key(dev, KEY_CAMERA, data[3]);
status->bOriginator,
status->bValue[0] ? "pressed" : "released", len);
uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
} else {
uvc_trace(UVC_TRACE_STATUS,
"Stream %u error event %02x len %d.\n",
data[1], data[2], len);
status->bOriginator, status->bEvent, len);
}
}
static void uvc_event_control(struct uvc_device *dev, u8 *data, int len)
{
char *attrs[3] = { "value", "info", "failure" };
#define UVC_CTRL_VALUE_CHANGE 0
#define UVC_CTRL_INFO_CHANGE 1
#define UVC_CTRL_FAILURE_CHANGE 2
#define UVC_CTRL_MIN_CHANGE 3
#define UVC_CTRL_MAX_CHANGE 4
if (len < 6 || data[2] != 0 || data[4] > 2) {
static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
u8 selector)
{
struct uvc_control *ctrl;
unsigned int i;
for (i = 0, ctrl = entity->controls; i < entity->ncontrols; i++, ctrl++)
if (ctrl->info.selector == selector)
return ctrl;
return NULL;
}
static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
const struct uvc_control_status *status,
struct uvc_video_chain **chain)
{
list_for_each_entry((*chain), &dev->chains, list) {
struct uvc_entity *entity;
struct uvc_control *ctrl;
list_for_each_entry(entity, &(*chain)->entities, chain) {
if (entity->id != status->bOriginator)
continue;
ctrl = uvc_event_entity_find_ctrl(entity,
status->bSelector);
if (ctrl)
return ctrl;
}
}
return NULL;
}
static bool uvc_event_control(struct urb *urb,
const struct uvc_control_status *status, int len)
{
static const char *attrs[] = { "value", "info", "failure", "min", "max" };
struct uvc_device *dev = urb->context;
struct uvc_video_chain *chain;
struct uvc_control *ctrl;
if (len < 6 || status->bEvent != 0 ||
status->bAttribute >= ARRAY_SIZE(attrs)) {
uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
"received.\n");
return;
return false;
}
uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
data[1], data[3], attrs[data[4]], len);
status->bOriginator, status->bSelector,
attrs[status->bAttribute], len);
/* Find the control. */
ctrl = uvc_event_find_ctrl(dev, status, &chain);
if (!ctrl)
return false;
switch (status->bAttribute) {
case UVC_CTRL_VALUE_CHANGE:
return uvc_ctrl_status_event(urb, chain, ctrl, status->bValue);
case UVC_CTRL_INFO_CHANGE:
case UVC_CTRL_FAILURE_CHANGE:
case UVC_CTRL_MIN_CHANGE:
case UVC_CTRL_MAX_CHANGE:
break;
}
return false;
}
static void uvc_status_complete(struct urb *urb)
@ -138,13 +221,23 @@ static void uvc_status_complete(struct urb *urb)
len = urb->actual_length;
if (len > 0) {
switch (dev->status[0] & 0x0f) {
case UVC_STATUS_TYPE_CONTROL:
uvc_event_control(dev, dev->status, len);
break;
case UVC_STATUS_TYPE_CONTROL: {
struct uvc_control_status *status =
(struct uvc_control_status *)dev->status;
case UVC_STATUS_TYPE_STREAMING:
uvc_event_streaming(dev, dev->status, len);
if (uvc_event_control(urb, status, len))
/* The URB will be resubmitted in work context. */
return;
break;
}
case UVC_STATUS_TYPE_STREAMING: {
struct uvc_streaming_status *status =
(struct uvc_streaming_status *)dev->status;
uvc_event_streaming(dev, status, len);
break;
}
default:
uvc_trace(UVC_TRACE_STATUS, "Unknown status event "

4
drivers/media/usb/uvc/uvc_v4l2.c
View file

@ -994,7 +994,7 @@ static int uvc_ioctl_s_ctrl(struct file *file, void *fh,
if (ret < 0)
return ret;
ret = uvc_ctrl_set(chain, &xctrl);
ret = uvc_ctrl_set(handle, &xctrl);
if (ret < 0) {
uvc_ctrl_rollback(handle);
return ret;
@ -1069,7 +1069,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
return ret;
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_set(chain, ctrl);
ret = uvc_ctrl_set(handle, ctrl);
if (ret < 0) {
uvc_ctrl_rollback(handle);
ctrls->error_idx = commit ? ctrls->count : i;

15
drivers/media/usb/uvc/uvcvideo.h
View file

@ -12,6 +12,7 @@
#include <linux/usb/video.h>
#include <linux/uvcvideo.h>
#include <linux/videodev2.h>
#include <linux/workqueue.h>
#include <media/media-device.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
@ -259,6 +260,8 @@ struct uvc_control {
initialized:1;
u8 *uvc_data;
struct uvc_fh *handle; /* File handle that last changed the control. */
};
struct uvc_format_desc {
@ -603,6 +606,14 @@ struct uvc_device {
u8 *status;
struct input_dev *input;
char input_phys[64];
struct uvc_ctrl_work {
struct work_struct work;
struct urb *urb;
struct uvc_video_chain *chain;
struct uvc_control *ctrl;
const void *data;
} async_ctrl;
};
enum uvc_handle_state {
@ -756,6 +767,8 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
int uvc_ctrl_init_device(struct uvc_device *dev);
void uvc_ctrl_cleanup_device(struct uvc_device *dev);
int uvc_ctrl_restore_values(struct uvc_device *dev);
bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
struct uvc_control *ctrl, const u8 *data);
int uvc_ctrl_begin(struct uvc_video_chain *chain);
int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
@ -773,7 +786,7 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
}
int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
int uvc_ctrl_set(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
struct uvc_xu_control_query *xqry);

2
include/uapi/linux/uvcvideo.h
View file

@ -28,6 +28,8 @@
#define UVC_CTRL_FLAG_RESTORE (1 << 6)
/* Control can be updated by the camera. */
#define UVC_CTRL_FLAG_AUTO_UPDATE (1 << 7)
/* Control supports asynchronous reporting */
#define UVC_CTRL_FLAG_ASYNCHRONOUS (1 << 8)
#define UVC_CTRL_FLAG_GET_RANGE \
(UVC_CTRL_FLAG_GET_CUR | UVC_CTRL_FLAG_GET_MIN | \