[PATCH v9 05/11] media: uvcvideo: Add support for compound controls

Yunke Cao
2022-10-25T05:56:04Z

Supports getting/setting current value.
Supports getting default value.
Handles V4L2_CTRL_FLAG_NEXT_COMPOUND.

Signed-off-by: Yunke Cao <yunkec@google.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
---
Changelog since v8:
- No change.
Changelog since v7:
- Fixed comments styles, indentation and a few other style issues.
- Renamed uvc_g/set_array() to uvc_g/set_compound().
- Moved size check to __uvc_ctrl_add_mapping().
- After setting a new value, copy it back to user.
- In __uvc_ctrl_set_compound(), check size before allocating.

drivers/media/usb/uvc/uvc_ctrl.c | 184 ++++++++++++++++++++++++++++---
drivers/media/usb/uvc/uvcvideo.h | 4 +
2 files changed, 170 insertions(+), 18 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 020303e2593b..fcfaa1ee892d 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -837,6 +837,28 @@ static void uvc_set_le_value(struct uvc_control_mapping *mapping,
}
}

+/*
+ * Extract the byte array specified by mapping->offset and mapping->data_size
+ * stored at 'data' to the output array 'data_out'.
+ */
+static int uvc_get_compound(struct uvc_control_mapping *mapping, const u8 *data,
+ u8 *data_out)
+{
+ memcpy(data_out, data + mapping->offset / 8, mapping->data_size / 8);
+ return 0;
+}
+
+/*
+ * Copy the byte array 'data_in' to the destination specified by mapping->offset
+ * and mapping->data_size stored at 'data'.
+ */
+static int uvc_set_compound(struct uvc_control_mapping *mapping,
+ const u8 *data_in, u8 *data)
+{
+ memcpy(data + mapping->offset / 8, data_in, mapping->data_size / 8);
+ return 0;
+}
+
static bool
uvc_ctrl_mapping_is_compound(const struct uvc_control_mapping *mapping)
{
@@ -859,7 +881,7 @@ static int uvc_entity_match_guid(const struct uvc_entity *entity,

static void __uvc_find_control(struct uvc_entity *entity, u32 v4l2_id,
struct uvc_control_mapping **mapping, struct uvc_control **control,
- int next)
+ int next, int next_compound)
{
struct uvc_control *ctrl;
struct uvc_control_mapping *map;
@@ -874,14 +896,17 @@ static void __uvc_find_control(struct uvc_entity *entity, u32 v4l2_id,
continue;

list_for_each_entry(map, &ctrl->info.mappings, list) {
- if ((map->id == v4l2_id) && !next) {
+ if (map->id == v4l2_id && !next && !next_compound) {
*control = ctrl;
*mapping = map;
return;
}

if ((*mapping == NULL || (*mapping)->id > map->id) &&
- (map->id > v4l2_id) && next) {
+ (map->id > v4l2_id) &&
+ ((!uvc_ctrl_mapping_is_compound(map) && next) ||
+ (uvc_ctrl_mapping_is_compound(map) &&
+ next_compound))) {
*control = ctrl;
*mapping = map;
}
@@ -895,6 +920,7 @@ static struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
struct uvc_control *ctrl = NULL;
struct uvc_entity *entity;
int next = v4l2_id & V4L2_CTRL_FLAG_NEXT_CTRL;
+ int next_compound = v4l2_id & V4L2_CTRL_FLAG_NEXT_COMPOUND;

*mapping = NULL;

@@ -903,12 +929,13 @@ static struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,

/* Find the control. */
list_for_each_entry(entity, &chain->entities, chain) {
- __uvc_find_control(entity, v4l2_id, mapping, &ctrl, next);
- if (ctrl && !next)
+ __uvc_find_control(entity, v4l2_id, mapping, &ctrl, next,
+ next_compound);
+ if (ctrl && !next && !next_compound)
return ctrl;
}

- if (ctrl == NULL && !next)
+ if (!ctrl && !next && !next_compound)
uvc_dbg(chain->dev, CONTROL, "Control 0x%08x not found\n",
v4l2_id);

@@ -1048,10 +1075,59 @@ static int __uvc_ctrl_get_std(struct uvc_video_chain *chain,
return 0;
}

+static int __uvc_ctrl_get_compound(struct uvc_control_mapping *mapping,
+ struct uvc_control *ctrl,
+ int id,
+ struct v4l2_ext_control *xctrl)
+{
+ u8 size;
+ u8 *data;
+ int ret;
+
+ size = mapping->v4l2_size / 8;
+ if (xctrl->size < size) {
+ xctrl->size = size;
+ return -ENOSPC;
+ }
+
+ data = kmalloc(size, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ ret = mapping->get_compound(mapping, uvc_ctrl_data(ctrl, id), data);
+ if (ret < 0)
+ goto out;
+
+ ret = copy_to_user(xctrl->ptr, data, size) ? -EFAULT : 0;
+
+out:
+ kfree(data);
+ return ret;
+}
+
+static int __uvc_ctrl_get_compound_cur(struct uvc_video_chain *chain,
+ struct uvc_control *ctrl,
+ struct uvc_control_mapping *mapping,
+ struct v4l2_ext_control *xctrl)
+{
+ int ret;
+
+ if (!uvc_ctrl_mapping_is_compound(mapping))
+ return -EINVAL;
+
+ ret = __uvc_ctrl_load_cur(chain, ctrl);
+ if (ret < 0)
+ return ret;
+
+ return __uvc_ctrl_get_compound(mapping, ctrl, UVC_CTRL_DATA_CURRENT,
+ xctrl);
+}
+
static int __uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
u32 found_id)
{
bool find_next = req_id & V4L2_CTRL_FLAG_NEXT_CTRL;
+ bool find_next_compound = req_id & V4L2_CTRL_FLAG_NEXT_COMPOUND;
unsigned int i;

req_id &= V4L2_CTRL_ID_MASK;
@@ -1059,7 +1135,7 @@ static int __uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
for (i = 0; i < ARRAY_SIZE(uvc_control_classes); i++) {
if (!(chain->ctrl_class_bitmap & BIT(i)))
continue;
- if (!find_next) {
+ if (!find_next && !find_next_compound) {
if (uvc_control_classes[i] == req_id)
return i;
continue;
@@ -1151,7 +1227,7 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,

if (mapping->master_id)
__uvc_find_control(ctrl->entity, mapping->master_id,
- &master_map, &master_ctrl, 0);
+ &master_map, &master_ctrl, 0, 0);
if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
s32 val = 0;
int ret;
@@ -1167,6 +1243,15 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
}

+ if (v4l2_ctrl->type >= V4L2_CTRL_COMPOUND_TYPES) {
+ v4l2_ctrl->flags |= V4L2_CTRL_FLAG_HAS_PAYLOAD;
+ v4l2_ctrl->default_value = 0;
+ v4l2_ctrl->minimum = 0;
+ v4l2_ctrl->maximum = 0;
+ v4l2_ctrl->step = 0;
+ return 0;
+ }
+
if (!ctrl->cached) {
int ret = uvc_ctrl_populate_cache(chain, ctrl);
if (ret < 0)
@@ -1400,7 +1485,7 @@ static void uvc_ctrl_send_slave_event(struct uvc_video_chain *chain,
u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
s32 val = 0;

- __uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0);
+ __uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0, 0);
if (ctrl == NULL)
return;

@@ -1706,7 +1791,7 @@ static int uvc_ctrl_find_ctrl_idx(struct uvc_entity *entity,

for (i = 0; i < ctrls->count; i++) {
__uvc_find_control(entity, ctrls->controls[i].id, &mapping,
- &ctrl_found, 0);
+ &ctrl_found, 0, 0);
if (uvc_control == ctrl_found)
return i;
}
@@ -1754,7 +1839,7 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
return -EINVAL;

if (uvc_ctrl_mapping_is_compound(mapping))
- return -EINVAL;
+ return __uvc_ctrl_get_compound_cur(chain, ctrl, mapping, xctrl);
else
return __uvc_ctrl_get_std(chain, ctrl, mapping, &xctrl->value);
}
@@ -1775,6 +1860,25 @@ int __uvc_ctrl_get_boundary_std(struct uvc_video_chain *chain,
return 0;
}

+static int __uvc_ctrl_get_boundary_compound(struct uvc_video_chain *chain,
+ struct uvc_control *ctrl,
+ struct uvc_control_mapping *mapping,
+ struct v4l2_ext_control *xctrl)
+{
+ int ret;
+
+ if (!uvc_ctrl_mapping_is_compound(mapping))
+ return -EINVAL;
+
+ if (!ctrl->cached) {
+ ret = uvc_ctrl_populate_cache(chain, ctrl);
+ if (ret < 0)
+ return ret;
+ }
+
+ return __uvc_ctrl_get_compound(mapping, ctrl, UVC_CTRL_DATA_DEF, xctrl);
+}
+
int uvc_ctrl_get_boundary(struct uvc_video_chain *chain,
struct v4l2_ext_control *xctrl)
{
@@ -1792,7 +1896,8 @@ int uvc_ctrl_get_boundary(struct uvc_video_chain *chain,
}

if (uvc_ctrl_mapping_is_compound(mapping))
- ret = -EINVAL;
+ ret = __uvc_ctrl_get_boundary_compound(chain, ctrl, mapping,
+ xctrl);
else
ret = __uvc_ctrl_get_boundary_std(chain, ctrl, mapping, xctrl);

@@ -1801,6 +1906,34 @@ int uvc_ctrl_get_boundary(struct uvc_video_chain *chain,
return ret;
}

+int __uvc_ctrl_set_compound(struct uvc_control_mapping *mapping,
+ struct v4l2_ext_control *xctrl,
+ struct uvc_control *ctrl)
+{
+ u8 *data;
+ int ret;
+
+ if (xctrl->size != mapping->v4l2_size / 8)
+ return -EINVAL;
+
+ data = kmalloc(xctrl->size, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ ret = copy_from_user(data, xctrl->ptr, xctrl->size);
+ if (ret < 0)
+ goto out;
+
+ ret = mapping->set_compound(mapping, data,
+ uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
+
+ __uvc_ctrl_get_compound(mapping, ctrl, UVC_CTRL_DATA_CURRENT, xctrl);
+
+out:
+ kfree(data);
+ return ret;
+}
+
int uvc_ctrl_set(struct uvc_fh *handle,
struct v4l2_ext_control *xctrl)
{
@@ -1902,12 +2035,14 @@ int uvc_ctrl_set(struct uvc_fh *handle,
ctrl->info.size);
}

- if (!uvc_ctrl_mapping_is_compound(mapping))
+ if (!uvc_ctrl_mapping_is_compound(mapping)) {
mapping->set(mapping, value,
uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
- else
- return -EINVAL;
-
+ } else {
+ ret = __uvc_ctrl_set_compound(mapping, xctrl, ctrl);
+ if (ret < 0)
+ return ret;
+ }

if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
ctrl->handle = handle;
@@ -2307,10 +2442,23 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
return -ENOMEM;
}

- if (map->get == NULL)
+ if (uvc_ctrl_mapping_is_compound(map)) {
+ if (map->data_size != map->v4l2_size)
+ return -EINVAL;
+
+ /* Only supports byte-aligned data. */
+ if (WARN_ON(map->offset % 8 || map->data_size % 8))
+ return -EINVAL;
+ }
+
+ if (!map->get && !uvc_ctrl_mapping_is_compound(map))
map->get = uvc_get_le_value;
- if (map->set == NULL)
+ if (!map->set && !uvc_ctrl_mapping_is_compound(map))
map->set = uvc_set_le_value;
+ if (!map->get_compound && uvc_ctrl_mapping_is_compound(map))
+ map->get_compound = uvc_get_compound;
+ if (!map->set_compound && uvc_ctrl_mapping_is_compound(map))
+ map->set_compound = uvc_set_compound;

for (i = 0; i < ARRAY_SIZE(uvc_control_classes); i++) {
if (V4L2_CTRL_ID2WHICH(uvc_control_classes[i]) ==
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 8f7938205a63..1e1bccd3b2e5 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -129,8 +129,12 @@ struct uvc_control_mapping {

s32 (*get)(struct uvc_control_mapping *mapping, u8 query,
const u8 *data);
+ int (*get_compound)(struct uvc_control_mapping *mapping, const u8 *data,
+ u8 *data_out);
void (*set)(struct uvc_control_mapping *mapping, s32 value,
u8 *data);
+ int (*set_compound)(struct uvc_control_mapping *mapping, const u8 *data_in,
+ u8 *data);
};

struct uvc_control {
--
2.38.0.135.g90850a2211-goog