We so far lacked support for hid_hw_raw_request(..., HID_REQ_SET_REPORT);
Add support for it and simply forward the request to user-space. Note that
SET_REPORT is synchronous, just like GET_REPORT, even though it does not
provide any data back besides an error code.
If a transport layer does SET_REPORT asynchronously, they can just ACK it
immediately by writing an uhid_set_report_reply to uhid.
This patch re-uses the synchronous uhid-report infrastructure to query
user-space. Note that this means you cannot run SET_REPORT and GET_REPORT
in parallel. However, that has always been a restriction of HID and due to
its blocking nature, this is just fine. Maybe some future transport layer
supports parallel requests (very unlikely), however, until then lets not
over-complicate things and avoid request-lookup-tables.
Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx>
---
drivers/hid/uhid.c | 206 +++++++++++++++++++++++++++++++---------------
include/uapi/linux/uhid.h | 17 ++++
2 files changed, 155 insertions(+), 68 deletions(-)
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 8bf613e..1951148 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -49,6 +49,7 @@ struct uhid_device {
wait_queue_head_t report_wait;
bool report_running;
u32 report_id;
+ u32 report_type;
struct uhid_event report_buf;
};
@@ -124,95 +125,166 @@ static int uhid_hid_parse(struct hid_device *hid)
return hid_parse_report(hid, uhid->rd_data, uhid->rd_size);
}
+/* must be called with report_lock held */
+static int __uhid_report_queue_and_wait(struct uhid_device *uhid,
+ struct uhid_event *ev,
+ __u32 *report_id)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+ *report_id = ++uhid->report_id;
+ uhid->report_type = ev->type;
+ uhid->report_running = true;
+ uhid_queue(uhid, ev);
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+
+ ret = wait_event_interruptible_timeout(uhid->report_wait,
+ !uhid->report_running || !uhid->running,
+ 5 * HZ);
+ if (!ret || !uhid->running || uhid->report_running)
+ ret = -EIO;
+ else if (ret < 0)
+ ret = -ERESTARTSYS;
+ else
+ ret = 0;
+
+ uhid->report_running = false;
+
+ return ret;
+}
+
+static void uhid_report_wake_up(struct uhid_device *uhid, u32 id,
+ const struct uhid_event *ev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&uhid->qlock, flags);
+
+ /* id for old report; drop it silently */
+ if (uhid->report_type != ev->type || uhid->report_id != id)
+ goto unlock;
+ if (!uhid->report_running)
+ goto unlock;
+
+ memcpy(&uhid->report_buf, ev, sizeof(*ev));
+ uhid->report_running = false;
+ wake_up_interruptible(&uhid->report_wait);
+
+unlock:
+ spin_unlock_irqrestore(&uhid->qlock, flags);
+}
+
static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum,
- __u8 *buf, size_t count, unsigned char rtype)
+ u8 *buf, size_t count, u8 rtype)
{
struct uhid_device *uhid = hid->driver_data;
- __u8 report_type;
+ struct uhid_get_report_reply_req *req;
struct uhid_event *ev;
- unsigned long flags;
int ret;
- size_t uninitialized_var(len);
- struct uhid_get_report_reply_req *req;
if (!uhid->running)
return -EIO;
- switch (rtype) {
- case HID_FEATURE_REPORT:
- report_type = UHID_FEATURE_REPORT;
- break;
- case HID_OUTPUT_REPORT:
- report_type = UHID_OUTPUT_REPORT;
- break;
- case HID_INPUT_REPORT:
- report_type = UHID_INPUT_REPORT;
- break;
- default:
- return -EINVAL;
- }
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->type = UHID_GET_REPORT;
+ ev->u.get_report.rnum = rnum;
+ ev->u.get_report.rtype = rtype;
ret = mutex_lock_interruptible(&uhid->report_lock);
- if (ret)
+ if (ret) {
+ kfree(ev);
return ret;
+ }
- ev = kzalloc(sizeof(*ev), GFP_KERNEL);
- if (!ev) {
- ret = -ENOMEM;
+ /* this _always_ takes ownership of @ev */
+ ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.get_report.id);
+ if (ret)
goto unlock;
+
+ req = &uhid->report_buf.u.get_report_reply;
+ if (req->err) {
+ ret = -EIO;
+ } else {
+ ret = min3(count, (size_t)req->size, (size_t)UHID_DATA_MAX);
+ memcpy(buf, req->data, ret);
}
- spin_lock_irqsave(&uhid->qlock, flags);
- ev->type = UHID_GET_REPORT;
- ev->u.get_report.id = ++uhid->report_id;
- ev->u.get_report.rnum = rnum;
- ev->u.get_report.rtype = report_type;
+unlock:
+ mutex_unlock(&uhid->report_lock);
+ return ret;
+}
- uhid->report_running = true;
- uhid_queue(uhid, ev);
- spin_unlock_irqrestore(&uhid->qlock, flags);
+static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum,
+ const u8 *buf, size_t count, u8 rtype)
+{
+ struct uhid_device *uhid = hid->driver_data;
+ struct uhid_event *ev;
+ int ret;
- ret = wait_event_interruptible_timeout(uhid->report_wait,
- !uhid->report_running || !uhid->running,
- 5 * HZ);
+ if (!uhid->running || count > UHID_DATA_MAX)
+ return -EIO;
- if (!ret || !uhid->running) {
- ret = -EIO;
- } else if (ret < 0) {
- ret = -ERESTARTSYS;
- } else {
- spin_lock_irqsave(&uhid->qlock, flags);
- req = &uhid->report_buf.u.get_report_reply;
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
- if (req->err) {
- ret = -EIO;
- } else {
- ret = 0;
- len = min(count,
- min_t(size_t, req->size, UHID_DATA_MAX));
- memcpy(buf, req->data, len);
- }
+ ev->type = UHID_SET_REPORT;
+ ev->u.set_report.rnum = rnum;
+ ev->u.set_report.rtype = rtype;
+ ev->u.set_report.size = count;
+ memcpy(ev->u.set_report.data, buf, count);
- spin_unlock_irqrestore(&uhid->qlock, flags);
+ ret = mutex_lock_interruptible(&uhid->report_lock);
+ if (ret) {
+ kfree(ev);
+ return ret;
}
- uhid->report_running = false;
+ /* this _always_ takes ownership of @ev */
+ ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.set_report.id);
+ if (ret)
+ goto unlock;
+
+ if (uhid->report_buf.u.set_report_reply.err)
+ ret = -EIO;
+ else
+ ret = count;
unlock:
mutex_unlock(&uhid->report_lock);
- return ret ? ret : len;
+ return ret;
}
static int uhid_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
__u8 *buf, size_t len, unsigned char rtype,
int reqtype)
{
+ u8 u_rtype;
+
+ switch (rtype) {
+ case HID_FEATURE_REPORT:
+ u_rtype = UHID_FEATURE_REPORT;
+ break;
+ case HID_OUTPUT_REPORT:
+ u_rtype = UHID_OUTPUT_REPORT;
+ break;
+ case HID_INPUT_REPORT:
+ u_rtype = UHID_INPUT_REPORT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
switch (reqtype) {
case HID_REQ_GET_REPORT:
- return uhid_hid_get_report(hid, reportnum, buf, len, rtype);
+ return uhid_hid_get_report(hid, reportnum, buf, len, u_rtype);
case HID_REQ_SET_REPORT:
- /* TODO: implement proper SET_REPORT functionality */
- return -ENOSYS;
+ return uhid_hid_set_report(hid, reportnum, buf, len, u_rtype);
default:
return -EIO;
}
@@ -490,25 +562,20 @@ static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
static int uhid_dev_get_report_reply(struct uhid_device *uhid,
struct uhid_event *ev)
{
- unsigned long flags;
-
if (!uhid->running)
return -EINVAL;
- spin_lock_irqsave(&uhid->qlock, flags);
-
- /* id for old report; drop it silently */
- if (uhid->report_id != ev->u.get_report_reply.id)
- goto unlock;
- if (!uhid->report_running)
- goto unlock;
+ uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev);
+ return 0;
+}
- memcpy(&uhid->report_buf, ev, sizeof(*ev));
- uhid->report_running = false;
- wake_up_interruptible(&uhid->report_wait);
+static int uhid_dev_set_report_reply(struct uhid_device *uhid,
+ struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
-unlock:
- spin_unlock_irqrestore(&uhid->qlock, flags);
+ uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev);
return 0;
}
@@ -637,6 +704,9 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
case UHID_GET_REPORT_REPLY:
ret = uhid_dev_get_report_reply(uhid, &uhid->input_buf);
break;
+ case UHID_SET_REPORT_REPLY:
+ ret = uhid_dev_set_report_reply(uhid, &uhid->input_buf);
+ break;
default:
ret = -EOPNOTSUPP;
}
diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
index 116536e..62aac0e 100644
--- a/include/uapi/linux/uhid.h
+++ b/include/uapi/linux/uhid.h
@@ -37,6 +37,8 @@ enum uhid_event_type {
UHID_GET_REPORT_REPLY,
UHID_CREATE2,
UHID_INPUT2,
+ UHID_SET_REPORT,
+ UHID_SET_REPORT_REPLY,
};
struct uhid_create2_req {
@@ -84,6 +86,19 @@ struct uhid_get_report_reply_req {
__u8 data[UHID_DATA_MAX];
} __attribute__((__packed__));
+struct uhid_set_report_req {
+ __u32 id;
+ __u8 rnum;
+ __u8 rtype;
+ __u16 size;
+ __u8 data[UHID_DATA_MAX];
+} __attribute__((__packed__));
+
+struct uhid_set_report_reply_req {
+ __u32 id;
+ __u16 err;
+} __attribute__((__packed__));
+
/*
* Compat Layer
* All these commands and requests are obsolete. You should avoid using them in
@@ -165,6 +180,8 @@ struct uhid_event {
struct uhid_get_report_reply_req get_report_reply;
struct uhid_create2_req create2;
struct uhid_input2_req input2;
+ struct uhid_set_report_req set_report;
+ struct uhid_set_report_reply_req set_report_reply;
} u;
} __attribute__((__packed__));
--
2.0.3
--
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