HID: uhid: Add UHID_CREATE2 + UHID_INPUT2
UHID_CREATE2:
HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
instead of a pointer. Enables use from languages that don't support pointers,
e.g. Python.
UHID_INPUT2:
Data array is the last field of struct uhid_input2_req. Enables userspace to
write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
of the data array that matters), instead of the entire struct uhid_input2_req.
Note:
UHID_CREATE2 increases the total size of struct uhid_event slightly, thus
increasing the size of messages that are queued for userspace. However, this
won't affect the userspace processing of these events.
[Jiri Kosina <jkosina@suse.cz>: adjust to hid_get_raw_report() and
hid_output_raw_report() API changes]
Change-Id: I7fb9c68e47bcd57067664079410780dd8e821198
Signed-off-by: Petri Gynther <pgynther@google.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt
index dc35a2b..ee65936 100644
--- a/Documentation/hid/uhid.txt
+++ b/Documentation/hid/uhid.txt
@@ -93,6 +93,11 @@
event to the kernel. The payload is of type struct uhid_create_req and
contains information about your device. You can start I/O now.
+ UHID_CREATE2:
+ Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array
+ inside struct uhid_create2_req, instead of a pointer to a separate array.
+ Enables use from languages that don't support pointers, e.g. Python.
+
UHID_DESTROY:
This destroys the internal HID device. No further I/O will be accepted. There
may still be pending messages that you can receive with read() but no further
@@ -105,6 +110,12 @@
contains a data-payload. This is the raw data that you read from your device.
The kernel will parse the HID reports and react on it.
+ UHID_INPUT2:
+ Same as UHID_INPUT, but the data array is the last field of uhid_input2_req.
+ Enables userspace to write only the required bytes to kernel (ev.type +
+ ev.u.input2.size + the part of the data array that matters), instead of
+ the entire struct uhid_input2_req.
+
UHID_FEATURE_ANSWER:
If you receive a UHID_FEATURE request you must answer with this request. You
must copy the "id" field from the request into the answer. Set the "err" field
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index cedc6da..9dc4fab 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -407,6 +407,67 @@
return ret;
}
+static int uhid_dev_create2(struct uhid_device *uhid,
+ const struct uhid_event *ev)
+{
+ struct hid_device *hid;
+ int ret;
+
+ if (uhid->running)
+ return -EALREADY;
+
+ uhid->rd_size = ev->u.create2.rd_size;
+ if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
+ return -EINVAL;
+
+ uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
+ if (!uhid->rd_data)
+ return -ENOMEM;
+
+ memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);
+
+ hid = hid_allocate_device();
+ if (IS_ERR(hid)) {
+ ret = PTR_ERR(hid);
+ goto err_free;
+ }
+
+ strncpy(hid->name, ev->u.create2.name, 127);
+ hid->name[127] = 0;
+ strncpy(hid->phys, ev->u.create2.phys, 63);
+ hid->phys[63] = 0;
+ strncpy(hid->uniq, ev->u.create2.uniq, 63);
+ hid->uniq[63] = 0;
+
+ hid->ll_driver = &uhid_hid_driver;
+ hid->bus = ev->u.create2.bus;
+ hid->vendor = ev->u.create2.vendor;
+ hid->product = ev->u.create2.product;
+ hid->version = ev->u.create2.version;
+ hid->country = ev->u.create2.country;
+ hid->driver_data = uhid;
+ hid->dev.parent = uhid_misc.this_device;
+
+ uhid->hid = hid;
+ uhid->running = true;
+
+ ret = hid_add_device(hid);
+ if (ret) {
+ hid_err(hid, "Cannot register HID device\n");
+ goto err_hid;
+ }
+
+ return 0;
+
+err_hid:
+ hid_destroy_device(hid);
+ uhid->hid = NULL;
+ uhid->running = false;
+err_free:
+ kfree(uhid->rd_data);
+ return ret;
+}
+
static int uhid_dev_destroy(struct uhid_device *uhid)
{
if (!uhid->running)
@@ -435,6 +496,17 @@
return 0;
}
+static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
+{
+ if (!uhid->running)
+ return -EINVAL;
+
+ hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
+ min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
+
+ return 0;
+}
+
static int uhid_dev_feature_answer(struct uhid_device *uhid,
struct uhid_event *ev)
{
@@ -571,12 +643,18 @@
case UHID_CREATE:
ret = uhid_dev_create(uhid, &uhid->input_buf);
break;
+ case UHID_CREATE2:
+ ret = uhid_dev_create2(uhid, &uhid->input_buf);
+ break;
case UHID_DESTROY:
ret = uhid_dev_destroy(uhid);
break;
case UHID_INPUT:
ret = uhid_dev_input(uhid, &uhid->input_buf);
break;
+ case UHID_INPUT2:
+ ret = uhid_dev_input2(uhid, &uhid->input_buf);
+ break;
case UHID_FEATURE_ANSWER:
ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
break;
diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
index 414b74b..1e3b09c 100644
--- a/include/uapi/linux/uhid.h
+++ b/include/uapi/linux/uhid.h
@@ -21,6 +21,7 @@
#include <linux/input.h>
#include <linux/types.h>
+#include <linux/hid.h>
enum uhid_event_type {
UHID_CREATE,
@@ -34,6 +35,8 @@
UHID_INPUT,
UHID_FEATURE,
UHID_FEATURE_ANSWER,
+ UHID_CREATE2,
+ UHID_INPUT2,
};
struct uhid_create_req {
@@ -50,6 +53,19 @@
__u32 country;
} __attribute__((__packed__));
+struct uhid_create2_req {
+ __u8 name[128];
+ __u8 phys[64];
+ __u8 uniq[64];
+ __u16 rd_size;
+ __u16 bus;
+ __u32 vendor;
+ __u32 product;
+ __u32 version;
+ __u32 country;
+ __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
+} __attribute__((__packed__));
+
#define UHID_DATA_MAX 4096
enum uhid_report_type {
@@ -63,6 +79,11 @@
__u16 size;
} __attribute__((__packed__));
+struct uhid_input2_req {
+ __u16 size;
+ __u8 data[UHID_DATA_MAX];
+} __attribute__((__packed__));
+
struct uhid_output_req {
__u8 data[UHID_DATA_MAX];
__u16 size;
@@ -100,6 +121,8 @@
struct uhid_output_ev_req output_ev;
struct uhid_feature_req feature;
struct uhid_feature_answer_req feature_answer;
+ struct uhid_create2_req create2;
+ struct uhid_input2_req input2;
} u;
} __attribute__((__packed__));
