HID: hid-led: add support for reading from LED devices

Add support for reading data from LED devices.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/hid/hid-led.c b/drivers/hid/hid-led.c
index d5d8d941c4b0..4075f095c2a2 100644
--- a/drivers/hid/hid-led.c
+++ b/drivers/hid/hid-led.c
@@ -115,6 +115,35 @@ static int hidled_send(struct hidled_device *ldev, __u8 *buf)
         return ret == ldev->config->report_size ? 0 : -EMSGSIZE;
 }
 
+/* reading data is supported for report type RAW_REQUEST only */
+static int hidled_recv(struct hidled_device *ldev, __u8 *buf)
+{
+        int ret;
+
+        if (ldev->config->report_type != RAW_REQUEST)
+                return -EINVAL;
+
+        buf[0] = ldev->config->report_id;
+
+        mutex_lock(&ldev->lock);
+
+        ret = hid_hw_raw_request(ldev->hdev, buf[0], buf,
+                                 ldev->config->report_size,
+                                 HID_FEATURE_REPORT,
+                                 HID_REQ_SET_REPORT);
+        if (ret < 0)
+                goto err;
+
+        ret = hid_hw_raw_request(ldev->hdev, buf[0], buf,
+                                 ldev->config->report_size,
+                                 HID_FEATURE_REPORT,
+                                 HID_REQ_GET_REPORT);
+err:
+        mutex_unlock(&ldev->lock);
+
+        return ret < 0 ? ret : 0;
+}
+
 static u8 riso_kagaku_index(struct hidled_rgb *rgb)
 {
         enum led_brightness r, g, b;