HID: logitech-dj: enable notifications on connect/disconnect

The receiver can send HID++ notifications to the DJ devices when the
physical devices are connected/disconnected.
Enable this feature by default.

This command uses a HID++ command instead of a DJ one, so use a direct
call to usbhid instead of using logi_dj_recv_send_report()

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 26 insertions, 1 deletions

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 9bc39421627f..c917ab61aafa 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -630,7 +630,9 @@ static int logi_dj_recv_query_paired_devices(struct dj_receiver_dev *djrcv_dev)
 static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
                                           unsigned timeout)
 {
+        struct hid_device *hdev = djrcv_dev->hdev;
         struct dj_report *dj_report;
+        u8 *buf;
         int retval;
 
         dj_report = kzalloc(sizeof(struct dj_report), GFP_KERNEL);
@@ -642,7 +644,6 @@ static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
         dj_report->report_params[CMD_SWITCH_PARAM_DEVBITFIELD] = 0x3F;
         dj_report->report_params[CMD_SWITCH_PARAM_TIMEOUT_SECONDS] = (u8)timeout;
         retval = logi_dj_recv_send_report(djrcv_dev, dj_report);
-        kfree(dj_report);
 
         /*
          * Ugly sleep to work around a USB 3.0 bug when the receiver is still
@@ -651,6 +652,30 @@ static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
          */
         msleep(50);
 
+        /*
+         * Magical bits to set up hidpp notifications when the dj devices
+         * are connected/disconnected.
+         *
+         * We can reuse dj_report because HIDPP_REPORT_SHORT_LENGTH is smaller
+         * than DJREPORT_SHORT_LENGTH.
+         */
+        buf = (u8 *)dj_report;
+
+        memset(buf, 0, HIDPP_REPORT_SHORT_LENGTH);
+
+        buf[0] = REPORT_ID_HIDPP_SHORT;
+        buf[1] = 0xFF;
+        buf[2] = 0x80;
+        buf[3] = 0x00;
+        buf[4] = 0x00;
+        buf[5] = 0x09;
+        buf[6] = 0x00;
+
+        hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
+                        HIDPP_REPORT_SHORT_LENGTH, HID_OUTPUT_REPORT,
+                        HID_REQ_SET_REPORT);
+
+        kfree(dj_report);
         return retval;
 }