HID: sony: Update copyright and add Dualshock 4 rate control note

Update the copyright notice with the current year and add a note
about values for controlling the Dualshock 4 reporting rate.

Processing reports at the default full rate of 1000hz can be too
demanding for some low-power embedded processors so noting
alternate values for people working with this hardware can be useful.

Thanks to Rostislav Pehlivanov for finding these values.

Signed-off-by: Frank Praznik <frank.praznik@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index 9b96f95..9bf4e36 100644 (file)
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -8,7 +8,7 @@
  *  Copyright (c) 2012 David Dillow <dave@thedillows.org>
  *  Copyright (c) 2006-2013 Jiri Kosina
  *  Copyright (c) 2013 Colin Leitner <colin.leitner@gmail.com>
- *  Copyright (c) 2014 Frank Praznik <frank.praznik@gmail.com>
+ *  Copyright (c) 2014-2016 Frank Praznik <frank.praznik@gmail.com>
  */
 
 /*
@@ -1879,6 +1879,17 @@ static void dualshock4_send_output_report(struct sony_sc *sc)
        u8 *buf = sc->output_report_dmabuf;
        int offset;
 
+       /*
+        * NOTE: The buf[1] field of the Bluetooth report controls
+        * the Dualshock 4 reporting rate.
+        *
+        * Known values include:
+        *
+        * 0x80 - 1000hz (full speed)
+        * 0xA0 - 31hz
+        * 0xB0 - 20hz
+        * 0xD0 - 66hz
+        */
        if (sc->quirks & DUALSHOCK4_CONTROLLER_USB) {
                memset(buf, 0, DS4_REPORT_0x05_SIZE);
                buf[0] = 0x05;