cros_ec: Support keyboard scanning with EC_CMD_GET_NEXT_EVENT

The cros_ec_keyb driver currently uses EC_CMD_MKBP_STATE to scan the
keyboard, but this host command was superseded by EC_CMD_GET_NEXT_EVENT
and unavailable on more recent devices (including gru-kevin), as it was
removed in cros-ec commit 87a071941b89 ("mkbp: Add support for buttons
and switches.") dated 2016-07-06.

The EC_CMD_GET_NEXT_EVENT has been available since cros-ec commit
d1ed75815efe ("MKBP event signalling implementation") dated 2014-10-20,
but it looks like it isn't included in firmware-* branches for at least
link, nyan-big, samus, snow, spring, panther and peach-pit which have
defconfigs in U-Boot. So this patch falls back to the old method if the
EC doesn't recognize the newer command.

The implementation is mostly adapted from Depthcharge commit
f88af26b44fc ("cros_ec: Change keyboard scanning method.").

On a gru-kevin, the current driver before this patch fails to read the
pressed keys with:

    out: cmd=0x60: 03 9d 60 00 00 00 00 00
    in-header: 03 fc 01 00 00 00 00 00
    in-data:
    ec_command_inptr: len=-1, din=0000000000000000
    check_for_keys: keyboard scan failed

However the keyboard works fine with the newer command:

    out: cmd=0x67: 03 96 67 00 00 00 00 00
    in-header: 03 ef 00 00 0e 00 00 00
    in-data: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ec_command_inptr: len=14, din=00000000f412df30
    key_matrix_decode: num_keys = 0
      0 valid keycodes found
    out: cmd=0x67: 03 96 67 00 00 00 00 00
    in-header: 03 df 00 00 0e 00 00 00
    in-data: 00 00 00 00 00 00 00 00 00 00 00 00 10 00
    ec_command_inptr: len=14, din=00000000f412df30
    key_matrix_decode: num_keys = 1
      valid=1, row=4, col=11
        keycode=28
      1 valid keycodes found
     {0d}

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/input/cros_ec_keyb.c b/drivers/input/cros_ec_keyb.c
index 00bf58f2b5d257b8b4fb33d38134a47b921f6cf1..0c0f52205b289ac0f5f11b303a9521aea3dac2d1 100644 (file)
--- a/drivers/input/cros_ec_keyb.c
+++ b/drivers/input/cros_ec_keyb.c
@@ -47,15 +47,35 @@ static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
        struct key_matrix_key *key;
        static struct mbkp_keyscan last_scan;
        static bool last_scan_valid;
-       struct mbkp_keyscan scan;
+       struct ec_response_get_next_event event;
+       struct mbkp_keyscan *scan = (struct mbkp_keyscan *)
+                                   &event.data.key_matrix;
        unsigned int row, col, bit, data;
        int num_keys;
+       int ret;
 
-       if (cros_ec_scan_keyboard(dev->parent, &scan)) {
-               debug("%s: keyboard scan failed\n", __func__);
+       /* Get pending MKBP event. It may not be a key matrix event. */
+       do {
+               ret = cros_ec_get_next_event(dev->parent, &event);
+               /* The EC has no events for us at this time. */
+               if (ret == -EC_RES_UNAVAILABLE)
+                       return -EIO;
+               else if (ret)
+                       break;
+       } while (event.event_type != EC_MKBP_EVENT_KEY_MATRIX);
+
+       /* Try the old command if the EC doesn't support the above. */
+       if (ret == -EC_RES_INVALID_COMMAND) {
+               if (cros_ec_scan_keyboard(dev->parent, scan)) {
+                       debug("%s: keyboard scan failed\n", __func__);
+                       return -EIO;
+               }
+       } else if (ret) {
+               debug("%s: Error getting next MKBP event. (%d)\n",
+                     __func__, ret);
                return -EIO;
        }
-       *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan));
+       *samep = last_scan_valid && !memcmp(&last_scan, scan, sizeof(*scan));
 
        /*
         * This is a bit odd. The EC has no way to tell us that it has run
@@ -64,14 +84,14 @@ static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
         * that this scan is the same as the last.
         */
        last_scan_valid = true;
-       memcpy(&last_scan, &scan, sizeof(last_scan));
+       memcpy(&last_scan, scan, sizeof(last_scan));
 
        for (col = num_keys = bit = 0; col < priv->matrix.num_cols;
                        col++) {
                for (row = 0; row < priv->matrix.num_rows; row++) {
                        unsigned int mask = 1 << (bit & 7);
 
-                       data = scan.data[bit / 8];
+                       data = scan->data[bit / 8];
                        if ((data & mask) && num_keys < max_count) {
                                key = keys + num_keys++;
                                key->row = row;

diff --git a/drivers/misc/cros_ec.c b/drivers/misc/cros_ec.c
index a5534b16673b5b0f29802a997bbcf3e1b76ed7fd..c3674908ee82c1bbfe892794d8cfba4439573a1b 100644 (file)
--- a/drivers/misc/cros_ec.c
+++ b/drivers/misc/cros_ec.c
@@ -415,6 +415,21 @@ int cros_ec_scan_keyboard(struct udevice *dev, struct mbkp_keyscan *scan)
        return 0;
 }
 
+int cros_ec_get_next_event(struct udevice *dev,
+                          struct ec_response_get_next_event *event)
+{
+       int ret;
+
+       ret = ec_command(dev, EC_CMD_GET_NEXT_EVENT, 0, NULL, 0,
+                        event, sizeof(*event));
+       if (ret < 0)
+               return ret;
+       else if (ret != sizeof(*event))
+               return -EC_RES_INVALID_RESPONSE;
+
+       return 0;
+}
+
 int cros_ec_read_id(struct udevice *dev, char *id, int maxlen)
 {
        struct ec_response_get_version *r;

diff --git a/include/cros_ec.h b/include/cros_ec.h
index f4b9b7a5c26e6c97cdd8bd9db1b15ededb18d0fc..f187bd0d4b5bc5d67e7cbb2e1014a044d87256c6 100644 (file)
--- a/include/cros_ec.h
+++ b/include/cros_ec.h
@@ -82,6 +82,17 @@ int cros_ec_read_id(struct udevice *dev, char *id, int maxlen);
  */
 int cros_ec_scan_keyboard(struct udevice *dev, struct mbkp_keyscan *scan);
 
+/**
+ * Get the next pending MKBP event from the ChromeOS EC device.
+ *
+ * Send a message requesting the next event and return the result.
+ *
+ * @param event                Place to put the event.
+ * @return 0 if ok, <0 on error.
+ */
+int cros_ec_get_next_event(struct udevice *dev,
+                          struct ec_response_get_next_event *event);
+
 /**
  * Read which image is currently running on the CROS-EC device.
  *