summaryrefslogtreecommitdiff
path: root/drivers/hid/i2c-hid/i2c-hid.c
diff options
context:
space:
mode:
authorStefan Agner <stefan.agner@toradex.com>2017-09-26 16:04:08 +0200
committerStefan Agner <stefan.agner@toradex.com>2017-09-26 18:11:18 +0200
commit1f4d46cea2bc1886a13ae9adfcd9e4243eed6a4c (patch)
tree2001999c70f8e46b192fc552590810aab35710e3 /drivers/hid/i2c-hid/i2c-hid.c
parentd152ae9d4704d8c7b3775e3b1a20e62aa3b1eed8 (diff)
parentb52c9082f2eb3a6f7fbbc86fad3eaa2a1725da66 (diff)
Merge tag 'v4.4.88' into toradex_vf_4.4-next
This is the 4.4.88 stable release
Diffstat (limited to 'drivers/hid/i2c-hid/i2c-hid.c')
-rw-r--r--drivers/hid/i2c-hid/i2c-hid.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index 0b80633bae91..d4d655a10df1 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -364,6 +364,15 @@ static int i2c_hid_hwreset(struct i2c_client *client)
if (ret)
return ret;
+ /*
+ * The HID over I2C specification states that if a DEVICE needs time
+ * after the PWR_ON request, it should utilise CLOCK stretching.
+ * However, it has been observered that the Windows driver provides a
+ * 1ms sleep between the PWR_ON and RESET requests and that some devices
+ * rely on this.
+ */
+ usleep_range(1000, 5000);
+
i2c_hid_dbg(ihid, "resetting...\n");
ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);