diff options
| author | Alex Shi <alex.shi@linaro.org> | 2017-07-18 14:31:54 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2017-07-18 14:31:54 +0800 |
| commit | 16e243013beb93902693c4bb90e4348c99588429 (patch) | |
| tree | 6a5858d948085974ef1f26bb1e4b546cfb44cfc5 /drivers/hid/i2c-hid/i2c-hid.c | |
| parent | 2120557722577d8cff75a33a799ad15582dbd8ef (diff) | |
| parent | 5289d9c979092878f2bf741d8b365ef7565fb6db (diff) | |
Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidlsk-v4.4-17.07-android
Diffstat (limited to 'drivers/hid/i2c-hid/i2c-hid.c')
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 9 |
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); |