From: Nick Dyer <[email protected]> Some maXTouch chips (eg mXT1386) will not respond on the first I2C request when they are in a sleep state. It must be retried after a delay for the chip to wake up.
Signed-off-by: Nick Dyer <[email protected]> Acked-by: Yufeng Shen <[email protected]> (cherry picked from ndyer/linux/for-upstream commit 63fd7a2cd03c3a572a5db39c52f4856819e1835d) [gdavis: Forward port and fix conflicts.] Signed-off-by: George G. Davis <[email protected]> Signed-off-by: Jiada Wang <[email protected]> --- drivers/input/touchscreen/atmel_mxt_ts.c | 45 ++++++++++++++++-------- 1 file changed, 30 insertions(+), 15 deletions(-) diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index d3e1cd677aa7..86c016dbec0d 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -216,6 +216,7 @@ enum t100_type { #define MXT_CRC_TIMEOUT 1000 /* msec */ #define MXT_FW_RESET_TIME 3000 /* msec */ #define MXT_FW_CHG_TIMEOUT 300 /* msec */ +#define MXT_WAKEUP_TIME 25 /* msec */ #define MXT_REGULATOR_DELAY 150 /* msec */ #define MXT_CHG_DELAY 100 /* msec */ #define MXT_POWERON_DELAY 150 /* msec */ @@ -723,6 +724,7 @@ static int __mxt_read_reg(struct i2c_client *client, struct i2c_msg xfer[2]; u8 buf[2]; int ret; + bool retry = false; buf[0] = reg & 0xff; buf[1] = (reg >> 8) & 0xff; @@ -739,17 +741,22 @@ static int __mxt_read_reg(struct i2c_client *client, xfer[1].len = len; xfer[1].buf = val; - ret = i2c_transfer(client->adapter, xfer, 2); - if (ret == 2) { - ret = 0; - } else { - if (ret >= 0) - ret = -EIO; - dev_err(&client->dev, "%s: i2c transfer failed (%d)\n", - __func__, ret); +retry_read: + ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer)); + if (ret != ARRAY_SIZE(xfer)) { + if (!retry) { + dev_dbg(&client->dev, "%s: i2c retry\n", __func__); + msleep(MXT_WAKEUP_TIME); + retry = true; + goto retry_read; + } else { + dev_err(&client->dev, "%s: i2c transfer failed (%d)\n", + __func__, ret); + return -EIO; + } } - return ret; + return 0; } static int mxt_read_blks(struct mxt_data *data, u16 start, u16 count, u8 *buf) @@ -779,6 +786,7 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, u8 *buf; size_t count; int ret; + bool retry = false; count = len + 2; buf = kmalloc(count, GFP_KERNEL); @@ -789,14 +797,21 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, buf[1] = (reg >> 8) & 0xff; memcpy(&buf[2], val, len); +retry_write: ret = i2c_master_send(client, buf, count); - if (ret == count) { - ret = 0; - } else { - if (ret >= 0) + if (ret != count) { + if (!retry) { + dev_dbg(&client->dev, "%s: i2c retry\n", __func__); + msleep(MXT_WAKEUP_TIME); + retry = true; + goto retry_write; + } else { + dev_err(&client->dev, "%s: i2c send failed (%d)\n", + __func__, ret); ret = -EIO; - dev_err(&client->dev, "%s: i2c send failed (%d)\n", - __func__, ret); + } + } else { + ret = 0; } kfree(buf); -- 2.19.2
