| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | From 8e7e594b685f3fe44cd4803e3a4634bed897c2f7 Mon Sep 17 00:00:00 2001 |
| 2 | From: Zhang Ying-22455 <ying.zhang22455@nxp.com> |
| 3 | Date: Fri, 14 Apr 2017 17:03:03 +0800 |
| 4 | Subject: [PATCH] i2c: imx: add workaround for erratum ERR010027 |
| 5 | |
| 6 | ERR010027: Attempting a start cycle while the bus is busy may |
| 7 | generate a short clock pulse. |
| 8 | |
| 9 | Software must ensure that the I2C BUS is idle by checking the |
| 10 | bus busy before switching to master mode and attempting a Start |
| 11 | cycle. |
| 12 | |
| 13 | Signed-off-by: Zhang Ying-22455 <ying.zhang22455@nxp.com> |
| 14 | --- |
| 15 | drivers/i2c/busses/i2c-imx.c | 8 ++++++++ |
| 16 | 1 file changed, 8 insertions(+) |
| 17 | |
| 18 | --- a/drivers/i2c/busses/i2c-imx.c |
| 19 | +++ b/drivers/i2c/busses/i2c-imx.c |
| 20 | @@ -968,6 +968,14 @@ static int i2c_imx_xfer(struct i2c_adapt |
| 21 | enable_runtime_pm = true; |
| 22 | } |
| 23 | |
| 24 | + /* |
| 25 | + * workround for ERR010027: ensure that the I2C BUS is idle |
| 26 | + * before switching to master mode and attempting a Start cycle |
| 27 | + */ |
| 28 | + result = i2c_imx_bus_busy(i2c_imx, 0); |
| 29 | + if (result) |
| 30 | + goto out; |
| 31 | + |
| 32 | result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); |
| 33 | if (result < 0) |
| 34 | goto out; |