openwrt/target/linux/layerscape/patches-5.4/808-i2c-0007-i2c-imx-add-wo...

35 lines
1.0 KiB
Diff

From 8e7e594b685f3fe44cd4803e3a4634bed897c2f7 Mon Sep 17 00:00:00 2001
From: Zhang Ying-22455 <ying.zhang22455@nxp.com>
Date: Fri, 14 Apr 2017 17:03:03 +0800
Subject: [PATCH] i2c: imx: add workaround for erratum ERR010027
ERR010027: Attempting a start cycle while the bus is busy may
generate a short clock pulse.
Software must ensure that the I2C BUS is idle by checking the
bus busy before switching to master mode and attempting a Start
cycle.
Signed-off-by: Zhang Ying-22455 <ying.zhang22455@nxp.com>
---
drivers/i2c/busses/i2c-imx.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -968,6 +968,14 @@ static int i2c_imx_xfer(struct i2c_adapt
enable_runtime_pm = true;
}
+ /*
+ * workround for ERR010027: ensure that the I2C BUS is idle
+ * before switching to master mode and attempting a Start cycle
+ */
+ result = i2c_imx_bus_busy(i2c_imx, 0);
+ if (result)
+ goto out;
+
result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
if (result < 0)
goto out;