openwrt/target/linux/layerscape/patches-5.4/808-i2c-0007-i2c-imx-add-workaround-for-erratum-ERR010027.patch
Yangbo Lu cddd459140 layerscape: add patches-5.4
Add patches for linux-5.4. The patches are from NXP LSDK-20.04 release
which was tagged LSDK-20.04-V5.4.
https://source.codeaurora.org/external/qoriq/qoriq-components/linux/

For boards LS1021A-IOT, and Traverse-LS1043 which are not involved in
LSDK, port the dts patches from 4.14.

The patches are sorted into the following categories:
  301-arch-xxxx
  302-dts-xxxx
  303-core-xxxx
  701-net-xxxx
  801-audio-xxxx
  802-can-xxxx
  803-clock-xxxx
  804-crypto-xxxx
  805-display-xxxx
  806-dma-xxxx
  807-gpio-xxxx
  808-i2c-xxxx
  809-jailhouse-xxxx
  810-keys-xxxx
  811-kvm-xxxx
  812-pcie-xxxx
  813-pm-xxxx
  814-qe-xxxx
  815-sata-xxxx
  816-sdhc-xxxx
  817-spi-xxxx
  818-thermal-xxxx
  819-uart-xxxx
  820-usb-xxxx
  821-vfio-xxxx

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
2020-05-07 12:53:06 +02:00

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
@@ -940,6 +940,14 @@ 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;