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-rw-r--r--target/linux/imx6/patches-3.12/0040-i2c-imx-retry-on-NAK.patch38
1 files changed, 38 insertions, 0 deletions
diff --git a/target/linux/imx6/patches-3.12/0040-i2c-imx-retry-on-NAK.patch b/target/linux/imx6/patches-3.12/0040-i2c-imx-retry-on-NAK.patch
new file mode 100644
index 0000000000..e876c6ed49
--- /dev/null
+++ b/target/linux/imx6/patches-3.12/0040-i2c-imx-retry-on-NAK.patch
@@ -0,0 +1,38 @@
+From: Tim Harvey <tharvey@gateworks.com>
+Subject: [PATCH] i2c: imx: retry on NAK
+
+In case of busy i2c try again to get ACK.
+
+Signed-off-by: Tim Harvey <tharvey@gateworks.com>
+Tested-by: Luka Perkov <luka@openwrt.org>
+---
+ drivers/i2c/busses/i2c-imx.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+--- a/drivers/i2c/busses/i2c-imx.c
++++ b/drivers/i2c/busses/i2c-imx.c
+@@ -62,6 +62,7 @@
+
+ /* Default value */
+ #define IMX_I2C_BIT_RATE 100000 /* 100kHz */
++#define IMX_I2C_MAX_RETRIES 3 /* number of retries to attempt */
+
+ /* IMX I2C registers */
+ #define IMX_I2C_IADR 0x00 /* i2c slave address */
+@@ -198,7 +199,7 @@ static int i2c_imx_acked(struct imx_i2c_
+ {
+ if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
+ dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
+- return -EIO; /* No ACK */
++ return -EAGAIN; /* try again */
+ }
+
+ dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
+@@ -533,6 +534,7 @@ static int __init i2c_imx_probe(struct p
+ i2c_imx->adapter.dev.parent = &pdev->dev;
+ i2c_imx->adapter.nr = pdev->id;
+ i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
++ i2c_imx->adapter.retries = IMX_I2C_MAX_RETRIES;
+ i2c_imx->base = base;
+
+ pinctrl = devm_pinctrl_get_select_default(&pdev->dev);