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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:
* the I2C register offset is different between SoCs,
@@ -298,7 +299,7 @@ static int i2c_imx_acked(struct imx_i2c_
{
if (imx_i2c_read_reg(i2c_imx, 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__);
@@ -635,6 +636,7 @@ static int i2c_imx_probe(struct platform
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;
/* Get I2C clock */
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