From b2c852e685aaf6bef83fa60e5a98b0bc000e4cb2 Mon Sep 17 00:00:00 2001 From: Luka Perkov Date: Tue, 10 Sep 2013 22:26:34 +0000 Subject: [PATCH] imx6: add i2c retry on NAK Signed-off-by: Tim Harvey SVN-Revision: 37935 --- .../0004-i2c-imx-retry-on-NAK.patch | 40 +++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 target/linux/imx6/patches-3.10/0004-i2c-imx-retry-on-NAK.patch diff --git a/target/linux/imx6/patches-3.10/0004-i2c-imx-retry-on-NAK.patch b/target/linux/imx6/patches-3.10/0004-i2c-imx-retry-on-NAK.patch new file mode 100644 index 0000000000..aea87eaa5f --- /dev/null +++ b/target/linux/imx6/patches-3.10/0004-i2c-imx-retry-on-NAK.patch @@ -0,0 +1,40 @@ +From 0d1ee1f265cf9730feb214ddd18bc430c0800e8b Mon Sep 17 00:00:00 2001 +From: Tim Harvey +Date: Tue, 10 Sep 2013 21:42:29 +0200 +Subject: [PATCH] i2c: imx: retry on NAK + +In case of busy i2c try again to get ACK. + +Signed-off-by: Tim Harvey +Tested-by: Luka Perkov +--- + 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);