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imx6: add i2c retry on NAK

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Signed-off-by: Tim Harvey <tharvey@gateworks.com>

SVN-Revision: 37935
This commit is contained in:
Luka Perkov 2013-09-10 22:26:34 +00:00
parent 460fb06e63
commit b2c852e685
1 changed files with 40 additions and 0 deletions
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40
target/linux/imx6/patches-3.10/0004-i2c-imx-retry-on-NAK.patch Normal file
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@ -0,0 +1,40 @@
From 0d1ee1f265cf9730feb214ddd18bc430c0800e8b Mon Sep 17 00:00:00 2001
From: Tim Harvey <tharvey@gateworks.com>
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 <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);