[PATCH V2 2/7] i2c: sprd: Add I2C driver to use 'reset framework' function

Huangzheng Lai
2023-10-23T08:13:19Z

Add the 'reset framework' function for I2C drivers, which
resets the I2C controller when a timeout exception occurs.

Signed-off-by: Huangzheng Lai <Huangzheng.Lai@unisoc.com>
---
drivers/i2c/busses/i2c-sprd.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index b44916c6741d..aa602958d4fd 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -17,6 +17,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>

#define I2C_CTL 0x00
#define I2C_ADDR_CFG 0x04
@@ -85,6 +86,7 @@ struct sprd_i2c {
u32 src_clk;
u32 bus_freq;
struct completion complete;
+ struct reset_control *rst;
u8 *buf;
u32 count;
int irq;
@@ -278,9 +280,17 @@ static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,

time_left = wait_for_completion_timeout(&i2c_dev->complete,
msecs_to_jiffies(I2C_XFER_TIMEOUT));
- if (!time_left)
+ if (!time_left) {
+ dev_err(i2c_dev->dev, "transfer timeout, I2C_STATUS = 0x%x\n",
+ readl(i2c_dev->base + I2C_STATUS));
+ if (i2c_dev->rst) {
+ int ret = reset_control_reset(i2c_dev->rst);
+
+ if (ret < 0)
+ dev_warn(i2c_dev->dev, "i2c soft reset failed, ret = %d\n", ret);
+ }
return -ETIMEDOUT;
-
+ }
return i2c_dev->err;
}

@@ -544,6 +554,11 @@ static int sprd_i2c_probe(struct platform_device *pdev)
return ret;

platform_set_drvdata(pdev, i2c_dev);
+ i2c_dev->rst = devm_reset_control_get(i2c_dev->dev, "i2c_rst");
+ if (IS_ERR(i2c_dev->rst)) {
+ dev_dbg(i2c_dev->dev, "reset control not configured!\n");
+ i2c_dev->rst = NULL;
+ }

ret = clk_prepare_enable(i2c_dev->clk);
if (ret)
--
2.17.1