From: Zhiwu Song <Zhiwu.Song@xxxxxxx>
Due to hardware ANOMALY, we need to reset I2C earlier after
we get NOACK while accessing non-existing clients, otherwise
we will get errors even we access existing clients later
Signed-off-by: Zhiwu Song <Zhiwu.Song@xxxxxxx>
Signed-off-by: Barry Song <Baohua.Song@xxxxxxx>
---
drivers/i2c/busses/i2c-sirf.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-sirf.c b/drivers/i2c/busses/i2c-sirf.c
index a63c7d5..055210e 100644
--- a/drivers/i2c/busses/i2c-sirf.c
+++ b/drivers/i2c/busses/i2c-sirf.c
@@ -65,6 +65,8 @@
#define SIRFSOC_I2C_START BIT(7)
#define SIRFSOC_I2C_DEFAULT_SPEED 100000
+#define SIRFSOC_I2C_ERR_NOACK 1
+#define SIRFSOC_I2C_ERR_TIMEOUT 2
struct sirfsoc_i2c {
void __iomem *base;
@@ -143,14 +145,24 @@ static irqreturn_t i2c_sirfsoc_irq(int irq, void *dev_id)
if (i2c_stat & SIRFSOC_I2C_STAT_ERR) {
/* Error conditions */
- siic->err_status = 1;
+ siic->err_status = SIRFSOC_I2C_ERR_NOACK;
writel(SIRFSOC_I2C_STAT_ERR, siic->base + SIRFSOC_I2C_STATUS);
if (i2c_stat & SIRFSOC_I2C_STAT_NACK)
- dev_err(&siic->adapter.dev, "ACK not received\n");
+ dev_dbg(&siic->adapter.dev, "ACK not received\n");
else
dev_err(&siic->adapter.dev, "I2C error\n");
+ /*
+ * Due to hardware ANOMALY, we need to reset I2C earlier after
+ * we get NOACK while accessing non-existing clients, otherwise
+ * we will get errors even we access existing clients later
+ */
+ writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
+ siic->base + SIRFSOC_I2C_CTRL);
+ while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+ cpu_relax();
+
complete(&siic->done);
} else if (i2c_stat & SIRFSOC_I2C_STAT_CMD_DONE) {
/* CMD buffer execution complete */
@@ -191,7 +203,6 @@ static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL);
/* timeout waiting for the xfer to finish or fail */
int timeout = msecs_to_jiffies((msg->len + 1) * 50);
- int ret = 0;
i2c_sirfsoc_set_address(siic, msg);
@@ -200,7 +211,7 @@ static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
i2c_sirfsoc_queue_cmd(siic);
if (wait_for_completion_timeout(&siic->done, timeout) == 0) {
- siic->err_status = 1;
+ siic->err_status = SIRFSOC_I2C_ERR_TIMEOUT;
dev_err(&siic->adapter.dev, "Transfer timeout\n");
}
@@ -208,16 +219,14 @@ static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
siic->base + SIRFSOC_I2C_CTRL);
writel(0, siic->base + SIRFSOC_I2C_CMD_START);
- if (siic->err_status) {
+ /* i2c control doesn't response, reset it */
+ if (siic->err_status == SIRFSOC_I2C_ERR_TIMEOUT) {
writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
siic->base + SIRFSOC_I2C_CTRL);
while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
cpu_relax();
-
- ret = -EIO;
}
-
- return ret;
+ return siic->err_status ? -EIO : 0;
}
static u32 i2c_sirfsoc_func(struct i2c_adapter *adap)
--
1.8.2.3
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