From: Zhiwu Song <[email protected]> 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 <[email protected]> Signed-off-by: Barry Song <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
