diff options
| author | Zhiwu Song <Zhiwu.Song@csr.com> | 2013-08-13 17:11:27 +0800 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2013-08-28 11:43:34 +0200 |
| commit | c984319ad9c54c269493b6bc0517e8c2dfca4456 (patch) | |
| tree | 87a41ed1f90e639973c321caec782445eb0c1b96 /drivers/i2c | |
| parent | 57cd1e3029e5fb4d238ad11fd0d7ad917179fdf2 (diff) | |
| download | linux-c984319ad9c54c269493b6bc0517e8c2dfca4456.tar.bz2 | |
i2c: sirf: reset i2c controller early after we get a noack
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@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-sirf.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/i2c/busses/i2c-sirf.c b/drivers/i2c/busses/i2c-sirf.c index 0ff22e29e7df..ff47a767f756 100644 --- a/drivers/i2c/busses/i2c-sirf.c +++ b/drivers/i2c/busses/i2c-sirf.c @@ -64,6 +64,8 @@ #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; @@ -142,14 +144,24 @@ 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 */ @@ -190,7 +202,6 @@ 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); @@ -199,7 +210,7 @@ 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"); } @@ -207,16 +218,14 @@ 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) |