Re: [PATCH 3/4] i2c: imx: add macros and printk to make debug easy

Sascha Hauer
2009-10-01T07:29:34Z

On Thu, Oct 01, 2009 at 09:13:32AM +0800, Richard Zhao wrote:
> When CONFIG_I2C_DEBUG_BUS is enabled, it helps dump registers at operation
> fail condition, and print i2c_msg to xfer.
>
> Signed-off-by: Richard Zhao <linuxzsc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Honestly I don't think we need this. It makes the driver too verbose for
my taste.

Sascha

>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index c1e541c..87faea4 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -125,6 +125,20 @@ struct imx_i2c_struct {
> /** Functions for IMX I2C adapter driver ***************************************
> *******************************************************************************/
>
> +#ifdef CONFIG_I2C_DEBUG_BUS
> +#define reg_dump(i2c_imx) \
> +{ \
> + printk(KERN_DEBUG "fun %s:%d ", __func__, __LINE__); \
> + printk(KERN_DEBUG "IADR %02x IFDR %02x I2CR %02x I2SR %02x\n", \
> + readb(i2c_imx->base + IMX_I2C_IADR), \
> + readb(i2c_imx->base + IMX_I2C_IFDR), \
> + readb(i2c_imx->base + IMX_I2C_I2CR), \
> + readb(i2c_imx->base + IMX_I2C_I2SR)); \
> +}
> +#else
> +#define reg_dump(i2c_imx)
> +#endif
> +
> static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> {
> unsigned long orig_jiffies = jiffies;
> @@ -146,6 +160,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
> dev_dbg(&i2c_imx->adapter.dev,
> "<%s> I2C bus is busy\n", __func__);
> + reg_dump(i2c_imx);
> return -EIO;
> }
> schedule();
> @@ -164,9 +179,11 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
>
> if (unlikely(result < 0)) {
> dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
> + reg_dump(i2c_imx);
> return result;
> } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
> dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
> + reg_dump(i2c_imx);
> return -ETIMEDOUT;
> }
> dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
> @@ -178,6 +195,7 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
> {
> if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
> dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
> + reg_dump(i2c_imx);
> return -EIO; /* No ACK */
> }
>
> @@ -197,17 +215,20 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
>
> result = i2c_imx_bus_busy(i2c_imx, 0);
> - if (result)
> + if (result) {
> + reg_dump(i2c_imx);
> return result;
> + }
>
> /* Start I2C transaction */
> temp = readb(i2c_imx->base + IMX_I2C_I2CR);
> temp |= I2CR_MSTA;
> writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
> result = i2c_imx_bus_busy(i2c_imx, 1);
> - if (result)
> + if (result) {
> + reg_dump(i2c_imx);
> return result;
> -
> + }
> temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
> writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
> return result;
> @@ -228,7 +249,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
> */
> udelay(i2c_imx->disable_delay);
>
> - i2c_imx_bus_busy(i2c_imx, 0);
> + if (i2c_imx_bus_busy(i2c_imx, 0))
> + reg_dump(i2c_imx);
>
> /* Disable I2C controller */
> writeb(0, i2c_imx->base + IMX_I2C_I2CR);
> @@ -389,7 +411,18 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
> struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
>
> dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
> -
> +#ifdef CONFIG_I2C_DEBUG_BUS
> + for (i = 0; i < num; i++) {
> + printk(KERN_DEBUG "msg%d addr %02x RD %d cnt %d d:", i,
> + msgs[i].addr, msgs[i].flags & I2C_M_RD, msgs[i].len);
> + if (!(msgs[i].flags & I2C_M_RD)) {
> + int j;
> + for (j = 0; j < msgs[i].len; j++)
> + printk("%02x ", msgs[i].buf[j]);
> + }
> + printk("\n");
> + }
> +#endif
> /* Start I2C transfer */
> result = i2c_imx_start(i2c_imx);
> if (result)
> @@ -404,8 +437,10 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
> temp |= I2CR_RSTA;
> writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
> result = i2c_imx_bus_busy(i2c_imx, 1);
> - if (result)
> + if (result) {
> + reg_dump(i2c_imx);
> goto fail0;
> + }
> }
> dev_dbg(&i2c_imx->adapter.dev,
> "<%s> transfer message: %d\n", __func__, i);
> @@ -562,7 +597,7 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
> res_size, i2c_imx->res->start);
> dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
> i2c_imx->adapter.name);
> - dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
> + dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
>
> return 0; /* Return OK */
>
> --
> 1.6.0.4
>
>

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