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

[Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

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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