[PATCH 1/4] i2c: imx: check busy bit when START/STOP

[PATCH 1/4] i2c: imx: check busy bit when START/STOP

[Richard Zhao]

After START/RESTART, wait for busy bit to be set and
after STOP, wait for busy bit to be clear.

Signed-off-by: Richard Zhao <linuxzsc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 4afba3e..156cc95 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -125,14 +125,19 @@ struct imx_i2c_struct {
 /** Functions for IMX I2C adapter driver ***************************************
 *******************************************************************************/
 
-static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
+static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 {
 	unsigned long orig_jiffies = jiffies;
+	unsigned int temp;
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 
-	/* wait for bus not busy */
-	while (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_IBB) {
+	temp = readb(i2c_imx->base + IMX_I2C_I2SR);
+	while (1) {
+		if (for_busy && (temp & I2SR_IBB))
+			break;
+		if (!for_busy && !(temp & I2SR_IBB))
+			break;
 		if (signal_pending(current)) {
 			dev_dbg(&i2c_imx->adapter.dev,
 				"<%s> I2C Interrupted\n", __func__);
@@ -144,6 +149,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
 			return -EIO;
 		}
 		schedule();
+		temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 	}
 
 	return 0;
@@ -179,20 +185,32 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 	return 0;
 }
 
-static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
+static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 {
 	unsigned int temp = 0;
+	int result;
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 
 	/* Enable I2C controller */
+	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 	writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
+
+	result = i2c_imx_bus_busy(i2c_imx, 0);
+	if (result)
+		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)
+		return result;
+
 	temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 	writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+	return result;
 }
 
 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
@@ -202,16 +220,16 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 	/* Stop I2C transaction */
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 	temp = readb(i2c_imx->base + IMX_I2C_I2CR);
-	temp &= ~I2CR_MSTA;
+	temp &= ~(I2CR_MSTA | I2CR_MTX);
 	writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
-	/* setup chip registers to defaults */
-	writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
-	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 	/*
 	 * This delay caused by an i.MXL hardware bug.
 	 * If no (or too short) delay, no "STOP" bit will be generated.
 	 */
 	udelay(i2c_imx->disable_delay);
+
+	i2c_imx_bus_busy(i2c_imx, 0);
+
 	/* Disable I2C controller */
 	writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 }
@@ -344,7 +362,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 			dev_dbg(&i2c_imx->adapter.dev,
 				"<%s> clear MSTA\n", __func__);
 			temp = readb(i2c_imx->base + IMX_I2C_I2CR);
-			temp &= ~I2CR_MSTA;
+			temp &= ~(I2CR_MSTA | I2CR_MTX);
 			writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 		} else if (i == (msgs->len - 2)) {
 			dev_dbg(&i2c_imx->adapter.dev,
@@ -370,14 +388,11 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 
-	/* Check if i2c bus is not busy */
-	result = i2c_imx_bus_busy(i2c_imx);
+	/* Start I2C transfer */
+	result = i2c_imx_start(i2c_imx);
 	if (result)
 		goto fail0;
 
-	/* Start I2C transfer */
-	i2c_imx_start(i2c_imx);
-
 	/* read/write data */
 	for (i = 0; i < num; i++) {
 		if (i) {
@@ -386,6 +401,9 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
 			temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 			temp |= I2CR_RSTA;
 			writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+			result =  i2c_imx_bus_busy(i2c_imx, 1);
+			if (result)
+				goto fail0;
 		}
 		dev_dbg(&i2c_imx->adapter.dev,
 			"<%s> transfer message: %d\n", __func__, i);
-- 
1.6.0.4

[PATCH 2/4] i2c: imx: only imx1 needs disable delay

[Richard Zhao]

check cpu_is_mx1() when set disable_delay.

Signed-off-by: Richard Zhao <linuxzsc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 156cc95..c1e541c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -254,14 +254,16 @@ static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 	/* Write divider value to register */
 	writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
 
-	/*
-	 * There dummy delay is calculated.
-	 * It should be about one I2C clock period long.
-	 * This delay is used in I2C bus disable function
-	 * to fix chip hardware bug.
-	 */
-	i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
-		+ (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
+	if (cpu_is_mx1()) {
+		/*
+		 * There dummy delay is calculated.
+		 * It should be about one I2C clock period long.
+		 * This delay is used in I2C bus disable function
+		 * to fix chip hardware bug.
+		 */
+		i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
+			+ (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
+	}
 
 	/* dev_dbg() can't be used, because adapter is not yet registered */
 #ifdef CONFIG_I2C_DEBUG_BUS
-- 
1.6.0.4

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

[Richard Zhao]

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>

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

[PATCH 4/4] i2c: imx: disable clock when it's possible to save power.

[Richard Zhao]

Enable clock before START, disable it after STOP.

Signed-off-by: Richard Zhao <linuxzsc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 87faea4..72ddea3 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -120,6 +120,7 @@ struct imx_i2c_struct {
 	wait_queue_head_t	queue;
 	unsigned long		i2csr;
 	unsigned int 		disable_delay;
+	unsigned int		ifdr; /* IMX_I2C_IFDR */
 };
 
 /** Functions for IMX I2C adapter driver ***************************************
@@ -210,6 +211,8 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 
+	clk_enable(i2c_imx->clk);
+	writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 	/* Enable I2C controller */
 	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 	writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
@@ -254,6 +257,7 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 
 	/* Disable I2C controller */
 	writeb(0, i2c_imx->base + IMX_I2C_I2CR);
+	clk_disable(i2c_imx->clk);
 }
 
 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
@@ -273,8 +277,8 @@ static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 	else
 		for (i = 0; i2c_clk_div[i][0] < div; i++);
 
-	/* Write divider value to register */
-	writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
+	/* Store divider value */
+	i2c_imx->ifdr = i2c_clk_div[i][1];
 
 	if (cpu_is_mx1()) {
 		/*
@@ -555,7 +559,6 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "can't get I2C clock\n");
 		goto fail3;
 	}
-	clk_enable(i2c_imx->clk);
 
 	/* Request IRQ */
 	ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
@@ -604,7 +607,6 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
 fail5:
 	free_irq(i2c_imx->irq, i2c_imx);
 fail4:
-	clk_disable(i2c_imx->clk);
 	clk_put(i2c_imx->clk);
 fail3:
 	release_mem_region(i2c_imx->res->start, resource_size(res));
@@ -641,8 +643,6 @@ static int __exit i2c_imx_remove(struct platform_device *pdev)
 	if (pdata && pdata->exit)
 		pdata->exit(&pdev->dev);
 
-	/* Disable I2C clock */
-	clk_disable(i2c_imx->clk);
 	clk_put(i2c_imx->clk);
 
 	release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
-- 
1.6.0.4

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

[Richard Zhao]

On Thu, Oct 1, 2009 at 5:30 PM, Richard Zhao <linuxzsc@gmail.com> wrote:
> On Thu, Oct 1, 2009 at 4:26 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
>> On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote:
>>> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
>>> > 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@gmail.com>
>>> >
>>> > 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
>>> >>
>>> >>
>>> >
>>> > --
>>> > Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
>>> > Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
>>> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
>>> > Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
>>> >
>>>
>>> 1. i2c is more important bus in embedded system than PC. Many PMICs
>>> are connected to cpu via i2c. Before system boot up, we depend much on
>>> printk message.
>>> 2. When we add a new i2c device, it's easy to have problems. Maybe
>>> it's hw issue, one device fails, all ones in the same bus fails. In
>>> such condition, debug message is very helpfull.
>>
>> The driver already consists to 15% of debug statements, there is
>> definitely no need to add even more. If anything, you could concentrate
>> on making the output more useful.
> The dump_reg are only added when operation fails. It's not used to
> track function call path or anything else.
> I'm not supposed to show detailed message when there's operation fail?
> The reason to add a switch to disable it is, when i2c tools scan the
> bus, it will cause operation fail.
>
> Richard
>>
>> Sascha
>>
>> --
>> Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
>> Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
>> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
>> Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
>>
>

Hi Sascha,

Follow your suggestion. I will remove the patch.

Thanks
Richard

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

[Richard Zhao]

On Thu, Oct 1, 2009 at 4:26 PM, Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
> On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote:
>> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
>> > 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
>> >>
>> >>
>> >
>> > --
>> > Pengutronix e.K.                           |                             |
>> > Industrial Linux Solutions                 | http://www.pengutronix.de/  |
>> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
>> > Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>> >
>>
>> 1. i2c is more important bus in embedded system than PC. Many PMICs
>> are connected to cpu via i2c. Before system boot up, we depend much on
>> printk message.
>> 2. When we add a new i2c device, it's easy to have problems. Maybe
>> it's hw issue, one device fails, all ones in the same bus fails. In
>> such condition, debug message is very helpfull.
>
> The driver already consists to 15% of debug statements, there is
> definitely no need to add even more. If anything, you could concentrate
> on making the output more useful.
The dump_reg are only added when operation fails. It's not used to
track function call path or anything else.
I'm not supposed to show detailed message when there's operation fail?
The reason to add a switch to disable it is, when i2c tools scan the
bus, it will cause operation fail.

Richard
>
> Sascha
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>

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

[Richard Zhao]

On Thu, Oct 1, 2009 at 4:26 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote:
>> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
>> > 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@gmail.com>
>> >
>> > 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
>> >>
>> >>
>> >
>> > --
>> > Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
>> > Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
>> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
>> > Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
>> >
>>
>> 1. i2c is more important bus in embedded system than PC. Many PMICs
>> are connected to cpu via i2c. Before system boot up, we depend much on
>> printk message.
>> 2. When we add a new i2c device, it's easy to have problems. Maybe
>> it's hw issue, one device fails, all ones in the same bus fails. In
>> such condition, debug message is very helpfull.
>
> The driver already consists to 15% of debug statements, there is
> definitely no need to add even more. If anything, you could concentrate
> on making the output more useful.
The dump_reg are only added when operation fails. It's not used to
track function call path or anything else.
I'm not supposed to show detailed message when there's operation fail?
The reason to add a switch to disable it is, when i2c tools scan the
bus, it will cause operation fail.

Richard
>
> Sascha
>
> --
> Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
> Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
> Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
>

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

[Sascha Hauer]

On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote:
> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
> > 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
> >>
> >>
> >
> > --
> > Pengutronix e.K.                           |                             |
> > Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> > Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> >
> 
> 1. i2c is more important bus in embedded system than PC. Many PMICs
> are connected to cpu via i2c. Before system boot up, we depend much on
> printk message.
> 2. When we add a new i2c device, it's easy to have problems. Maybe
> it's hw issue, one device fails, all ones in the same bus fails. In
> such condition, debug message is very helpfull.

The driver already consists to 15% of debug statements, there is
definitely no need to add even more. If anything, you could concentrate
on making the output more useful.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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

[Sascha Hauer]

On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote:
> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > 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@gmail.com>
> >
> > 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
> >>
> >>
> >
> > --
> > Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
> > Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
> > Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
> >
> 
> 1. i2c is more important bus in embedded system than PC. Many PMICs
> are connected to cpu via i2c. Before system boot up, we depend much on
> printk message.
> 2. When we add a new i2c device, it's easy to have problems. Maybe
> it's hw issue, one device fails, all ones in the same bus fails. In
> such condition, debug message is very helpfull.

The driver already consists to 15% of debug statements, there is
definitely no need to add even more. If anything, you could concentrate
on making the output more useful.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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

[Richard Zhao]

On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
> 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
>>
>>
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>

1. i2c is more important bus in embedded system than PC. Many PMICs
are connected to cpu via i2c. Before system boot up, we depend much on
printk message.
2. When we add a new i2c device, it's easy to have problems. Maybe
it's hw issue, one device fails, all ones in the same bus fails. In
such condition, debug message is very helpfull.

Thanks
Richard

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

[Richard Zhao]

On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 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@gmail.com>
>
> 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
>>
>>
>
> --
> Pengutronix e.K. ? ? ? ? ? ? ? ? ? ? ? ? ? | ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
> Industrial Linux Solutions ? ? ? ? ? ? ? ? | http://www.pengutronix.de/ ?|
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 ? ?|
> Amtsgericht Hildesheim, HRA 2686 ? ? ? ? ? | Fax: ? +49-5121-206917-5555 |
>

1. i2c is more important bus in embedded system than PC. Many PMICs
are connected to cpu via i2c. Before system boot up, we depend much on
printk message.
2. When we add a new i2c device, it's easy to have problems. Maybe
it's hw issue, one device fails, all ones in the same bus fails. In
such condition, debug message is very helpfull.

Thanks
Richard

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

[Sascha Hauer]

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
> 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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

[Sascha Hauer]

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@gmail.com>

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
> 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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

[Richard Zhao]

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>

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

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

[Richard Zhao]

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@gmail.com>

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