Re: [PATCH 2/4] i2c: imx: only imx1 needs disable delay
On Thu, Oct 01, 2009 at 09:13:31AM +0800, Richard Zhao wrote:
check cpu_is_mx1() when set disable_delay.
Signed-off-by: Richard Zhao linux...@gmail.com
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 = (50U * 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 = (50U * i2c_clk_div[i][0]
+ + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
+ }
I think you should put the udelay(i2c_imx-disable_delay) in
cpu_is_mx1() rather than the calculation.
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- |
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 3/4] i2c: imx: add macros and printk to make debug easy
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 linux...@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
Re: [PATCH 4/4] i2c: imx: disable clock when it's possible to save power.
On Thu, Oct 01, 2009 at 09:13:33AM +0800, Richard Zhao wrote:
Enable clock before START, disable it after STOP.
The clk_diable/enable calls in suspend/resume should be removed also.
Sascha
Signed-off-by: Richard Zhao linux...@gmail.com
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 intdisable_delay;
+ unsigned intifdr; /* 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
--
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- |
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 4/4] i2c: imx: disable clock when it's possible to save power.
On Thu, Oct 1, 2009 at 3:34 PM, Sascha Hauer s.ha...@pengutronix.de wrote:
On Thu, Oct 01, 2009 at 09:13:33AM +0800, Richard Zhao wrote:
Enable clock before START, disable it after STOP.
The clk_diable/enable calls in suspend/resume should be removed also.
Sascha
Signed-off-by: Richard Zhao linux...@gmail.com
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
--
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- |
I don't think we have any suspend/resume routine. And we won't need it any more.
Thanks
Richard
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/4] i2c: imx: only imx1 needs disable delay
On Thu, Oct 1, 2009 at 3:26 PM, Sascha Hauer s.ha...@pengutronix.de wrote:
On Thu, Oct 01, 2009 at 09:13:31AM +0800, Richard Zhao wrote:
check cpu_is_mx1() when set disable_delay.
Signed-off-by: Richard Zhao linux...@gmail.com
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 = (50U * 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 = (50U * i2c_clk_div[i][0]
+ + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
+ }
I think you should put the udelay(i2c_imx-disable_delay) in
cpu_is_mx1() rather than the calculation.
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- |
Do you think udelay(0) wast any more time than if()?
And Could I get all you comments in a single patch loop?
Thanks
Richard
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 4/4] i2c: imx: disable clock when it's possible to save power.
On Thu, Oct 01, 2009 at 03:56:29PM +0800, Richard Zhao wrote:
On Thu, Oct 1, 2009 at 3:34 PM, Sascha Hauer s.ha...@pengutronix.de wrote:
On Thu, Oct 01, 2009 at 09:13:33AM +0800, Richard Zhao wrote:
Enable clock before START, disable it after STOP.
The clk_diable/enable calls in suspend/resume should be removed also.
Sascha
Signed-off-by: Richard Zhao linux...@gmail.com
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
--
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- |
I don't think we have any suspend/resume routine. And we won't need it any
more.
Ups, my bad. I have it in my local tree and didn't realize it isn't
upstream.
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- |
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP
On Thu, Oct 1, 2009 at 9:13 AM, Richard Zhao linux...@gmail.com wrote:
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 linux...@gmail.com
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;
}
Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP
On Thu, Oct 01, 2009 at 04:03:20PM +0800, Richard Zhao wrote:
On Thu, Oct 1, 2009 at 9:13 AM, Richard Zhao linux...@gmail.com wrote:
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 linux...@gmail.com
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 +
Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP
On Thu, Oct 1, 2009 at 4:38 PM, Sascha Hauer s.ha...@pengutronix.de wrote:
On Thu, Oct 01, 2009 at 04:03:20PM +0800, Richard Zhao wrote:
On Thu, Oct 1, 2009 at 9:13 AM, Richard Zhao linux...@gmail.com wrote:
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 linux...@gmail.com
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 |=
Re: [PATCH 3/4] i2c: imx: add macros and printk to make debug easy
On Thu, Oct 1, 2009 at 4:26 PM, Sascha Hauer s.ha...@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.ha...@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 linux...@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)
+
Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP
On Fri, Oct 2, 2009 at 12:37 AM, Wolfram Sang w.s...@pengutronix.de wrote: Ah, so 'make the driver work on i.MX51' is a good statement which should be part of the commit message. Well, maybe I can mention it. But I think the good point is to present what you modified, not the side effect. It is not the side effect but the intention :) As no code is changed without a need, the reason really should be in the patch description. No, it's not intention. I'm just trying to make the controller work in a right way. Without this patch, maybe some other fast cpus have problem too. I just tested mx31 and mx51. I will add Without this patch, i2c on some fast SoCs (for example imx51) will not work. Is it ok for you? Yes. But I don't have multi-master system. So I can't say that. The code is just taken from Freescale latest code. Without it, It could also cause a device error. I forget the details. Anyway, it doesn't make anything wrong. Do you know where the details are explained? No, I don't. I don't have device in hand now. If you have, could you please help do a simple test? Use hw to simulate multi-master system. Before execute xfer, you first pull down SDA, then pull down SDC. It simulates a START. and execute xfer to see whether IBB is set? Thanks Richard Regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkrE2uEACgkQD27XaX1/VRumZQCeL4x9oaBKKjSKzJLlRrkfvvqg nlEAoLpQdpI3TeKEvK13rs46kSZRDsZU =7kM6 -END PGP SIGNATURE- -- To unsubscribe from this list: send the line unsubscribe linux-i2c in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
