diff mbox

[v2,2/3] i2c: davinci: Add PM Runtime Support

Message ID 20170816221715.15027-3-fcooper@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Franklin Cooper Aug. 16, 2017, 10:17 p.m. UTC
66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
like other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
is required to insure the power domain used by the specific I2C instance is
properly turned on along with its functional clock.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
---
Version 2 changes:
Move initial calls to pm runtime autosuspend before pm_runtime_enable

 drivers/i2c/busses/i2c-davinci.c | 62 ++++++++++++++++++++++++++++++++++------
 1 file changed, 54 insertions(+), 8 deletions(-)

Comments

Wolfram Sang Aug. 17, 2017, 4:24 p.m. UTC | #1
On Wed, Aug 16, 2017 at 05:17:14PM -0500, Franklin S Cooper Jr wrote:
> 66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
> like other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
> is required to insure the power domain used by the specific I2C instance is
> properly turned on along with its functional clock.
> 
> Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>

I'd need a review from the driver maintainers here. Which are Sekhar
Nori and Kevin Hilman(?) according to MAINTAINERS. Is that still
correct?

> ---
> Version 2 changes:
> Move initial calls to pm runtime autosuspend before pm_runtime_enable
> 
>  drivers/i2c/busses/i2c-davinci.c | 62 ++++++++++++++++++++++++++++++++++------
>  1 file changed, 54 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
> index b8c4353..6b1930d 100644
> --- a/drivers/i2c/busses/i2c-davinci.c
> +++ b/drivers/i2c/busses/i2c-davinci.c
> @@ -36,6 +36,7 @@
>  #include <linux/gpio.h>
>  #include <linux/of_device.h>
>  #include <linux/platform_data/i2c-davinci.h>
> +#include <linux/pm_runtime.h>
>  
>  /* ----- global defines ----------------------------------------------- */
>  
> @@ -122,6 +123,9 @@
>  /* set the SDA GPIO low */
>  #define DAVINCI_I2C_DCLR_PDCLR1	BIT(1)
>  
> +/* timeout for pm runtime autosuspend */
> +#define DAVINCI_I2C_PM_TIMEOUT	1000	/* ms */
> +
>  struct davinci_i2c_dev {
>  	struct device           *dev;
>  	void __iomem		*base;
> @@ -541,10 +545,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>  
>  	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
>  
> +	ret = pm_runtime_get_sync(dev->dev);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret);
> +		pm_runtime_put_noidle(dev->dev);
> +		return ret;
> +	}
> +
>  	ret = i2c_davinci_wait_bus_not_busy(dev);
>  	if (ret < 0) {
>  		dev_warn(dev->dev, "timeout waiting for bus ready\n");
> -		return ret;
> +		goto out;
>  	}
>  
>  	for (i = 0; i < num; i++) {
> @@ -552,14 +563,19 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>  		dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
>  			ret);
>  		if (ret < 0)
> -			return ret;
> +			goto out;
>  	}
>  
> +	ret = num;
>  #ifdef CONFIG_CPU_FREQ
>  	complete(&dev->xfr_complete);
>  #endif
>  
> -	return num;
> +out:
> +	pm_runtime_mark_last_busy(dev->dev);
> +	pm_runtime_put_autosuspend(dev->dev);
> +
> +	return ret;
>  }
>  
>  static u32 i2c_davinci_func(struct i2c_adapter *adap)
> @@ -599,6 +615,9 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
>  	int count = 0;
>  	u16 w;
>  
> +	if (pm_runtime_suspended(dev->dev))
> +		return IRQ_NONE;
> +
>  	while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
>  		dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
>  		if (count++ == 100) {
> @@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  	dev->clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(dev->clk))
>  		return PTR_ERR(dev->clk);
> -	clk_prepare_enable(dev->clk);
>  
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
> @@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  		goto err_unuse_clocks;
>  	}
>  
> +	pm_runtime_set_autosuspend_delay(dev->dev,
> +					 DAVINCI_I2C_PM_TIMEOUT);
> +	pm_runtime_use_autosuspend(dev->dev);
> +
> +	pm_runtime_enable(dev->dev);
> +
> +	r = pm_runtime_get_sync(dev->dev);
> +	if (r < 0) {
> +		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
> +		goto err_unuse_clocks;
> +	}
> +
>  	i2c_davinci_init(dev);
>  
>  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
> @@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  	if (r)
>  		goto err_unuse_clocks;
>  
> +	pm_runtime_mark_last_busy(dev->dev);
> +	pm_runtime_put_autosuspend(dev->dev);
> +
>  	return 0;
>  
>  err_unuse_clocks:
> -	clk_disable_unprepare(dev->clk);
> +	pm_runtime_dont_use_autosuspend(dev->dev);
> +	pm_runtime_put_sync(dev->dev);
> +	pm_runtime_disable(dev->dev);
> +
>  	dev->clk = NULL;
>  	return r;
>  }
> @@ -860,16 +896,26 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  static int davinci_i2c_remove(struct platform_device *pdev)
>  {
>  	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
> +	int ret;
>  
>  	i2c_davinci_cpufreq_deregister(dev);
>  
>  	i2c_del_adapter(&dev->adapter);
>  
> -	clk_disable_unprepare(dev->clk);
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&pdev->dev);
> +		return ret;
> +	}
> +
>  	dev->clk = NULL;
>  
>  	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
>  
> +	pm_runtime_dont_use_autosuspend(dev->dev);
> +	pm_runtime_put_sync(dev->dev);
> +	pm_runtime_disable(dev->dev);
> +
>  	return 0;
>  }
>  
> @@ -880,7 +926,6 @@ static int davinci_i2c_suspend(struct device *dev)
>  
>  	/* put I2C into reset */
>  	davinci_i2c_reset_ctrl(i2c_dev, 0);
> -	clk_disable_unprepare(i2c_dev->clk);
>  
>  	return 0;
>  }
> @@ -889,7 +934,6 @@ static int davinci_i2c_resume(struct device *dev)
>  {
>  	struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);
>  
> -	clk_prepare_enable(i2c_dev->clk);
>  	/* take I2C out of reset */
>  	davinci_i2c_reset_ctrl(i2c_dev, 1);
>  
> @@ -899,6 +943,8 @@ static int davinci_i2c_resume(struct device *dev)
>  static const struct dev_pm_ops davinci_i2c_pm = {
>  	.suspend        = davinci_i2c_suspend,
>  	.resume         = davinci_i2c_resume,
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				      pm_runtime_force_resume)
>  };
>  
>  #define davinci_i2c_pm_ops (&davinci_i2c_pm)
> -- 
> 2.9.4.dirty
>
Sekhar Nori Aug. 21, 2017, 9:05 a.m. UTC | #2
On Thursday 17 August 2017 03:47 AM, Franklin S Cooper Jr wrote:

> @@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  	dev->clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(dev->clk))
>  		return PTR_ERR(dev->clk);
> -	clk_prepare_enable(dev->clk);
>  
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
> @@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  		goto err_unuse_clocks;

This goto is wrong now. There is no need to unwind the pm_runtime setup
on a devm_ioremap_resource() failure. You can just return error here.

>  	}
>  
> +	pm_runtime_set_autosuspend_delay(dev->dev,
> +					 DAVINCI_I2C_PM_TIMEOUT);
> +	pm_runtime_use_autosuspend(dev->dev);
> +
> +	pm_runtime_enable(dev->dev);
> +
> +	r = pm_runtime_get_sync(dev->dev);
> +	if (r < 0) {
> +		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
> +		goto err_unuse_clocks;
> +	}
> +
>  	i2c_davinci_init(dev);
>  
>  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
> @@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>  	if (r)
>  		goto err_unuse_clocks;
>  
> +	pm_runtime_mark_last_busy(dev->dev);
> +	pm_runtime_put_autosuspend(dev->dev);
> +
>  	return 0;
>  
>  err_unuse_clocks:
> -	clk_disable_unprepare(dev->clk);
> +	pm_runtime_dont_use_autosuspend(dev->dev);
> +	pm_runtime_put_sync(dev->dev);
> +	pm_runtime_disable(dev->dev);
> +
>  	dev->clk = NULL;

This null setting of clk seems quite bogus and can be cleaned-up.

>  	return r;
>  }

Thanks,
Sekhar
Sekhar Nori Aug. 21, 2017, 9:09 a.m. UTC | #3
Hi Wolfram,

On Thursday 17 August 2017 09:54 PM, Wolfram Sang wrote:
> On Wed, Aug 16, 2017 at 05:17:14PM -0500, Franklin S Cooper Jr wrote:
>> 66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
>> like other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
>> is required to insure the power domain used by the specific I2C instance is
>> properly turned on along with its functional clock.
>>
>> Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
> 
> I'd need a review from the driver maintainers here. Which are Sekhar
> Nori and Kevin Hilman(?) according to MAINTAINERS. Is that still
> correct?

I just finished the review (sent the comments). Thanks for the reminder!

Also, tested the patches using i2cdetect and suspend/resume on OMAP-L138
LCDK board.

Regards,
Sekhar
Franklin Cooper Aug. 22, 2017, 1:17 a.m. UTC | #4
On 08/21/2017 04:05 AM, Sekhar Nori wrote:
> On Thursday 17 August 2017 03:47 AM, Franklin S Cooper Jr wrote:
> 
>> @@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>  	dev->clk = devm_clk_get(&pdev->dev, NULL);
>>  	if (IS_ERR(dev->clk))
>>  		return PTR_ERR(dev->clk);
>> -	clk_prepare_enable(dev->clk);
>>  
>>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
>> @@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>  		goto err_unuse_clocks;
> 
> This goto is wrong now. There is no need to unwind the pm_runtime setup
> on a devm_ioremap_resource() failure. You can just return error here.

Ok
> 
>>  	}
>>  
>> +	pm_runtime_set_autosuspend_delay(dev->dev,
>> +					 DAVINCI_I2C_PM_TIMEOUT);
>> +	pm_runtime_use_autosuspend(dev->dev);
>> +
>> +	pm_runtime_enable(dev->dev);
>> +
>> +	r = pm_runtime_get_sync(dev->dev);
>> +	if (r < 0) {
>> +		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
>> +		goto err_unuse_clocks;
>> +	}
>> +
>>  	i2c_davinci_init(dev);
>>  
>>  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
>> @@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>  	if (r)
>>  		goto err_unuse_clocks;
>>  
>> +	pm_runtime_mark_last_busy(dev->dev);
>> +	pm_runtime_put_autosuspend(dev->dev);
>> +
>>  	return 0;
>>  
>>  err_unuse_clocks:
>> -	clk_disable_unprepare(dev->clk);
>> +	pm_runtime_dont_use_autosuspend(dev->dev);
>> +	pm_runtime_put_sync(dev->dev);
>> +	pm_runtime_disable(dev->dev);
>> +
>>  	dev->clk = NULL;
> 
> This null setting of clk seems quite bogus and can be cleaned-up.

Do you mean that I should just remove this line?
> 
>>  	return r;
>>  }
> 
> Thanks,
> Sekhar
>
Sekhar Nori Aug. 22, 2017, 5:22 a.m. UTC | #5
On Tuesday 22 August 2017 06:47 AM, Franklin S Cooper Jr wrote:
> 
> 
> On 08/21/2017 04:05 AM, Sekhar Nori wrote:
>> On Thursday 17 August 2017 03:47 AM, Franklin S Cooper Jr wrote:
>>
>>> @@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  	dev->clk = devm_clk_get(&pdev->dev, NULL);
>>>  	if (IS_ERR(dev->clk))
>>>  		return PTR_ERR(dev->clk);
>>> -	clk_prepare_enable(dev->clk);
>>>  
>>>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
>>> @@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  		goto err_unuse_clocks;
>>
>> This goto is wrong now. There is no need to unwind the pm_runtime setup
>> on a devm_ioremap_resource() failure. You can just return error here.
> 
> Ok
>>
>>>  	}
>>>  
>>> +	pm_runtime_set_autosuspend_delay(dev->dev,
>>> +					 DAVINCI_I2C_PM_TIMEOUT);
>>> +	pm_runtime_use_autosuspend(dev->dev);
>>> +
>>> +	pm_runtime_enable(dev->dev);
>>> +
>>> +	r = pm_runtime_get_sync(dev->dev);
>>> +	if (r < 0) {
>>> +		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
>>> +		goto err_unuse_clocks;
>>> +	}
>>> +
>>>  	i2c_davinci_init(dev);
>>>  
>>>  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
>>> @@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  	if (r)
>>>  		goto err_unuse_clocks;
>>>  
>>> +	pm_runtime_mark_last_busy(dev->dev);
>>> +	pm_runtime_put_autosuspend(dev->dev);
>>> +
>>>  	return 0;
>>>  
>>>  err_unuse_clocks:
>>> -	clk_disable_unprepare(dev->clk);
>>> +	pm_runtime_dont_use_autosuspend(dev->dev);
>>> +	pm_runtime_put_sync(dev->dev);
>>> +	pm_runtime_disable(dev->dev);
>>> +
>>>  	dev->clk = NULL;
>>
>> This null setting of clk seems quite bogus and can be cleaned-up.
> 
> Do you mean that I should just remove this line?

Yes, and I noticed a similar line in at least one more place that can be
removed as well.

Thanks,
Sekhar
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index b8c4353..6b1930d 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -36,6 +36,7 @@ 
 #include <linux/gpio.h>
 #include <linux/of_device.h>
 #include <linux/platform_data/i2c-davinci.h>
+#include <linux/pm_runtime.h>
 
 /* ----- global defines ----------------------------------------------- */
 
@@ -122,6 +123,9 @@ 
 /* set the SDA GPIO low */
 #define DAVINCI_I2C_DCLR_PDCLR1	BIT(1)
 
+/* timeout for pm runtime autosuspend */
+#define DAVINCI_I2C_PM_TIMEOUT	1000	/* ms */
+
 struct davinci_i2c_dev {
 	struct device           *dev;
 	void __iomem		*base;
@@ -541,10 +545,17 @@  i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
 	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
 
+	ret = pm_runtime_get_sync(dev->dev);
+	if (ret < 0) {
+		dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret);
+		pm_runtime_put_noidle(dev->dev);
+		return ret;
+	}
+
 	ret = i2c_davinci_wait_bus_not_busy(dev);
 	if (ret < 0) {
 		dev_warn(dev->dev, "timeout waiting for bus ready\n");
-		return ret;
+		goto out;
 	}
 
 	for (i = 0; i < num; i++) {
@@ -552,14 +563,19 @@  i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 		dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
 			ret);
 		if (ret < 0)
-			return ret;
+			goto out;
 	}
 
+	ret = num;
 #ifdef CONFIG_CPU_FREQ
 	complete(&dev->xfr_complete);
 #endif
 
-	return num;
+out:
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
+	return ret;
 }
 
 static u32 i2c_davinci_func(struct i2c_adapter *adap)
@@ -599,6 +615,9 @@  static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 	int count = 0;
 	u16 w;
 
+	if (pm_runtime_suspended(dev->dev))
+		return IRQ_NONE;
+
 	while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
 		dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
 		if (count++ == 100) {
@@ -802,7 +821,6 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(dev->clk))
 		return PTR_ERR(dev->clk);
-	clk_prepare_enable(dev->clk);
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dev->base = devm_ioremap_resource(&pdev->dev, mem);
@@ -811,6 +829,18 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 		goto err_unuse_clocks;
 	}
 
+	pm_runtime_set_autosuspend_delay(dev->dev,
+					 DAVINCI_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(dev->dev);
+
+	pm_runtime_enable(dev->dev);
+
+	r = pm_runtime_get_sync(dev->dev);
+	if (r < 0) {
+		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
+		goto err_unuse_clocks;
+	}
+
 	i2c_davinci_init(dev);
 
 	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
@@ -849,10 +879,16 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 	if (r)
 		goto err_unuse_clocks;
 
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
 	return 0;
 
 err_unuse_clocks:
-	clk_disable_unprepare(dev->clk);
+	pm_runtime_dont_use_autosuspend(dev->dev);
+	pm_runtime_put_sync(dev->dev);
+	pm_runtime_disable(dev->dev);
+
 	dev->clk = NULL;
 	return r;
 }
@@ -860,16 +896,26 @@  static int davinci_i2c_probe(struct platform_device *pdev)
 static int davinci_i2c_remove(struct platform_device *pdev)
 {
 	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
+	int ret;
 
 	i2c_davinci_cpufreq_deregister(dev);
 
 	i2c_del_adapter(&dev->adapter);
 
-	clk_disable_unprepare(dev->clk);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		return ret;
+	}
+
 	dev->clk = NULL;
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
 
+	pm_runtime_dont_use_autosuspend(dev->dev);
+	pm_runtime_put_sync(dev->dev);
+	pm_runtime_disable(dev->dev);
+
 	return 0;
 }
 
@@ -880,7 +926,6 @@  static int davinci_i2c_suspend(struct device *dev)
 
 	/* put I2C into reset */
 	davinci_i2c_reset_ctrl(i2c_dev, 0);
-	clk_disable_unprepare(i2c_dev->clk);
 
 	return 0;
 }
@@ -889,7 +934,6 @@  static int davinci_i2c_resume(struct device *dev)
 {
 	struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 
-	clk_prepare_enable(i2c_dev->clk);
 	/* take I2C out of reset */
 	davinci_i2c_reset_ctrl(i2c_dev, 1);
 
@@ -899,6 +943,8 @@  static int davinci_i2c_resume(struct device *dev)
 static const struct dev_pm_ops davinci_i2c_pm = {
 	.suspend        = davinci_i2c_suspend,
 	.resume         = davinci_i2c_resume,
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
 };
 
 #define davinci_i2c_pm_ops (&davinci_i2c_pm)