2014-11-10 01:59:51

by Wenyou Yang

[permalink] [raw]
Subject: [PATCH v4] i2c/at91: adopt pinctrl support

Amend the at91 i2c pin controller to optionally take a pin control
handle and set the state of the pins to:
- "default" on boot and resume.
- "sleep" on suspend().

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle

Signed-off-by: Wenyou Yang <[email protected]>
---
Hi Wolfram,

Thanks a lot.

The change of this version is to remove
pinctrl_pm_select_default_state(&pdev->dev) from the _probe function.

Best Regards,
Wenyou Yang

drivers/i2c/busses/i2c-at91.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 7c335f4..77fb647 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -32,6 +32,7 @@
#include <linux/slab.h>
#include <linux/platform_data/dma-atmel.h>
#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>

#define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */
#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
@@ -851,6 +852,8 @@ static int at91_twi_runtime_suspend(struct device *dev)

clk_disable_unprepare(twi_dev->clk);

+ pinctrl_pm_select_sleep_state(dev);
+
return 0;
}

@@ -858,6 +861,8 @@ static int at91_twi_runtime_resume(struct device *dev)
{
struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);

+ pinctrl_pm_select_default_state(dev);
+
return clk_prepare_enable(twi_dev->clk);
}

--
1.7.9.5


2014-11-10 11:13:31

by Sergei Shtylyov

[permalink] [raw]
Subject: Re: [PATCH v4] i2c/at91: adopt pinctrl support

Hello.

On 11/10/2014 4:55 AM, Wenyou Yang wrote:

> Amend the at91 i2c pin controller

You're amending the hardware itself, really? :-)

> to optionally take a pin controlhandle

I don't see the code that does this.

> and set the state of the pins to:
> - "default" on boot and resume.

I don't see where you are changing anything for the probe() method.
Perhaps you meant the driver core code which selects the dafault profile
automatically?

> - "sleep" on suspend().

> This should make it possible to optimize energy usage for the pins
> both for the suspend/resume cycle

> Signed-off-by: Wenyou Yang <[email protected]>
> ---
> Hi Wolfram,
>
> Thanks a lot.
>
> The change of this version is to remove
> pinctrl_pm_select_default_state(&pdev->dev) from the _probe function.

Aha, you've specifically removed this...

WBR, Sergei

2014-11-11 00:54:42

by Wenyou Yang

[permalink] [raw]
Subject: RE: [PATCH v4] i2c/at91: adopt pinctrl support

Hi,

> -----Original Message-----
> From: Sergei Shtylyov [mailto:[email protected]]
> Sent: Monday, November 10, 2014 7:13 PM
> To: Yang, Wenyou; [email protected]; Desroches, Ludovic
> Cc: [email protected]; Ferre, Nicolas; [email protected]; linux-
> [email protected]; [email protected]
> Subject: Re: [PATCH v4] i2c/at91: adopt pinctrl support
>
> Hello.
>
> On 11/10/2014 4:55 AM, Wenyou Yang wrote:
>
> > Amend the at91 i2c pin controller
>
> You're amending the hardware itself, really? :-)
>
> > to optionally take a pin controlhandle
>
> I don't see the code that does this.
>
> > and set the state of the pins to:
> > - "default" on boot and resume.
>
> I don't see where you are changing anything for the probe() method.
> Perhaps you meant the driver core code which selects the dafault profile
> automatically?
Yes, the driver core code default do, so remove the redundant code from _probe function.

>
> > - "sleep" on suspend().
>
> > This should make it possible to optimize energy usage for the pins
> > both for the suspend/resume cycle
>
> > Signed-off-by: Wenyou Yang <[email protected]>
> > ---
> > Hi Wolfram,
> >
> > Thanks a lot.
> >
> > The change of this version is to remove
> > pinctrl_pm_select_default_state(&pdev->dev) from the _probe function.
>
> Aha, you've specifically removed this...
>
> WBR, Sergei

Best Regards,
Wenyou Yang

2014-11-12 15:49:50

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH v4] i2c/at91: adopt pinctrl support

On Mon, Nov 10, 2014 at 09:55:52AM +0800, Wenyou Yang wrote:
> Amend the at91 i2c pin controller to optionally take a pin control
> handle and set the state of the pins to:
> - "default" on boot and resume.
> - "sleep" on suspend().
>
> This should make it possible to optimize energy usage for the pins
> both for the suspend/resume cycle
>
> Signed-off-by: Wenyou Yang <[email protected]>

Applied to for-next, thanks!


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