[PATCH v4] i2c/at91: adopt pinctrl support

[PATCH v4] i2c/at91: adopt pinctrl support

[Wenyou Yang]

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 <wenyou.yang@atmel.com>
---
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

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

[Sergei Shtylyov]

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 <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> ---
> 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

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

[Yang, Wenyou]

Hi,

> -----Original Message-----
> From: Sergei Shtylyov [mailto:sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org]
> Sent: Monday, November 10, 2014 7:13 PM
> To: Yang, Wenyou; wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org; Desroches, Ludovic
> Cc: khilman-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org; Ferre, Nicolas; linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-
> i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
> 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 <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> > ---
> > 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

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

[Wolfram Sang]

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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 <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>

Applied to for-next, thanks!


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