[PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Hebbar Gururaja]

Amend the hsmmc controller to optionally take a pin control handle and
set the state of the pins to:

- "default" on boot, resume and before performing a mmc transfer
- "idle" after initial default, after resume default, and after each
mmc/sd card access
- "sleep" on suspend()

By optionally putting the pins into sleep state in the suspend callback
we can accomplish two things.
- One is to minimize current leakage from pins and thus save power,
- second, we can prevent the IP from driving pins output in an
uncontrolled manner, which may happen if the power domain drops the
domain regulator.

If any of the above pin states are missing in dt, a warning message
about the missing state is displayed.
If certain pin-states are not available, to remove this warning message
pass respective state name with null phandler.

Signed-off-by: Hebbar Gururaja <gururaja.hebbar-l0cyMroinI0@public.gmane.org>
Cc: Balaji T K <balajitk-l0cyMroinI0@public.gmane.org>
Cc: Chris Ball <cjb-2X9k7bc8m7Mdnm+yROfE0A@public.gmane.org>
Cc: linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
:100644 100644 6e44025... a2d69aa... M	drivers/mmc/host/omap_hsmmc.c
 drivers/mmc/host/omap_hsmmc.c |   79 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 74 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 6e44025..a2d69aa 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -183,6 +183,12 @@ struct omap_hsmmc_host {
 	struct omap_hsmmc_next	next_data;
 
 	struct	omap_mmc_platform_data	*pdata;
+
+	/* Three pin states - default, idle & sleep */
+	struct pinctrl			*pinctrl;
+	struct pinctrl_state		*pins_default;
+	struct pinctrl_state		*pins_idle;
+	struct pinctrl_state		*pins_sleep;
 };
 
 static int omap_hsmmc_card_detect(struct device *dev, int slot)
@@ -1775,7 +1781,6 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 	const struct of_device_id *match;
 	dma_cap_mask_t mask;
 	unsigned tx_req, rx_req;
-	struct pinctrl *pinctrl;
 
 	match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev);
 	if (match) {
@@ -1982,10 +1987,46 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 
 	omap_hsmmc_disable_irq(host);
 
-	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
-	if (IS_ERR(pinctrl))
-		dev_warn(&pdev->dev,
-			"pins are not configured from the driver\n");
+	host->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (!IS_ERR(host->pinctrl)) {
+		host->pins_default = pinctrl_lookup_state(host->pinctrl,
+							PINCTRL_STATE_DEFAULT);
+		if (IS_ERR(host->pins_default))
+			dev_dbg(&pdev->dev, "could not get default pinstate\n");
+		else
+			if (pinctrl_select_state(host->pinctrl,
+						 host->pins_default))
+				dev_err(&pdev->dev,
+					"could not set default pinstate\n");
+
+		host->pins_idle = pinctrl_lookup_state(host->pinctrl,
+							PINCTRL_STATE_IDLE);
+		if (IS_ERR(host->pins_idle))
+			dev_dbg(&pdev->dev, "could not get idle pinstate\n");
+		else
+			/* If possible, let's idle until the first transfer */
+			if (pinctrl_select_state(host->pinctrl,
+						 host->pins_idle))
+				dev_err(&pdev->dev,
+					"could not set idle pinstate\n");
+
+		host->pins_sleep = pinctrl_lookup_state(host->pinctrl,
+							PINCTRL_STATE_SLEEP);
+		if (IS_ERR(host->pins_sleep))
+			dev_dbg(&pdev->dev, "could not get sleep pinstate\n");
+	} else {
+		/*
+		* Since we continue even when pinctrl node is not found,
+		* Invalidate pins as not available. This is to make sure that
+		* IS_ERR(pins_xxx) results in failure when used.
+		*/
+		host->pins_default = ERR_PTR(-ENODATA);
+		host->pins_idle = ERR_PTR(-ENODATA);
+		host->pins_sleep = ERR_PTR(-ENODATA);
+
+		dev_dbg(&pdev->dev, "did not get pins for mmc error: %li\n",
+			PTR_ERR(host->pinctrl));
+	}
 
 	omap_hsmmc_protect_card(host);
 
@@ -2135,6 +2176,12 @@ static int omap_hsmmc_suspend(struct device *dev)
 		clk_disable_unprepare(host->dbclk);
 err:
 	pm_runtime_put_sync(host->dev);
+
+	/* Optionally let pins go into sleep states */
+	if (!IS_ERR(host->pins_sleep))
+		if (pinctrl_select_state(host->pinctrl, host->pins_sleep))
+			dev_err(dev, "could not set pins to sleep state\n");
+
 	return ret;
 }
 
@@ -2152,6 +2199,16 @@ static int omap_hsmmc_resume(struct device *dev)
 
 	pm_runtime_get_sync(host->dev);
 
+	/* First go to the default state */
+	if (!IS_ERR(host->pins_default))
+		if (pinctrl_select_state(host->pinctrl, host->pins_default))
+			dev_err(host->dev, "could not set pins to default state\n");
+
+	/* Then let's idle the pins until the next transfer happens */
+	if (!IS_ERR(host->pins_idle))
+		if (pinctrl_select_state(host->pinctrl, host->pins_idle))
+			dev_err(host->dev, "couldn't set pins to idle state\n");
+
 	if (host->dbclk)
 		clk_prepare_enable(host->dbclk);
 
@@ -2185,6 +2242,12 @@ static int omap_hsmmc_runtime_suspend(struct device *dev)
 
 	host = platform_get_drvdata(to_platform_device(dev));
 	omap_hsmmc_context_save(host);
+
+	/* Optionally let pins go into sleep states */
+	if (!IS_ERR(host->pins_idle))
+		if (pinctrl_select_state(host->pinctrl, host->pins_idle))
+			dev_err(dev, "could not set pins to idle state\n");
+
 	dev_dbg(dev, "disabled\n");
 
 	return 0;
@@ -2195,6 +2258,12 @@ static int omap_hsmmc_runtime_resume(struct device *dev)
 	struct omap_hsmmc_host *host;
 
 	host = platform_get_drvdata(to_platform_device(dev));
+
+	/* Optionaly enable pins to be muxed in and configured */
+	if (!IS_ERR(host->pins_default))
+		if (pinctrl_select_state(host->pinctrl, host->pins_default))
+			dev_err(host->dev, "could not set default pins\n");
+
 	omap_hsmmc_context_restore(host);
 	dev_dbg(dev, "enabled\n");
 
-- 
1.7.9.5

Re: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Linus Walleij]

On Fri, May 31, 2013 at 12:13 PM, Hebbar Gururaja
<gururaja.hebbar@ti.com> wrote:

> Amend the hsmmc controller to optionally take a pin control handle and
> set the state of the pins to:
>
> - "default" on boot, resume and before performing a mmc transfer
> - "idle" after initial default, after resume default, and after each
> mmc/sd card access
> - "sleep" on suspend()
>
> By optionally putting the pins into sleep state in the suspend callback
> we can accomplish two things.
> - One is to minimize current leakage from pins and thus save power,
> - second, we can prevent the IP from driving pins output in an
> uncontrolled manner, which may happen if the power domain drops the
> domain regulator.
>
> If any of the above pin states are missing in dt, a warning message
> about the missing state is displayed.
> If certain pin-states are not available, to remove this warning message
> pass respective state name with null phandler.
>
> Signed-off-by: Hebbar Gururaja <gururaja.hebbar@ti.com>
> Cc: Balaji T K <balajitk@ti.com>
> Cc: Chris Ball <cjb@laptop.org>
> Cc: linux-mmc@vger.kernel.org
> Cc: linux-omap@vger.kernel.org

This is perfectly correct.
Acked-by: Linus Walleij <linus.walleij@linaro.org>

As the PM code seems to be similar across platforms I have had
loose plans to move this to the device core as well, but right now
I'm too busy with other things, and it can surely be refactored later.

Yours,
Linus Walleij

Re: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Linus Walleij]

On Tue, Jun 4, 2013 at 9:11 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Fri, May 31, 2013 at 12:13 PM, Hebbar Gururaja
> <gururaja.hebbar@ti.com> wrote:
>
>> Amend the hsmmc controller to optionally take a pin control handle and
>> set the state of the pins to:
>>
>> - "default" on boot, resume and before performing a mmc transfer
>> - "idle" after initial default, after resume default, and after each
>> mmc/sd card access
>> - "sleep" on suspend()
>>
>> By optionally putting the pins into sleep state in the suspend callback
>> we can accomplish two things.
>> - One is to minimize current leakage from pins and thus save power,
>> - second, we can prevent the IP from driving pins output in an
>> uncontrolled manner, which may happen if the power domain drops the
>> domain regulator.
>>
>> If any of the above pin states are missing in dt, a warning message
>> about the missing state is displayed.
>> If certain pin-states are not available, to remove this warning message
>> pass respective state name with null phandler.
>>
>> Signed-off-by: Hebbar Gururaja <gururaja.hebbar@ti.com>
>> Cc: Balaji T K <balajitk@ti.com>
>> Cc: Chris Ball <cjb@laptop.org>
>> Cc: linux-mmc@vger.kernel.org
>> Cc: linux-omap@vger.kernel.org
>
> This is perfectly correct.
> Acked-by: Linus Walleij <linus.walleij@linaro.org>

So please consider my other option given in patch 2 instead.

Yours,
Linus Walleij

RE: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Hebbar, Gururaja]

On Tue, Jun 04, 2013 at 12:49:57, Linus Walleij wrote:
> On Tue, Jun 4, 2013 at 9:11 AM, Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> > On Fri, May 31, 2013 at 12:13 PM, Hebbar Gururaja
> > <gururaja.hebbar-l0cyMroinI0@public.gmane.org> wrote:
> >
> >> Amend the hsmmc controller to optionally take a pin control handle and
> >> set the state of the pins to:
> >>
> >> - "default" on boot, resume and before performing a mmc transfer
> >> - "idle" after initial default, after resume default, and after each
> >> mmc/sd card access
> >> - "sleep" on suspend()
> >>
> >> By optionally putting the pins into sleep state in the suspend callback
> >> we can accomplish two things.
> >> - One is to minimize current leakage from pins and thus save power,
> >> - second, we can prevent the IP from driving pins output in an
> >> uncontrolled manner, which may happen if the power domain drops the
> >> domain regulator.
> >>
> >> If any of the above pin states are missing in dt, a warning message
> >> about the missing state is displayed.
> >> If certain pin-states are not available, to remove this warning message
> >> pass respective state name with null phandler.
> >>
> >> Signed-off-by: Hebbar Gururaja <gururaja.hebbar-l0cyMroinI0@public.gmane.org>
> >> Cc: Balaji T K <balajitk-l0cyMroinI0@public.gmane.org>
> >> Cc: Chris Ball <cjb-2X9k7bc8m7Mdnm+yROfE0A@public.gmane.org>
> >> Cc: linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> >> Cc: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> >
> > This is perfectly correct.
> > Acked-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> 
> So please consider my other option given in patch 2 instead.

I will check how I can be a part of this implementation

> 
> Yours,
> Linus Walleij
> 


Regards, 
Gururaja

Re: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Tony Lindgren]

* Hebbar Gururaja <gururaja.hebbar-l0cyMroinI0@public.gmane.org> [130531 03:19]:
> Amend the hsmmc controller to optionally take a pin control handle and
> set the state of the pins to:
> 
> - "default" on boot, resume and before performing a mmc transfer
> - "idle" after initial default, after resume default, and after each
> mmc/sd card access
> - "sleep" on suspend()
> 
> By optionally putting the pins into sleep state in the suspend callback
> we can accomplish two things.
> - One is to minimize current leakage from pins and thus save power,
> - second, we can prevent the IP from driving pins output in an
> uncontrolled manner, which may happen if the power domain drops the
> domain regulator.
> 
> If any of the above pin states are missing in dt, a warning message
> about the missing state is displayed.
> If certain pin-states are not available, to remove this warning message
> pass respective state name with null phandler.

There's a similar patch in the "[RESEND PATCH v2 1/3] mmc: omap_hsmmc:
Enable SDIO IRQ using a GPIO in idle mode" thread. It also makes the
SDIO interrupts to work, so we need to consider that too.

We can merge the dynamic pinmuxing parts separately, but they should
be in a separate function like I posted later on in the thread above.

Regards,

Tony 

Re: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Balaji T K]

On Tuesday 04 June 2013 08:16 PM, Tony Lindgren wrote:
> * Hebbar Gururaja <gururaja.hebbar@ti.com> [130531 03:19]:
>> Amend the hsmmc controller to optionally take a pin control handle and
>> set the state of the pins to:
>>
>> - "default" on boot, resume and before performing a mmc transfer
>> - "idle" after initial default, after resume default, and after each
>> mmc/sd card access
>> - "sleep" on suspend()
>>
>> By optionally putting the pins into sleep state in the suspend callback
>> we can accomplish two things.
>> - One is to minimize current leakage from pins and thus save power,
>> - second, we can prevent the IP from driving pins output in an
>> uncontrolled manner, which may happen if the power domain drops the
>> domain regulator.
>>
>> If any of the above pin states are missing in dt, a warning message
>> about the missing state is displayed.
>> If certain pin-states are not available, to remove this warning message
>> pass respective state name with null phandler.
>
> There's a similar patch in the "[RESEND PATCH v2 1/3] mmc: omap_hsmmc:
> Enable SDIO IRQ using a GPIO in idle mode" thread. It also makes the
> SDIO interrupts to work, so we need to consider that too.
>

Hi Tony,

I will try to combine both of these and make use of
pinctrl_pm_select_[*]_state helper functions.


> We can merge the dynamic pinmuxing parts separately, but they should
> be in a separate function like I posted later on in the thread above.
>
> Regards,
>
> Tony
>

Re: [PATCH 09/11] mmc: omap_hsmmc: enhance pinctrl support

[Tony Lindgren]

* Balaji T K <balajitk@ti.com> [130607 06:42]:
> On Tuesday 04 June 2013 08:16 PM, Tony Lindgren wrote:
> >* Hebbar Gururaja <gururaja.hebbar@ti.com> [130531 03:19]:
> >>Amend the hsmmc controller to optionally take a pin control handle and
> >>set the state of the pins to:
> >>
> >>- "default" on boot, resume and before performing a mmc transfer
> >>- "idle" after initial default, after resume default, and after each
> >>mmc/sd card access
> >>- "sleep" on suspend()
> >>
> >>By optionally putting the pins into sleep state in the suspend callback
> >>we can accomplish two things.
> >>- One is to minimize current leakage from pins and thus save power,
> >>- second, we can prevent the IP from driving pins output in an
> >>uncontrolled manner, which may happen if the power domain drops the
> >>domain regulator.
> >>
> >>If any of the above pin states are missing in dt, a warning message
> >>about the missing state is displayed.
> >>If certain pin-states are not available, to remove this warning message
> >>pass respective state name with null phandler.
> >
> >There's a similar patch in the "[RESEND PATCH v2 1/3] mmc: omap_hsmmc:
> >Enable SDIO IRQ using a GPIO in idle mode" thread. It also makes the
> >SDIO interrupts to work, so we need to consider that too.
> >
> 
> Hi Tony,
> 
> I will try to combine both of these and make use of
> pinctrl_pm_select_[*]_state helper functions.

OK thanks, I'll separate out the pinctrl parts from Andreas' patch
and repost.

Regards,

Tony