[PATCH 5/5] fbdev: omap2: panel-dpi: allow specification of a vcc regulator

[PATCH 5/5] fbdev: omap2: panel-dpi: allow specification of a vcc regulator

[Uwe Kleine-König]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

To allow supporting displays that need some logic to enable power to the
display add support for a vcc-supply property to drive a regulator.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 Documentation/devicetree/bindings/video/panel-dpi.txt |  1 +
 drivers/video/fbdev/omap2/displays-new/panel-dpi.c    | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/video/panel-dpi.txt b/Documentation/devicetree/bindings/video/panel-dpi.txt
index 1a1d8f6f884f..eaa39d1b1279 100644
--- a/Documentation/devicetree/bindings/video/panel-dpi.txt
+++ b/Documentation/devicetree/bindings/video/panel-dpi.txt
@@ -8,6 +8,7 @@ Optional properties:
 - label: a symbolic name for the panel
 - enable-gpios: panel enable gpio
 - reset-gpios: GPIO to control the RESET pin
+- vcc-supply: phandle of regulator that will be used to enable power to the display
 
 Required nodes:
 - "panel-timing" containing video timings
diff --git a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
index 7e2f9e0813dc..65c6d9e6862b 100644
--- a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
+++ b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
+#include <linux/regulator/consumer.h>
 
 #include <video/omapdss.h>
 #include <video/omap-panel-data.h>
@@ -33,6 +34,7 @@ struct panel_drv_data {
 
 	struct gpio_desc *enable_gpio;
 	struct gpio_desc *reset_gpio;
+	struct regulator *vcc_supply;
 };
 
 #define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
@@ -84,6 +86,12 @@ static int panel_dpi_enable(struct omap_dss_device *dssdev)
 	if (r)
 		return r;
 
+	r = regulator_enable(ddata->vcc_supply);
+	if (r) {
+		in->ops.dpi->disable(in);
+		return r;
+	}
+
 	gpiod_set_value_cansleep(ddata->reset_gpio, 0);
 	gpiod_set_value_cansleep(ddata->enable_gpio, 1);
 
@@ -107,6 +115,7 @@ static void panel_dpi_disable(struct omap_dss_device *dssdev)
 		gpio_set_value_cansleep(ddata->backlight_gpio, 0);
 
 	gpiod_set_value_cansleep(ddata->enable_gpio, 0);
+	regulator_disable(ddata->vcc_supply);
 
 	in->ops.dpi->disable(in);
 
@@ -218,6 +227,10 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
 	if (IS_ERR(ddata->reset_gpio))
 		return PTR_ERR(ddata->reset_gpio);
 
+	ddata->vcc_supply = devm_regulator_get(&pdev->dev, "vcc");
+	if (IS_ERR(ddata->vcc_supply))
+		return PTR_ERR(ddata->vcc_supply);
+
 	ddata->backlight_gpio = -ENOENT;
 
 	r = of_get_display_timing(node, "panel-timing", &timing);
-- 
2.6.2

Re: [PATCH 5/5] fbdev: omap2: panel-dpi: allow specification of a vcc regulator

[Tomi Valkeinen]

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On 10/12/15 15:11, Uwe Kleine-König wrote:
> From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> To allow supporting displays that need some logic to enable power to the
> display add support for a vcc-supply property to drive a regulator.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  Documentation/devicetree/bindings/video/panel-dpi.txt |  1 +
>  drivers/video/fbdev/omap2/displays-new/panel-dpi.c    | 13 +++++++++++++
>  2 files changed, 14 insertions(+)

Same comments here about the bindings.

> diff --git a/Documentation/devicetree/bindings/video/panel-dpi.txt b/Documentation/devicetree/bindings/video/panel-dpi.txt
> index 1a1d8f6f884f..eaa39d1b1279 100644
> --- a/Documentation/devicetree/bindings/video/panel-dpi.txt
> +++ b/Documentation/devicetree/bindings/video/panel-dpi.txt
> @@ -8,6 +8,7 @@ Optional properties:
>  - label: a symbolic name for the panel
>  - enable-gpios: panel enable gpio
>  - reset-gpios: GPIO to control the RESET pin
> +- vcc-supply: phandle of regulator that will be used to enable power to the display
>  
>  Required nodes:
>  - "panel-timing" containing video timings
> diff --git a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
> index 7e2f9e0813dc..65c6d9e6862b 100644
> --- a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
> +++ b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
> @@ -15,6 +15,7 @@
>  #include <linux/slab.h>
>  #include <linux/of.h>
>  #include <linux/of_gpio.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include <video/omapdss.h>
>  #include <video/omap-panel-data.h>
> @@ -33,6 +34,7 @@ struct panel_drv_data {
>  
>  	struct gpio_desc *enable_gpio;
>  	struct gpio_desc *reset_gpio;
> +	struct regulator *vcc_supply;
>  };
>  
>  #define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
> @@ -84,6 +86,12 @@ static int panel_dpi_enable(struct omap_dss_device *dssdev)
>  	if (r)
>  		return r;
>  
> +	r = regulator_enable(ddata->vcc_supply);
> +	if (r) {
> +		in->ops.dpi->disable(in);
> +		return r;
> +	}
> +
>  	gpiod_set_value_cansleep(ddata->reset_gpio, 0);
>  	gpiod_set_value_cansleep(ddata->enable_gpio, 1);
>  
> @@ -107,6 +115,7 @@ static void panel_dpi_disable(struct omap_dss_device *dssdev)
>  		gpio_set_value_cansleep(ddata->backlight_gpio, 0);
>  
>  	gpiod_set_value_cansleep(ddata->enable_gpio, 0);
> +	regulator_disable(ddata->vcc_supply);
>  
>  	in->ops.dpi->disable(in);
>  
> @@ -218,6 +227,10 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
>  	if (IS_ERR(ddata->reset_gpio))
>  		return PTR_ERR(ddata->reset_gpio);
>  
> +	ddata->vcc_supply = devm_regulator_get(&pdev->dev, "vcc");
> +	if (IS_ERR(ddata->vcc_supply))
> +		return PTR_ERR(ddata->vcc_supply);
> +
>  	ddata->backlight_gpio = -ENOENT;
>  
>  	r = of_get_display_timing(node, "panel-timing", &timing);

Some panels might need to sleep before/after the regulator, but the same
goes for enable gpio. And we don't have a sane way to handle that at the
moment, so I think this is fine.

 Tomi


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Re: [PATCH 5/5] fbdev: omap2: panel-dpi: allow specification of a vcc regulator

[Adam Ford]

Tomi,

Do you have any thought on how to approach adding sleep/delay
functions?  I have a display that requires a small delay before and
after the enable gpio toggle.  I assume that some may require a delay
after the regulator starts for it to be be ready.  For now I have a
temp hack that just inserts a blanket 300mS wait, but I'd rather have
something mainstreamed in the device tree, but I don't want to walk
over someone else's work either.

I'd love to help if you have an idea of how you vision it.

adam

On Wed, Dec 16, 2015 at 11:38 AM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
>
>
> On 10/12/15 15:11, Uwe Kleine-König wrote:
>> From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
>>
>> To allow supporting displays that need some logic to enable power to the
>> display add support for a vcc-supply property to drive a regulator.
>>
>> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
>> ---
>>  Documentation/devicetree/bindings/video/panel-dpi.txt |  1 +
>>  drivers/video/fbdev/omap2/displays-new/panel-dpi.c    | 13 +++++++++++++
>>  2 files changed, 14 insertions(+)
>
> Same comments here about the bindings.
>
>> diff --git a/Documentation/devicetree/bindings/video/panel-dpi.txt b/Documentation/devicetree/bindings/video/panel-dpi.txt
>> index 1a1d8f6f884f..eaa39d1b1279 100644
>> --- a/Documentation/devicetree/bindings/video/panel-dpi.txt
>> +++ b/Documentation/devicetree/bindings/video/panel-dpi.txt
>> @@ -8,6 +8,7 @@ Optional properties:
>>  - label: a symbolic name for the panel
>>  - enable-gpios: panel enable gpio
>>  - reset-gpios: GPIO to control the RESET pin
>> +- vcc-supply: phandle of regulator that will be used to enable power to the display
>>
>>  Required nodes:
>>  - "panel-timing" containing video timings
>> diff --git a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
>> index 7e2f9e0813dc..65c6d9e6862b 100644
>> --- a/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
>> +++ b/drivers/video/fbdev/omap2/displays-new/panel-dpi.c
>> @@ -15,6 +15,7 @@
>>  #include <linux/slab.h>
>>  #include <linux/of.h>
>>  #include <linux/of_gpio.h>
>> +#include <linux/regulator/consumer.h>
>>
>>  #include <video/omapdss.h>
>>  #include <video/omap-panel-data.h>
>> @@ -33,6 +34,7 @@ struct panel_drv_data {
>>
>>       struct gpio_desc *enable_gpio;
>>       struct gpio_desc *reset_gpio;
>> +     struct regulator *vcc_supply;
>>  };
>>
>>  #define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
>> @@ -84,6 +86,12 @@ static int panel_dpi_enable(struct omap_dss_device *dssdev)
>>       if (r)
>>               return r;
>>
>> +     r = regulator_enable(ddata->vcc_supply);
>> +     if (r) {
>> +             in->ops.dpi->disable(in);
>> +             return r;
>> +     }
>> +
>>       gpiod_set_value_cansleep(ddata->reset_gpio, 0);
>>       gpiod_set_value_cansleep(ddata->enable_gpio, 1);
>>
>> @@ -107,6 +115,7 @@ static void panel_dpi_disable(struct omap_dss_device *dssdev)
>>               gpio_set_value_cansleep(ddata->backlight_gpio, 0);
>>
>>       gpiod_set_value_cansleep(ddata->enable_gpio, 0);
>> +     regulator_disable(ddata->vcc_supply);
>>
>>       in->ops.dpi->disable(in);
>>
>> @@ -218,6 +227,10 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
>>       if (IS_ERR(ddata->reset_gpio))
>>               return PTR_ERR(ddata->reset_gpio);
>>
>> +     ddata->vcc_supply = devm_regulator_get(&pdev->dev, "vcc");
>> +     if (IS_ERR(ddata->vcc_supply))
>> +             return PTR_ERR(ddata->vcc_supply);
>> +
>>       ddata->backlight_gpio = -ENOENT;
>>
>>       r = of_get_display_timing(node, "panel-timing", &timing);
>
> Some panels might need to sleep before/after the regulator, but the same
> goes for enable gpio. And we don't have a sane way to handle that at the
> moment, so I think this is fine.
>
>  Tomi
>

Re: [PATCH 5/5] fbdev: omap2: panel-dpi: allow specification of a vcc regulator

[Tomi Valkeinen]

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Hi,

On 19/12/15 22:41, Adam Ford wrote:
> Tomi,
> 
> Do you have any thought on how to approach adding sleep/delay
> functions?  I have a display that requires a small delay before and
> after the enable gpio toggle.  I assume that some may require a delay
> after the regulator starts for it to be be ready.  For now I have a
> temp hack that just inserts a blanket 300mS wait, but I'd rather have
> something mainstreamed in the device tree, but I don't want to walk
> over someone else's work either.

I don't think it makes sense to add explicit entries for these, as we'd
just end up with lots of entries in the DT files for "wait-before-vcc",
"wait-after-vcc", etc.

There was a patch series some time ago, trying to add generic power
up/down sequences defined in DT. I don't think that ever got merged, as
there wasn't a consensus on the DT side. I can't find the series right
now, as I don't remember the author or the subject...

I think that kind of generic sequence framework would make sense, and
getting it merged without the DT side should be easier. Then the drivers
could have built-in sequences for certain panels.

 Tomi


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