[PATCH] ARM: dts: da850-evm: fix tca6416 for use with GPIO hogs

[PATCH] ARM: dts: da850-evm: fix tca6416 for use with GPIO hogs

[Kevin Hilman]

In order GPIOS from this controller to be used with the "gpio-hogs"
property, the tca6416 node has to properly labeled as a gpio-controller,
and use #gpio-cells.

With that, the SEL_A, SEL_B, SEL_C lines that are used to select VPIF
input can be configured using GPIO hogs.

As an example, example, the configuration below selects the analog video
input on the da850-evm UI board:

&tca6416 {
	 status = "okay";

	 sel_a {
		gpio-hog;
		gpios = <7 GPIO_ACTIVE_HIGH>;
		output-high;
		line-name = "ADC_ENn";
	 };
	 sel_b {
		gpio-hog;
		gpios = <6 GPIO_ACTIVE_HIGH>;
		output-high;
		line-name = "CAMERA_ENn";
	 };
	 sel_c {
		gpio-hog;
		gpios = <5 GPIO_ACTIVE_HIGH>;
		output-low;
		line-name = "VIDEO_IN_ENn";
	 };
};

Signed-off-by: Kevin Hilman <khilman@baylibre.com>
---
 arch/arm/boot/dts/da850-evm.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/da850-evm.dts b/arch/arm/boot/dts/da850-evm.dts
index 8d244cd76c36..a423e8ebfb37 100644
--- a/arch/arm/boot/dts/da850-evm.dts
+++ b/arch/arm/boot/dts/da850-evm.dts
@@ -82,6 +82,8 @@
 			tca6416: gpio at 20 {
 				compatible = "ti,tca6416";
 				reg = <0x20>;
+				gpio-controller;
+				#gpio-cells = <2>;
 			};
 		};
 		wdt: wdt at 21000 {
-- 
2.9.3

[PATCH] ARM: dts: da850-evm: fix tca6416 for use with GPIO hogs

[Sekhar Nori]

Hi Kevin,

On Wednesday 31 May 2017 06:51 AM, Kevin Hilman wrote:
> In order GPIOS from this controller to be used with the "gpio-hogs"
> property, the tca6416 node has to properly labeled as a gpio-controller,
> and use #gpio-cells.
> 
> With that, the SEL_A, SEL_B, SEL_C lines that are used to select VPIF
> input can be configured using GPIO hogs.
> 
> As an example, example, the configuration below selects the analog video
> input on the da850-evm UI board:
> 
> &tca6416 {
> 	 status = "okay";
> 
> 	 sel_a {
> 		gpio-hog;
> 		gpios = <7 GPIO_ACTIVE_HIGH>;
> 		output-high;
> 		line-name = "ADC_ENn";
> 	 };
> 	 sel_b {
> 		gpio-hog;
> 		gpios = <6 GPIO_ACTIVE_HIGH>;
> 		output-high;
> 		line-name = "CAMERA_ENn";
> 	 };
> 	 sel_c {
> 		gpio-hog;
> 		gpios = <5 GPIO_ACTIVE_HIGH>;
> 		output-low;
> 		line-name = "VIDEO_IN_ENn";
> 	 };
> };
> 
> Signed-off-by: Kevin Hilman <khilman@baylibre.com>

This patch looks good to me. On the topic of using gpio hogs for this
sort of thing, in the past I felt using enable-gpios property is better.

My reasoning given to Bartosz is here:
https://patchwork.kernel.org/patch/9578031/

Thanks,
Sekhar

[PATCH] ARM: dts: da850-evm: fix tca6416 for use with GPIO hogs

[Kevin Hilman]

On Thu, Jun 1, 2017 at 11:01 PM, Sekhar Nori <nsekhar@ti.com> wrote:
> Hi Kevin,
>
> On Wednesday 31 May 2017 06:51 AM, Kevin Hilman wrote:
>> In order GPIOS from this controller to be used with the "gpio-hogs"
>> property, the tca6416 node has to properly labeled as a gpio-controller,
>> and use #gpio-cells.
>>
>> With that, the SEL_A, SEL_B, SEL_C lines that are used to select VPIF
>> input can be configured using GPIO hogs.
>>
>> As an example, example, the configuration below selects the analog video
>> input on the da850-evm UI board:
>>
>> &tca6416 {
>>        status = "okay";
>>
>>        sel_a {
>>               gpio-hog;
>>               gpios = <7 GPIO_ACTIVE_HIGH>;
>>               output-high;
>>               line-name = "ADC_ENn";
>>        };
>>        sel_b {
>>               gpio-hog;
>>               gpios = <6 GPIO_ACTIVE_HIGH>;
>>               output-high;
>>               line-name = "CAMERA_ENn";
>>        };
>>        sel_c {
>>               gpio-hog;
>>               gpios = <5 GPIO_ACTIVE_HIGH>;
>>               output-low;
>>               line-name = "VIDEO_IN_ENn";
>>        };
>> };
>>
>> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
>
> This patch looks good to me. On the topic of using gpio hogs for this
> sort of thing, in the past I felt using enable-gpios property is better.
>
> My reasoning given to Bartosz is here:
> https://patchwork.kernel.org/patch/9578031/

Sure, that's fine when they are used for a specific functionality, but
using gpio-hog is very useful for testing/debugging, so this patch
just aims at fixing the basics.

That being said, I'm still not convinced what the best place for this
is because they're not really part of the VPIF either (e.g. they
control the character LCD which has nothing to do with the VPIF.)

In any case, I'm not trying to solve that problem in this patch, so
thanks for the review.

Kevin

[PATCH] ARM: dts: da850-evm: fix tca6416 for use with GPIO hogs

[Sekhar Nori]

On Saturday 03 June 2017 01:57 AM, Kevin Hilman wrote:
> On Thu, Jun 1, 2017 at 11:01 PM, Sekhar Nori <nsekhar@ti.com> wrote:
>> Hi Kevin,
>>
>> On Wednesday 31 May 2017 06:51 AM, Kevin Hilman wrote:
>>> In order GPIOS from this controller to be used with the "gpio-hogs"
>>> property, the tca6416 node has to properly labeled as a gpio-controller,
>>> and use #gpio-cells.
>>>
>>> With that, the SEL_A, SEL_B, SEL_C lines that are used to select VPIF
>>> input can be configured using GPIO hogs.
>>>
>>> As an example, example, the configuration below selects the analog video
>>> input on the da850-evm UI board:
>>>
>>> &tca6416 {
>>>        status = "okay";
>>>
>>>        sel_a {
>>>               gpio-hog;
>>>               gpios = <7 GPIO_ACTIVE_HIGH>;
>>>               output-high;
>>>               line-name = "ADC_ENn";
>>>        };
>>>        sel_b {
>>>               gpio-hog;
>>>               gpios = <6 GPIO_ACTIVE_HIGH>;
>>>               output-high;
>>>               line-name = "CAMERA_ENn";
>>>        };
>>>        sel_c {
>>>               gpio-hog;
>>>               gpios = <5 GPIO_ACTIVE_HIGH>;
>>>               output-low;
>>>               line-name = "VIDEO_IN_ENn";
>>>        };
>>> };
>>>
>>> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
>>
>> This patch looks good to me. On the topic of using gpio hogs for this
>> sort of thing, in the past I felt using enable-gpios property is better.
>>
>> My reasoning given to Bartosz is here:
>> https://patchwork.kernel.org/patch/9578031/
> 
> Sure, that's fine when they are used for a specific functionality, but
> using gpio-hog is very useful for testing/debugging, so this patch
> just aims at fixing the basics.

Agreed.

> That being said, I'm still not convinced what the best place for this
> is because they're not really part of the VPIF either (e.g. they
> control the character LCD which has nothing to do with the VPIF.)

Agreed too. And this reminds me that this was discussed earlier.

https://patchwork.kernel.org/patch/9586853/

> In any case, I'm not trying to solve that problem in this patch, so
> thanks for the review.

I have now applied the patch to my v4.13/dt branch.

Thanks,
Sekhar