[PATCH] extcon-usb-gpio: add enable pin support

[PATCH] extcon-usb-gpio: add enable pin support

[Sergei Shtylyov]

Sometimes  there's a real  OTG chip behind the USB ID signal mapped to a GPIO
pin: in my case it's Maxim Integrated MAX3355E which  integrates Vbus charge
pump and comparators and passes  thru the ID  signal  from an OTG connector.
This chip also has the SHDN# pin which  should be  driven high for the normal
operation  and low to  save power;  it  is connected to a GPIO pin as well on,
hence  we'll have  to  teach the driver to parse the new optional device tree
property, "enable-gpio"...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
The patch is against the 'extcon-next' branch of the 'extcon.git' repo.

 Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt |    3 +++
 drivers/extcon/extcon-usb-gpio.c                             |    5 +++++
 2 files changed, 8 insertions(+)

Index: extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
=================================--- extcon.orig/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
+++ extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
@@ -7,6 +7,9 @@ Required properties:
 - compatible: Should be "linux,extcon-usb-gpio"
 - id-gpio: gpio for USB ID pin. See gpio binding.
 
+Optional properties:
+- enable-gpio: gpio for the enable pin. See gpio binding.
+
 Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below:
 	extcon_usb1 {
 		compatible = "linux,extcon-usb-gpio";
Index: extcon/drivers/extcon/extcon-usb-gpio.c
=================================--- extcon.orig/drivers/extcon/extcon-usb-gpio.c
+++ extcon/drivers/extcon/extcon-usb-gpio.c
@@ -33,6 +33,7 @@ struct usb_extcon_info {
 	struct device *dev;
 	struct extcon_dev *edev;
 
+	struct gpio_desc *enable_gpiod;
 	struct gpio_desc *id_gpiod;
 	int id_irq;
 
@@ -99,6 +100,8 @@ static int usb_extcon_probe(struct platf
 		return -ENOMEM;
 
 	info->dev = dev;
+	info->enable_gpiod = devm_gpiod_get_optional(&pdev->dev, "enable",
+						     GPIOD_OUT_HIGH);
 	info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
 	if (IS_ERR(info->id_gpiod)) {
 		dev_err(dev, "failed to get ID GPIO\n");
@@ -155,6 +158,8 @@ static int usb_extcon_remove(struct plat
 
 	cancel_delayed_work_sync(&info->wq_detcable);
 
+	gpiod_set_value_cansleep(info->enable_gpiod, 0);
+
 	return 0;
 }
 

Re: [PATCH] extcon-usb-gpio: add enable pin support

[Rob Herring]

On Fri, Dec 11, 2015 at 02:07:05AM +0300, Sergei Shtylyov wrote:
> Sometimes  there's a real  OTG chip behind the USB ID signal mapped to a GPIO
> pin: in my case it's Maxim Integrated MAX3355E which  integrates Vbus charge
> pump and comparators and passes  thru the ID  signal  from an OTG connector.
> This chip also has the SHDN# pin which  should be  driven high for the normal
> operation  and low to  save power;  it  is connected to a GPIO pin as well on,
> hence  we'll have  to  teach the driver to parse the new optional device tree
> property, "enable-gpio"...

Some wierd spacing going on here.

> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> The patch is against the 'extcon-next' branch of the 'extcon.git' repo.
> 
>  Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt |    3 +++
>  drivers/extcon/extcon-usb-gpio.c                             |    5 +++++
>  2 files changed, 8 insertions(+)
> 
> Index: extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> =================================> --- extcon.orig/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> +++ extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> @@ -7,6 +7,9 @@ Required properties:
>  - compatible: Should be "linux,extcon-usb-gpio"
>  - id-gpio: gpio for USB ID pin. See gpio binding.
>  
> +Optional properties:
> +- enable-gpio: gpio for the enable pin. See gpio binding.

Use -gpios as -gpio is deprecated. 

> +
>  Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below:
>  	extcon_usb1 {
>  		compatible = "linux,extcon-usb-gpio";
> Index: extcon/drivers/extcon/extcon-usb-gpio.c
> =================================> --- extcon.orig/drivers/extcon/extcon-usb-gpio.c
> +++ extcon/drivers/extcon/extcon-usb-gpio.c
> @@ -33,6 +33,7 @@ struct usb_extcon_info {
>  	struct device *dev;
>  	struct extcon_dev *edev;
>  
> +	struct gpio_desc *enable_gpiod;
>  	struct gpio_desc *id_gpiod;
>  	int id_irq;
>  
> @@ -99,6 +100,8 @@ static int usb_extcon_probe(struct platf
>  		return -ENOMEM;
>  
>  	info->dev = dev;
> +	info->enable_gpiod = devm_gpiod_get_optional(&pdev->dev, "enable",
> +						     GPIOD_OUT_HIGH);
>  	info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
>  	if (IS_ERR(info->id_gpiod)) {
>  		dev_err(dev, "failed to get ID GPIO\n");
> @@ -155,6 +158,8 @@ static int usb_extcon_remove(struct plat
>  
>  	cancel_delayed_work_sync(&info->wq_detcable);
>  
> +	gpiod_set_value_cansleep(info->enable_gpiod, 0);

Shouldn't you support either polarity?

Rob

Re: [PATCH] extcon-usb-gpio: add enable pin support

[Sergei Shtylyov]

Hello.

On 12/11/2015 06:53 AM, Rob Herring wrote:

>> Sometimes  there's a real  OTG chip behind the USB ID signal mapped to a GPIO
>> pin: in my case it's Maxim Integrated MAX3355E which  integrates Vbus charge
>> pump and comparators and passes  thru the ID  signal  from an OTG connector.
>> This chip also has the SHDN# pin which  should be  driven high for the normal
>> operation  and low to  save power;  it  is connected to a GPIO pin as well on,
>> hence  we'll have  to  teach the driver to parse the new optional device tree
>> property, "enable-gpio"...
>
> Some wierd spacing going on here.

    I like my text properly filling up the given columns. What's the problem? :-)

>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>
>> ---
>> The patch is against the 'extcon-next' branch of the 'extcon.git' repo.
>>
>>   Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt |    3 +++
>>   drivers/extcon/extcon-usb-gpio.c                             |    5 +++++
>>   2 files changed, 8 insertions(+)
>>
>> Index: extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
>> =================================>> --- extcon.orig/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
>> +++ extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
>> @@ -7,6 +7,9 @@ Required properties:
>>   - compatible: Should be "linux,extcon-usb-gpio"
>>   - id-gpio: gpio for USB ID pin. See gpio binding.
>>
>> +Optional properties:
>> +- enable-gpio: gpio for the enable pin. See gpio binding.
>
> Use -gpios as -gpio is deprecated.

    Didn't know, thanks.

[...]
>> Index: extcon/drivers/extcon/extcon-usb-gpio.c
>> =================================>> --- extcon.orig/drivers/extcon/extcon-usb-gpio.c
>> +++ extcon/drivers/extcon/extcon-usb-gpio.c
[...]
>> @@ -99,6 +100,8 @@ static int usb_extcon_probe(struct platf
>>   		return -ENOMEM;
>>
>>   	info->dev = dev;
>> +	info->enable_gpiod = devm_gpiod_get_optional(&pdev->dev, "enable",
>> +						     GPIOD_OUT_HIGH);
>>   	info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
>>   	if (IS_ERR(info->id_gpiod)) {
>>   		dev_err(dev, "failed to get ID GPIO\n");
>> @@ -155,6 +158,8 @@ static int usb_extcon_remove(struct plat
>>
>>   	cancel_delayed_work_sync(&info->wq_detcable);
>>
>> +	gpiod_set_value_cansleep(info->enable_gpiod, 0);

> Shouldn't you support either polarity?

    The gpiolib does that for me -- devm_gpiod_get_optional() should read the 
polarity from DT.

> Rob

MBR, Sergei

Re: [PATCH] extcon-usb-gpio: add enable pin support

[Chanwoo Choi]

Hi Sergei,

On 2015년 12월 11일 08:07, Sergei Shtylyov wrote:
> Sometimes  there's a real  OTG chip behind the USB ID signal mapped to a GPIO
> pin: in my case it's Maxim Integrated MAX3355E which  integrates Vbus charge
> pump and comparators and passes  thru the ID  signal  from an OTG connector.

s/thru/through ?

> This chip also has the SHDN# pin which  should be  driven high for the normal
> operation  and low to  save power;  it  is connected to a GPIO pin as well on,
> hence  we'll have  to  teach the driver to parse the new optional device tree
> property, "enable-gpio"...

This patch description includes the double space between words. Also, I think
you need to write the patch description again for formal style.

This patch adds the specific 'enable-gpio' pin to express the SHDN#pin for MAX3355E.
I think it is not regular and standard case because maybe USB specification
don't include the SHDN#pin information. I think it not appropriate way.
Instead, you better to make the MAX3355 extcon driver to support this case.

Thanks,
Chanwoo 

> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> The patch is against the 'extcon-next' branch of the 'extcon.git' repo.
> 
>  Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt |    3 +++
>  drivers/extcon/extcon-usb-gpio.c                             |    5 +++++
>  2 files changed, 8 insertions(+)
> 
> Index: extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> =================================> --- extcon.orig/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> +++ extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
> @@ -7,6 +7,9 @@ Required properties:
>  - compatible: Should be "linux,extcon-usb-gpio"
>  - id-gpio: gpio for USB ID pin. See gpio binding.
>  
> +Optional properties:
> +- enable-gpio: gpio for the enable pin. See gpio binding.
> +
>  Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below:
>  	extcon_usb1 {
>  		compatible = "linux,extcon-usb-gpio";
> Index: extcon/drivers/extcon/extcon-usb-gpio.c
> =================================> --- extcon.orig/drivers/extcon/extcon-usb-gpio.c
> +++ extcon/drivers/extcon/extcon-usb-gpio.c
> @@ -33,6 +33,7 @@ struct usb_extcon_info {
>  	struct device *dev;
>  	struct extcon_dev *edev;
>  
> +	struct gpio_desc *enable_gpiod;
>  	struct gpio_desc *id_gpiod;
>  	int id_irq;
>  
> @@ -99,6 +100,8 @@ static int usb_extcon_probe(struct platf
>  		return -ENOMEM;
>  
>  	info->dev = dev;
> +	info->enable_gpiod = devm_gpiod_get_optional(&pdev->dev, "enable",
> +						     GPIOD_OUT_HIGH);
>  	info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
>  	if (IS_ERR(info->id_gpiod)) {
>  		dev_err(dev, "failed to get ID GPIO\n");
> @@ -155,6 +158,8 @@ static int usb_extcon_remove(struct plat
>  
>  	cancel_delayed_work_sync(&info->wq_detcable);
>  
> +	gpiod_set_value_cansleep(info->enable_gpiod, 0);
> +
>  	return 0;
>  }
>  
> 
> --
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> 

Re: [PATCH] extcon-usb-gpio: add enable pin support

[Sergei Shtylyov]

Hello.

On 12/11/2015 07:05 AM, Chanwoo Choi wrote:

>> Sometimes  there's a real  OTG chip behind the USB ID signal mapped to a GPIO
>> pin: in my case it's Maxim Integrated MAX3355E which  integrates Vbus charge
>> pump and comparators and passes  thru the ID  signal  from an OTG connector.
>
> s/thru/through ?

    "Thru" is valid English.

>> This chip also has the SHDN# pin which  should be  driven high for the normal
>> operation  and low to  save power;  it  is connected to a GPIO pin as well on,
>> hence  we'll have  to  teach the driver to parse the new optional device tree
>> property, "enable-gpio"...

> This patch description includes the double space between words. Also, I think

    So what?

> you need to write the patch description again for formal style.

    Not sure I understand you.

> This patch adds the specific 'enable-gpio' pin to express the SHDN#pin for MAX3355E.
> I think it is not regular and standard case because maybe USB specification
> don't include the SHDN#pin information.

    Certainly, it's not a USB pin.

> I think it not appropriate way.
> Instead, you better to make the MAX3355 extcon driver to support this case.

    OK, just didn't want to duplicate most of this driver there...

> Thanks,
> Chanwoo

MBR, Sergei