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@xxxxxxxxxxxxxxxxxx>
> >
> > ---
> > 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/