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

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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

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