From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Date: Fri, 11 Dec 2015 18:33:18 +0000 Subject: Re: [PATCH] extcon-usb-gpio: add enable pin support Message-Id: <566B16EE.5080206@cogentembedded.com> List-Id: References: <4393960.B6dD3UkQy3@wasted.cogentembedded.com> <20151211035312.GA9088@rob-hp-laptop> In-Reply-To: <20151211035312.GA9088@rob-hp-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rob Herring Cc: pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, myungjoo.ham@samsung.com, cw00.choi@samsung.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org 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 >> >> --- >> 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