> -----Original Message-----
> From: dmitry.torokhov@xxxxxxxxx <dmitry.torokhov@xxxxxxxxx>
> Sent: Thursday, October 22, 2020 3:56 AM
> To: Jun Li <jun.li@xxxxxxx>
> Cc: heikki.krogerus@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx;
> rafael@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
> andriy.shevchenko@xxxxxxxxxxxxxxx; hdegoede@xxxxxxxxxx;
> lee.jones@xxxxxxxxxx; mika.westerberg@xxxxxxxxxxxxxxx;
> prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx;
> laurent.pinchart+renesas@xxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; Peter Chen
> <peter.chen@xxxxxxx>
> Subject: Re: [PATCH v4 4/4] usb: typec: mux: add typec switch simple driver
>
> Hi,
>
> On Mon, Oct 19, 2020 at 05:03:15PM +0800, Li Jun wrote:
> > +
> > +static int typec_switch_simple_set(struct typec_switch *sw,
> > + enum typec_orientation orientation) {
> > + struct typec_switch_simple *typec_sw = typec_switch_get_drvdata(sw);
> > +
> > + mutex_lock(&typec_sw->lock);
>
> Why is this lock needed? It looks like we are passing requests directly to
> gpiochip which I expect would take care of this.
Checked some gpiochips, looks like with only GPIO, yes, this lock is not required,
I will remove it.
>
> > +
> > + switch (orientation) {
> > + case TYPEC_ORIENTATION_NORMAL:
> > + if (typec_sw->sel_gpio)
> > + gpiod_set_value_cansleep(typec_sw->sel_gpio, 1);
> > + break;
> > + case TYPEC_ORIENTATION_REVERSE:
> > + if (typec_sw->sel_gpio)
> > + gpiod_set_value_cansleep(typec_sw->sel_gpio, 0);
> > + break;
> > + case TYPEC_ORIENTATION_NONE:
> > + break;
> > + }
> > +
> > + mutex_unlock(&typec_sw->lock);
> > +
> > + return 0;
> > +}
> > +
> > +static int typec_switch_simple_probe(struct platform_device *pdev) {
> > + struct typec_switch_simple *typec_sw;
> > + struct device *dev = &pdev->dev;
> > + struct typec_switch_desc sw_desc;
> > +
> > + typec_sw = devm_kzalloc(dev, sizeof(*typec_sw), GFP_KERNEL);
> > + if (!typec_sw)
> > + return -ENOMEM;
> > +q
> > + platform_set_drvdata(pdev, typec_sw);
> > +
> > + sw_desc.drvdata = typec_sw;
> > + sw_desc.fwnode = dev->fwnode;
> > + sw_desc.set = typec_switch_simple_set;
> > + mutex_init(&typec_sw->lock);
> > +
> > + /* Get the super speed active channel selection GPIO */
> > + typec_sw->sel_gpio = devm_gpiod_get_optional(dev, "switch",
> > + GPIOD_OUT_LOW);
>
> Does this driver make sense without the GPIO? Should it be made mandatory?
My old version made it to be mandatory, I change it to be optional in this version
for possible extend to other simple typec switch design which do not use GPIO as
this is going to be a generic typec switch driver. yes, for current implementation,
this driver will only register a typec switch in sys if without GPIO provided.
Li Jun
>
> Thanks.
>
> --
> Dmitry
