On Wed, Apr 29, 2020 at 11:17:27PM +0530, Manivannan Sadhasivam wrote:
> Hi Greg,
>
> On Wed, Apr 29, 2020 at 01:26:51AM +0530, mani@xxxxxxxxxx wrote:
> > From: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> >
> > Add gpiochip support for Maxlinear/Exar USB to serial converter
> > for controlling the available gpios.
> >
> > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > Cc: linux-gpio@xxxxxxxxxxxxxxx
> > Signed-off-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> > ---
> > drivers/usb/serial/xr_serial.c | 186 ++++++++++++++++++++++++++++++++-
> > drivers/usb/serial/xr_serial.h | 7 ++
> > 2 files changed, 192 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c
> > index ea4a0b167d3f..d86fd40839f8 100644
> > --- a/drivers/usb/serial/xr_serial.c
> > +++ b/drivers/usb/serial/xr_serial.c
> > @@ -476,6 +476,189 @@ static void xr_break_ctl(struct tty_struct *tty, int break_state)
> > state);
> > }
> >
> > +#ifdef CONFIG_GPIOLIB
> > +
>
> [...]
>
> > +
> > +static int xr_gpio_init(struct usb_serial_port *port)
> > +{
> > + struct xr_port_private *port_priv = usb_get_serial_port_data(port);
> > + int ret = 0;
> > +
> > + if (port_priv->idProduct == XR21V141X_ID)
> > + ret = xr21v141x_gpio_init(port);
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > + port_priv->gc.label = "xr_gpios";
> > + port_priv->gc.request = xr_gpio_request;
> > + port_priv->gc.get_direction = xr_gpio_direction_get;
> > + port_priv->gc.direction_input = xr_gpio_direction_input;
> > + port_priv->gc.direction_output = xr_gpio_direction_output;
> > + port_priv->gc.get = xr_gpio_get;
> > + port_priv->gc.set = xr_gpio_set;
> > + port_priv->gc.owner = THIS_MODULE;
> > + port_priv->gc.parent = &port->dev;
> > + port_priv->gc.base = -1;
> > + port_priv->gc.can_sleep = true;
> > +
> > + ret = gpiochip_add_data(&port_priv->gc, port);
> > + if (!ret)
> > + port_priv->gpio_registered = true;
> > +
> > + return ret;
> > +}
> > +
> > +static void xr_gpio_remove(struct usb_serial_port *port)
> > +{
> > + struct xr_port_private *port_priv = usb_get_serial_port_data(port);
> > +
> > + if (port_priv->gpio_registered) {
> > + gpiochip_remove(&port_priv->gc);
> > + port_priv->gpio_registered = false;
> > + }
> > +}
> > +
> > +#else
> > +
> > +static int xr_gpio_init(struct usb_serial_port *port)
> > +{
> > + return 0;
> > +}
> > +
> > +static void xr_gpio_remove(struct usb_serial_port *port)
> > +{
> > + /* Nothing to do */
> > +}
> > +
> > +#endif
> > +
> > static int xr_port_probe(struct usb_serial_port *port)
> > {
> > struct usb_serial *serial = port->serial;
> > @@ -495,13 +678,14 @@ static int xr_port_probe(struct usb_serial_port *port)
> >
> > usb_set_serial_port_data(port, port_priv);
> >
> > - return 0;
> > + return xr_gpio_init(port);
>
> Just realised that the gpiochip is registered for 2 interfaces exposed by
> this chip. This is due to the fact that this chip presents CDC-ACM model,
> so there are 2 interfaces (interrupt and bulk IN/OUT).
>
> We shouldn't need gpiochip for interface 0. So what is the recommended way
> to filter that?
Not create the gpiochip for interface 0? :)
I really don't know what else to say here, sorry.
greg k-h
