RE: [PATCH] gpio: vf610: add get_direction() support

[Bough Chen <haibo.chen@xxxxxxx>]

> -----Original Message-----
> From: Stefan Wahren <wahrenst@xxxxxxx>
> Sent: 2024年7月22日 18:32
> To: Bough Chen <haibo.chen@xxxxxxx>; linus.walleij@xxxxxxxxxx;
> brgl@xxxxxxxx
> Cc: linux-gpio@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> imx@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] gpio: vf610: add get_direction() support
> 
> Hi Haibo,
> 
> Am 22.07.24 um 08:28 schrieb haibo.chen@xxxxxxx:
> > From: Haibo Chen <haibo.chen@xxxxxxx>
> >
> > For IP which do not contain PDDR, currently use the pinmux API
> > pinctrl_gpio_direction_input() to config the output/input, pinmux
> > currently do not support get_direction(). So here add the GPIO
> > get_direction() support only for the IP which has Port Data Direction
> > Register (PDDR).
> >
> > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
> > ---
> >   drivers/gpio/gpio-vf610.c | 19 +++++++++++++++++++
> >   1 file changed, 19 insertions(+)
> >
> > diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
> > index 07e5e6323e86..08ca8377b19c 100644
> > --- a/drivers/gpio/gpio-vf610.c
> > +++ b/drivers/gpio/gpio-vf610.c
> > @@ -151,6 +151,19 @@ static int vf610_gpio_direction_output(struct
> gpio_chip *chip, unsigned gpio,
> >   	return pinctrl_gpio_direction_output(chip, gpio);
> >   }
> >
> > +static int vf610_gpio_get_direction(struct gpio_chip *gc, unsigned
> > +int gpio) {
> > +	struct vf610_gpio_port *port = gpiochip_get_data(gc);
> > +	unsigned long mask = BIT(gpio);
> thanks for sending this patch. I'm fine with this patch, but could we use u32 to
> make it clear about the range of the mask?

Yes, u32 seems more clear here, but I notice all other place use unsigned long, so I keep the same code style.
I go through the history of this driver, seems no specific explanation about the unsigned long. 
If anyone know the reason, please comment.

Best Regards
Haibo Chen 
> 
> Regards
> > +
> > +	mask &= vf610_gpio_readl(port->gpio_base + GPIO_PDDR);
> > +
> > +	if (mask)
> > +		return GPIO_LINE_DIRECTION_OUT;
> > +
> > +	return GPIO_LINE_DIRECTION_IN;
> > +}
> > +
> >   static void vf610_gpio_irq_handler(struct irq_desc *desc)
> >   {
> >   	struct vf610_gpio_port *port =
> > @@ -362,6 +375,12 @@ static int vf610_gpio_probe(struct platform_device
> *pdev)
> >   	gc->get = vf610_gpio_get;
> >   	gc->direction_output = vf610_gpio_direction_output;
> >   	gc->set = vf610_gpio_set;
> > +	/*
> > +	 * only IP has Port Data Direction Register(PDDR) can
> > +	 * support get direction
> > +	 */
> > +	if (port->sdata->have_paddr)
> > +		gc->get_direction = vf610_gpio_get_direction;
> >
> >   	/* Mask all GPIO interrupts */
> >   	for (i = 0; i < gc->ngpio; i++)