[PATCH] gpio: mxs: implement get_direction callback

[Uwe Kleine-König]

Hello Richard,

> >>>> So finally the prototypes would be:
> >>>> int mctrl_gpio_request_irqs(struct mctrl_gpios*, struct
> >>>> uart_port*, irqhandler_t);
> >>>> void mctrl_gpio_free_irqs(struct mctrl_gpios*);
> >>
> >> I think:
> >>
> >>         struct mctrl_gpios {
> >>                 struct uart_port *port;
> >>                 struct {
> >>                         gpio_desc *gpio;
> >>                         unsigned int irq;
> I think it's just "int irq;" there
irqs are unsigned. Some functions returning an irq use "int", but
depending on who you ask this only for error reporting or a relict.
Use 0 for invalid/unused in mctrl_gpio*.

> > Yes. I tried to assign irq value in mctrl_gpio_init() only.
> > There was another issue if CONFIG_GPIOLIB is not defined but it looks mctrl_
> > disable/enable_ms()
> > and mctrl_ irq handler solve the problem.
> >
> >>   Not sure there is a corresponding request_irq variant for that.
> >
> >
> > What would you propose?
> In atmel_request_gpio_irq(), the function irq_set_status_flags(irq,
> IRQ_NOAUTOEN); is used before request_irq to prevent the irq from
> being enabled when requested.
I'm not sure this is allowed. How do you handle request_irq failing? (I
just checked: you don't.) Consider another thread just doing
request_irq($yourirq, ...) between

	irq_set_status_flags(irq[i], IRQ_NOAUTOEN);

and

	err = request_irq(irq[i], ...

.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |