Thread (41 messages) 41 messages, 5 authors, 2014-11-18

[PATCH] gpio: mxs: implement get_direction callback

From: Richard Genoud <hidden>
Date: 2014-11-17 10:06:13
Also in: linux-gpio, linux-serial

2014-11-17 10:59 GMT+01:00 Uwe Kleine-K?nig [off-list ref]:
Hello Richard,
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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*.
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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.
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  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], ...
well, in this case, request_irq() will fail and all the previously
requested irqs will be freed:
    /*
     * If something went wrong, rollback.
     */
    while (err && (--i >= 0))
        if (irq[i] >= 0)
            free_irq(irq[i], port);
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