2008-03-14 06:48:14     bfin_gpio.c non-GPIO port protection

2008-03-14 06:48:14     bfin_gpio.c non-GPIO port protection

Diego Serafin (ITALY)

Message: 52535    Hi everybody,

The function that sets up a blackfin PF port to GPIO or specific function (port_setup) allows reconfiguration of the port itself to GPIO mode even if the port's FER register was set to enable a peripheral function instead.

void port_setup(unsigned short gpio, unsigned short usage)

{

    if (usage == GPIO_USAGE) {

        if (*port_fer[gpio_bank(gpio)] & gpio_bit(gpio))

            printk(KERN_WARNING "bfin-gpio: Possible Conflict with Peripheral "

                   "usage and GPIO %d detected!\n", gpio);

        *port_fer[gpio_bank(gpio)] &= ~gpio_bit(gpio);

    } else

        *port_fer[gpio_bank(gpio)] |= gpio_bit(gpio);

    SSYNC();

}

Wouldn't be safer to _not_ allow peripheral-function-to-GPIO port reconfiguration instead of printing only a kern warning? IMHO using module bfin_pflags from user's space could be very dangerous without this policy.

Regards,

Diego.

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2008-03-14 07:02:01     Re: bfin_gpio.c non-GPIO port protection

Mike Frysinger (UNITED STATES)

Message: 52537    i'm guessing you're looking at an older kernel ... this is already fixed in 2008R1+

you use the peripheral request function to request a pin for peripheral usage and gpio request will fail if it's already been allocated as a peripheral

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2008-03-14 09:05:23     Re: bfin_gpio.c non-GPIO port protection

Diego Serafin (ITALY)

Message: 52542    Do'h!

I'm still on 2007R1 .... sorry

Thank you Mike,

Diego