Re: [PATCH v3 4/4] gpio: brcmstb: support wakeup from S5 cold boot

Gregory Fong
2015-07-14T02:31:33Z

On Mon, Jul 13, 2015 at 6:03 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Thu, Jun 18, 2015 at 3:00 AM, Gregory Fong <gregory.0xf0@gmail.com> wrote:
>
>> For wake from S5, we need to:
>> - register a reboot handler
>> - set wakeup capability before requesting IRQ so wakeup count is
>> incremented
>> - mask all GPIO IRQs and clear any pending interrupts during driver
>> probe to since no driver will yet be registered to handle any IRQs
>> carried over from boot at that time, and it's possible that the
>> booted kernel does not request the same IRQ anyway.
>>
>> This means that /sys/.../power/wakeup_count is valid at boot time, and
>> we can properly account for S5 wakeup stats. e.g.:
>>
>> ### After waking from S5 from a GPIO key
>> # cat /sys/bus/platform/drivers/brcmstb-gpio/f04172c0.gpio/power/wakeup
>> enabled
>> # cat /sys/bus/platform/drivers/brcmstb-gpio/f04172c0.gpio/power/wakeup_count
>> 1
>>
>> Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
>
> (...)
>> -static int brcmstb_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
>> +static int __brcmstb_gpio_irq_set_wake(struct brcmstb_gpio_priv *priv,
>> + unsigned int enable)
>> {
>> - struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
>> - struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
>> int ret = 0;
>
> I don't usually like to refactor code with __foo wrapper functions with
> underscores or double underscores in front of them.
>
> Is it possible to give this a more unique name?

Sure, just have to come up with a good one :-).

>
>> + /*
>> + * Mask all interrupts by default, since wakeup interrupts may
>> + * be retained from S5 cold boot
>> + */
>> + bank->bgc.write_reg(reg_base + GIO_MASK(bank->id), 0);
>
> Aha I see, that's some clever code, nice.
>
> Yours,
> Linus Walleij