gpio-omap: wakeup mask

Hi everyone,

we have a device with an am335x and are using some gpios on bank0 to wake up the device from suspend to ram.

We have some user buttons which are configured in the devicetree as gpio-keys and one power-key which should wake up the device:

&buttons {
        power {
                label = "Power";
                gpios = <&gpio0 6 1>;
                linux,code = <116>;
                gpio-key,wakeup;
        };

        one {
                label = "One";
                gpios = <&gpio0 11 1>;
                linux,code = <2>;
        };

        : : :
}

The problem is, that the device wakes up on any trigger on bank 0. No matter which button was pressed. "gpio-key,wakeup" seems not to have any influence.

Now, if I comment the following lines out in drivers/gpio/gpio-omap.c :
set_gpio_trigger(...).

321
322 if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
323 _gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0);
324 bank->context.wake_en =
325 readl_relaxed(bank->base + bank->regs->wkup_en);
326 }
327

Everything works as expected. But I don't really understand why? Is this a bug, or does this break something else I have not discovered yet?

Quoted 40 lines · Pascal Huerst

Hi everyone,

we have a device with an am335x and are using some gpios on bank0 to wake up the device from suspend to ram.

We have some user buttons which are configured in the devicetree as gpio-keys and one power-key which should wake up the device:

&buttons {
        power {
                label = "Power";
                gpios = <&gpio0 6 1>;
                linux,code = <116>;
                gpio-key,wakeup;
        };

        one {
                label = "One";
                gpios = <&gpio0 11 1>;
                linux,code = <2>;
        };

        : : :
}

The problem is, that the device wakes up on any trigger on bank 0. No matter which button was pressed. "gpio-key,wakeup" seems not to have any influence.

Now, if I comment the following lines out in drivers/gpio/gpio-omap.c :
set_gpio_trigger(...).

321
322 if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
323 _gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0);
324 bank->context.wake_en =
325 readl_relaxed(bank->base + bank->regs->wkup_en);
326 }
327

Quoted 2 lines

Everything works as expected. But I don't really understand why? Is this a bug, or does this break something else I have not discovered yet?

The GPIO wake-up events are working from off-idle for omap3 the last time I checked, so sounds like this is some am335x related issue.

What does your bank->context.wake_en mask get set to with this code?

Hey Tony, all

Quoted 41 lines · Tony Lindgren

Quoted 40 lines · Pascal Huerst

Hi everyone,

we have a device with an am335x and are using some gpios on bank0 to wake up the device from suspend to ram.

We have some user buttons which are configured in the devicetree as gpio-keys and one power-key which should wake up the device:

&buttons {
        power {
                label = "Power";
                gpios = <&gpio0 6 1>;
                linux,code = <116>;
                gpio-key,wakeup;
        };

        one {
                label = "One";
                gpios = <&gpio0 11 1>;
                linux,code = <2>;
        };

        : : :
}

The problem is, that the device wakes up on any trigger on bank 0. No matter which button was pressed. "gpio-key,wakeup" seems not to have any influence.

Now, if I comment the following lines out in drivers/gpio/gpio-omap.c :
set_gpio_trigger(...).

321
322 if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
323 _gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0);
324 bank->context.wake_en =
325 readl_relaxed(bank->base + bank->regs->wkup_en);
326 }
327

Quoted 6 lines

Quoted 2 lines

Everything works as expected. But I don't really understand why? Is this a bug, or does this break something else I have not discovered yet?

The GPIO wake-up events are working from off-idle for omap3 the last time I checked, so sounds like this is some am335x related issue.

Ok, that sounds reasonable.

Quoted 1 line

What does your bank->context.wake_en mask get set to with this code?

by calling 'echo mem > /sys/power/state' followed by a wakeup, I get the following:

[   28.992866] bank->context->wake_en = 00080040
[   29.020974] PM: noirq resume of devices complete after 22.439 msecs

Quoted 55 lines · Pascal Huerst

Hey Tony, all

Quoted 41 lines · Tony Lindgren

Quoted 40 lines · Pascal Huerst

Hi everyone,

we have a device with an am335x and are using some gpios on bank0 to wake up the device from suspend to ram.

We have some user buttons which are configured in the devicetree as gpio-keys and one power-key which should wake up the device:

&buttons {
        power {
                label = "Power";
                gpios = <&gpio0 6 1>;
                linux,code = <116>;
                gpio-key,wakeup;
        };

        one {
                label = "One";
                gpios = <&gpio0 11 1>;
                linux,code = <2>;
        };

        : : :
}

The problem is, that the device wakes up on any trigger on bank 0. No matter which button was pressed. "gpio-key,wakeup" seems not to have any influence.

Now, if I comment the following lines out in drivers/gpio/gpio-omap.c :
set_gpio_trigger(...).

321
322 if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
323 _gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0);
324 bank->context.wake_en =
325 readl_relaxed(bank->base + bank->regs->wkup_en);
326 }
327

Quoted 6 lines

Quoted 2 lines

Everything works as expected. But I don't really understand why? Is this a bug, or does this break something else I have not discovered yet?

The GPIO wake-up events are working from off-idle for omap3 the last time I checked, so sounds like this is some am335x related issue.

Ok, that sounds reasonable.

Quoted 1 line

What does your bank->context.wake_en mask get set to with this code?

Quoted 5 lines

by calling 'echo mem > /sys/power/state' followed by a wakeup, I get the following:

[   28.992866] bank->context->wake_en = 00080040
[   29.020974] PM: noirq resume of devices complete after 22.439 msecs

I guess that's for gpio bank 0 with no bit 11 as your dts has it configured.

If you just comment out the _gpio_rmw part above do things work as expected?

Then if that works as expected, maybe write only some unused bits into wkup_en register and see if it still wakes to all events while it should not?

It might be worth comparing the GPIO registers between am37xx and am335x for the wkup_en register.

Quoted 2 lines · Tony Lindgren

If you just comment out the _gpio_rmw part above do things work as expected?

Yes. It only wakes up on gpio 6 not on gpio 11 anymore.

Quoted 3 lines

Then if that works as expected, maybe write only some unused bits into wkup_en register and see if it still wakes to all events while it should not?

If I use the following testcode, everything works as expected:

//WARN(true, "WARN: bank->base = %08X\n", bank->base);

if (likely(!(bank->non_wakeup_gpios & gpio_bit))) {
//_gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0); writel(0xABC00000, base + bank->regs->wkup_en);

bank->context.wake_en = readl_relaxed(bank->base +

    bank->regs->wkup_en);
  printk("bank->base = %08X gpio = %i bank->context->wake_en = %08X\n",
    bank->base, gpio, bank->context.wake_en);
}

Quoted 15 lines · Pascal Huerst

Quoted 2 lines · Tony Lindgren

If you just comment out the _gpio_rmw part above do things work as expected?

Yes. It only wakes up on gpio 6 not on gpio 11 anymore.

Quoted 3 lines

Then if that works as expected, maybe write only some unused bits into wkup_en register and see if it still wakes to all events while it should not?

If I use the following testcode, everything works as expected:

//WARN(true, "WARN: bank->base = %08X\n", bank->base);

Quoted 8 lines

if (likely(!(bank->non_wakeup_gpios & gpio_bit))) { //_gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0); writel(0xABC00000, base + bank->regs->wkup_en);

bank->context.wake_en = readl_relaxed(bank->base + bank->regs->wkup_en); printk("bank->base = %08X gpio = %i bank->context->wake_en = %08X\n", bank->base, gpio, bank->context.wake_en); }

Hmm weird. It sounds like something like the following is happening:

1. The first GPIO bank is always powered, and does not need to set wake-up events

2. When setting the GPIO wake-up events it seems that enabling any wake-up event for the first (16?) bits wakes up the system

You might want to check this with some spare GPIOs not in the first bank and see if you need the wake-up events and if enabling some bits enables more than one GPIO for wake-up events.

Quoted 28 lines · Tony Lindgren

Quoted 15 lines · Pascal Huerst

Quoted 2 lines · Tony Lindgren

If you just comment out the _gpio_rmw part above do things work as expected?

Yes. It only wakes up on gpio 6 not on gpio 11 anymore.

Quoted 3 lines

Then if that works as expected, maybe write only some unused bits into wkup_en register and see if it still wakes to all events while it should not?

If I use the following testcode, everything works as expected:

//WARN(true, "WARN: bank->base = %08X\n", bank->base);

Quoted 8 lines

if (likely(!(bank->non_wakeup_gpios & gpio_bit))) { //_gpio_rmw(base, bank->regs->wkup_en, gpio_bit, trigger != 0); writel(0xABC00000, base + bank->regs->wkup_en);

bank->context.wake_en = readl_relaxed(bank->base + bank->regs->wkup_en); printk("bank->base = %08X gpio = %i bank->context->wake_en = %08X\n", bank->base, gpio, bank->context.wake_en); }

Hmm weird. It sounds like something like the following is happening:

Quoted 2 lines

1. The first GPIO bank is always powered, and does not need to set wake-up events

I dont think so. If I apply my hack (commenting the _gpio_rmw() call) and don't have a wakeup source in the dt, I have to reboot the system, sonce im not able to wake it up anymore. Or did I miss something?

Quoted 6 lines

2. When setting the GPIO wake-up events it seems that enabling any wake-up event for the first (16?) bits wakes up the system

You might want to check this with some spare GPIOs not in the first bank and see if you need the wake-up events and if enabling some bits enables more than one GPIO for wake-up events.

Im not sure if this makes sense, since only the first gpio bank can act as a wakeup source. So it should not be possible.