Re: gpio-omap: wakeup mask

On 09.07.2014 12:41, Tony Lindgren wrote:

* Pascal Huerst [off-list ref] [140709 03:18]:

quoted

Hey Tony, all

On 04.07.2014 09:27, Tony Lindgren wrote:

quoted

* Pascal Huerst [off-list ref] [140702 05:12]:

quoted

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?

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

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

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

Yes that's right. I forgot to print the context, too. If I do so, it's:

[   31.034972] bank->base = F9E07000 gpio = 6 bank->context->wake_en =
00080040

respectively:

[   31.846992] bank->base = F9E07000 gpio = 11 bank->context->wake_en =
00080040

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.

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);
}

This produces the following output:

[   35.319228] PM: Syncing filesystems ... done.
[   35.358702] Freezing user space processes ... (elapsed 0.003 seconds)
done.
[   35.369754] Freezing remaining freezable tasks ... (elapsed 0.002
seconds) done.
[   35.380734] PM: Sending message for entering DeepSleep mode
[   35.515932] bank->base = F9E07000 gpio = 19 bank->context->wake_en =
ABC00000
[   35.529319] PM: suspend of devices complete after 137.218 msecs
[   35.544410] PM: late suspend of devices complete after 8.715 msecs
[   35.562247] omap_hwmod: cpgmac0: _wait_target_disable failed
[   35.569325] PM: noirq suspend of devices complete after 18.289 msecs
[   35.576156] PM: GFX domain entered low power state
[   35.576156] PM: Could not transition all powerdomains to target state
[   35.576156] PM: Wakeup source GPIO0
[   35.576156] PM Wakeup source extra: 00000840
[   35.576329] bank->base = F9E07000 gpio = 6 bank->context->wake_en =
ABC00000
[   35.583710] bank->base = F9E07000 gpio = 11 bank->context->wake_en =
ABC00000
[   35.614846] PM: noirq resume of devices complete after 22.582 msecs
[   35.622009] bank->base = F9E07000 gpio = 6 bank->context->wake_en =
ABC00000
[   35.631798] bank->base = F9E07000 gpio = 11 bank->context->wake_en =
ABC00000
[   35.639511] bank->base = F9E07000 gpio = 19 bank->context->wake_en =
ABC00000
[   35.647116] bank->base = FA04C000 gpio = 9 bank->context->wake_en =
ABC00000
[   35.654547] bank->base = FA04C000 gpio = 12 bank->context->wake_en =
ABC00000
[   35.662015] bank->base = FA04C000 gpio = 13 bank->context->wake_en =
ABC00000
[   35.669526] bank->base = FA04C000 gpio = 14 bank->context->wake_en =
ABC00000
[   35.677039] bank->base = FA04C000 gpio = 15 bank->context->wake_en =
ABC00000
[   35.685035] bank->base = FA1AC000 gpio = 17 bank->context->wake_en =
ABC00000
[   35.692507] bank->base = FA1AC000 gpio = 18 bank->context->wake_en =
ABC00000
[   35.706466] PM: early resume of devices complete after 6.235 msecs
[   35.715010] net eth0: initializing cpsw version 1.12 (0)
[   35.794388] net eth0: phy found : id is : 0x4dd076
[   35.849941] mmc0: error -110 during resume (card was removed?)
[   35.856164] dpm_run_callback(): mmc_bus_resume+0x0/0x74 returns -110
[   35.862828] PM: Device mmc0:0001 failed to resume: error -110
[   35.914573] PM: resume of devices complete after 201.604 msecs
[   35.927336] PM: Sending message for resetting M3 state machine
[   35.934236] Restarting tasks ... done.

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

I had a quick look, but did not find anything. May be I will have to
look into that again.

Thanks
Pascal