Messages in this thread | | | Subject | Re: gpio_keys and how PXA27x sets gpio_set_wake() (was Re: sharp c-3000 aka spitz: fix warn_on introduced in 2.6.32-rc1) | From | Stanislav Brabec <> | Date | Tue, 26 Jan 2010 11:13:44 +0100 |
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Eric Miao wrota:
> I prefer 2) - the ugly and hardcoded setup in spitz_pm.c should really > be removed. That's why the gpio_set_wake() and keypad_set_wake() > are introduced.
I am unsure, whether gpio_keys driver is interested in the way, how wake happens. I guess that is interested only in the fact, that wake happened.
Handling platform specific edge/level wake setup would only complicate the code. (In fact, even the PXA270 platform code does not exist yet - arch/arm/mach-pxa/mfp-pxa2xx.c:__mfp_config_gpio() is not capable to configure Power Manager Keyboard Wake-Up Enable Register (PKWR).)
I talked to Vojtěch Pavlík and he told that 1 is correct: Follow include/linux/interrupt.h. Setting edge/level wake mode should be done in the platform file. The driver could use just irq_set_wake() and don't care about details. And irq_set_wake() should do something useful even for PKWR capable GPIO.
> keypad_set_wake() is really specifically introduced for use by pxa27x_keypad > and no generic GPIO stuffs. So it's really annoying a GPIO will use > the PKWR as a wakeup GPIO, I'd recommend one still get this hard coded > into the platform file, with combination of WAKEUP_ON_LEVEL_HIGH (which > is specifically designed for keypad GPIOs) and keypad_set_wake().
Well, keypad_set_wake() seems to be possibly broken for GPIO 38. Imagine a device, that has a small keypad, but GPIO 38 has a different purpose that requires an edge triggered wakeup (PWER). I think that keypad_set_wake() reprograms it to PKWR.
The problem affects gpio_keys: It is a driver implementing "one key per gpio". It now handles On/Off and lid switches on Zaurus. Lid switches are on "normal" GPIOs, On/Off switch is wired to PKWR capable GPIO.
> The spitz, however, is doing a good job on this though it's using a GPIO > emulated matrix keypad, that there is a separate SPITZ_GPIO_KEY_INT, > which triggers whenever there is any key press on this matrix (I don't > know how that's designed in HW, but it seems to do that job), and > which can be setup as a GPIO wakeup.
SPITZ_GPIO_KEY_INT happens if AC adapter is connected or key is pressed. Surprisingly, the key press logic is part of NAND flash controller CPLD. SPITZ_GPIO_KEY_INT==0 - it makes possible to wake Zaurus even from deep sleep by any key press. It would be impossible only with PKWR.
I guess that this and implementation of keypad_set_wake() is a reason, why most devices suspend and resume correctly even if the irq_set_wake() refuses to configure wake and the warning is only visible symptom.
________________________________________________________________________ Stanislav Brabec http://www.penguin.cz/~utx
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