From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric.y.miao@gmail.com (Eric Miao) Date: Tue, 26 Jan 2010 18:20:13 +0800 Subject: 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) In-Reply-To: <1264500824.4480.79.camel@utx.utx.cz> References: <20100106071026.GD1382@ucw.cz> <20100107065230.GA1303@ucw.cz> <1264275669.9100.11.camel@utx.utx.cz> <1264286611.11766.49.camel@utx.utx.cz> <1264500824.4480.79.camel@utx.utx.cz> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 2010/1/26 Stanislav Brabec : > 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).) > That's why WAKEUP_ON_EDGE_* is introduced, no need for gpio-keys to know this. > I talked to Vojt?ch Pavl?k 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. > I don't mind if IRQF_TRIGGER_ will always be correct regarding the wakeup edge/level settings in MFP, but honestly - I don't think so. >> 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. Unless someone specifies that by GPIO38_GPIO | WAKEUP_ON_LEVEL_HIGH, keypad_set_wake() will never try to enable the bit in 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. > Ain't On/Off switch one of the matrix key? And so SPITZ_GPIO_KEY_INT could be used to handle that? >> 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.