On Wed, Apr 06, 2016 at 11:32:55AM +0000, Nava kishore Manne wrote: > > -----Original Message----- > > From: Linus Walleij [mailto:linus.walleij@xxxxxxxxxx] > > Sent: Monday, April 04, 2016 4:38 PM > > To: Nava kishore Manne > > Cc: Dmitry Torokhov; Andersson, Björn; Nava kishore Manne; Peng Fan; > > Linux Input; linux-kernel@xxxxxxxxxxxxxxx > > Subject: Re: [LINUX PATCH v2] gpio_keys: Added support to read the > > IRQ_FLAGS from devicetree > > > > On Mon, Apr 4, 2016 at 11:56 AM, Nava kishore Manne > > <nava.manne@xxxxxxxxxx> wrote: > > > > > This patch adds the support to read the IRQ_FLAGS from the device > > > instead of hard code the flags in gpio_keys_setup_key(). > > > > NACK > > > > > sw14 { > > > label = "sw14"; > > > gpios = <&gpio0 12 1>; > > > /* > > > * Triggering Type: > > > * > > > * 1 - edge rising > > > * 2 - edge falling > > > * 4 - level active high > > > * 8 - level active low > > > * > > > */ > > > > You are completely violating the existing GPIO flags from include/dt- > > bindings/gpio/gpio.h > > > > As you will see, for a twocell GPIO flags are already clearly defined for 0,1,2 > > and 3. (Bit 0 & 1). > > > > Further, these IRQ edge/level flags already exist in include/dt- > > bindings/interrupt-controller/irq.h > > but you should not be using those either, because they do not mix with a > > GPIO specifier, it's a bit like oil and water. > > > > The standard GPIO bindings already has > > GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW > > which makes it pretty clear that a GPIO line marked as GPIO_ACTIVE_HIGH > > should trigger either on rising edge or level active high and vice versa. > > > > The only information you could *possibly* lack is whether the IRQ should be > > edge or level triggered. > > > > But level triggered GPIO buttons *does* *not* *make* > > *sense* *at* *all*. > > > > Think about it: > > > > The IRQ line goes level high or low because a user pressed a button with > > his/her thumb. Then that is wired in as a level IRQ. So what are we going to > > do? Wait in the interrupt handler until the user removes his/her thumb? > > > > Level IRQs on GPIOs only makes sense for devices off-chip where you can > > talk to the device and ACK the interrupt, and in this case "talk" does not > > mean wire up a speaker telling the user to remove the thumb from the > > button because we have recieved the interrupt, albeit that would be the > > real-world analogy. > > > > Please tell us what you are actually trying to solve. > > > One of Our gpio-controller was supporting only edge rising interrupts. > For that reason I implementing the below logic to read the interrupt > trigger level from the DT. If it is wrong could you please provide the > pointer to solve this issue? How will you handle key releases if you can only signal key presses? gpio-keys driver needs to be notified about both edges. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html