From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/5] gpio/omap: Add DT support to GPIO driver
Date: Fri, 22 Mar 2013 17:52:27 -0500 [thread overview]
Message-ID: <514CE0AB.6060207@ti.com> (raw)
In-Reply-To: <514C79E1.4090106@wwwdotorg.org>
On 03/22/2013 10:33 AM, Stephen Warren wrote:
> On 03/22/2013 02:10 AM, Linus Walleij wrote:
>> On Fri, Mar 15, 2013 at 12:21 PM, Javier Martinez Canillas
>> <martinez.javier@gmail•com> wrote:
>>
>>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
>>> index 159f5c5..f5feb43 100644
>>> --- a/drivers/gpio/gpio-omap.c
>>> +++ b/drivers/gpio/gpio-omap.c
>>> @@ -807,6 +807,13 @@ static void gpio_unmask_irq(struct irq_data *d)
>>> spin_unlock_irqrestore(&bank->lock, flags);
>>> }
>>>
>>> +static int gpio_irq_request(struct irq_data *d)
>>> +{
>>> + struct gpio_bank *bank = irq_data_get_irq_chip_data(d);
>>> +
>>> + return gpio_request(irq_to_gpio(bank, d->irq), "gpio-irq");
>>> +}
>>> +
>>> static struct irq_chip gpio_irq_chip = {
>>> .name = "GPIO",
>>> .irq_shutdown = gpio_irq_shutdown,
>>> @@ -815,6 +822,7 @@ static struct irq_chip gpio_irq_chip = {
>>> .irq_unmask = gpio_unmask_irq,
>>> .irq_set_type = gpio_irq_type,
>>> .irq_set_wake = gpio_wake_enable,
>>> + .irq_request = gpio_irq_request,
>>> };
>>
>> This is just turning everything on it's head. The normal order of things
>> is this sequence for GPIO 14 something like:
>>
>> gpio_request(14);
>> int irq = gpio_to_irq(14);
>> request_any_context_irq(irq);
>
> That doesn't make any sense at all. Drivers don't want to care whether
> the IRQ number they receive is a GPIO-that-can-act-like-an-IRQ or a pure
> dedicated IRQ input.
>
> To fully support the model you proprose, a driver would have to:
>
> if (gpio_is_valid(pdata->gpio)) {
> gpio_request_one(pdata->gpio, GPIOF_IN, "foo irq");
> irq = gpio_to_irq(pdata->gpio);
> } else
> irq = pdata->irq;
> request_irq(...);
>
> which means complex code in each driver, plus requiring some indication
> in platform data and/or device tree re: whether the IRQ is hosted by a
> GPIO or not.
I tend to agree with Stephen here. When we had discussed this previously
you had mentioned about adding a platform function to request the gpio
[1], but I could see this adding a bunch more platform files when we are
trying to get rid of all the board-xxx.c files for OMAP. So if you don't
like the approach suggested by Stephen and implemented by Javier, then
may be we need to means to request/reserve gpios in the dts as you had
suggested before [1].
So it seems to me that there are two options at the moment ...
1. Add a irq_chip request as suggested by Stephen.
2. Reserve/request gpios in the dts when registering a gpio chip.
Cheers
Jon
[1] http://permalink.gmane.org/gmane.linux.ports.arm.omap/92327
next prev parent reply other threads:[~2013-03-22 22:52 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-15 16:04 [PATCH 0/5] gpio/omap: Cleanup and adaptation to Device Tree Benoit Cousson
2012-02-15 16:04 ` [PATCH 1/5] gpio/omap: Remove bank->id information and misc cleanup Benoit Cousson
2012-02-16 5:53 ` DebBarma, Tarun Kanti
2012-02-16 9:33 ` Cousson, Benoit
2012-02-15 16:04 ` [PATCH 2/5] gpio/omap: Use devm_ API and add request_mem_region Benoit Cousson
2012-02-16 5:41 ` DebBarma, Tarun Kanti
2012-02-16 6:35 ` Grant Likely
2012-02-16 7:11 ` DebBarma, Tarun Kanti
2012-02-16 6:37 ` Shubhrajyoti
2012-02-16 8:56 ` Cousson, Benoit
2012-02-15 16:04 ` [PATCH 3/5] gpio/omap: Add DT support to GPIO driver Benoit Cousson
2012-02-22 14:23 ` Rob Herring
2012-02-22 14:31 ` Cousson, Benoit
2012-02-22 17:23 ` Rob Herring
2012-02-22 18:29 ` Stephen Warren
2012-02-24 15:30 ` Cousson, Benoit
2013-02-26 10:01 ` Javier Martinez Canillas
2013-02-26 16:33 ` Stephen Warren
2013-02-26 22:40 ` Jon Hunter
2013-02-26 22:44 ` Stephen Warren
2013-02-26 23:01 ` Jon Hunter
2013-02-26 23:06 ` Stephen Warren
2013-02-26 23:45 ` Jon Hunter
2013-02-27 0:13 ` Stephen Warren
2013-02-27 1:07 ` Jon Hunter
2013-02-27 3:57 ` Javier Martinez Canillas
2013-02-27 17:50 ` Stephen Warren
2013-02-27 20:05 ` Javier Martinez Canillas
2013-02-27 23:16 ` Jon Hunter
2013-02-28 12:17 ` Javier Martinez Canillas
2013-02-28 20:49 ` Jon Hunter
2013-03-02 20:05 ` Grant Likely
2013-03-07 23:14 ` Jon Hunter
2013-03-15 11:21 ` Javier Martinez Canillas
2013-03-22 8:10 ` Linus Walleij
2013-03-22 15:33 ` Stephen Warren
2013-03-22 22:52 ` Jon Hunter [this message]
2013-03-27 13:52 ` Linus Walleij
2013-03-27 16:09 ` Stephen Warren
2013-03-27 20:55 ` Linus Walleij
2013-03-29 17:01 ` Stephen Warren
2013-04-10 18:12 ` Linus Walleij
2013-04-10 20:29 ` Stephen Warren
2013-04-10 21:28 ` Linus Walleij
2013-04-11 20:30 ` Stephen Warren
2013-04-11 22:16 ` Linus Walleij
2013-04-11 22:47 ` Stephen Warren
2013-04-14 1:35 ` Javier Martinez Canillas
2013-04-14 20:53 ` Linus Walleij
2013-04-15 11:25 ` Javier Martinez Canillas
2013-04-15 16:58 ` Stephen Warren
2013-04-15 21:40 ` Jon Hunter
2013-04-15 21:44 ` Jon Hunter
2013-04-15 22:16 ` Stephen Warren
2013-04-15 23:04 ` Jon Hunter
2013-04-16 18:40 ` Stephen Warren
2013-04-16 19:27 ` Jon Hunter
2013-04-16 21:57 ` Jon Hunter
2013-04-16 22:11 ` Stephen Warren
2013-04-16 23:14 ` Jon Hunter
2013-04-17 0:41 ` Javier Martinez Canillas
2013-04-17 2:00 ` Jon Hunter
2013-04-17 7:55 ` Javier Martinez Canillas
2013-04-17 13:25 ` Jon Hunter
2013-04-17 13:42 ` Javier Martinez Canillas
2013-04-17 13:52 ` Jon Hunter
2013-04-17 14:21 ` Javier Martinez Canillas
2013-04-17 16:18 ` Javier Martinez Canillas
2013-04-26 7:31 ` Linus Walleij
2013-04-26 21:31 ` Jon Hunter
2013-06-11 21:25 ` Grant Likely
2013-06-12 9:43 ` Linus Walleij
2013-04-17 15:41 ` Stephen Warren
2013-04-26 7:27 ` Linus Walleij
2013-04-26 21:25 ` Jon Hunter
2013-05-03 14:35 ` Linus Walleij
2013-04-26 7:11 ` Linus Walleij
2013-04-26 6:59 ` Linus Walleij
2013-04-15 16:53 ` Stephen Warren
2013-04-15 20:00 ` Jon Hunter
2013-04-11 22:49 ` Javier Martinez Canillas
2013-04-11 22:51 ` Stephen Warren
2013-04-10 21:44 ` Arnd Bergmann
2013-02-27 3:33 ` Javier Martinez Canillas
2013-02-27 17:47 ` Stephen Warren
2013-02-27 20:00 ` Javier Martinez Canillas
2013-02-26 23:08 ` Jon Hunter
2013-02-27 3:47 ` Javier Martinez Canillas
2013-02-27 20:13 ` Jon Hunter
2013-02-27 23:41 ` Linus Walleij
2013-02-28 13:04 ` Benoit Cousson
2013-03-01 0:09 ` Linus Walleij
2013-03-01 0:42 ` Jon Hunter
2012-02-15 16:04 ` [PATCH 4/5] arm/dts: OMAP4: Add gpio nodes Benoit Cousson
2012-02-15 16:04 ` [PATCH 5/5] arm/dts: OMAP3: " Benoit Cousson
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