Re: [PATCH v5 07/12] leds: leds-gpio: Add support for GPIO descriptors

From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Grant Likely <grant.likely@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>,
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
	Aaron Lu <aaron.lu@intel.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Alexandre Courbot <gnurou@gmail.com>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Bryan Wu <cooloney@gmail.com>,
	Darren Hart <dvhart@linux.intel.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v5 07/12] leds: leds-gpio: Add support for GPIO descriptors
Date: Fri, 31 Oct 2014 11:55:35 +0200	[thread overview]
Message-ID: <20141031095535.GV1304@lahna.fi.intel.com> (raw)
In-Reply-To: <CACRpkdYQwzwLJOCx76uONCpTsUtxhePaByyYPz-52Xw9L+DYQQ@mail.gmail.com>

On Fri, Oct 31, 2014 at 10:41:38AM +0100, Linus Walleij wrote:
> On Thu, Oct 30, 2014 at 5:15 PM, Mika Westerberg
> <mika.westerberg@linux.intel.com> wrote:
> > On Thu, Oct 30, 2014 at 04:40:05PM +0100, Linus Walleij wrote:
> >> > Yes, I'll just let dust to settle before sending out a patch that
> >> > converts the existing users of platform_gpio_blink_set() callback to
> >> > gpio descriptors.
> >>
> >> Dust settle = 2 weeks, 18 months, 5 years?
> >
> > I started to do the conversion already but then noticed that it is not
> > that trivial after all.
> 
> Thanks for looking into this.
> 
> > For example we have one user in arch/arm/mach-orion5x/dns323-setup.c:
> >
> > static struct gpio_led_platform_data dns323ab_led_data = {
> >         .num_leds       = ARRAY_SIZE(dns323ab_leds),
> >         .leds           = dns323ab_leds,
> >         .gpio_blink_set = orion_gpio_led_blink_set,
> > };
> >
> > orion_gpio_led_blink_set() is part of orion specific custom GPIO
> > "driver" defined in arch/arm/plat-orion/gpio.c and as far as I can tell
> > cannot use GPIO descriptors as it directly programs these numbers to the
> > hardware.
> >
> > We can convert the descriptor to a number in the beginning of
> > orion_gpio_led_blink_set() if that helps.
> >
> > Other two users: rx1950_led_blink_set() and h1940_led_blink_set() seem
> > to have similar needs for the numeric value.
> 
> Doing the conversion from descriptor to gpio number in the
> platforms is *much desired*, because it is a nice divide-and-conquer
> approach.
> 
> For example mach-orion is going to be deleted and replaced
> with mach-mvebu at some time, so then part of the problem
> goes away entirely.

OK, thanks. I'll do the GPIO descriptor -> number conversions in the
platform code then.