From: gregory.clement@free-electrons•com (Gregory CLEMENT)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2] gpio: mvebu: fix gpio bank registration when pwm is used
Date: Tue, 30 May 2017 15:16:59 +0200 [thread overview]
Message-ID: <87y3tetrg4.fsf@free-electrons.com> (raw)
In-Reply-To: <20170530122848.2803-2-richard.genoud@gmail.com> (Richard Genoud's message of "Tue, 30 May 2017 14:28:48 +0200")
Hi Richard,
On mar., mai 30 2017, Richard Genoud <richard.genoud@gmail•com> wrote:
> If more than one gpio bank has the "pwm" property, only one will be
> registered successfully, all the others will fail with:
> mvebu-gpio: probe of f1018140.gpio failed with error -17
>
> That's because in alloc_pwms(), the chip->base (aka "int pwm"), was not
> set (thus, ==0) ; and 0 is a meaningful start value in alloc_pwm().
> What was intended is chip->base = -1.
> Like that, the numbering will be done auto-magically
>
> Tested on clearfog-pro (Marvell 88F6828)
>
> Signed-off-by: Richard Genoud <richard.genoud@gmail•com>
> ---
> drivers/gpio/gpio-mvebu.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
> index cdef2c78cb3b..4734923e11fd 100644
> --- a/drivers/gpio/gpio-mvebu.c
> +++ b/drivers/gpio/gpio-mvebu.c
> @@ -768,6 +768,7 @@ static int mvebu_pwm_probe(struct platform_device *pdev,
> mvpwm->chip.dev = dev;
> mvpwm->chip.ops = &mvebu_pwm_ops;
> mvpwm->chip.npwm = mvchip->chip.ngpio;
> + mvpwm->chip.base = -1;
Why not using
mvpwm->chip.base = id * MVEBU_MAX_GPIO_PER_BANK;
as it is done in the mvebu_gpio_probe() function?
I think that if you use base = -1, then the number start from (512 -
number of pin already use). So starting from a low number for one
compatible and a high number for an other compatible could be confusing.
Besides that I agree that mvpwm->chip.base must be initialized and here
again for adding mor context to this patch, we could add:
Fixes: 757642f9a584 ("gpio: mvebu: Add limited PWM support")
Gregory
>
> spin_lock_init(&mvpwm->lock);
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2017-05-30 13:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-30 12:28 [PATCH 1/2] gpio: mvebu: fix blink counter register selection Richard Genoud
2017-05-30 12:28 ` [PATCH 2/2] gpio: mvebu: fix gpio bank registration when pwm is used Richard Genoud
2017-05-30 13:16 ` Gregory CLEMENT [this message]
2017-05-30 14:45 ` Richard Genoud
2017-05-30 15:14 ` Ralph Sennhauser
2017-05-30 16:35 ` Richard Genoud
2017-05-30 13:01 ` [PATCH 1/2] gpio: mvebu: fix blink counter register selection Gregory CLEMENT
2017-05-30 13:06 ` Gregory CLEMENT
2017-05-30 15:18 ` Ralph Sennhauser
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