[PATCHv2 2/2] gpio: mvebu: fix gpio bank registration when pwm is used
From: Gregory CLEMENT <hidden>
Date: 2017-06-01 14:57:51
Also in:
linux-gpio, linux-pwm, lkml
Hi Richard, On jeu., juin 01 2017, Richard Genoud [off-list ref] 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 mvpwm->chip->base = -1.
Like that, the numbering will be done auto-magically
Moreover, as the region might be already occupied by another pwm, we
shouldn't force:
mvpwm->chip->base = 0
nor
mvpwm->chip->base = id * MVEBU_MAX_GPIO_PER_BANK;
Tested on clearfog-pro (Marvell 88F6828)
Fixes: 757642f9a584 ("gpio: mvebu: Add limited PWM support")
Signed-off-by: Richard Genoud <redacted>Reviewed-by: Gregory CLEMENT <redacted> Thanks, Gregory
quoted hunk
--- drivers/gpio/gpio-mvebu.c | 7 +++++++ 1 file changed, 7 insertions(+)diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index cdef2c78cb3b..5104b6398139 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c@@ -768,6 +768,13 @@ 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; + /* + * There may already be some PWM allocated, so we can't force + * mvpwm->chip.base to a fixed point like mvchip->chip.base. + * So, we let pwmchip_add() do the numbering and take the next free + * region. + */ + mvpwm->chip.base = -1; 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