Re: [PATCH 6/6] pwm: imx: Introduce "polarity_supported" flag to PWMv2 driver

From: Boris Brezillon
Date: Mon Oct 24 2016 - 11:34:19 EST


On Mon, 24 Oct 2016 17:28:52 +0200
Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> wrote:

> On Sun, 23 Oct 2016 23:45:46 +0200
> Lukasz Majewski <l.majewski@xxxxxxxxx> wrote:
>
> > The need for set_polarity() function has been removed by implementing
> > PWM atomic support (apply() callback).
> >
> > To indicate that the PWMv2 supports polarity inversion, new flag -
> > "polarity_supported" has been introduced.
> >
> > Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxx>
> > ---
> > drivers/pwm/pwm-imx.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> > index 02d3dfd..be3034d 100644
> > --- a/drivers/pwm/pwm-imx.c
> > +++ b/drivers/pwm/pwm-imx.c
> > @@ -258,6 +258,7 @@ static struct pwm_ops imx_pwm_ops_v2 = {
> > };
> >
> > struct imx_pwm_data {
> > + bool polarity_supported;
> > struct pwm_ops *pwm_ops;
> > };
> >
> > @@ -266,6 +267,7 @@ static struct imx_pwm_data imx_pwm_data_v1 = {
> > };
> >
> > static struct imx_pwm_data imx_pwm_data_v2 = {
> > + .polarity_supported = true,
> > .pwm_ops = &imx_pwm_ops_v2,
> > };
> >
> > @@ -313,7 +315,7 @@ static int imx_pwm_probe(struct platform_device *pdev)
> > imx->chip.base = -1;
> > imx->chip.npwm = 1;
> > imx->chip.can_sleep = true;
> > - if (data->pwm_ops->set_polarity) {
> > + if (data->polarity_supported) {
>
> You're still breaking backward compatibility with DTs defining
> #pwm-cells = 2.
>
> Please test the #pwm-cells value before deciding which of_xlate should
> be used.

Nevermind, I didn't look at [1] and [2].
But still, your series is not bisectable: this change should be part of
patch 5 where you remove the ->set_polarity implementation. Otherwise,
this means you don't support polarity setting between patch 5 and 6.

>
> > dev_dbg(&pdev->dev, "PWM supports output inversion\n");
> > imx->chip.of_xlate = of_pwm_xlate_with_flags;
> > imx->chip.of_pwm_n_cells = 3;
>

[1]http://patchwork.ozlabs.org/patch/679706/
[2]http://patchwork.ozlabs.org/patch/679707/