Re: [PATCH 3/3] pwm: jz4740: Add support for the JZ4725B

[Paul Cercueil]

Hi Uwe,

Le dim. 24 mai 2020 à 19:37, Uwe Kleine-König 
<u.kleine-koenig@xxxxxxxxxxxxxx> a écrit :
> On Mon, Apr 13, 2020 at 02:14:45PM +0200, Paul Cercueil wrote:
> >  The PWM hardware in the JZ4725B works the same as in the JZ4740, 
> > but has
> >  only six channels available.
> >
> >  Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> >  ---
> >
> >  Notes:
> >      I did not add documentation for the new jz4725b-pwm compatible
> >      string on purpose. The reason is that the documentation file
> >      for the Timer/Counter Unit (TCU) of Ingenic SoCs will be
> >      completely rewritten from .txt to YAML in a separate patchset.
> >
> >   drivers/pwm/pwm-jz4740.c | 20 +++++++++++++++++---
> >   1 file changed, 17 insertions(+), 3 deletions(-)
> >
> >  diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
> >  index f566f9d248d6..bb27934fb6c2 100644
> >  --- a/drivers/pwm/pwm-jz4740.c
> >  +++ b/drivers/pwm/pwm-jz4740.c
> >  @@ -22,6 +22,10 @@
> >
> >   #define NUM_PWM 8
> >
> >  +struct soc_info {
> >  +	unsigned int num_pwms;
> >  +};
> >  +
> >   struct jz4740_pwm_chip {
> >   	struct pwm_chip chip;
> >   	struct regmap *map;
> >  @@ -36,7 +40,7 @@ static bool jz4740_pwm_can_use_chn(struct 
> > jz4740_pwm_chip *jz,
> >   				   unsigned int channel)
> >   {
> >   	/* Enable all TCU channels for PWM use by default except channels 
> > 0/1 */
> >  -	u32 pwm_channels_mask = GENMASK(NUM_PWM - 1, 2);
> >  +	u32 pwm_channels_mask = GENMASK(jz->chip.npwm - 1, 2);
> >
> >   	device_property_read_u32(jz->chip.dev->parent,
> >   				 "ingenic,pwm-channels-mask",
> >  @@ -214,6 +218,7 @@ static int jz4740_pwm_probe(struct 
> > platform_device *pdev)
> >   {
> >   	struct device *dev = &pdev->dev;
> >   	struct jz4740_pwm_chip *jz4740;
> >  +	const struct soc_info *info = device_get_match_data(dev);
> >
> >   	jz4740 = devm_kzalloc(dev, sizeof(*jz4740), GFP_KERNEL);
> >   	if (!jz4740)
> >  @@ -227,8 +232,8 @@ static int jz4740_pwm_probe(struct 
> > platform_device *pdev)
> >
> >   	jz4740->chip.dev = dev;
> >   	jz4740->chip.ops = &jz4740_pwm_ops;
> >  -	jz4740->chip.npwm = NUM_PWM;
> >   	jz4740->chip.base = -1;
> >  +	jz4740->chip.npwm = info ? info->num_pwms : NUM_PWM;
>
> Can info be actually NULL? I don't think so, so you can just use
> info->num_pwms here and drop the definition of NUM_PWM.

In *theory* it can be NULL if the kernel is configured without 
CONFIG_OF, which will never happen on any board supported by this 
driver. I can add a dependency on CONFIG_OF in V2, then use 
info->num_pwms there.

cheers,
-Paul

> >   	jz4740->chip.of_xlate = of_pwm_xlate_with_flags;
> >   	jz4740->chip.of_pwm_n_cells = 3;
>
> Best regards
> Uwe
>
> --
> Pengutronix e.K.                           | Uwe Kleine-König        
>     |
> Industrial Linux Solutions                 | 
> https://www.pengutronix.de/ |