Re: [PATCH v2 2/2] leds: add Qualcomm PM8941 WLED driver

Bjorn Andersson
2015-01-29T19:08:04Z

On Thu 29 Jan 04:48 PST 2015, Ivan T. Ivanov wrote:

>
> Hi Bjorn,
>
> Just few nitpick comments.
>

Thanks.

> On Fri, 2015-01-23 at 16:54 -0800, Bjorn Andersson wrote:
> > From: Courtney Cavin cavin@sonymobile.com>
> >
> > This adds support for the WLED ('White' LED) block on Qualcomm's
> > PM8941 PMICs.
> >
> > Signed-off-by: Courtney Cavin cavin@sonymobile.com>
> > Signed-off-by: Bjorn Andersson andersson@sonymobile.com>
> > ---
> > drivers/leds/Kconfig | 8 +
> > drivers/leds/Makefile | 1 +
> > drivers/leds/leds-pm8941-wled.c | 459 ++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 468 insertions(+)
> > create mode 100644 drivers/leds/leds-pm8941-wled.c
> >
>
> <snip>
>
> > +
> > +#define PM8941_WLED_REG_VAL_BASE 0x40
> > +#define PM8941_WLED_REG_VAL_MAX 0xFFF
> > +
> > +#define PM8941_WLED_REG_MOD_EN 0x46
> > +#define PM8941_WLED_REG_MOD_EN_BIT BIT(7)
> > +#define PM8941_WLED_REG_MOD_EN_MASK BIT(7)
>
> Is it possible bit definitions to have same indentation like registers offsets?
>

Well, yes ;)

But I like the separation, so unless Bryan would like me to change it I prefer
to leave it as is.

> >
> > +struct pm8941_wled_config {
> > + u32 i_boost_limit;
> > + u32 ovp;
> > + u32 switch_freq;
> > + u32 num_strings;
> > + u32 i_limit;
> > + bool cs_out_en;
> > + bool ext_gen;
> > + bool cabc_en;
> > +};
> > +
>
> Could this be further squashed to bellow structure?
>

It could, but I see that it would simplify things.

> > +struct pm8941_wled {
> > + struct regmap *regmap;
> > + u16 addr;
> > +
> > + struct led_classdev cdev;
> > +
> > + struct pm8941_wled_config cfg;
> > +};
> > +
> >
>
> <snip>
>
> > +static void pm8941_wled_set_brightness(struct led_classdev *cdev,
> > + enum
> > led_brightness value)
> > +{
> > + if (pm8941_wled_set(cdev, value)) {
>
> pm8941_wled_set() is used only here, could it be merged into this function?
>

It could, but that would just mean that we move these lines into the tail of
pm8941_wled_set and replace all the returns with a bunch of gotos. So I don't
think it's cleaner.

> > + dev_err(cdev->dev, "Unable to set brightness\n");
> > + return;
> > + }
> > + cdev->brightness = value;
> > +}
> > +
> >
>
> Otherwise it looks good. Driver is loaded and device is detected
> properly (i have added readings for type and subtype registers).
> Do you know where I can measure result from changing brightness
> sysfs entry. I am using 8074 dragonboard?
>

I'm not sure how this is exposed on the dragonboard. I've tested it on Xperia
Z1 (honami) and the display lights up nicely.

Regards,
Bjorn