Re: [PATCH 2/2] leds: lm3692x: Allow to set ovp and brigthness mode

Guido Günther
2019-12-24T11:30:13Z

Hi Dan,
I'm a bit confused about the regmap_write -> regmap_update_bits switch
(see below), maybe you can shed some light on it?

On Tue, Dec 17, 2019 at 06:53:45AM -0600, Dan Murphy wrote:
> Guido
>
> On 12/16/19 6:28 AM, Guido Günther wrote:
> > Overvoltage protection and brightness mode are currently hardcoded
> > as disabled in the driver. Make these configurable via DT.
>
> Can we split these up to two separate patch series?
>
> We are adding 2 separate features and if something is incorrect with one of
> the changes it is a bit hard to debug.
>
> >
> > Signed-off-by: Guido Günther <agx@sigxcpu.org>
> > ---
> > drivers/leds/leds-lm3692x.c | 43 +++++++++++++++++++++++++++++++------
> > 1 file changed, 37 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
> > index 8b408102e138..2c084b333628 100644
> > --- a/drivers/leds/leds-lm3692x.c
> > +++ b/drivers/leds/leds-lm3692x.c
> > @@ -114,6 +114,7 @@ struct lm3692x_led {
> > struct regulator *regulator;
> > int led_enable;
> > int model_id;
> > + u8 boost_ctrl, brightness_ctrl;
> > };
> > static const struct reg_default lm3692x_reg_defs[] = {
> > @@ -249,10 +250,7 @@ static int lm3692x_init(struct lm3692x_led *led)
> > if (ret)
> > goto out;
> > - ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
> > - LM3692X_BOOST_SW_1MHZ |
> > - LM3692X_BOOST_SW_NO_SHIFT |
> > - LM3692X_OCP_PROT_1_5A);
> > + ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
> > if (ret)
> > goto out;
>
> regmap_update_bits

The driver is writing full register values (regmap_write) here as
before, do you want that to change? Likely i'm overlooking something.

> > @@ -268,8 +266,7 @@ static int lm3692x_init(struct lm3692x_led *led)
> > if (ret)
> > goto out;
> > - ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
> > - LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
> > + ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, led->brightness_ctrl);
> > if (ret)
> > goto out;
> regmap_update_bits

Same here.

> > @@ -326,6 +323,8 @@ static int lm3692x_probe_dt(struct lm3692x_led *led)
> > {
> > struct fwnode_handle *child = NULL;
> > struct led_init_data init_data = {};
> > + u32 ovp = 0;
> > + bool exp_mode;
> > int ret;
> > led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
> > @@ -350,6 +349,38 @@ static int lm3692x_probe_dt(struct lm3692x_led *led)
> > led->regulator = NULL;
> > }
> > + led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
> > + LM3692X_BOOST_SW_NO_SHIFT |
> > + LM3692X_OCP_PROT_1_5A;
> Make this a #define and then it can be reused as a mask for
> regmap_update_bits
> > + ret = device_property_read_u32(&led->client->dev,
> > + "ti,overvoltage-volts", &ovp);
> > + if (!ret) {
>
> if (ret)
>
>     set boost_ctrl to default value since the default is not 0
>
> led->boost_ctrl |= LM3692X_OVP_29V;
>
> else
>
>      do case
>

Fixed.

> > + switch (ovp) {
> > + case 0:
> > + break;
> > + case 22:
> If the value is 21v why is this case 22?  DT binding says 21 is the first
> value

Fixed, also added the 17V for the case where both bits a are 0.

> > + led->boost_ctrl |= LM3692X_OVP_21V;
> > + break;
> > + case 25:
> > + led->boost_ctrl |= LM3692X_OVP_25V;
> > + break;
> > + case 29:
> > + led->boost_ctrl |= LM3692X_OVP_29V;
> > + break;
> > + default:
> > + dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
> > + return -EINVAL;
> > + }
> > + }
> > + dev_dbg(&led->client->dev, "OVP: %dV", ovp);
> > +
> extra debug statement

dropped.

> > + led->brightness_ctrl = LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN;
> Same comment as before on the #define
> > + exp_mode = device_property_read_bool(&led->client->dev,
> > + "ti,brightness-mapping-exponential");
> > + dev_dbg(&led->client->dev, "Exponential brightness: %d", exp_mode);
>
> extra debug statement

dropped.

Cheers and thanks for the comments,
-- Guido

>
> Dan
>
>