leds: pca963x: workaround group blink scaling issue
PCA9632TK part seems to incorrectly blink at ~1.3x of the programmed rate. This patchset add a nxp,period-scale devicetree property to adjust for this misconfiguration. Signed-off-by: Matt Ranostay <matt@ranostay.consulting> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
This commit is contained in:
parent
ed25e9cae1
commit
35c7d30179
|
@ -7,6 +7,9 @@ Optional properties:
|
|||
- nxp,totem-pole : use totem pole (push-pull) instead of open-drain (pca9632 defaults
|
||||
to open-drain, newer chips to totem pole)
|
||||
- nxp,hw-blink : use hardware blinking instead of software blinking
|
||||
- nxp,period-scale : In some configurations, the chip blinks faster than expected.
|
||||
This parameter provides a scaling ratio (fixed point, decimal divided
|
||||
by 1000) to compensate, e.g. 1300=1.3x and 750=0.75x.
|
||||
|
||||
Each led is represented as a sub-node of the nxp,pca963x device.
|
||||
|
||||
|
|
|
@ -59,6 +59,7 @@ struct pca963x_chipdef {
|
|||
u8 grpfreq;
|
||||
u8 ledout_base;
|
||||
int n_leds;
|
||||
unsigned int scaling;
|
||||
};
|
||||
|
||||
static struct pca963x_chipdef pca963x_chipdefs[] = {
|
||||
|
@ -189,6 +190,14 @@ static int pca963x_led_set(struct led_classdev *led_cdev,
|
|||
return pca963x_brightness(pca963x, value);
|
||||
}
|
||||
|
||||
static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
|
||||
unsigned int val)
|
||||
{
|
||||
unsigned int scaling = pca963x->chip->chipdef->scaling;
|
||||
|
||||
return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
|
||||
}
|
||||
|
||||
static int pca963x_blink_set(struct led_classdev *led_cdev,
|
||||
unsigned long *delay_on, unsigned long *delay_off)
|
||||
{
|
||||
|
@ -207,14 +216,14 @@ static int pca963x_blink_set(struct led_classdev *led_cdev,
|
|||
time_off = 500;
|
||||
}
|
||||
|
||||
period = time_on + time_off;
|
||||
period = pca963x_period_scale(pca963x, time_on + time_off);
|
||||
|
||||
/* If period not supported by hardware, default to someting sane. */
|
||||
if ((period < PCA963X_BLINK_PERIOD_MIN) ||
|
||||
(period > PCA963X_BLINK_PERIOD_MAX)) {
|
||||
time_on = 500;
|
||||
time_off = 500;
|
||||
period = time_on + time_off;
|
||||
period = pca963x_period_scale(pca963x, 1000);
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -222,7 +231,7 @@ static int pca963x_blink_set(struct led_classdev *led_cdev,
|
|||
* (time_on / period) = (GDC / 256) ->
|
||||
* GDC = ((time_on * 256) / period)
|
||||
*/
|
||||
gdc = (time_on * 256) / period;
|
||||
gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
|
||||
|
||||
/*
|
||||
* From manual: period = ((GFRQ + 1) / 24) in seconds.
|
||||
|
@ -294,6 +303,9 @@ pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
|
|||
else
|
||||
pdata->blink_type = PCA963X_SW_BLINK;
|
||||
|
||||
if (of_property_read_u32(np, "nxp,period-scale", &chip->scaling))
|
||||
chip->scaling = 1000;
|
||||
|
||||
return pdata;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue