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| author | Matt Ranostay <mranostay@gmail.com> | 2016-10-13 06:16:12 -0700 |
|---|---|---|
| committer | Jacek Anaszewski <j.anaszewski@samsung.com> | 2016-11-22 12:07:04 +0100 |
| commit | 35c7d30179fbc17af7281ccea18e6d74c003e448 (patch) | |
| tree | d49f1992a6f3578f64d7750396d86a2f20db6a96 /drivers/leds | |
| parent | ed25e9cae1ab8e84556c9413fd5de0a9da8f3657 (diff) | |
| download | linux-35c7d30179fbc17af7281ccea18e6d74c003e448.tar.gz | |
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>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/leds-pca963x.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c index 407eba11e187..b6ce1f2ec33e 100644 --- a/drivers/leds/leds-pca963x.c +++ b/drivers/leds/leds-pca963x.c @@ -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; } |