When the fdt does not provide a list of brightness states, pwmbl(4)
builds a 256 state ramp (i.e. state[i] = i with 0 <= i < 256).
The following diff keeps that behaviour, but gets rid of the malloc
call for that ramp, since the values are trivially known.
Compiles but not tested due to the lack of such hardware.
Index: sys/dev/fdt/pwmbl.c
===================================================================
RCS file: /OpenBSD/src/sys/dev/fdt/pwmbl.c,v
retrieving revision 1.6
diff -u -p -r1.6 pwmbl.c
--- sys/dev/fdt/pwmbl.c 24 Oct 2021 17:52:26 -0000 1.6
+++ sys/dev/fdt/pwmbl.c 4 Jul 2022 18:45:16 -0000
@@ -35,7 +35,7 @@ struct pwmbl_softc {
struct device sc_dev;
uint32_t *sc_pwm;
int sc_pwm_len;
- uint32_t *sc_levels;
+ uint32_t *sc_levels; /* NULL if simple ramp */
int sc_nlevels;
uint32_t sc_max_level;
uint32_t sc_def_level;
@@ -73,7 +73,7 @@ pwmbl_attach(struct device *parent, stru
struct pwmbl_softc *sc = (struct pwmbl_softc *)self;
struct fdt_attach_args *faa = aux;
uint32_t *gpios;
- int i, len;
+ int len;
len = OF_getproplen(faa->fa_node, "pwms");
if (len < 0) {
@@ -95,7 +95,7 @@ pwmbl_attach(struct device *parent, stru
}
len = OF_getproplen(faa->fa_node, "brightness-levels");
- if (len > 0) {
+ if (len >= sizeof(uint32_t)) {
sc->sc_levels = malloc(len, M_DEVBUF, M_WAITOK);
OF_getpropintarray(faa->fa_node, "brightness-levels",
sc->sc_levels, len);
@@ -107,13 +107,9 @@ pwmbl_attach(struct device *parent, stru
sc->sc_def_level = sc->sc_nlevels - 1;
sc->sc_def_level = sc->sc_levels[sc->sc_def_level];
} else {
+ /* No levels, assume a simple 0..255 ramp. */
sc->sc_nlevels = 256;
- sc->sc_levels = mallocarray(sc->sc_nlevels,
- sizeof(uint32_t), M_DEVBUF, M_WAITOK);
- for (i = 0; i < sc->sc_nlevels; i++)
- sc->sc_levels[i] = i;
- sc->sc_max_level = sc->sc_levels[sc->sc_nlevels - 1];
- sc->sc_def_level = sc->sc_levels[sc->sc_nlevels - 1];
+ sc->sc_max_level = sc->sc_def_level = sc->sc_nlevels - 1;
}
printf("\n");
@@ -144,17 +140,22 @@ pwmbl_find_brightness(struct pwmbl_softc
uint32_t mid;
int i;
- for (i = 0; i < sc->sc_nlevels - 1; i++) {
- mid = (sc->sc_levels[i] + sc->sc_levels[i + 1]) / 2;
- if (sc->sc_levels[i] <= level && level <= mid)
+ if (sc->sc_levels) {
+ for (i = 0; i < sc->sc_nlevels - 1; i++) {
+ mid = (sc->sc_levels[i] + sc->sc_levels[i + 1]) / 2;
+ if (sc->sc_levels[i] <= level && level <= mid)
+ return sc->sc_levels[i];
+ if (mid < level && level <= sc->sc_levels[i + 1])
+ return sc->sc_levels[i + 1];
+ }
+ if (level < sc->sc_levels[0])
+ return sc->sc_levels[0];
+ else
return sc->sc_levels[i];
- if (mid < level && level <= sc->sc_levels[i + 1])
- return sc->sc_levels[i + 1];
+
+ } else {
+ return level < sc->sc_nlevels ? level : sc->sc_nlevels - 1;
}
- if (level < sc->sc_levels[0])
- return sc->sc_levels[0];
- else
- return sc->sc_levels[i];
}
int
