misc: ws2812-pio-rp1: Allow gamma to be disabled

pelwell · pelwell · commit b59cb73d8680 · 2025-10-26T17:12:38.000Z
Modify the gamma logic such that setting the brightness in DT to zero causes the supplied pixel values to be passed through unmodified. See: #7108 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
diff --git a/drivers/misc/ws2812-pio-rp1.c b/drivers/misc/ws2812-pio-rp1.c
@@ -142,8 +142,8 @@ static uint8_t ws2812_apply_gamma(uint8_t brightness, uint8_t val)
 {
 	int bright;
 
-	if (!val)
-		return 0;
+	if (!val || !brightness)
+		return val;
 	bright = (val * brightness) / 255;
 	return ws2812_gamma[bright];
 }

Original file line number	Diff line number	Diff line change
`@@ -142,8 +142,8 @@ static uint8_t ws2812_apply_gamma(uint8_t brightness, uint8_t val)`
`142`	`142`	`{`
`143`	`143`	`int bright;`
`144`	`144`
`145`		`- if (!val)`
`146`		`- return 0;`
	`145`	`+ if (!val \|\| !brightness)`
	`146`	`+ return val;`
`147`	`147`	`bright = (val * brightness) / 255;`
`148`	`148`	`return ws2812_gamma[bright];`
`149`	`149`	`}`