drm: expand gamma_set

Expand the crtc_gamma_set function to accept a starting offset. The
reason for this is to eventually use this function for setcolreg from
drm_fb_helper.c. The fbdev colormap function can start at any offset in
the color map.

Signed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c
index dbd9a63..bfd4ca2 100644
--- a/drivers/gpu/drm/nouveau/nv50_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv50_crtc.c
@@ -398,15 +398,12 @@ nv50_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 
 static void
 nv50_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
-		    uint32_t size)
+		    uint32_t start, uint32_t size)
 {
+	int end = (start + size > 256) ? 256 : start + size, i;
 	struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
-	int i;
-
-	if (size != 256)
-		return;
 
-	for (i = 0; i < 256; i++) {
+	for (i = start; i < end; i++) {
 		nv_crtc->lut.r[i] = r[i];
 		nv_crtc->lut.g[i] = g[i];
 		nv_crtc->lut.b[i] = b[i];