[PATCH v3 05/16] drm/fb-helper: do a generic fb_setcmap helper in terms of crtc .gamma_set

[Peter Rosin <peda@axentia.se>]

This makes the redundant fb helpers .load_lut, .gamma_set and .gamma_get
completely obsolete.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/gpu/drm/drm_fb_helper.c | 165 +++++++++++++++++++++++-----------------
 1 file changed, 94 insertions(+), 71 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index b75b1f2..7f8199a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1257,27 +1257,6 @@ void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
 }
 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
 
-static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
-		     u16 blue, u16 regno, struct fb_info *info)
-{
-	struct drm_fb_helper *fb_helper = info->par;
-	struct drm_framebuffer *fb = fb_helper->fb;
-
-	/*
-	 * The driver really shouldn't advertise pseudo/directcolor
-	 * visuals if it can't deal with the palette.
-	 */
-	if (WARN_ON(!fb_helper->funcs->gamma_set ||
-		    !fb_helper->funcs->gamma_get))
-		return -EINVAL;
-
-	WARN_ON(fb->format->cpp[0] != 1);
-
-	fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
-
-	return 0;
-}
-
 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 {
 	u32 *palette = (u32 *)info->pseudo_palette;
@@ -1310,54 +1289,68 @@ static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 	return 0;
 }
 
-/**
- * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
- * @cmap: cmap to set
- * @info: fbdev registered by the helper
- */
-int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
+static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
 {
 	struct drm_fb_helper *fb_helper = info->par;
-	struct drm_device *dev = fb_helper->dev;
-	const struct drm_crtc_helper_funcs *crtc_funcs;
-	u16 *red, *green, *blue, *transp;
 	struct drm_crtc *crtc;
 	u16 *r, *g, *b;
-	int i, j, rc = 0;
-	int start;
+	int i, ret = 0;
 
-	if (oops_in_progress)
-		return -EBUSY;
+	for (i = 0; i < fb_helper->crtc_count; i++) {
+		crtc = fb_helper->crtc_info[i].mode_set.crtc;
+		if (!crtc->funcs->gamma_set || !crtc->gamma_size)
+			return -EINVAL;
 
-	mutex_lock(&fb_helper->lock);
-	if (!drm_fb_helper_is_bound(fb_helper)) {
-		mutex_unlock(&fb_helper->lock);
-		return -EBUSY;
-	}
+		if (cmap->start + cmap->len > crtc->gamma_size)
+			return -EINVAL;
 
-	drm_modeset_lock_all(dev);
-	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
-		rc = setcmap_pseudo_palette(cmap, info);
-		goto out;
+		r = crtc->gamma_store;
+		g = r + crtc->gamma_size;
+		b = g + crtc->gamma_size;
+
+		memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
+		memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
+		memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
+
+		ret = crtc->funcs->gamma_set(crtc, r, g, b,
+					     crtc->gamma_size, NULL);
+		if (ret)
+			return ret;
 	}
 
-	for (i = 0; i < fb_helper->crtc_count; i++) {
-		crtc = fb_helper->crtc_info[i].mode_set.crtc;
-		crtc_funcs = crtc->helper_private;
+	return ret;
+}
 
-		red = cmap->red;
-		green = cmap->green;
-		blue = cmap->blue;
-		transp = cmap->transp;
-		start = cmap->start;
+static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_crtc_state *crtc_state;
+	struct drm_atomic_state *state;
+	struct drm_crtc *crtc;
+	u16 *r, *g, *b;
+	int i, ret = 0;
 
-		if (!crtc->gamma_size) {
-			rc = -EINVAL;
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+	drm_modeset_acquire_init(&ctx, 0);
+retry:
+	ret = drm_modeset_lock_all_ctx(dev, &ctx);
+	if (ret)
+		goto fini;
+	state->acquire_ctx = &ctx;
+	for (i = 0; i < fb_helper->crtc_count; i++) {
+		crtc = fb_helper->crtc_info[i].mode_set.crtc;
+		if (!crtc->funcs->gamma_set) {
+			ret = -EINVAL;
 			goto out;
 		}
 
-		if (cmap->start + cmap->len > crtc->gamma_size) {
-			rc = -EINVAL;
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state)) {
+			ret = PTR_ERR(crtc_state);
 			goto out;
 		}
 
@@ -1369,27 +1362,57 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 		memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
 		memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
 
-		for (j = 0; j < cmap->len; j++) {
-			u16 hred, hgreen, hblue, htransp = 0xffff;
+		ret = crtc->funcs->gamma_set(crtc, r, g, b,
+					     crtc->gamma_size, crtc_state);
+		if (ret)
+			goto out;
+	}
 
-			hred = *red++;
-			hgreen = *green++;
-			hblue = *blue++;
+	ret = drm_atomic_commit(state);
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
 
-			if (transp)
-				htransp = *transp++;
+out:
+	drm_modeset_drop_locks(&ctx);
+fini:
+	drm_modeset_acquire_fini(&ctx);
+	drm_atomic_state_put(state);
 
-			rc = setcolreg(crtc, hred, hgreen, hblue, start++, info);
-			if (rc)
-				goto out;
-		}
-		if (crtc_funcs->load_lut)
-			crtc_funcs->load_lut(crtc);
+	return ret;
+}
+
+/**
+ * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
+ * @cmap: cmap to set
+ * @info: fbdev registered by the helper
+ */
+int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	int ret;
+
+	if (oops_in_progress)
+		return -EBUSY;
+
+	mutex_lock(&fb_helper->lock);
+
+	if (!drm_fb_helper_is_bound(fb_helper)) {
+		mutex_unlock(&fb_helper->lock);
+		return -EBUSY;
 	}
- out:
-	drm_modeset_unlock_all(dev);
+
+	if (info->fix.visual == FB_VISUAL_TRUECOLOR)
+		ret = setcmap_pseudo_palette(cmap, info);
+	else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
+		ret = setcmap_atomic(cmap, info);
+	else
+		ret = setcmap_legacy(cmap, info);
+
 	mutex_unlock(&fb_helper->lock);
-	return rc;
+
+	return ret;
 }
 EXPORT_SYMBOL(drm_fb_helper_setcmap);
 
-- 
2.1.4