drm/fb-helper: separate the fb_setcmap helper into atomic and legacy paths

The legacy path implements setcmap in terms of crtc .gamma_set.

The atomic path implements setcmap by directly updating the crtc gamma_lut
property.

This has a couple of benefits:
- it makes the redundant fb helpers .load_lut, .gamma_set and .gamma_get
  completely obsolete. They are now unused and subject for removal.
- atomic drivers that support clut modes get fbdev support for those from
  the drm core. This includes atmel-hlcdc, but perhaps others as well?

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170713162538.22788-4-peda@axentia.se

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 721511da4de6ddaef0f593537c93aa74d5b4e31a..42090fe00ef9652736e4378ff09cbf0a9d5ce41b 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1195,27 +1195,6 @@ 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;
@@ -1248,57 +1227,138 @@ 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;
+       drm_modeset_lock_all(fb_helper->dev);
+       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;
+
+               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;
        }
+       drm_modeset_unlock_all(fb_helper->dev);
 
-       drm_modeset_lock_all(dev);
-       if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
-               rc = setcmap_pseudo_palette(cmap, info);
-               goto out;
+       return ret;
+}
+
+static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
+                                                      struct fb_cmap *cmap)
+{
+       struct drm_device *dev = crtc->dev;
+       struct drm_property_blob *gamma_lut;
+       struct drm_color_lut *lut;
+       int size = crtc->gamma_size;
+       int i;
+
+       if (!size || cmap->start + cmap->len > size)
+               return ERR_PTR(-EINVAL);
+
+       gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
+       if (IS_ERR(gamma_lut))
+               return gamma_lut;
+
+       lut = (struct drm_color_lut *)gamma_lut->data;
+       if (cmap->start || cmap->len != size) {
+               u16 *r = crtc->gamma_store;
+               u16 *g = r + crtc->gamma_size;
+               u16 *b = g + crtc->gamma_size;
+
+               for (i = 0; i < cmap->start; i++) {
+                       lut[i].red = r[i];
+                       lut[i].green = g[i];
+                       lut[i].blue = b[i];
+               }
+               for (i = cmap->start + cmap->len; i < size; i++) {
+                       lut[i].red = r[i];
+                       lut[i].green = g[i];
+                       lut[i].blue = b[i];
+               }
+       }
+
+       for (i = 0; i < cmap->len; i++) {
+               lut[cmap->start + i].red = cmap->red[i];
+               lut[cmap->start + i].green = cmap->green[i];
+               lut[cmap->start + i].blue = cmap->blue[i];
+       }
+
+       return gamma_lut;
+}
+
+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_property_blob *gamma_lut = NULL;
+       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;
+       bool replaced;
+
+       drm_modeset_acquire_init(&ctx, 0);
+
+       state = drm_atomic_state_alloc(dev);
+       if (!state) {
+               ret = -ENOMEM;
+               goto out_ctx;
        }
 
+       state->acquire_ctx = &ctx;
+retry:
        for (i = 0; i < fb_helper->crtc_count; i++) {
                crtc = fb_helper->crtc_info[i].mode_set.crtc;
-               crtc_funcs = crtc->helper_private;
 
-               red = cmap->red;
-               green = cmap->green;
-               blue = cmap->blue;
-               transp = cmap->transp;
-               start = cmap->start;
-
-               if (!crtc->gamma_size) {
-                       rc = -EINVAL;
-                       goto out;
+               if (!gamma_lut)
+                       gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
+               if (IS_ERR(gamma_lut)) {
+                       ret = PTR_ERR(gamma_lut);
+                       gamma_lut = NULL;
+                       goto out_state;
                }
 
-               if (cmap->start + cmap->len > crtc->gamma_size) {
-                       rc = -EINVAL;
-                       goto out;
+               crtc_state = drm_atomic_get_crtc_state(state, crtc);
+               if (IS_ERR(crtc_state)) {
+                       ret = PTR_ERR(crtc_state);
+                       goto out_state;
                }
 
+               replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
+                                                     NULL);
+               replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
+               replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
+                                                     gamma_lut);
+               crtc_state->color_mgmt_changed |= replaced;
+       }
+
+       ret = drm_atomic_commit(state);
+       if (ret)
+               goto out_state;
+
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               crtc = fb_helper->crtc_info[i].mode_set.crtc;
+
                r = crtc->gamma_store;
                g = r + crtc->gamma_size;
                b = g + crtc->gamma_size;
@@ -1306,28 +1366,57 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
                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));
+       }
+
+out_state:
+       if (ret == -EDEADLK)
+               goto backoff;
+
+       drm_property_blob_put(gamma_lut);
+       drm_atomic_state_put(state);
+out_ctx:
+       drm_modeset_drop_locks(&ctx);
+       drm_modeset_acquire_fini(&ctx);
 
-               for (j = 0; j < cmap->len; j++) {
-                       u16 hred, hgreen, hblue, htransp = 0xffff;
+       return ret;
 
-                       hred = *red++;
-                       hgreen = *green++;
-                       hblue = *blue++;
+backoff:
+       drm_atomic_state_clear(state);
+       drm_modeset_backoff(&ctx);
+       goto retry;
+}
 
-                       if (transp)
-                               htransp = *transp++;
+/**
+ * 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;
 
-                       rc = setcolreg(crtc, hred, hgreen, hblue, start++, info);
-                       if (rc)
-                               goto out;
-               }
-               if (crtc_funcs->load_lut)
-                       crtc_funcs->load_lut(crtc);
+       if (oops_in_progress)
+               return -EBUSY;
+
+       mutex_lock(&fb_helper->lock);
+
+       if (!drm_fb_helper_is_bound(fb_helper)) {
+               ret = -EBUSY;
+               goto out;
        }
- 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);
+
+out:
        mutex_unlock(&fb_helper->lock);
-       return rc;
+
+       return ret;
 }
 EXPORT_SYMBOL(drm_fb_helper_setcmap);