drm: sti: fix clocking issues in crtc

fix and simplify clock management in crtc to avoid unbalanced
call to clk_prepare_enable and clk_disable_unprepare functions
remove unused functions

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

1 files changed, 29 insertions, 30 deletions

diff --git a/drivers/gpu/drm/sti/sti_crtc.c b/drivers/gpu/drm/sti/sti_crtc.c
index 7fab3af7473b..c7d734dc3cf4 100644
--- a/drivers/gpu/drm/sti/sti_crtc.c
+++ b/drivers/gpu/drm/sti/sti_crtc.c
@@ -23,22 +23,11 @@
 static void sti_crtc_enable(struct drm_crtc *crtc)
 {
         struct sti_mixer *mixer = to_sti_mixer(crtc);
-        struct device *dev = mixer->dev;
-        struct sti_compositor *compo = dev_get_drvdata(dev);
 
         DRM_DEBUG_DRIVER("\n");
 
         mixer->status = STI_MIXER_READY;
 
-        /* Prepare and enable the compo IP clock */
-        if (mixer->id == STI_MIXER_MAIN) {
-                if (clk_prepare_enable(compo->clk_compo_main))
-                        DRM_INFO("Failed to prepare/enable compo_main clk\n");
-        } else {
-                if (clk_prepare_enable(compo->clk_compo_aux))
-                        DRM_INFO("Failed to prepare/enable compo_aux clk\n");
-        }
-
         drm_crtc_vblank_on(crtc);
 }
 
@@ -57,9 +46,8 @@ sti_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode)
         struct sti_mixer *mixer = to_sti_mixer(crtc);
         struct device *dev = mixer->dev;
         struct sti_compositor *compo = dev_get_drvdata(dev);
-        struct clk *clk;
+        struct clk *compo_clk, *pix_clk;
         int rate = mode->clock * 1000;
-        int res;
 
         DRM_DEBUG_KMS("CRTC:%d (%s) mode:%d (%s)\n",
                       crtc->base.id, sti_mixer_to_str(mixer),
@@ -74,32 +62,46 @@ sti_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode)
                       mode->vsync_start, mode->vsync_end,
                       mode->vtotal, mode->type, mode->flags);
 
-        /* Set rate and prepare/enable pixel clock */
-        if (mixer->id == STI_MIXER_MAIN)
-                clk = compo->clk_pix_main;
-        else
-                clk = compo->clk_pix_aux;
+        if (mixer->id == STI_MIXER_MAIN) {
+                compo_clk = compo->clk_compo_main;
+                pix_clk = compo->clk_pix_main;
+        } else {
+                compo_clk = compo->clk_compo_aux;
+                pix_clk = compo->clk_pix_aux;
+        }
+
+        /* Prepare and enable the compo IP clock */
+        if (clk_prepare_enable(compo_clk)) {
+                DRM_INFO("Failed to prepare/enable compositor clk\n");
+                goto compo_error;
+        }
 
-        res = clk_set_rate(clk, rate);
-        if (res < 0) {
+        /* Set rate and prepare/enable pixel clock */
+        if (clk_set_rate(pix_clk, rate) < 0) {
                 DRM_ERROR("Cannot set rate (%dHz) for pix clk\n", rate);
-                return -EINVAL;
+                goto pix_error;
         }
-        if (clk_prepare_enable(clk)) {
+        if (clk_prepare_enable(pix_clk)) {
                 DRM_ERROR("Failed to prepare/enable pix clk\n");
-                return -EINVAL;
+                goto pix_error;
         }
 
         sti_vtg_set_config(mixer->id == STI_MIXER_MAIN ?
                         compo->vtg_main : compo->vtg_aux, &crtc->mode);
 
-        res = sti_mixer_active_video_area(mixer, &crtc->mode);
-        if (res) {
+        if (sti_mixer_active_video_area(mixer, &crtc->mode)) {
                 DRM_ERROR("Can't set active video area\n");
-                return -EINVAL;
+                goto mixer_error;
         }
 
-        return res;
+        return 0;
+
+mixer_error:
+        clk_disable_unprepare(pix_clk);
+pix_error:
+        clk_disable_unprepare(compo_clk);
+compo_error:
+        return -EINVAL;
 }
 
 static void sti_crtc_disable(struct drm_crtc *crtc)
@@ -130,7 +132,6 @@ static void sti_crtc_disable(struct drm_crtc *crtc)
 static void
 sti_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
-        sti_crtc_enable(crtc);
         sti_crtc_mode_set(crtc, &crtc->state->adjusted_mode);
 }
 
@@ -221,9 +222,7 @@ static void sti_crtc_atomic_flush(struct drm_crtc *crtc,
 static const struct drm_crtc_helper_funcs sti_crtc_helper_funcs = {
         .enable = sti_crtc_enable,
         .disable = sti_crtc_disabling,
-        .mode_set = drm_helper_crtc_mode_set,
         .mode_set_nofb = sti_crtc_mode_set_nofb,
-        .mode_set_base = drm_helper_crtc_mode_set_base,
         .atomic_begin = sti_crtc_atomic_begin,
         .atomic_flush = sti_crtc_atomic_flush,
 };