[PATCH 3/3] drm/ingenic: ipu: Only enable clock when needed

[Paul Cercueil]

Instead of keeping the IPU clock enabled constantly, enable and disable
it on demand, when the IPU plane is used.

Signed-off-by: Paul Cercueil <p...@crapouillou.net>
---
 drivers/gpu/drm/ingenic/ingenic-ipu.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-ipu.c 
b/drivers/gpu/drm/ingenic/ingenic-ipu.c
index f4f0abcd6692..17e682cf1eba 100644
--- a/drivers/gpu/drm/ingenic/ingenic-ipu.c
+++ b/drivers/gpu/drm/ingenic/ingenic-ipu.c
@@ -49,6 +49,7 @@ struct ingenic_ipu {
        struct regmap *map;
        struct clk *clk;
        const struct soc_info *soc_info;
+       bool clk_enabled;
 
        unsigned int num_w, num_h, denom_w, denom_h;
 
@@ -288,12 +289,23 @@ static void ingenic_ipu_plane_atomic_update(struct 
drm_plane *plane,
        const struct drm_format_info *finfo;
        u32 ctrl, stride = 0, coef_index = 0, format = 0;
        bool needs_modeset, upscaling_w, upscaling_h;
+       int err;
 
        if (!state || !state->fb)
                return;
 
        finfo = drm_format_info(state->fb->format->format);
 
+       if (!ipu->clk_enabled) {
+               err = clk_enable(ipu->clk);
+               if (err) {
+                       dev_err(ipu->dev, "Unable to enable clock: %d\n", err);
+                       return;
+               }
+
+               ipu->clk_enabled = true;
+       }
+
        /* Reset all the registers if needed */
        needs_modeset = drm_atomic_crtc_needs_modeset(state->crtc->state);
        if (needs_modeset) {
@@ -578,6 +590,11 @@ static void ingenic_ipu_plane_atomic_disable(struct 
drm_plane *plane,
        regmap_clear_bits(ipu->map, JZ_REG_IPU_CTRL, JZ_IPU_CTRL_CHIP_EN);
 
        ingenic_drm_plane_disable(ipu->master, plane);
+
+       if (ipu->clk_enabled) {
+               clk_disable(ipu->clk);
+               ipu->clk_enabled = false;
+       }
 }
 
 static const struct drm_plane_helper_funcs ingenic_ipu_plane_helper_funcs = {
@@ -761,9 +778,9 @@ static int ingenic_ipu_bind(struct device *dev, struct 
device *master, void *d)
        drm_object_attach_property(&plane->base, ipu->sharpness_prop,
                                   ipu->sharpness);
 
-       err = clk_prepare_enable(ipu->clk);
+       err = clk_prepare(ipu->clk);
        if (err) {
-               dev_err(dev, "Unable to enable clock\n");
+               dev_err(dev, "Unable to prepare clock\n");
                return err;
        }
 
@@ -775,7 +792,7 @@ static void ingenic_ipu_unbind(struct device *dev,
 {
        struct ingenic_ipu *ipu = dev_get_drvdata(dev);
 
-       clk_disable_unprepare(ipu->clk);
+       clk_unprepare(ipu->clk);
 }
 
 static const struct component_ops ingenic_ipu_ops = {
-- 
2.27.0