drm/komeda: Add engine clock requirement check for the downscaling

For downscaling there is a restriction, the downscaling needed engine
clock can not acceed the real engine clock, and the clock requirement
mostly depend on the specific HW, to solve this problem:
1. Add a pipeline func - downscaling_clk_check for CORE to query the real
   HW if downscaling can be supported.
2. Add new property clock ratio which is the ratio of:
     (mclk << 32) / pxlclk
   then User driver can use this ratio to do the clock check to avoid post
   an invalid downscaling to kernel.

v2: Rebase and Delete debug print

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c b/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
index 0bf5c7b..2ea282c 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
+++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
@@ -677,6 +677,47 @@ static int d71_scaler_init(struct d71_dev *d71,
        return 0;
 }
 
+static int d71_downscaling_clk_check(struct komeda_pipeline *pipe,
+                                    struct drm_display_mode *mode,
+                                    unsigned long mclk_rate,
+                                    struct komeda_data_flow_cfg *dflow)
+{
+       u32 h_in = dflow->in_w;
+       u32 v_in = dflow->in_h;
+       u32 v_out = dflow->out_h;
+       u64 fraction, denominator;
+
+       /* D71 downscaling must satisfy the following equation
+        *
+        *   MCLK                   h_in * v_in
+        * ------- >= ---------------------------------------------
+        *  PXLCLK     (h_total - (1 + 2 * v_in / v_out)) * v_out
+        *
+        * In only horizontal downscaling situation, the right side should be
+        * multiplied by (h_total - 3) / (h_active - 3), then equation becomes
+        *
+        *   MCLK          h_in
+        * ------- >= ----------------
+        *  PXLCLK     (h_active - 3)
+        *
+        * To avoid precision lost the equation 1 will be convert to:
+        *
+        *   MCLK             h_in * v_in
+        * ------- >= -----------------------------------
+        *  PXLCLK     (h_total -1 ) * v_out -  2 * v_in
+        */
+       if (v_in == v_out) {
+               fraction = h_in;
+               denominator = mode->hdisplay - 3;
+       } else {
+               fraction = h_in * v_in;
+               denominator = (mode->htotal - 1) * v_out -  2 * v_in;
+       }
+
+       return mclk_rate * denominator >= mode->clock * 1000 * fraction ?
+              0 : -EINVAL;
+}
+
 static void d71_improc_update(struct komeda_component *c,
                              struct komeda_component_state *state)
 {
@@ -939,3 +980,7 @@ int d71_probe_block(struct d71_dev *d71,
 
        return err;
 }
+
+const struct komeda_pipeline_funcs d71_pipeline_funcs = {
+       .downscaling_clk_check = d71_downscaling_clk_check,
+};

diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
index 3a7248d..1c914f8 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
@@ -390,7 +390,7 @@ static int d71_enum_resources(struct komeda_dev *mdev)
 
        for (i = 0; i < d71->num_pipelines; i++) {
                pipe = komeda_pipeline_add(mdev, sizeof(struct d71_pipeline),
-                                          NULL);
+                                          &d71_pipeline_funcs);
                if (IS_ERR(pipe)) {
                        err = PTR_ERR(pipe);
                        goto err_cleanup;

diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.h b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.h
index 7465c57..84f1878 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.h
@@ -43,6 +43,8 @@ struct d71_dev {
 
 #define to_d71_pipeline(x)     container_of(x, struct d71_pipeline, base)
 
+extern const struct komeda_pipeline_funcs d71_pipeline_funcs;
+
 int d71_probe_block(struct d71_dev *d71,
                    struct block_header *blk, u32 __iomem *reg);
 void d71_read_block_header(u32 __iomem *reg, struct block_header *blk);

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 6712603..24a9613 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -18,6 +18,22 @@
 #include "komeda_dev.h"
 #include "komeda_kms.h"
 
+static void komeda_crtc_update_clock_ratio(struct komeda_crtc_state *kcrtc_st)
+{
+       u64 pxlclk, mclk;
+
+       if (!kcrtc_st->base.active) {
+               kcrtc_st->clock_ratio = 0;
+               return;
+       }
+
+       pxlclk = kcrtc_st->base.adjusted_mode.clock * 1000;
+       mclk = komeda_calc_mclk(kcrtc_st) << 32;
+
+       do_div(mclk, pxlclk);
+       kcrtc_st->clock_ratio = mclk;
+}
+
 /**
  * komeda_crtc_atomic_check - build display output data flow
  * @crtc: DRM crtc
@@ -38,6 +54,9 @@ komeda_crtc_atomic_check(struct drm_crtc *crtc,
        struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(state);
        int err;
 
+       if (drm_atomic_crtc_needs_modeset(state))
+               komeda_crtc_update_clock_ratio(kcrtc_st);
+
        if (state->active) {
                err = komeda_build_display_data_flow(kcrtc, kcrtc_st);
                if (err)
@@ -52,11 +71,12 @@ komeda_crtc_atomic_check(struct drm_crtc *crtc,
        return 0;
 }
 
-static u32 komeda_calc_mclk(struct komeda_crtc_state *kcrtc_st)
+unsigned long komeda_calc_mclk(struct komeda_crtc_state *kcrtc_st)
 {
-       unsigned long mclk = kcrtc_st->base.adjusted_mode.clock * 1000;
+       struct komeda_dev *mdev = kcrtc_st->base.crtc->dev->dev_private;
+       unsigned long pxlclk = kcrtc_st->base.adjusted_mode.clock;
 
-       return mclk;
+       return clk_round_rate(mdev->mclk, pxlclk * 1000);
 }
 
 /* For active a crtc, mainly need two parts of preparation
@@ -404,6 +424,7 @@ komeda_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
        __drm_atomic_helper_crtc_duplicate_state(crtc, &new->base);
 
        new->affected_pipes = old->active_pipes;
+       new->clock_ratio = old->clock_ratio;
 
        return &new->base;
 }
@@ -432,6 +453,24 @@ static void komeda_crtc_vblank_disable(struct drm_crtc *crtc)
        mdev->funcs->on_off_vblank(mdev, kcrtc->master->id, false);
 }
 
+static int
+komeda_crtc_atomic_get_property(struct drm_crtc *crtc,
+                               const struct drm_crtc_state *state,
+                               struct drm_property *property, uint64_t *val)
+{
+       struct komeda_crtc *kcrtc = to_kcrtc(crtc);
+       struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(state);
+
+       if (property == kcrtc->clock_ratio_property) {
+               *val = kcrtc_st->clock_ratio;
+       } else {
+               DRM_DEBUG_DRIVER("Unknown property %s\n", property->name);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 static const struct drm_crtc_funcs komeda_crtc_funcs = {
        .gamma_set              = drm_atomic_helper_legacy_gamma_set,
        .destroy                = drm_crtc_cleanup,
@@ -442,6 +481,7 @@ static const struct drm_crtc_funcs komeda_crtc_funcs = {
        .atomic_destroy_state   = komeda_crtc_atomic_destroy_state,
        .enable_vblank          = komeda_crtc_vblank_enable,
        .disable_vblank         = komeda_crtc_vblank_disable,
+       .atomic_get_property    = komeda_crtc_atomic_get_property,
 };
 
 int komeda_kms_setup_crtcs(struct komeda_kms_dev *kms,
@@ -477,6 +517,22 @@ int komeda_kms_setup_crtcs(struct komeda_kms_dev *kms,
        return 0;
 }
 
+static int komeda_crtc_create_clock_ratio_property(struct komeda_crtc *kcrtc)
+{
+       struct drm_crtc *crtc = &kcrtc->base;
+       struct drm_property *prop;
+
+       prop = drm_property_create_range(crtc->dev, DRM_MODE_PROP_ATOMIC,
+                                        "CLOCK_RATIO", 0, U64_MAX);
+       if (!prop)
+               return -ENOMEM;
+
+       drm_object_attach_property(&crtc->base, prop, 0);
+       kcrtc->clock_ratio_property = prop;
+
+       return 0;
+}
+
 static struct drm_plane *
 get_crtc_primary(struct komeda_kms_dev *kms, struct komeda_crtc *crtc)
 {
@@ -513,6 +569,10 @@ static int komeda_crtc_add(struct komeda_kms_dev *kms,
 
        crtc->port = kcrtc->master->of_output_port;
 
+       err = komeda_crtc_create_clock_ratio_property(kcrtc);
+       if (err)
+               return err;
+
        return 0;
 }
 

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index f16e9e5..db59a90 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -79,6 +79,9 @@ struct komeda_crtc {
 
        /** @disable_done: this flip_done is for tracing the disable */
        struct completion *disable_done;
+
+       /** @clock_ratio_property: property for ratio of (mclk << 32)/pxlclk */
+       struct drm_property *clock_ratio_property;
 };
 
 /**
@@ -101,6 +104,9 @@ struct komeda_crtc_state {
         * the active pipelines in once display instance
         */
        u32 active_pipes;
+
+       /** @clock_ratio: ratio of (mclk << 32)/pxlclk */
+       u64 clock_ratio;
 };
 
 /** struct komeda_kms_dev - for gather KMS related things */
@@ -142,6 +148,8 @@ is_only_changed_connector(struct drm_crtc_state *st, struct drm_connector *conn)
        return BIT(drm_connector_index(conn)) == changed_connectors;
 }
 
+unsigned long komeda_calc_mclk(struct komeda_crtc_state *kcrtc_st);
+
 int komeda_kms_setup_crtcs(struct komeda_kms_dev *kms, struct komeda_dev *mdev);
 
 int komeda_kms_add_crtcs(struct komeda_kms_dev *kms, struct komeda_dev *mdev);

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
index 9ffe11c..d0bf7d5 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.h
@@ -316,8 +316,14 @@ struct komeda_data_flow_cfg {
        u8 en_scaling : 1;
 };
 
-/** struct komeda_pipeline_funcs */
 struct komeda_pipeline_funcs {
+       /* check if the mclk (main engine clock) can satisfy the clock
+        * requirements of the downscaling that specified by dflow
+        */
+       int (*downscaling_clk_check)(struct komeda_pipeline *pipe,
+                                    struct drm_display_mode *mode,
+                                    unsigned long mclk_rate,
+                                    struct komeda_data_flow_cfg *dflow);
        /* dump_register: Optional, dump registers to seq_file */
        void (*dump_register)(struct komeda_pipeline *pipe,
                              struct seq_file *sf);

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
index 9f07ef6..01544c2 100644 (file)
--- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
@@ -387,6 +387,7 @@ static bool scaling_ratio_valid(u32 size_in, u32 size_out,
 
 static int
 komeda_scaler_check_cfg(struct komeda_scaler *scaler,
+                       struct komeda_crtc_state *kcrtc_st,
                        struct komeda_data_flow_cfg *dflow)
 {
        u32 hsize_in, vsize_in, hsize_out, vsize_out;
@@ -428,6 +429,20 @@ komeda_scaler_check_cfg(struct komeda_scaler *scaler,
                DRM_DEBUG_ATOMIC("Invalid vertical scaling ratio");
                return -EINVAL;
        }
+
+       if (hsize_in > hsize_out || vsize_in > vsize_out) {
+               struct komeda_pipeline *pipe = scaler->base.pipeline;
+               int err;
+
+               err = pipe->funcs->downscaling_clk_check(pipe,
+                                       &kcrtc_st->base.adjusted_mode,
+                                       komeda_calc_mclk(kcrtc_st), dflow);
+               if (err) {
+                       DRM_DEBUG_ATOMIC("mclk can't satisfy the clock requirement of the downscaling\n");
+                       return err;
+               }
+       }
+
        return 0;
 }
 
@@ -452,7 +467,7 @@ komeda_scaler_validate(void *user,
                return -EINVAL;
        }
 
-       err = komeda_scaler_check_cfg(scaler, dflow);
+       err = komeda_scaler_check_cfg(scaler, kcrtc_st, dflow);
        if (err)
                return err;