drm/vc4: hdmi: Move clock calculation into its own function

The code to compute our clock rate for a given setup will be called in
multiple places in the next patches, so let's create a separate function
for it.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220222164042.403112-4-maxime@cerno.tech

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index d4cebb5..e5d9d54 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1258,6 +1258,38 @@ vc4_hdmi_encoder_clock_valid(const struct vc4_hdmi *vc4_hdmi,
        return MODE_OK;
 }
 
+static unsigned long long
+vc4_hdmi_encoder_compute_mode_clock(const struct drm_display_mode *mode,
+                                   unsigned int bpc)
+{
+       unsigned long long clock = mode->clock * 1000;
+
+       if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+               clock = clock * 2;
+
+       clock = clock * bpc;
+       do_div(clock, 8);
+
+       return clock;
+}
+
+static int
+vc4_hdmi_encoder_compute_clock(const struct vc4_hdmi *vc4_hdmi,
+                              struct vc4_hdmi_connector_state *vc4_state,
+                              const struct drm_display_mode *mode,
+                              unsigned int bpc)
+{
+       unsigned long long clock;
+
+       clock = vc4_hdmi_encoder_compute_mode_clock(mode, bpc);
+       if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, clock) != MODE_OK)
+               return -EINVAL;
+
+       vc4_state->tmds_char_rate = clock;
+
+       return 0;
+}
+
 #define WIFI_2_4GHz_CH1_MIN_FREQ       2400000000ULL
 #define WIFI_2_4GHz_CH1_MAX_FREQ       2422000000ULL
 
@@ -1270,6 +1302,7 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
        struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
        unsigned long long tmds_char_rate = mode->clock * 1000;
        unsigned long long tmds_bit_rate;
+       int ret;
 
        if (vc4_hdmi->variant->unsupported_odd_h_timings &&
            ((mode->hdisplay % 2) || (mode->hsync_start % 2) ||
@@ -1290,21 +1323,10 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
                tmds_char_rate = mode->clock * 1000;
        }
 
-       if (conn_state->max_bpc == 12) {
-               tmds_char_rate = tmds_char_rate * 150;
-               do_div(tmds_char_rate, 100);
-       } else if (conn_state->max_bpc == 10) {
-               tmds_char_rate = tmds_char_rate * 125;
-               do_div(tmds_char_rate, 100);
-       }
-
-       if (mode->flags & DRM_MODE_FLAG_DBLCLK)
-               tmds_char_rate = tmds_char_rate * 2;
-
-       if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, tmds_char_rate) != MODE_OK)
-               return -EINVAL;
-
-       vc4_state->tmds_char_rate = tmds_char_rate;
+       ret = vc4_hdmi_encoder_compute_clock(vc4_hdmi, vc4_state, mode,
+                                            conn_state->max_bpc);
+       if (ret)
+               return ret;
 
        return 0;
 }