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Diffstat (limited to '')
| -rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c index dda904ec0534..c12f9bd12904 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c @@ -208,8 +208,27 @@ static int sun4i_hdmi_get_modes(struct drm_connector *connector) return ret; } +static int sun4i_hdmi_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode) +{ + struct sun4i_hdmi *hdmi = drm_connector_to_sun4i_hdmi(connector); + long rate = mode->clock * 1000; + long diff = rate / 200; /* +-0.5% allowed by HDMI spec */ + long rounded_rate; + + /* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */ + if (rate > 165000000) + return MODE_CLOCK_HIGH; + rounded_rate = clk_round_rate(hdmi->tmds_clk, rate); + if (max(rounded_rate, rate) - min(rounded_rate, rate) < diff && + rounded_rate > 0) + return MODE_OK; + return MODE_NOCLOCK; +} + static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = { .get_modes = sun4i_hdmi_get_modes, + .mode_valid = sun4i_hdmi_mode_valid, }; static enum drm_connector_status |