drm/rockchip: dw_hdmi: Filter modes based on hdmiphy_clk

RK3228 and RK3328 clock rate is being validated against a mpll config
table intended for a Synopsys phy, and not the used inno-hdmi-phy.

Instead get a reference to the hdmiphy clk and validate rates against
it to enable use of HDMI2.0 modes, e.g. 4K@60Hz, on RK3228 and RK3328.

For Synopsis phy the max_tmds_clock validation is sufficient.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Diederik de Haas <didi.debian@cknow.org> # Rock64
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240908145511.3331451-2-jonas@kwiboo.se

Author: Kwiboo

drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c

@@ -76,6 +76,7 @@ struct rockchip_hdmi {
 	struct rockchip_encoder encoder;
 	const struct rockchip_hdmi_chip_data *chip_data;
 	const struct dw_hdmi_plat_data *plat_data;
+	struct clk *hdmiphy_clk;
 	struct clk *ref_clk;
 	struct clk *grf_clk;
 	struct dw_hdmi *hdmi;
@@ -251,10 +252,7 @@ dw_hdmi_rockchip_mode_valid(struct dw_hdmi *dw_hdmi, void *data,
 			    const struct drm_display_mode *mode)
 {
 	struct rockchip_hdmi *hdmi = data;
-	const struct dw_hdmi_mpll_config *mpll_cfg = rockchip_mpll_cfg;
 	int pclk = mode->clock * 1000;
-	bool exact_match = hdmi->plat_data->phy_force_vendor;
-	int i;
 
 	if (hdmi->chip_data->max_tmds_clock &&
 	    mode->clock > hdmi->chip_data->max_tmds_clock)
@@ -263,26 +261,18 @@ dw_hdmi_rockchip_mode_valid(struct dw_hdmi *dw_hdmi, void *data,
 	if (hdmi->ref_clk) {
 		int rpclk = clk_round_rate(hdmi->ref_clk, pclk);
 
-		if (abs(rpclk - pclk) > pclk / 1000)
+		if (rpclk < 0 || abs(rpclk - pclk) > pclk / 1000)
 			return MODE_NOCLOCK;
 	}
 
-	for (i = 0; mpll_cfg[i].mpixelclock != (~0UL); i++) {
-		/*
-		 * For vendor specific phys force an exact match of the pixelclock
-		 * to preserve the original behaviour of the driver.
-		 */
-		if (exact_match && pclk == mpll_cfg[i].mpixelclock)
-			return MODE_OK;
-		/*
-		 * The Synopsys phy can work with pixelclocks up to the value given
-		 * in the corresponding mpll_cfg entry.
-		 */
-		if (!exact_match && pclk <= mpll_cfg[i].mpixelclock)
-			return MODE_OK;
+	if (hdmi->hdmiphy_clk) {
+		int rpclk = clk_round_rate(hdmi->hdmiphy_clk, pclk);
+
+		if (rpclk < 0 || abs(rpclk - pclk) > pclk / 1000)
+			return MODE_NOCLOCK;
 	}
 
-	return MODE_BAD;
+	return MODE_OK;
 }
 
 static void dw_hdmi_rockchip_encoder_disable(struct drm_encoder *encoder)
@@ -607,6 +597,15 @@ static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master,
 		return ret;
 	}
 
+	if (hdmi->phy) {
+		struct of_phandle_args clkspec;
+
+		clkspec.np = hdmi->phy->dev.of_node;
+		hdmi->hdmiphy_clk = of_clk_get_from_provider(&clkspec);
+		if (IS_ERR(hdmi->hdmiphy_clk))
+			hdmi->hdmiphy_clk = NULL;
+	}
+
 	if (hdmi->chip_data == &rk3568_chip_data) {
 		regmap_write(hdmi->regmap, RK3568_GRF_VO_CON1,
 			     HIWORD_UPDATE(RK3568_HDMI_SDAIN_MSK |