drm/rockchip: vop2: Improve display modes handling on RK3588 HDMI1

The RK3588 specific implementation is currently quite limited in terms
of handling the full range of display modes supported by the connected
screens, e.g. 2560x1440@75Hz, 2048x1152@60Hz, 1024x768@60Hz are just a
few of them.

Additionally, it doesn't cope well with non-integer refresh rates like
59.94, 29.97, 23.98, etc.

Make use of HDMI1 PHY PLL as a more accurate DCLK source to handle
all display modes up to 4K@60Hz.

Signed-off-by: Cristian Ciocaltea <[e-mail]>
Signed-off-by: Heiko Stuebner <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/rockchip/rockchip_drm_vop2.c

···
 	struct clk *aclk;
 	struct clk *pclk;
 	struct clk *pll_hdmiphy0;
+	struct clk *pll_hdmiphy1;
 
 	/* optional internal rgb encoder */
 	struct rockchip_rgb *rgb;
···
 	 * Switch to HDMI PHY PLL as DCLK source for display modes up
 	 * to 4K@60Hz, if available, otherwise keep using the system CRU.
 	 */
-	if (vop2->pll_hdmiphy0 && clock <= VOP2_MAX_DCLK_RATE) {
+	if ((vop2->pll_hdmiphy0 || vop2->pll_hdmiphy1) && clock <= VOP2_MAX_DCLK_RATE) {
 		drm_for_each_encoder_mask(encoder, crtc->dev, crtc_state->encoder_mask) {
 			struct rockchip_encoder *rkencoder = to_rockchip_encoder(encoder);
 
 			if (rkencoder->crtc_endpoint_id == ROCKCHIP_VOP2_EP_HDMI0) {
+				if (!vop2->pll_hdmiphy0)
+					break;
+
 				if (!vp->dclk_src)
 					vp->dclk_src = clk_get_parent(vp->dclk);
 
···
 				if (ret < 0)
 					drm_warn(vop2->drm,
 						 "Could not switch to HDMI0 PHY PLL: %d\n", ret);
+				break;
+			}
+
+			if (rkencoder->crtc_endpoint_id == ROCKCHIP_VOP2_EP_HDMI1) {
+				if (!vop2->pll_hdmiphy1)
+					break;
+
+				if (!vp->dclk_src)
+					vp->dclk_src = clk_get_parent(vp->dclk);
+
+				ret = clk_set_parent(vp->dclk, vop2->pll_hdmiphy1);
+				if (ret < 0)
+					drm_warn(vop2->drm,
+						 "Could not switch to HDMI1 PHY PLL: %d\n", ret);
 				break;
 			}
 		}
···
 		drm_err(vop2->drm, "failed to get pll_hdmiphy0\n");
 		return PTR_ERR(vop2->pll_hdmiphy0);
 	}
+
+	vop2->pll_hdmiphy1 = devm_clk_get_optional(vop2->dev, "pll_hdmiphy1");
+	if (IS_ERR(vop2->pll_hdmiphy1))
+		return dev_err_probe(drm->dev, PTR_ERR(vop2->pll_hdmiphy1),
+				     "failed to get pll_hdmiphy1\n");
 
 	vop2->irq = platform_get_irq(pdev, 0);
 	if (vop2->irq < 0) {