[PATCH v2 3/5] drm/rockchip: vop2: Improve display modes handling on RK3588 HDMI0

Cristian Ciocaltea
2024-12-11T10:20:20Z

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 HDMI0 PHY PLL as a more accurate DCLK source to handle
all display modes up to 4K@60Hz.

Tested-by: FUKAUMI Naoki <naoki@radxa.com>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 34 ++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
index 8b2f53ffefdbf1cc8737b3a86e630a03a7fd9348..393fe6aa170aaee9663c4a6d98c1cd6a5ef79392 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
@@ -158,6 +158,7 @@ struct vop2_video_port {
struct drm_crtc crtc;
struct vop2 *vop2;
struct clk *dclk;
+ struct clk *dclk_src;
unsigned int id;
const struct vop2_video_port_data *data;

@@ -212,6 +213,7 @@ struct vop2 {
struct clk *hclk;
struct clk *aclk;
struct clk *pclk;
+ struct clk *pll_hdmiphy0;

/* optional internal rgb encoder */
struct rockchip_rgb *rgb;
@@ -220,6 +222,8 @@ struct vop2 {
struct vop2_win win[];
};

+#define VOP2_MAX_DCLK_RATE 600000 /* kHz */
+
#define vop2_output_if_is_hdmi(x) ((x) == ROCKCHIP_VOP2_EP_HDMI0 || \
(x) == ROCKCHIP_VOP2_EP_HDMI1)

@@ -1033,6 +1037,9 @@ static void vop2_crtc_atomic_disable(struct drm_crtc *crtc,

vop2_crtc_disable_irq(vp, VP_INT_DSP_HOLD_VALID);

+ if (vp->dclk_src)
+ clk_set_parent(vp->dclk, vp->dclk_src);
+
clk_disable_unprepare(vp->dclk);

vop2->enable_count--;
@@ -2049,6 +2056,27 @@ static void vop2_crtc_atomic_enable(struct drm_crtc *crtc,

vop2_vp_write(vp, RK3568_VP_MIPI_CTRL, 0);

+ /*
+ * 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 && mode->crtc_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 (!vp->dclk_src)
+ vp->dclk_src = clk_get_parent(vp->dclk);
+
+ ret = clk_set_parent(vp->dclk, vop2->pll_hdmiphy0);
+ if (ret < 0)
+ drm_warn(vop2->drm,
+ "Could not switch to HDMI0 PHY PLL: %d\n", ret);
+ break;
+ }
+ }
+ }
+
clk_set_rate(vp->dclk, clock);

vop2_post_config(crtc);
@@ -3167,6 +3195,12 @@ static int vop2_bind(struct device *dev, struct device *master, void *data)
return PTR_ERR(vop2->pclk);
}

+ vop2->pll_hdmiphy0 = devm_clk_get_optional(vop2->dev, "pll_hdmiphy0");
+ if (IS_ERR(vop2->pll_hdmiphy0)) {
+ drm_err(vop2->drm, "failed to get pll_hdmiphy0\n");
+ return PTR_ERR(vop2->pll_hdmiphy0);
+ }
+
vop2->irq = platform_get_irq(pdev, 0);
if (vop2->irq < 0) {
drm_err(vop2->drm, "cannot find irq for vop2\n");

--
2.47.0