linux-kernel - [PATCH v3 100/105] drm/vc4: hdmi: Implement finer-grained hooks

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Date:   Wed, 27 May 2020 17:49:10 +0200
From:   Maxime Ripard <maxime@...no.tech>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>,
        Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org,
        linux-rpi-kernel@...ts.infradead.org,
        bcm-kernel-feedback-list@...adcom.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        Tim Gover <tim.gover@...pberrypi.com>,
        Phil Elwell <phil@...pberrypi.com>,
        Maxime Ripard <maxime@...no.tech>
Subject: [PATCH v3 100/105] drm/vc4: hdmi: Implement finer-grained hooks

In order to prevent some pixels getting stuck in an unflushable FIFO on
bcm2711, we need to enable the HVS, the pixelvalve (the CRTC) and the HDMI
controller (the encoder) in an intertwined way, and with tight delays.

However, the atomic callbacks don't really provide a way to work with
either constraints, so we need to roll our own callbacks so that we can
provide those guarantees.

Since those callbacks have been implemented and called in the CRTC code, we
can just implement them in the HDMI driver now.

Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 43 +++++++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index a97f378c6d2d..86ce8d247a00 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -320,18 +320,28 @@ static void vc4_hdmi_set_infoframes(struct drm_encoder *encoder)
 		vc4_hdmi_set_audio_infoframe(encoder);
 }
 
-static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
+static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder)
 {
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
-	int ret;
 
 	HDMI_WRITE(HDMI_RAM_PACKET_CONFIG, 0);
+}
+
+static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder)
+{
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 
 	if (vc4_hdmi->variant->phy_disable)
 		vc4_hdmi->variant->phy_disable(vc4_hdmi);
 
 	HDMI_WRITE(HDMI_VID_CTL,
 		   HDMI_READ(HDMI_VID_CTL) & ~VC4_HD_VID_CTL_ENABLE);
+}
+
+static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
+{
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+	int ret;
 
 	clk_disable_unprepare(vc4_hdmi->hsm_clock);
 	clk_disable_unprepare(vc4_hdmi->pixel_clock);
@@ -449,11 +459,10 @@ static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
 		  "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
 }
 
-static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
+static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder)
 {
 	struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
 	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
-	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
 	unsigned long pixel_rate, hsm_rate;
 	int ret;
 
@@ -521,6 +530,13 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 
 	if (vc4_hdmi->variant->set_timings)
 		vc4_hdmi->variant->set_timings(vc4_hdmi, mode);
+}
+
+static void vc4_hdmi_encoder_pre_crtc_enable(struct drm_encoder *encoder)
+{
+	struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
+	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
 
 	if (vc4_encoder->hdmi_monitor &&
 	    drm_default_rgb_quant_range(mode) == HDMI_QUANTIZATION_RANGE_LIMITED) {
@@ -536,6 +552,16 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 	}
 
 	HDMI_WRITE(HDMI_FIFO_CTL, VC4_HDMI_FIFO_CTL_MASTER_SLAVE_N);
+}
+
+static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder)
+{
+	struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
+	bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
+	bool vsync_pos = mode->flags & DRM_MODE_FLAG_PVSYNC;
+	int ret;
 
 	HDMI_WRITE(HDMI_VID_CTL,
 		   HDMI_READ(HDMI_VID_CTL) |
@@ -582,6 +608,10 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 	vc4_hdmi_recenter_fifo(vc4_hdmi);
 }
 
+static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
+{
+}
+
 static enum drm_mode_status
 vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
 			    const struct drm_display_mode *mode)
@@ -1359,6 +1389,11 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	variant = of_device_get_match_data(dev);
 	vc4_hdmi->variant = variant;
 	vc4_hdmi->encoder.base.type = variant->encoder_type;
+	vc4_hdmi->encoder.base.pre_crtc_configure = vc4_hdmi_encoder_pre_crtc_configure;
+	vc4_hdmi->encoder.base.pre_crtc_enable = vc4_hdmi_encoder_pre_crtc_enable;
+	vc4_hdmi->encoder.base.post_crtc_enable = vc4_hdmi_encoder_post_crtc_enable;
+	vc4_hdmi->encoder.base.post_crtc_disable = vc4_hdmi_encoder_post_crtc_disable;
+	vc4_hdmi->encoder.base.post_crtc_powerdown = vc4_hdmi_encoder_post_crtc_powerdown;
 	encoder = &vc4_hdmi->encoder.base.base;
 
 	ret = variant->init_resources(vc4_hdmi);
-- 
git-series 0.9.1