drm/vc4: hdmi: Rework hdmi_enable_4kp60 detection code

In order to support higher HDMI frequencies, users have to set the
hdmi_enable_4kp60 parameter in their config.txt file.

This will have the side-effect of raising the maximum of the core clock,
tied to the HVS, and managed by the HVS driver.

However, we are querying this in the HDMI driver by poking into the HVS
structure to get our struct clk handle.

Let's make this part of the HVS bind implementation to have all the core
clock related setup in the same place.
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220815-rpi-fix-4k-60-v5-5-fe9e7ac8b111@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_drv.h

@@ -326,6 +326,8 @@ struct vc4_hvs {
 
 	struct clk *core_clk;
 
+	unsigned long max_core_rate;
+
 	/* Memory manager for CRTCs to allocate space in the display
 	 * list.  Units are dwords.
 	 */
@@ -337,6 +339,14 @@ struct vc4_hvs {
 	struct drm_mm_node mitchell_netravali_filter;
 
 	struct debugfs_regset32 regset;
+
+	/*
+	 * Even if HDMI0 on the RPi4 can output modes requiring a pixel
+	 * rate higher than 297MHz, it needs some adjustments in the
+	 * config.txt file to be able to do so and thus won't always be
+	 * available.
+	 */
+	bool vc5_hdmi_enable_hdmi_20;
 };
 
 struct vc4_plane {

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -46,7 +46,6 @@
 #include <linux/pm_runtime.h>
 #include <linux/rational.h>
 #include <linux/reset.h>
-#include <soc/bcm2835/raspberrypi-clocks.h>
 #include <sound/dmaengine_pcm.h>
 #include <sound/hdmi-codec.h>
 #include <sound/pcm_drm_eld.h>
@@ -460,6 +459,7 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector,
 static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 {
 	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
+	struct vc4_dev *vc4 = to_vc4_dev(connector->dev);
 	int ret = 0;
 	struct edid *edid;
 
@@ -483,7 +483,7 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 	ret = drm_add_edid_modes(connector, edid);
 	kfree(edid);
 
-	if (vc4_hdmi->disable_4kp60) {
+	if (!vc4->hvs->vc5_hdmi_enable_hdmi_20) {
 		struct drm_device *drm = connector->dev;
 		const struct drm_display_mode *mode;
 
@@ -1757,11 +1757,12 @@ vc4_hdmi_encoder_clock_valid(const struct vc4_hdmi *vc4_hdmi,
 {
 	const struct drm_connector *connector = &vc4_hdmi->connector;
 	const struct drm_display_info *info = &connector->display_info;
+	struct vc4_dev *vc4 = to_vc4_dev(connector->dev);
 
 	if (clock > vc4_hdmi->variant->max_pixel_clock)
 		return MODE_CLOCK_HIGH;
 
-	if (vc4_hdmi->disable_4kp60 && clock > HDMI_14_MAX_TMDS_CLK)
+	if (!vc4->hvs->vc5_hdmi_enable_hdmi_20 && clock > HDMI_14_MAX_TMDS_CLK)
 		return MODE_CLOCK_HIGH;
 
 	if (info->max_tmds_clock && clock > (info->max_tmds_clock * 1000))
@@ -3428,14 +3429,6 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	vc4_hdmi->disable_wifi_frequencies =
 		of_property_read_bool(dev->of_node, "wifi-2.4ghz-coexistence");
 
-	if (variant->max_pixel_clock == 600000000) {
-		struct vc4_dev *vc4 = to_vc4_dev(drm);
-		unsigned int max_rate = rpi_firmware_clk_get_max_rate(vc4->hvs->core_clk);
-
-		if (max_rate < 550000000)
-			vc4_hdmi->disable_4kp60 = true;
-	}
-
 	ret = devm_pm_runtime_enable(dev);
 	if (ret)
 		return ret;

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -156,14 +156,6 @@ struct vc4_hdmi {
 	 */
 	bool disable_wifi_frequencies;
 
-	/*
-	 * Even if HDMI0 on the RPi4 can output modes requiring a pixel
-	 * rate higher than 297MHz, it needs some adjustments in the
-	 * config.txt file to be able to do so and thus won't always be
-	 * available.
-	 */
-	bool disable_4kp60;
-
 	struct cec_adapter *cec_adap;
 	struct cec_msg cec_rx_msg;
 	bool cec_tx_ok;

drivers/gpu/drm/vc4/vc4_hvs.c

@@ -28,6 +28,8 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_vblank.h>
 
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
 #include "vc4_drv.h"
 #include "vc4_regs.h"
 
@@ -791,12 +793,33 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 	hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
 
 	if (vc4->is_vc5) {
+		struct rpi_firmware *firmware;
+		struct device_node *node;
+		unsigned int max_rate;
+
+		node = rpi_firmware_find_node();
+		if (!node)
+			return -EINVAL;
+
+		firmware = rpi_firmware_get(node);
+		of_node_put(node);
+		if (!firmware)
+			return -EPROBE_DEFER;
+
 		hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
 		if (IS_ERR(hvs->core_clk)) {
 			dev_err(&pdev->dev, "Couldn't get core clock\n");
 			return PTR_ERR(hvs->core_clk);
 		}
 
+		max_rate = rpi_firmware_clk_get_max_rate(firmware,
+							 RPI_FIRMWARE_CORE_CLK_ID);
+		rpi_firmware_put(firmware);
+		if (max_rate >= 550000000)
+			hvs->vc5_hdmi_enable_hdmi_20 = true;
+
+		hvs->max_core_rate = max_rate;
+
 		ret = clk_prepare_enable(hvs->core_clk);
 		if (ret) {
 			dev_err(&pdev->dev, "Couldn't enable the core clock\n");