drm: apple: Add DPTX support

This is required for DP Altmode, DP Thunderbolt tunneling and HDMI
output on 14/16-inch Macbook Pros and M2* desktop devices.

M2* desktops and 14 and 16 inch Macbook Pros expose a DisplayPort to
HDMI converter which is driven by the DP output of one of the DCP/DCPext
display coprocessor/controller blocks.
Two gpio pins are used for power control. Another gpio pin acts as HDMI
hpd.
Do not use the hpd as direct drm_connector interrupt since that is
already wired to DCPs hotplug notification. Instead use it to trigger
link setup via the dptx endpoint.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>

Author: svenpeter42

drivers/gpu/drm/apple/Kconfig

@@ -7,5 +7,6 @@ config DRM_APPLE
 	select DRM_KMS_DMA_HELPER
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS
+	select MULTIPLEXER
 	help
 	  Say Y if you have an Apple Silicon chipset.

drivers/gpu/drm/apple/Makefile

@@ -4,7 +4,8 @@ CFLAGS_trace.o = -I$(src)
 
 appledrm-y := apple_drv.o
 
-apple_dcp-y := afk.o dcp.o dcp_backlight.o iomfb.o parser.o
+apple_dcp-y := afk.o dcp.o dcp_backlight.o dptxep.o iomfb.o parser.o systemep.o
+apple_dcp-y += ibootep.o
 apple_dcp-y += iomfb_v12_3.o
 apple_dcp-y += iomfb_v13_3.o
 apple_dcp-$(CONFIG_TRACING) += trace.o

drivers/gpu/drm/apple/apple_drv.c

@@ -313,7 +313,7 @@ static const struct drm_crtc_helper_funcs apple_crtc_helper_funcs = {
 static int apple_probe_per_dcp(struct device *dev,
 			       struct drm_device *drm,
 			       struct platform_device *dcp,
-			       int num)
+			       int num, bool dcp_ext)
 {
 	struct apple_crtc *crtc;
 	struct apple_connector *connector;
@@ -345,6 +345,10 @@ static int apple_probe_per_dcp(struct device *dev,
 	drm_connector_helper_add(&connector->base,
 				 &apple_connector_helper_funcs);
 
+	// HACK:
+	if (dcp_ext)
+		connector->base.fwnode = fwnode_handle_get(dev->fwnode);
+
 	ret = drm_connector_init(drm, &connector->base, &apple_connector_funcs,
 				 dcp_get_connector_type(dcp));
 	if (ret)
@@ -396,6 +400,7 @@ static int apple_get_fb_resource(struct device *dev, const char *name,
 
 static const struct of_device_id apple_dcp_id_tbl[] = {
 	{ .compatible = "apple,dcp" },
+	{ .compatible = "apple,dcpext" },
 	{},
 };
 
@@ -408,18 +413,20 @@ static int apple_drm_init_dcp(struct device *dev)
 	int i, ret, num_dcp = 0;
 
 	for_each_matching_node(np, apple_dcp_id_tbl) {
+		bool dcp_ext;
 		if (!of_device_is_available(np)) {
 			of_node_put(np);
 			continue;
 		}
+		dcp_ext = of_device_is_compatible(np, "apple,dcpext");
 
 		dcp[num_dcp] = of_find_device_by_node(np);
 		of_node_put(np);
 		if (!dcp[num_dcp])
 			continue;
 
 		ret = apple_probe_per_dcp(dev, &apple->drm, dcp[num_dcp],
-					  num_dcp);
+					  num_dcp, dcp_ext);
 		if (ret)
 			continue;
 

drivers/gpu/drm/apple/dcp-internal.h

@@ -7,9 +7,12 @@
 #include <linux/backlight.h>
 #include <linux/device.h>
 #include <linux/mutex.h>
+#include <linux/mux/consumer.h>
+#include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/scatterlist.h>
 
+#include "dptxep.h"
 #include "iomfb.h"
 #include "iomfb_v12_3.h"
 #include "iomfb_v13_3.h"
@@ -94,6 +97,10 @@ struct dcp_panel {
 	bool has_mini_led;
 };
 
+struct apple_dcp_hw_data {
+	u32 num_dptx_ports;
+};
+
 /* TODO: move IOMFB members to its own struct */
 struct apple_dcp {
 	struct device *dev;
@@ -103,6 +110,8 @@ struct apple_dcp {
 	struct apple_crtc *crtc;
 	struct apple_connector *connector;
 
+	struct apple_dcp_hw_data hw;
+
 	/* firmware version and compatible firmware version */
 	enum dcp_firmware_version fw_compat;
 
@@ -127,6 +136,8 @@ struct apple_dcp {
 	struct resource *disp_registers[MAX_DISP_REGISTERS];
 	unsigned int nr_disp_registers;
 
+	u32 index;
+
 	/* Bitmap of memory descriptors used for mappings made by the DCP */
 	DECLARE_BITMAP(memdesc_map, DCP_MAX_MAPPINGS);
 
@@ -191,6 +202,29 @@ struct apple_dcp {
 
 	/* integrated panel if present */
 	struct dcp_panel panel;
+
+	struct apple_dcp_afkep *systemep;
+	struct completion systemep_done;
+
+	struct apple_dcp_afkep *ibootep;
+
+	struct apple_dcp_afkep *dptxep;
+
+	struct dptx_port dptxport[2];
+
+	/* these fields are output port specific */
+	struct phy *phy;
+	struct mux_control *xbar;
+
+	struct gpio_desc *hdmi_hpd;
+	struct gpio_desc *hdmi_pwren;
+	struct gpio_desc *dp2hdmi_pwren;
+
+	struct mutex hpd_mutex;
+
+	u32 dptx_phy;
+	u32 dptx_die;
+	int hdmi_hpd_irq;
 };
 
 int dcp_backlight_register(struct apple_dcp *dcp);