drm/amd/display: Add front end for dp debugfs files

As part of hardware certification, read-write access to
the link rate, lane count, voltage swing, pre-emphasis,
and PHY test pattern of DP connectors is required.  This commit
adds debugfs files that will correspond to these values.
The file operations are not yet implemented: currently
writing or reading them does nothing.

Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/Makefile

@@ -32,7 +32,7 @@ AMDGPUDM += amdgpu_dm_services.o amdgpu_dm_helpers.o
 endif
 
 ifneq ($(CONFIG_DEBUG_FS),)
-AMDGPUDM += amdgpu_dm_crc.o
+AMDGPUDM += amdgpu_dm_crc.o amdgpu_dm_debugfs.o
 endif
 
 subdir-ccflags-y += -I$(FULL_AMD_DISPLAY_PATH)/dc

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -39,6 +39,9 @@
 #include "dm_helpers.h"
 #include "dm_services_types.h"
 #include "amdgpu_dm_mst_types.h"
+#if defined(CONFIG_DEBUG_FS)
+#include "amdgpu_dm_debugfs.h"
+#endif
 
 #include "ivsrcid/ivsrcid_vislands30.h"
 
@@ -3619,6 +3622,13 @@ static int amdgpu_dm_connector_init(struct amdgpu_display_manager *dm,
 		&aconnector->base, &aencoder->base);
 
 	drm_connector_register(&aconnector->base);
+#if defined(CONFIG_DEBUG_FS)
+	res = connector_debugfs_init(aconnector);
+	if (res) {
+		DRM_ERROR("Failed to create debugfs for connector");
+		goto out_free;
+	}
+#endif
 
 	if (connector_type == DRM_MODE_CONNECTOR_DisplayPort
 		|| connector_type == DRM_MODE_CONNECTOR_eDP)

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c

@@ -0,0 +1,170 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#include <linux/debugfs.h>
+
+#include "dc.h"
+#include "dc_link.h"
+
+#include "amdgpu.h"
+#include "amdgpu_dm.h"
+#include "amdgpu_dm_debugfs.h"
+
+static ssize_t dp_link_rate_debugfs_read(struct file *f, char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to read link rate */
+	return 1;
+}
+
+static ssize_t dp_link_rate_debugfs_write(struct file *f, const char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to write link rate */
+	return 1;
+}
+
+static ssize_t dp_lane_count_debugfs_read(struct file *f, char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to read lane count */
+	return 1;
+}
+
+static ssize_t dp_lane_count_debugfs_write(struct file *f, const char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to write lane count */
+	return 1;
+}
+
+static ssize_t dp_voltage_swing_debugfs_read(struct file *f, char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to read voltage swing */
+	return 1;
+}
+
+static ssize_t dp_voltage_swing_debugfs_write(struct file *f, const char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to write voltage swing */
+	return 1;
+}
+
+static ssize_t dp_pre_emphasis_debugfs_read(struct file *f, char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to read pre-emphasis */
+	return 1;
+}
+
+static ssize_t dp_pre_emphasis_debugfs_write(struct file *f, const char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to write pre-emphasis */
+	return 1;
+}
+
+static ssize_t dp_phy_test_pattern_debugfs_read(struct file *f, char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to read PHY test pattern */
+	return 1;
+}
+
+static ssize_t dp_phy_test_pattern_debugfs_write(struct file *f, const char __user *buf,
+				 size_t size, loff_t *pos)
+{
+	/* TODO: create method to write PHY test pattern */
+	return 1;
+}
+
+static const struct file_operations dp_link_rate_fops = {
+	.owner = THIS_MODULE,
+	.read = dp_link_rate_debugfs_read,
+	.write = dp_link_rate_debugfs_write,
+	.llseek = default_llseek
+};
+
+static const struct file_operations dp_lane_count_fops = {
+	.owner = THIS_MODULE,
+	.read = dp_lane_count_debugfs_read,
+	.write = dp_lane_count_debugfs_write,
+	.llseek = default_llseek
+};
+
+static const struct file_operations dp_voltage_swing_fops = {
+	.owner = THIS_MODULE,
+	.read = dp_voltage_swing_debugfs_read,
+	.write = dp_voltage_swing_debugfs_write,
+	.llseek = default_llseek
+};
+
+static const struct file_operations dp_pre_emphasis_fops = {
+	.owner = THIS_MODULE,
+	.read = dp_pre_emphasis_debugfs_read,
+	.write = dp_pre_emphasis_debugfs_write,
+	.llseek = default_llseek
+};
+
+static const struct file_operations dp_phy_test_pattern_fops = {
+	.owner = THIS_MODULE,
+	.read = dp_phy_test_pattern_debugfs_read,
+	.write = dp_phy_test_pattern_debugfs_write,
+	.llseek = default_llseek
+};
+
+static const struct {
+	char *name;
+	const struct file_operations *fops;
+} dp_debugfs_entries[] = {
+		{"link_rate", &dp_link_rate_fops},
+		{"lane_count", &dp_lane_count_fops},
+		{"voltage_swing", &dp_voltage_swing_fops},
+		{"pre_emphasis", &dp_pre_emphasis_fops},
+		{"phy_test_pattern", &dp_phy_test_pattern_fops}
+};
+
+int connector_debugfs_init(struct amdgpu_dm_connector *connector)
+{
+	int i;
+	struct dentry *ent, *dir = connector->base.debugfs_entry;
+
+	if (connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
+		for (i = 0; i < ARRAY_SIZE(dp_debugfs_entries); i++) {
+			ent = debugfs_create_file(dp_debugfs_entries[i].name,
+						  0644,
+						  dir,
+						  connector,
+						  dp_debugfs_entries[i].fops);
+			if (IS_ERR(ent))
+				return PTR_ERR(ent);
+		}
+	}
+
+	return 0;
+}
+

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __AMDGPU_DM_DEBUGFS_H__
+#define __AMDGPU_DM_DEBUGFS_H__
+
+#include "amdgpu.h"
+#include "amdgpu_dm.h"
+
+int connector_debugfs_init(struct amdgpu_dm_connector *connector);
+
+#endif