drm/msm/dp: add debugfs support to DP driver

To prepare the MSM DP driver for running video pattern
compliance tests introduce debugfs module for it.

Changes in v2: rebase on top of latest patchset of dependency

Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/Makefile

@@ -96,7 +96,8 @@ msm-y := \
 	msm_gpu_tracepoints.o \
 	msm_gpummu.o
 
-msm-$(CONFIG_DEBUG_FS) += adreno/a5xx_debugfs.o
+msm-$(CONFIG_DEBUG_FS) += adreno/a5xx_debugfs.o \
+	dp/dp_debug.o
 
 msm-$(CONFIG_DRM_MSM_GPU_STATE)	+= adreno/a6xx_gpu_state.o
 

drivers/gpu/drm/msm/dp/dp_debug.c

@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt)"[drm-dp] %s: " fmt, __func__
+
+#include <linux/debugfs.h>
+#include <drm/drm_connector.h>
+
+#include "dp_parser.h"
+#include "dp_catalog.h"
+#include "dp_aux.h"
+#include "dp_ctrl.h"
+#include "dp_debug.h"
+#include "dp_display.h"
+
+#define DEBUG_NAME "drm_dp"
+
+struct dp_debug_private {
+	struct dentry *root;
+
+	struct dp_usbpd *usbpd;
+	struct dp_link *link;
+	struct dp_panel *panel;
+	struct drm_connector **connector;
+	struct device *dev;
+
+	struct dp_debug dp_debug;
+};
+
+static int dp_debug_check_buffer_overflow(int rc, int *max_size, int *len)
+{
+	if (rc >= *max_size) {
+		DRM_ERROR("buffer overflow\n");
+		return -EINVAL;
+	}
+	*len += rc;
+	*max_size = SZ_4K - *len;
+
+	return 0;
+}
+
+static ssize_t dp_debug_read_info(struct file *file, char __user *user_buff,
+		size_t count, loff_t *ppos)
+{
+	struct dp_debug_private *debug = file->private_data;
+	char *buf;
+	u32 len = 0, rc = 0;
+	u64 lclk = 0;
+	u32 max_size = SZ_4K;
+	u32 link_params_rate;
+	struct drm_display_mode *drm_mode;
+
+	if (!debug)
+		return -ENODEV;
+
+	if (*ppos)
+		return 0;
+
+	buf = kzalloc(SZ_4K, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	drm_mode = &debug->panel->dp_mode.drm_mode;
+
+	rc = snprintf(buf + len, max_size, "\tname = %s\n", DEBUG_NAME);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\tdp_panel\n\t\tmax_pclk_khz = %d\n",
+			debug->panel->max_pclk_khz);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\tdrm_dp_link\n\t\trate = %u\n",
+			debug->panel->link_info.rate);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			 "\t\tnum_lanes = %u\n",
+			debug->panel->link_info.num_lanes);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tcapabilities = %lu\n",
+			debug->panel->link_info.capabilities);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\tdp_panel_info:\n\t\tactive = %dx%d\n",
+			drm_mode->hdisplay,
+			drm_mode->vdisplay);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tback_porch = %dx%d\n",
+			drm_mode->htotal - drm_mode->hsync_end,
+			drm_mode->vtotal - drm_mode->vsync_end);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tfront_porch = %dx%d\n",
+			drm_mode->hsync_start - drm_mode->hdisplay,
+			drm_mode->vsync_start - drm_mode->vdisplay);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tsync_width = %dx%d\n",
+			drm_mode->hsync_end - drm_mode->hsync_start,
+			drm_mode->vsync_end - drm_mode->vsync_start);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tactive_low = %dx%d\n",
+			debug->panel->dp_mode.h_active_low,
+			debug->panel->dp_mode.v_active_low);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\th_skew = %d\n",
+			drm_mode->hskew);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\trefresh rate = %d\n",
+			drm_mode_vrefresh(drm_mode));
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tpixel clock khz = %d\n",
+			drm_mode->clock);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tbpp = %d\n",
+			debug->panel->dp_mode.bpp);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	/* Link Information */
+	rc = snprintf(buf + len, max_size,
+			"\tdp_link:\n\t\ttest_requested = %d\n",
+			debug->link->sink_request);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tnum_lanes = %d\n",
+			debug->link->link_params.num_lanes);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	link_params_rate = debug->link->link_params.rate;
+	rc = snprintf(buf + len, max_size,
+			"\t\tbw_code = %d\n",
+			drm_dp_link_rate_to_bw_code(link_params_rate));
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	lclk = debug->link->link_params.rate * 1000;
+	rc = snprintf(buf + len, max_size,
+			"\t\tlclk = %lld\n", lclk);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tv_level = %d\n",
+			debug->link->phy_params.v_level);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	rc = snprintf(buf + len, max_size,
+			"\t\tp_level = %d\n",
+			debug->link->phy_params.p_level);
+	if (dp_debug_check_buffer_overflow(rc, &max_size, &len))
+		goto error;
+
+	if (copy_to_user(user_buff, buf, len))
+		goto error;
+
+	*ppos += len;
+
+	kfree(buf);
+	return len;
+ error:
+	kfree(buf);
+	return -EINVAL;
+}
+
+static const struct file_operations dp_debug_fops = {
+	.open = simple_open,
+	.read = dp_debug_read_info,
+};
+
+static int dp_debug_init(struct dp_debug *dp_debug)
+{
+	int rc = 0;
+	struct dp_debug_private *debug = container_of(dp_debug,
+			struct dp_debug_private, dp_debug);
+	struct dentry *dir, *file;
+
+	dir = debugfs_create_dir(DEBUG_NAME, NULL);
+	if (IS_ERR_OR_NULL(dir)) {
+		rc = PTR_ERR(dir);
+		DRM_ERROR("[%s] debugfs create dir failed, rc = %d\n",
+				  DEBUG_NAME, rc);
+		goto error;
+	}
+
+	file = debugfs_create_file("dp_debug", 0444, dir,
+			debug, &dp_debug_fops);
+	if (IS_ERR_OR_NULL(file)) {
+		rc = PTR_ERR(file);
+		DRM_ERROR("[%s] debugfs create file failed, rc=%d\n",
+				  DEBUG_NAME, rc);
+		goto error_remove_dir;
+	}
+
+	debug->root = dir;
+	return rc;
+ error_remove_dir:
+	debugfs_remove(dir);
+ error:
+	return rc;
+}
+
+struct dp_debug *dp_debug_get(struct device *dev, struct dp_panel *panel,
+		struct dp_usbpd *usbpd, struct dp_link *link,
+		struct drm_connector **connector)
+{
+	int rc = 0;
+	struct dp_debug_private *debug;
+	struct dp_debug *dp_debug;
+
+	if (!dev || !panel || !usbpd || !link) {
+		DRM_ERROR("invalid input\n");
+		rc = -EINVAL;
+		goto error;
+	}
+
+	debug = devm_kzalloc(dev, sizeof(*debug), GFP_KERNEL);
+	if (!debug) {
+		rc = -ENOMEM;
+		goto error;
+	}
+
+	debug->dp_debug.debug_en = false;
+	debug->usbpd = usbpd;
+	debug->link = link;
+	debug->panel = panel;
+	debug->dev = dev;
+	debug->connector = connector;
+
+	dp_debug = &debug->dp_debug;
+	dp_debug->vdisplay = 0;
+	dp_debug->hdisplay = 0;
+	dp_debug->vrefresh = 0;
+
+	rc = dp_debug_init(dp_debug);
+	if (rc) {
+		devm_kfree(dev, debug);
+		goto error;
+	}
+
+	return dp_debug;
+ error:
+	return ERR_PTR(rc);
+}
+
+static int dp_debug_deinit(struct dp_debug *dp_debug)
+{
+	struct dp_debug_private *debug;
+
+	if (!dp_debug)
+		return -EINVAL;
+
+	debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
+
+	debugfs_remove_recursive(debug->root);
+
+	return 0;
+}
+
+void dp_debug_put(struct dp_debug *dp_debug)
+{
+	struct dp_debug_private *debug;
+
+	if (!dp_debug)
+		return;
+
+	debug = container_of(dp_debug, struct dp_debug_private, dp_debug);
+
+	dp_debug_deinit(dp_debug);
+
+	devm_kfree(debug->dev, debug);
+}

drivers/gpu/drm/msm/dp/dp_debug.h

@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef _DP_DEBUG_H_
+#define _DP_DEBUG_H_
+
+#include "dp_panel.h"
+#include "dp_link.h"
+
+/**
+ * struct dp_debug
+ * @debug_en: specifies whether debug mode enabled
+ * @vdisplay: used to filter out vdisplay value
+ * @hdisplay: used to filter out hdisplay value
+ * @vrefresh: used to filter out vrefresh value
+ * @tpg_state: specifies whether tpg feature is enabled
+ */
+struct dp_debug {
+	bool debug_en;
+	int aspect_ratio;
+	int vdisplay;
+	int hdisplay;
+	int vrefresh;
+};
+
+#if defined(CONFIG_DEBUG_FS)
+
+/**
+ * dp_debug_get() - configure and get the DisplayPlot debug module data
+ *
+ * @dev: device instance of the caller
+ * @panel: instance of panel module
+ * @usbpd: instance of usbpd module
+ * @link: instance of link module
+ * @connector: double pointer to display connector
+ * return: pointer to allocated debug module data
+ *
+ * This function sets up the debug module and provides a way
+ * for debugfs input to be communicated with existing modules
+ */
+struct dp_debug *dp_debug_get(struct device *dev, struct dp_panel *panel,
+		struct dp_usbpd *usbpd, struct dp_link *link,
+		struct drm_connector **connector);
+/**
+ * dp_debug_put()
+ *
+ * Cleans up dp_debug instance
+ *
+ * @dp_debug: instance of dp_debug
+ */
+void dp_debug_put(struct dp_debug *dp_debug);
+
+#else
+
+static inline
+struct dp_debug *dp_debug_get(struct device *dev, struct dp_panel *panel,
+		struct dp_usbpd *usbpd, struct dp_link *link,
+		struct drm_connector **connector)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void dp_debug_put(struct dp_debug *dp_debug)
+{
+}
+
+#endif /* defined(CONFIG_DEBUG_FS) */
+
+#endif /* _DP_DEBUG_H_ */