msm: camera: common: create a common root folder for debugfs

Create common root folder under debugfs root named camera at probe. Add
utility functions to create subdirectories under the common camera root.

CRs-Fixed: 3093049
Change-Id: Ia4cefb5d2263ecabf1b9d70deefa1ee624b04f07
Signed-off-by: Anand Ravi <quic_ananravi@quicinc.com>

drivers/cam_utils/cam_debug_util.c

@@ -1,11 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2017-2021, The Linux Foundataion. All rights reserved.
+ * Copyright (c) 2017-2021, The Linux Foundation. All rights reserved.
  */
 
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/debugfs.h>
 #include "cam_trace.h"
 
 #include "cam_debug_util.h"
@@ -22,6 +23,85 @@ module_param(debug_priority, uint, 0644);
 
 struct camera_debug_settings cam_debug;
 
+struct dentry *cam_debugfs_root;
+
+void cam_debugfs_init(void)
+{
+	struct dentry *tmp;
+
+	if (!cam_debugfs_available()) {
+		cam_debugfs_root = NULL;
+		CAM_DBG(CAM_UTIL, "debugfs not available");
+		return;
+	}
+
+	if (cam_debugfs_root) {
+		CAM_WARN(CAM_UTIL, "already created debugfs root");
+		return;
+	}
+
+	tmp = debugfs_create_dir("camera", NULL);
+	if (IS_ERR_VALUE(tmp)) {
+		CAM_ERR(CAM_UTIL, "failed to create debugfs root folder (rc=%d)", PTR_ERR(tmp));
+		return;
+	}
+
+	cam_debugfs_root = tmp;
+	CAM_DBG(CAM_UTIL, "successfully created debugfs root");
+}
+
+void cam_debugfs_deinit(void)
+{
+	if (!cam_debugfs_available())
+		return;
+
+	debugfs_remove_recursive(cam_debugfs_root);
+	cam_debugfs_root = NULL;
+}
+
+int cam_debugfs_create_subdir(const char *name, struct dentry **subdir)
+{
+	struct dentry *tmp;
+
+	if (!cam_debugfs_root) {
+		CAM_WARN(CAM_UTIL, "debugfs root not created");
+		*subdir = NULL;
+		return -ENODEV;
+	}
+
+	if (!subdir) {
+		CAM_ERR(CAM_UTIL, "invalid subdir pointer %pK", subdir);
+		return -EINVAL;
+	}
+
+	tmp = debugfs_create_dir(name, cam_debugfs_root);
+	if (IS_ERR_VALUE(tmp)) {
+		CAM_ERR(CAM_UTIL, "failed to create debugfs subdir (name=%s, rc=%d)", name,
+			PTR_ERR(tmp));
+		return PTR_ERR(tmp);
+	}
+
+	*subdir = tmp;
+	return 0;
+}
+
+int cam_debugfs_lookup_subdir(const char *name, struct dentry **subdir)
+{
+	if (!cam_debugfs_root) {
+		CAM_WARN(CAM_UTIL, "debugfs root not created");
+		*subdir = NULL;
+		return -ENODEV;
+	}
+
+	if (!subdir) {
+		CAM_ERR(CAM_UTIL, "invalid subdir pointer %pK", subdir);
+		return -EINVAL;
+	}
+
+	*subdir = debugfs_lookup(name, cam_debugfs_root);
+	return (*subdir) ? 0 : -ENOENT;
+}
+
 const struct camera_debug_settings *cam_debug_get_settings()
 {
 	return &cam_debug;

drivers/cam_utils/cam_debug_util.h

@@ -360,4 +360,59 @@ const struct camera_debug_settings *cam_debug_get_settings(void);
 ssize_t cam_debug_sysfs_node_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count);
 
+/**
+ * cam_debugfs_init()
+ *
+ * @brief: create camera debugfs root folder
+ */
+void cam_debugfs_init(void);
+
+/**
+ * cam_debugfs_deinit()
+ *
+ * @brief: remove camera debugfs root folder
+ */
+void cam_debugfs_deinit(void);
+
+/**
+ * cam_debugfs_create_subdir()
+ *
+ * @brief:  create a directory within the camera debugfs root folder
+ *
+ * @name:   name of the directory
+ * @subdir: pointer to the newly created directory entry
+ *
+ * @return: 0 on success, negative on failure
+ */
+int cam_debugfs_create_subdir(const char *name, struct dentry **subdir);
+
+/**
+ * cam_debugfs_lookup_subdir()
+ *
+ * @brief:  lookup a directory within the camera debugfs root folder
+ *
+ * @name:   name of the directory
+ * @subdir: pointer to the successfully found directory entry
+ *
+ * @return: 0 on success, negative on failure
+ */
+int cam_debugfs_lookup_subdir(const char *name, struct dentry **subdir);
+
+/**
+ * cam_debugfs_available()
+ *
+ * @brief:  Check if debugfs is enabled for camera. Use this function before creating any
+ *          debugfs entries.
+ *
+ * @return: true if enabled, false otherwise
+ */
+static inline bool cam_debugfs_available(void)
+{
+	#if defined(CONFIG_DEBUG_FS)
+		return true;
+	#else
+		return false;
+	#endif
+}
+
 #endif /* _CAM_DEBUG_UTIL_H_ */

drivers/cam_utils/cam_soc_util.c

@@ -22,6 +22,8 @@
 #define CAM_SS_START_PRESIL 0x08c00000
 #define CAM_SS_START        0x0ac00000
 
+#define CAM_CLK_DIRNAME "clk"
+
 static uint skip_mmrm_set_rate;
 module_param(skip_mmrm_set_rate, uint, 0644);
 
@@ -684,23 +686,32 @@ DEFINE_SIMPLE_ATTRIBUTE(cam_soc_util_clk_lvl_control,
  */
 static int cam_soc_util_create_clk_lvl_debugfs(struct cam_hw_soc_info *soc_info)
 {
-	char debugfs_dir_name[64];
 	int rc = 0;
-	struct dentry *dbgfileptr = NULL;
+	struct dentry *dbgfileptr = NULL, *clkdirptr = NULL;
+
+	if (!cam_debugfs_available())
+		return 0;
 
 	if (soc_info->dentry) {
-		CAM_DBG(CAM_UTIL, "Debugfs entry for %s already exist",
+		CAM_DBG(CAM_UTIL, "Debugfs entry for %s already exists",
 			soc_info->dev_name);
 		goto end;
 	}
 
-	memset(debugfs_dir_name, 0, sizeof(debugfs_dir_name));
-	strlcat(debugfs_dir_name, "clk_dir_", sizeof(debugfs_dir_name));
-	strlcat(debugfs_dir_name, soc_info->dev_name, sizeof(debugfs_dir_name));
+	rc = cam_debugfs_lookup_subdir(CAM_CLK_DIRNAME, &clkdirptr);
+	if (rc) {
+		rc = cam_debugfs_create_subdir(CAM_CLK_DIRNAME, &clkdirptr);
+		if (rc) {
+			CAM_ERR(CAM_UTIL, "DebugFS could not create clk directory!");
+			rc = -ENOENT;
+			goto end;
+		}
+	}
 
-	dbgfileptr = debugfs_create_dir(debugfs_dir_name, NULL);
-	if (!dbgfileptr) {
-		CAM_ERR(CAM_UTIL,"DebugFS could not create directory!");
+	dbgfileptr = debugfs_create_dir(soc_info->dev_name, clkdirptr);
+	if (IS_ERR_OR_NULL(dbgfileptr)) {
+		CAM_ERR(CAM_UTIL, "DebugFS could not create directory for dev:%s!",
+			soc_info->dev_name);
 		rc = -ENOENT;
 		goto end;
 	}
@@ -711,32 +722,11 @@ static int cam_soc_util_create_clk_lvl_debugfs(struct cam_hw_soc_info *soc_info)
 		soc_info->dentry, soc_info, &cam_soc_util_clk_lvl_options);
 	dbgfileptr = debugfs_create_file("clk_lvl_control", 0644,
 		soc_info->dentry, soc_info, &cam_soc_util_clk_lvl_control);
-	if (IS_ERR(dbgfileptr)) {
-		if (PTR_ERR(dbgfileptr) == -ENODEV)
-			CAM_WARN(CAM_UTIL, "DebugFS not enabled in kernel!");
-		else
-			rc = PTR_ERR(dbgfileptr);
-	}
+	rc = PTR_ERR_OR_ZERO(dbgfileptr);
 end:
 	return rc;
 }
 
-/**
- * cam_soc_util_remove_clk_lvl_debugfs()
- *
- * @brief:      Removes the debugfs files used to view/control
- *              device clk rates
- *
- * @soc_info:   Device soc information
- *
- */
-static void cam_soc_util_remove_clk_lvl_debugfs(
-	struct cam_hw_soc_info *soc_info)
-{
-	debugfs_remove_recursive(soc_info->dentry);
-	soc_info->dentry = NULL;
-}
-
 int cam_soc_util_get_level_from_string(const char *string,
 	enum cam_vote_level *level)
 {
@@ -2836,8 +2826,7 @@ int cam_soc_util_release_platform_resource(struct cam_hw_soc_info *soc_info)
 	/* release for gpio */
 	cam_soc_util_request_gpio_table(soc_info, false);
 
-	if (soc_info->clk_control_enable)
-		cam_soc_util_remove_clk_lvl_debugfs(soc_info);
+	soc_info->dentry = NULL;
 
 	return 0;
 }