os/pm: Update pm_procfs to show domain information

This commit extend pm_procfs to list all the domains inside 'proc/power/domains' directory based on domain_id. Now, every directory in proc/power has 'info' file which shows all the power management information related to current directory.

os/fs/procfs/fs_procfs.c

@@ -153,7 +153,8 @@ static const struct procfs_entry_s g_procfsentries[] = {
 #endif
 
 #if defined(CONFIG_PM) && !defined(CONFIG_FS_PROCFS_EXCLUDE_POWER)
-	{"power/domains**", &power_procfsoperations},
+	{"power**", &power_procfsoperations},
+	{"power/*", &power_procfsoperations},
 #endif
 
 #if !defined(CONFIG_FS_PROCFS_EXCLUDE_UPTIME)

os/include/tinyara/pm/pm.h

@@ -183,6 +183,7 @@ enum pm_state_e {
 								 */
 	PM_COUNT,
 };
+static const char *pm_state_name[PM_COUNT] = {"PM_NORMAL", "PM_IDLE", "PM_STANDBY", "PM_SLEEP"};
 
 /* This enumeration provides all power management related wakeup source code. */
 

os/pm/pm.h

@@ -132,6 +132,9 @@ struct pm_global_s {
 	/* Timer to decrease state */
 
 	WDOG_ID wdog;
+
+	/* No. of Registered Domains */
+	uint16_t ndomains;
 };
 
 /****************************************************************************

os/pm/pm_domain_register.c

@@ -106,6 +106,7 @@ int pm_domain_register(char *domain)
 				return ERROR;
 			}
 			strncpy(pm_domain_map[index], domain, length + 1);
+			g_pmglobals.ndomains++;
 #ifdef CONFIG_PM_METRICS
 			/* For newly registered domain initialize its pm metrics*/
 			pm_metrics_update_domain(index);

os/pm/pm_procfs.c

@@ -97,6 +97,8 @@
 struct power_dir_s {
 	struct procfs_dir_priv_s base; /* Base directory private data */
 	uint8_t direntry;
+	int domain_id;
+	uint8_t dtype;
 };
 
 /* This structure describes one open "file" */
@@ -129,6 +131,22 @@ static int power_stat(const char *relpath, FAR struct stat *buf);
  * Private Data
  ****************************************************************************/
 
+#define POWER         "power"
+#define POWER_DOMAINS "domains"
+#define POWER_STATE   "state"
+#define POWER_INFO    "info"
+
+/*
+ * Level 1 : /proc/power
+ * Level 2 : /proc/power/domains
+ * Level 3 : /proc/power/domains/{domain_name}
+ * Level 4 : /proc/power/domains/{domain_name}/info
+*/
+
+#define POWER_LEVEL_1   1
+#define POWER_LEVEL_2   2
+#define POWER_LEVEL_3   3
+#define POWER_LEVEL_4   4
 
 /****************************************************************************
  * Public Data
@@ -159,6 +177,30 @@ const struct procfs_operations power_procfsoperations = {
  * Private Functions
  ****************************************************************************/
 
+static void power_read_domain_info(int domain_id, void (*readprint)(const char *, ...))
+{
+	readprint("%-15s : %d\n", "Domain ID", domain_id);
+	readprint("%-15s : %s\n", "Domain Name", pm_domain_map[domain_id]);
+	readprint("%-15s : %d\n", "Suspend Count", g_pmglobals.suspend_count[domain_id]);
+}
+
+static void power_read_domains(void (*readprint)(const char *, ...))
+{
+	int domain_id;
+	readprint(" DOMAIN ID |            DOMAIN NAME            | SUSPEND COUNTS \n");
+	readprint("-----------|-----------------------------------|----------------\n");
+	for (domain_id = 0; domain_id < g_pmglobals.ndomains; domain_id++) {
+		readprint(" %9d | %33s | %14d \n", domain_id, pm_domain_map[domain_id], g_pmglobals.suspend_count[domain_id]);
+	}
+}
+
+static void power_read_state(void (*readprint)(const char *, ...))
+{
+	enum pm_state_e pm_state;
+	for (pm_state = PM_NORMAL; pm_state < PM_COUNT; pm_state++) {
+		readprint("%s %s\n", (pm_state == g_pmglobals.state) ? "*" : " ", pm_state_name[pm_state]);
+	}
+}
 /****************************************************************************
  * Name: power_find_dirref
  *
@@ -170,67 +212,76 @@ const struct procfs_operations power_procfsoperations = {
 
 static int power_find_dirref(FAR const char *relpath, FAR struct power_dir_s *dir)
 {
-	uint16_t len;
-	FAR char *str;
-	int i;
-
-	/* Skip the "power/domains" portion of relpath. We accept it only now */
-	len = strlen(POWER_SUBDIRPATH_DOMAINS);
-	if (strncmp(relpath, POWER_SUBDIRPATH_DOMAINS, len) != 0) {
-		fdbg("Invalid Path : Failed to find path %s \n", relpath);
-		return -ENOENT;
-	}
-	relpath += len;
-
-	if (relpath[0] == '/') {
-		relpath++;
-	}
-
-	if (relpath[0] == '\0') {
-		/* Requesting directory listing of registered device drivers for PM */
-		dir->base.level = 1;
-		dir->base.index = 0;
-		dir->base.nentries = CONFIG_PM_NDOMAINS;
-		/* Search PM registry to the number of registered device driver */
-		return OK;
-	}
-
-	str = NULL;
-
-	if (!str) {
-		fdbg("ERROR: Invalid path \"%s\"\n", relpath);
-		return -ENOENT;
-	}
-
-	len = str - relpath;
-
-	relpath += len;
-
-	if (relpath[0] == '/') {
-		relpath++;
-	}
-
-	if (relpath[0] == '\0') {
-		/* Requesting directory listing of a specific device driver or entry */
-		dir->base.level = 2;
-		dir->base.index = 0;
-		dir->base.nentries = g_power_direntrycount;
-		dir->direntry = 0;
-		return OK;
+	char *str;
+	int domain_id;
+	/* Function to check path is starting with given name */
+	int checkStart(char *name, bool isDirectory) {
+		uint16_t length = strlen(name);
+		if (strncmp(str, name, length) != 0) {
+			return ERROR;
+		}
+		str += length;
+		if (str[0] == '\0') {
+			return OK;
+		}
+		if (isDirectory && (str[0] == '/')) {
+			str++;
+			return OK;
+		}
+		return ERROR;
 	}
-
-	/* This is 3 level. Only files exist only in this level. */
-	dir->base.level = 3;
-	dir->base.nentries = 1;
-	dir->base.index = 0;
-	dir->direntry = 0;
-	for (i = 0; i < g_power_direntrycount; i++) {
-		if (strcmp(relpath, g_power_direntry[i].name) == 0) {
-			dir->direntry = i;
+	str = relpath;
+	dir->domain_id = -1;
+	/* Check relpath has "power" mount point */
+	if (checkStart(POWER, true) == OK) {
+		if (str[0] == '\0') {
+			dir->base.level = POWER_LEVEL_1;
+			dir->base.index = 0;
+			dir->base.nentries = 2;
+			dir->dtype = DTYPE_DIRECTORY;
+			return OK;
+		}
+		/* Check relpath has "domains" mount point */
+		if (checkStart(POWER_DOMAINS, true) == OK) {
+			if (str[0] == '\0') {
+				dir->base.level = POWER_LEVEL_2;
+				dir->base.index = 0;
+				dir->base.nentries = g_pmglobals.ndomains + 1;
+				dir->dtype = DTYPE_DIRECTORY;
+				return OK;
+			}
+			/* Iterate over each domain_name till you find match */
+			for (domain_id = 0; domain_id < g_pmglobals.ndomains; domain_id++) {
+				if (checkStart(pm_domain_map[domain_id], true) == OK) {
+					dir->domain_id = domain_id;
+					if (str[0] == '\0') {
+						dir->base.level = POWER_LEVEL_3;
+						dir->base.index = 0;
+						dir->base.nentries = 1;
+						dir->dtype = DTYPE_DIRECTORY;	
+						return OK;
+					}
+					break;
+				}
+			}
+			/* Check relpath has "info" mount point */
+			if (checkStart(POWER_INFO, false) == OK) {
+				dir->base.level = (dir->domain_id != -1) ? POWER_LEVEL_4 : POWER_LEVEL_3;
+				dir->base.index = 0;
+				dir->base.nentries = 0;
+				dir->dtype = DTYPE_FILE;
+				return OK;
+			}
+		/* Check relpath has "state" mount point */
+		} else if (checkStart(POWER_STATE, false) == OK) {
+			dir->base.level = POWER_LEVEL_2;
+			dir->base.index = 0;
+			dir->base.nentries = 0;
+			dir->dtype = DTYPE_FILE;
 			return OK;
 		}
 	}
-
+	fdbg("Invalid Path : Failed to find path %s \n", relpath);
 	return -ENOENT;
 }
 
@@ -296,29 +347,56 @@ static int power_close(FAR struct file *filep)
 static ssize_t power_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
 {
 	FAR struct power_file_s *priv;
-	ssize_t ret;
-
-	fvdbg("buffer=%p buflen=%d\n", buffer, (int)buflen);
-
-	/* Recover our private data from the struct file instance */
-
-	priv = (FAR struct power_file_s *)filep->f_priv;
-	DEBUGASSERT(priv);
-
-	/* Perform the read based on the directory entry */
-
-	ret = 0;
-
-	if (priv->dir.base.level == 3 && priv->dir.direntry < g_power_direntrycount) {
-		ret = g_power_direntry[priv->dir.direntry].read(filep, buffer, buflen);
+	size_t totalsize;
+	int domain_id;
+	int last_read;
+	int pm_state;
+	/* Function to copy domain information into buffer */
+	void readprint(const char *format, ...) {
+		size_t copysize;
+		va_list args;
+		va_start(args, format);
+		copysize = vsnprintf(buffer, buflen, format, args);
+		va_end(args);
+		/* Take min of buflen and copysize */
+		if (buflen < copysize) {
+			copysize = buflen - 1;
+		}
+		/* No need to copy information if we have already read information earlier */
+		if (copysize <= last_read) {
+			last_read -= copysize;
+			return;
+		}
+		/* Overwrite the last read information */
+		if (last_read) {
+			copysize -= last_read;
+			strncpy(buffer, buffer + last_read, copysize);
+			last_read = 0;
+		}
+		/* Increment the buffer pointer */
+		buflen -= copysize;
+		buffer += copysize;
+		totalsize += copysize;
+		priv->offset += copysize;
 	}
 
-	/* Update the file offset */
-	if (ret > 0) {
-		filep->f_pos += ret;
+	priv = (FAR struct power_file_s *)filep->f_priv;
+	domain_id = priv->dir.domain_id;
+	totalsize = 0;
+	last_read = priv->offset;
+	/* Read the content of "{domain_name}/info" */
+	if ((priv->dir.base.level == POWER_LEVEL_4) && (priv->dir.base.index == 0) && (domain_id >= 0)) {
+		power_read_domain_info(domain_id, readprint);
+	/* Read the content of "domains/info" */
+	} else if ((priv->dir.base.level == POWER_LEVEL_3) && (priv->dir.base.index == 0)) {
+		power_read_domains(readprint);
+	/* Read the content of "power/state" */
+	} else if ((priv->dir.base.level == POWER_LEVEL_2) && (priv->dir.base.index == 0)) {
+		power_read_state(readprint);
 	}
-
-	return ret;
+	/* Indicate we have already provided all the data */
+	filep->f_pos += totalsize;
+	return totalsize;
 }
 
 /****************************************************************************
@@ -337,7 +415,7 @@ static ssize_t power_write(FAR struct file *filep, FAR const char *buffer, size_
 	priv = (FAR struct power_file_s *)filep->f_priv;
 	DEBUGASSERT(priv);
 
-	/* Perform the read based on the directory entry */
+	/* pm_procfs does not have write operation, one must code write logic here */
 
 	ret = 0;
 
@@ -466,35 +544,46 @@ static int power_readdir(struct fs_dirent_s *dir)
 	/* Have we reached the end of the directory */
 	index = powerdir->base.index;
 	if (index >= powerdir->base.nentries) {
-		fdbg("Entry %d: End of directory\n", index);
 		return -ENOENT;
 	}
-
-	if (powerdir->base.level < 1 || powerdir->base.level > 3) {
-		fdbg("Invalid directory level\n");
-		return -ENOENT;
-	}
-
-	if (powerdir->base.level == 1) {
-		/* Listing the contents of domains */
-		if (index >= 0 && index < CONFIG_PM_NDOMAINS) {
+	switch (powerdir->base.level) {
+		/* List the content of "power" directory */
+	case POWER_LEVEL_1:
+		switch (index) {
+		case 0:
 			dir->fd_dir.d_type = DTYPE_DIRECTORY;
-			snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), "%d", index);
+			snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), POWER_DOMAINS);
 			powerdir->base.index++;
-			return OK;
+			break;
+		case 1:
+			dir->fd_dir.d_type = DTYPE_FILE;
+			snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), POWER_STATE);
+			powerdir->base.index++;
+			break;
+		}
+		break;
+	/* List the content of "domains" directory */
+	case POWER_LEVEL_2:
+		if (index == g_pmglobals.ndomains) {
+			dir->fd_dir.d_type = DTYPE_FILE;
+			snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), POWER_INFO);
+		} else {
+			dir->fd_dir.d_type = DTYPE_DIRECTORY;
+			snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), pm_domain_map[index]);
 		}
-	} else if (powerdir->base.level == 2) {
-		/* Listing the contents of a specific domain */
-		dir->fd_dir.d_type = g_power_direntry[powerdir->base.index].type;
-		strncpy(dir->fd_dir.d_name, g_power_direntry[powerdir->base.index].name, NAME_MAX + 1);
 		powerdir->base.index++;
-		return OK;
-	} else if (powerdir->base.level == 3) {
-		fdbg("%s : Not a directory\n", g_power_direntry[index].name);
-		return -ENOTDIR;
+		break;
+	/* List the content of "{domain_name}" directory*/
+	case POWER_LEVEL_3:
+		dir->fd_dir.d_type = DTYPE_FILE;
+		snprintf(dir->fd_dir.d_name, sizeof(dir->fd_dir.d_name), POWER_INFO);
+		powerdir->base.index++;
+		break;
+	default:
+		fdbg("Invalid directory level\n");
+		return -ENOENT;
 	}
-
-	return -ENOENT;
+	return OK;
 }
 
 /****************************************************************************
@@ -534,7 +623,7 @@ static int power_stat(const char *relpath, struct stat *buf)
 	ret = power_find_dirref(relpath, &dir);
 
 	if (ret == OK) {
-		if (dir.base.level < 3) {
+		if (dir.dtype == DTYPE_DIRECTORY) {
 			/* This is a directory */
 			buf->st_mode = S_IFDIR | S_IROTH | S_IRGRP | S_IRUSR;
 		} else {