Programmatic access to remote power measurements

README

@@ -18,7 +18,7 @@ from sandbox/cdba/cdba-server. Available devices are read from $HOME/.cdba
 = Client side
 The client is invoked as:
 
-  cdba -b <board> -h <host> [-c <power-cylce-count>] boot.img
+  cdba -b <board> -h <host> [-c <power-cylce-count>] [-s <status-fifo>] boot.img
 
 <host> will be connected to using ssh and <board> will be selected for
 operation. As the board's fastboot interface shows up the given boot.img will
@@ -31,9 +31,23 @@ If the optional -c is given, the board will upon receiving the tilde sequence
 restart the board the given number of times. Each time booting the given
 boot.img.
 
+The optional -s argument can be used to specify that a fifo should be created
+and opened. cdba will request the server to start sending status/measurement
+updates, which will be written to this fifo.
+
+= Server side
+
 == Device configuration
 The list of attached devices is read from $HOME/.cdba and is YAML formatted.
 
+== Status command
+
+The "status-cmd" property for a board specifies a command line that should be
+executed to perform measurements and report status updates to the client. The
+command is expected to run for the duration of the board session and should
+produce a continuous stream of json-formatted lines of status updates according
+to the format defined in this document.
+
 === Example
 devices:
   - board: db2k
@@ -110,3 +124,38 @@ devices:
     fastboot: cacafada
     fastboot_set_active: true
     fastboot_key_timeout: 2
+
+= Status messages
+
+The status messages that are used by the client fifo and the server's status
+command should be json-formatted, with one status update per line.
+
+Each message should contain one timestamp member "ts", and one or more
+measurement members. Like so:
+
+  {"ts":%d.%03d, "name": {["mv"|"ma"]: %u}(, "name2": {["mv"|"ma"]: %u})*}
+
+The timestamp member ("ts"), should provide the time since first measurement in
+decimal form with millisecond accuracy.
+
+The key for the measurement members should be an identifier of the measured
+resources, and the value should be an object with members for each unit
+measured for the given resource and the measured value.
+
+Valid units to report are "mv", "ma", and "mw".
+
+Note that the cadence of measurement might differ between different items to be
+measured, so not all status messages contains data for all items that can be
+measured.
+
+== Examples
+
+Single resource "dc" measured at 20.271s, with voltage and current reported:
+
+  {"ts":20.271, "dc":{ "mv": 12165, "ma": 114}}
+
+Multiple resources measured in a single status message, followed by single
+resource measurement, all with voltage and current reported:
+
+  {"ts":38.341, "battery":{"mv":8023, "ma":725}, "vdd_cx":{"mv":750, "ma":466}}
+  {"ts":44.339, "battery":{"mv":8023, "ma":733}}

cdb_assist.c

@@ -43,6 +43,7 @@
 
 #include "cdba-server.h"
 #include "device.h"
+#include "status.h"
 
 struct cdb_assist {
 	char serial[9];
@@ -338,23 +339,37 @@ static void cdb_gpio(struct cdb_assist *cdb, int gpio, bool on)
 	cdb_ctrl_write(cdb, &cmd[gpio][on], 1);
 }
 
-static void cdb_assist_print_status(struct device *dev)
+static void cdb_assist_print_status(void *data)
+{
+	struct cdb_assist *cdb = data;
+	struct status_value vbat[] = {
+		{
+			.unit = STATUS_MV,
+			.value = cdb->voltage_set,
+		},
+		{
+			.unit = STATUS_MA,
+			.value = cdb->current_actual,
+		},
+		{}
+	};
+	struct status_value vref[] = {
+		{
+			.unit = STATUS_MV,
+			.value = cdb->vref,
+		},
+		{}
+	};
+
+	status_send_values("vbat", vbat);
+	status_send_values("vref", vref);
+}
+
+static void cdb_assist_status_enable(struct device *dev)
 {
 	struct cdb_assist *cdb = dev->cdb;
-	char buf[128];
-	int n;
 
-	n = sprintf(buf, "%umV %umA%s%s%s%s%s ref: %umV",
-			 cdb->voltage_set,
-			 cdb->current_actual,
-			 cdb->vbat ? " vbat" : "",
-			 cdb->vbus ? " vbus" : "",
-			 cdb->btn[0] ? " btn1" : "",
-			 cdb->btn[1] ? " btn2" : "",
-			 cdb->btn[2] ? " btn3" : "",
-			 cdb->vref);
-
-	cdba_send_buf(MSG_STATUS_UPDATE, n, buf);
+	watch_timer_add(1000, cdb_assist_print_status, cdb);
 }
 
 static void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV)
@@ -384,7 +399,7 @@ const struct control_ops cdb_assist_ops = {
 	.open = cdb_assist_open,
 	.close = cdb_assist_close,
 	.power = cdb_assist_power,
-	.print_status = cdb_assist_print_status,
+	.status_enable = cdb_assist_status_enable,
 	.usb = cdb_assist_usb,
 	.key = cdb_assist_key,
 };

cdba-server.c

@@ -210,7 +210,7 @@ static int handle_stdin(int fd, void *buf)
 			// fprintf(stderr, "fastboot boot\n");
 			break;
 		case MSG_STATUS_UPDATE:
-			device_print_status(selected_device);
+			device_status_enable(selected_device);
 			break;
 		case MSG_VBUS_ON:
 			device_usb(selected_device, true);

cdba.c

@@ -52,6 +52,8 @@ static bool quit;
 static bool fastboot_repeat;
 static bool fastboot_done;
 
+static int status_fd = -1;
+
 static const char *fastboot_file;
 
 static struct termios *tty_unbuffer(void)
@@ -398,12 +400,40 @@ static void request_fastboot_files(void)
 
 static void handle_status_update(const void *data, size_t len)
 {
-	char *str = alloca(len + 1);
+	if (status_fd < 0)
+		return;
+
+	write(status_fd, data, len);
+}
+
+static void status_enable_fn(struct work *work, int ssh_stdin)
+{
+	cdba_send(ssh_stdin, MSG_STATUS_UPDATE);
+
+	free(work);
+}
+
+static void status_pipe_open(const char *path)
+{
+	struct work *work;
+	int ret;
+	int fd;
+
+	ret = mkfifo(path, 0600);
+	if (ret < 0 && errno != EEXIST)
+		err(1, "failed to create fifo %s", path);
+
+	fd = open(path, O_RDWR | O_NONBLOCK);
+	if (fd < 0)
+		err(1, "failed to open fifo %s", path);
 
-	memcpy(str, data, len);
-	str[len] = '\n';
+	status_fd = fd;
 
-	write(STDOUT_FILENO, str, len + 1);
+	/* Queue a MSG_STATUS_UPDATE request */
+	work = malloc(sizeof(*work));
+	work->fn = status_enable_fn;
+
+	list_add(&work_items, &work->node);
 }
 
 static void handle_list_devices(const void *data, size_t len)
@@ -577,6 +607,7 @@ int main(int argc, char **argv)
 	struct timeval timeout_total_tv;
 	struct termios *orig_tios;
 	const char *server_binary = "cdba-server";
+	const char *status_pipe = NULL;
 	int timeout_inactivity = 0;
 	int timeout_total = 600;
 	struct work *next;
@@ -597,7 +628,7 @@ int main(int argc, char **argv)
 	int opt;
 	int ret;
 
-	while ((opt = getopt(argc, argv, "b:c:C:h:ilRt:S:T:")) != -1) {
+	while ((opt = getopt(argc, argv, "b:c:C:h:ilRt:S:s:T:")) != -1) {
 		switch (opt) {
 		case 'b':
 			board = optarg;
@@ -623,6 +654,9 @@ int main(int argc, char **argv)
 		case 'S':
 			server_binary = optarg;
 			break;
+		case 's':
+			status_pipe = optarg;
+			break;
 		case 't':
 			timeout_total = atoi(optarg);
 			break;
@@ -661,6 +695,9 @@ int main(int argc, char **argv)
 		break;
 	}
 
+	if (status_pipe)
+		status_pipe_open(status_pipe);
+
 	ret = fork_ssh(host, server_binary, ssh_fds);
 	if (ret)
 		err(1, "failed to connect to \"%s\"", host);

config-samples/sample11.yaml

@@ -0,0 +1,8 @@
+---
+devices:
+  - board: myboard
+    name: "My Board"
+    alpaca: /dev/ttyACM0
+    console: /dev/ttyUSB0
+    fastboot: cacafada
+    status-cmd: /usr/bin/sample-measure-app --sample-rate 100 /dev/measure0

device.c

@@ -45,6 +45,7 @@
 #include "fastboot.h"
 #include "list.h"
 #include "ppps.h"
+#include "status-cmd.h"
 
 #define ARRAY_SIZE(x) ((sizeof(x)/sizeof((x)[0])))
 
@@ -260,10 +261,18 @@ int device_power(struct device *device, bool on)
 		return device_power_off(device);
 }
 
-void device_print_status(struct device *device)
+void device_status_enable(struct device *device)
 {
-	if (device_has_control(device, print_status))
-		device_control(device, print_status);
+	if (device->status_enabled)
+		return;
+
+	if (device_has_control(device, status_enable))
+		device_control(device, status_enable);
+
+	if (device->status_cmd)
+		status_cmd_open(device);
+
+	device->status_enabled = true;
 }
 
 void device_usb(struct device *device, bool on)
@@ -300,6 +309,11 @@ void device_boot(struct device *device, const void *data, size_t len)
 		fastboot_set_active(device->fastboot, device->set_active);
 	fastboot_download(device->fastboot, data, len);
 	device->boot(device);
+
+	if (device->status_enabled && !device->usb_always_on) {
+		warnx("disabling USB, use ^A V to enable");
+		device_usb(device, false);
+	}
 }
 
 void device_send_break(struct device *device)

device.h

@@ -17,7 +17,7 @@ struct control_ops {
 	int (*power)(struct device *dev, bool on);
 	void (*usb)(struct device *dev, bool on);
 	void (*key)(struct device *device, int key, bool asserted);
-	void (*print_status)(struct device *dev);
+	void (*status_enable)(struct device *dev);
 };
 
 struct console_ops {
@@ -46,6 +46,8 @@ struct device {
 	int state;
 	bool has_power_key;
 
+	bool status_enabled;
+
 	void (*boot)(struct device *);
 
 	const struct control_ops *control_ops;
@@ -56,6 +58,8 @@ struct device {
 	void *cdb;
 	void *console;
 
+	char *status_cmd;
+
 	struct list_head node;
 };
 
@@ -73,7 +77,7 @@ struct device *device_open(const char *board,
 void device_close(struct device *dev);
 int device_power(struct device *device, bool on);
 
-void device_print_status(struct device *device);
+void device_status_enable(struct device *device);
 void device_usb(struct device *device, bool on);
 int device_write(struct device *device, const void *buf, size_t len);
 

device_parser.c

@@ -193,6 +193,8 @@ static void parse_board(struct device_parser *dp)
 			dev->ppps_path = strdup(value);
 		} else if (!strcmp(key, "ppps3_path")) {
 			dev->ppps3_path = strdup(value);
+		} else if (!strcmp(key, "status-cmd")) {
+			dev->status_cmd = strdup(value);
 		} else {
 			fprintf(stderr, "device parser: unknown key \"%s\"\n", key);
 			exit(1);

meson.build

@@ -58,6 +58,13 @@ server_deps = [dependency('libudev', required: server_opt),
 	       dependency('yaml-0.1', required: server_opt),
 	       gpiod_dep,
 	       ftdi_dep]
+
+# E.g. Debian reuires -lutil for forkpty
+if not compiler.has_function('forkpty')
+  util_dep = compiler.find_library('util')
+  server_deps += util_dep
+endif
+
 server_srcs = ['cdba-server.c',
 	       'cdb_assist.c',
 	       'circ_buf.c',
@@ -71,7 +78,9 @@ server_srcs = ['cdba-server.c',
 	       'local-gpio.c',
 	       'console.c',
 	       'qcomlt_dbg.c',
-	       'ppps.c']
+	       'ppps.c',
+               'status.c',
+               'status-cmd.c']
 
 if gpiod_dep.version().version_compare('>=2.0')
 	server_srcs += ['local-gpio-v2.c']