Allow extra delay or no delay at all in GPIO sequences

There was already a 100 ms delay between each GPIO activation.
By specifiying an empty GPIO (just the comma) extra delays
can now be introduced.

By using '&' instead of comma between GPIOs, no delay at all
will take place between the GPIO activations.

[Tormod: rework documentation]
Signed-off-by: Tormod Volden <debian.tormod@gmail.com>

Author: romansavrulin

init.c

@@ -167,9 +167,17 @@ static int gpio_sequence(struct port_interface *port, const char *s, size_t l)
 	struct gpio_list *to_free;
 #endif
 	int ret, level, gpio;
+	int sleep_time = 0;
+	int delimiter = 0;
+	const char *sig_str = NULL;
 
+	fprintf(stdout, "\nGPIO sequence start\n");
 	ret = 1;
 	while (ret == 1 && *s && l > 0) {
+		sig_str = NULL;
+		sleep_time = 0;
+		delimiter = 0;
+
 		if (*s == '-') {
 			level = 0;
 			s++;
@@ -184,38 +192,64 @@ static int gpio_sequence(struct port_interface *port, const char *s, size_t l)
 				l--;
 			}
 		} else if (!strncmp(s, "rts", 3)) {
+			sig_str = s;
 			gpio = -GPIO_RTS;
 			s += 3;
 			l -= 3;
 		} else if (!strncmp(s, "dtr", 3)) {
+			sig_str = s;
 			gpio = -GPIO_DTR;
 			s += 3;
 			l -= 3;
 		} else if (!strncmp(s, "brk", 3)) {
+			sig_str = s;
 			gpio = -GPIO_BRK;
 			s += 3;
 			l -= 3;
-		} else {
-			fprintf(stderr, "Character \'%c\' is not a digit\n", *s);
-			ret = 0;
-			break;
-		}
-
-		if (*s && (l > 0)) {
+		} else if (*s && (l > 0)) {
+			delimiter = 1;
+			/* The ',' delimiter adds a 100 ms delay between signal toggles.
+			 * i.e -rts,dtr will reset rts, wait 100 ms, set dtr.
+			 *
+			 * The '&' delimiter adds no delay between signal toggles.
+			 * i.e -rts&dtr will reset rts and immediately set dtr.
+			 *
+			 * Example: -rts&dtr,,,rts,-dtr will reset rts and set dtr
+			 * without delay, then wait 300 ms, set rts, wait 100 ms, reset dtr.
+			 */
 			if (*s == ',') {
 				s++;
 				l--;
+				sleep_time = 100000;
+			} else if (*s == '&') {
+				s++;
+				l--;
 			} else {
 				fprintf(stderr, "Character \'%c\' is not a separator\n", *s);
 				ret = 0;
 				break;
 			}
+		} else {
+			fprintf(stderr, "Character \'%c\' is not a digit\n", *s);
+			ret = 0;
+			break;
+		}
+
+		if (!delimiter) { /* actual gpio/port signal driving */
+			if (gpio < 0) {
+				gpio = -gpio;
+				fprintf(stdout, " setting port signal %.3s to %i\n", sig_str, level);
+				ret = (port->gpio(port, gpio, level) == PORT_ERR_OK);
+			} else {
+				fprintf(stdout, " setting gpio %i to %i\n", gpio, level);
+				ret = drive_gpio(gpio, level, &gpio_to_release);
+			}
+		}
+
+		if (sleep_time) {
+			fprintf(stdout, " delay %i us\n", sleep_time);
+			usleep(sleep_time);
 		}
-		if (gpio < 0)
-			ret = (port->gpio(port, -gpio, level) == PORT_ERR_OK);
-		else
-			ret = drive_gpio(gpio, level, &gpio_to_release);
-		usleep(100000);
 	}
 #if defined(__linux__)
 	while (gpio_to_release) {
@@ -225,7 +259,7 @@ static int gpio_sequence(struct port_interface *port, const char *s, size_t l)
 		free(to_free);
 	}
 #endif
-	usleep(500000);
+	fprintf(stdout, "GPIO sequence end\n\n");
 	return ret;
 }
 

main.c

@@ -822,10 +822,20 @@ void show_help(char *name) {
 		"	-c		Resume the connection (don't send initial INIT)\n"
 		"			*Baud rate must be kept the same as the first init*\n"
 		"			This is useful if the reset fails\n"
+		"	-R		Reset device at exit.\n"
 		"	-i GPIO_string	GPIO sequence to enter/exit bootloader mode\n"
 		"			GPIO_string=[entry_seq][:[exit_seq]]\n"
-		"			sequence=[-]n[,sequence]\n"
-		"	-R		Reset device at exit.\n"
+		"			sequence=[[-]signal]&|,[sequence]\n"
+		"\n"
+		"GPIO sequence:\n"
+		"	The following signals can appear in a sequence:\n"
+		"	  Integer number representing GPIO pin\n"
+		"	  'dtr', 'rts' or 'brk' representing serial port signal\n"
+		"	The sequence can use the following delimiters:\n"
+		"	  ',' adds 100 ms delay between signals\n"
+		"	  '&' adds no delay between signals\n"
+		"	The following modifiers can be prepended to a signal:\n"
+		"	  '-' reset signal (low) instead of setting it (high)\n"
 		"\n"
 		"Examples:\n"
 		"	Get device information:\n"
@@ -846,9 +856,14 @@ void show_help(char *name) {
 		"		%s -g 0x0 /dev/ttyS0\n"
 		"\n"
 		"	GPIO sequence:\n"
-		"	- entry sequence: GPIO_3=low, GPIO_2=low, GPIO_2=high\n"
-		"	- exit sequence: GPIO_3=high, GPIO_2=low, GPIO_2=high\n"
-		"		%s -R -i -3,-2,2:3,-2,2 /dev/ttyS0\n",
+		"	- entry sequence: GPIO_3=low, GPIO_2=low, 100ms delay, GPIO_2=high\n"
+		"	- exit sequence: GPIO_3=high, GPIO_2=low, 300ms delay, GPIO_2=high\n"
+		"		%s -i '-3&-2,2:3&-2,,,2' /dev/ttyS0\n"
+		"	GPIO sequence adding delay after port opening:\n"
+		"	- entry sequence: delay 500ms\n"
+		"	- exit sequence: rts=high, dtr=low, 300ms delay, GPIO_2=high\n"
+		"		%s -R -i ',,,,,:rts&-dtr,,,2' /dev/ttyS0\n",
+		name,
 		name,
 		name,
 		name,

stm32flash.1

@@ -226,7 +226,7 @@ The format of
 .RS
 GPIO_string = [entry sequence][:[exit sequence]]
 .P
-sequence = [\-]n[,sequence]
+sequence = [[\-]signal]&|,[sequence]
 .RE
 .PD
 .P
@@ -239,7 +239,15 @@ The string "brk" forces the UART to send a BREAK sequence on TX line;
 after BREAK the UART is returned in normal "non\-break" mode.
 Note: the string "\-brk" has no effect and is ignored.
 .PD
-
+.P
+The ',' delimiter adds 100 ms of delay between signal toggles, whereas
+the '&' delimiter adds no delay.
+An empty signal, thus repeated ',' delimiters, can be used to insert larger
+delays in multiples of 100 ms.
+E.g. "rts,,,,\-dtr" will set RTS, then wait 400 ms, then reset DTR.
+"rts&\-dtr" will set RTS and reset DTR without delay. You can use ',' delimiters 
+alone to simply add a delay between opening port and starting to flash.
+.DP
 .P
 Note that since version 0.6, an exit sequence will always be executed if
 specified, regardless of the -R option, to ensure the signals are reset.
@@ -280,15 +288,30 @@ As example, supposing GPIO_3 connected to PA5 and GPIO_2 to STM32W's reset.
 The command:
 .PD 0
 .RS
-stm32flash \-i \-3,\-2,2:3,\-2,2 /dev/ttyS0
+stm32flash \-i '\-3&\-2,2:3&\-2,,,2' /dev/ttyS0
 .RE
 provides:
 .IP \(bu 2
-entry sequence: GPIO_3=low, GPIO_2=low, GPIO_2=high
+entry sequence: GPIO_3=low, GPIO_2=low, 100 ms delay, GPIO_2=high
 .IP \(bu 2
-exit sequence: GPIO_3=high, GPIO_2=low, GPIO_2=high
+exit sequence: GPIO_3=high, GPIO_2=low, 300 ms delay, GPIO_2=high
 .PD
 
+
+GPIO sequence to bring delays on start after port opening.
+The command:
+.PD 0
+.RS
+stm32flash \-i ',,,,,:rts&\-dtr,,,2' /dev/ttyS0\n",
+.RE
+provides:
+.IP \(bu 2
+entry sequence: delay 500 ms
+.IP \(bu 2
+exit sequence: RTS=high, DTR=low, 300 ms delay, GPIO_2=high
+.PD
+
+
 .SH EXAMPLES
 Get device information:
 .RS