From 5487578ee7c95c8eeb089a17ee75f4b64142e5df Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Fri, 28 Dec 2012 22:45:26 -0300
Subject: [PATCH] lpc111x-isp/lpc111x.c: restructure code (WIP)

---
 lpc111x-isp/lpc111x.c | 133 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 113 insertions(+), 20 deletions(-)

diff --git a/lpc111x-isp/lpc111x.c b/lpc111x-isp/lpc111x.c
index 4680bd8..24b6195 100644
--- a/lpc111x-isp/lpc111x.c
+++ b/lpc111x-isp/lpc111x.c
@@ -15,9 +15,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
-#include <termios.h>
-#include <fcntl.h>
-#include <errno.h>
+#include <alloca.h>
 
 #include <ubb/ubb.h>
 #include <ubb/swuart.h>
@@ -31,11 +29,19 @@
 #define	HOST_RX		TGT_TX
 #define	HOST_TX		TGT_RX
 
+#define	AUTOBAUD_TRIES	10
+#define	SYNC		"Synchronized"
 
-static void dump(uint8_t *s, int len)
+
+/* ----- Debugging and tracing --------------------------------------------- */
+
+
+static void trace(const char *label, const uint8_t *s, int len)
 {
 	const uint8_t *end = s+len;
 
+	if (label)
+		printf("%s ", label);
 	for (end = s+len; s != end; s++) {
 		if (*s >= ' ' && *s <= '~')
 			printf("%c", *s);
@@ -51,13 +57,94 @@ static void dump(uint8_t *s, int len)
 }
 
 
+static void trace_out(const void *s, int len)
+{
+	trace(">>>", s, len);
+}
+
+
+static void trace_in(const uint8_t *s, int len)
+{
+	trace("<<<", s, len);
+}
+
+
+/* ----- Dialog functions -------------------------------------------------- */
+
+
+static int dialog(const char *cmd, void *buf, int buf_len, int idle)
+{
+	int cmd_len = strlen(cmd);
+	char *tx_buf = alloca(cmd_len+3);
+	uint8_t *rx_buf = alloca(cmd_len+2+buf_len);
+	int got;
+
+	memcpy(tx_buf, cmd, cmd_len);
+	memcpy(tx_buf+cmd_len, "\r\n", 2);
+
+	trace_out(tx_buf, cmd_len+2);
+	got = swuart_trx(tx_buf, cmd_len+2, rx_buf, cmd_len+2+buf_len,
+	    idle, idle);
+
+	if (got < cmd_len+2) {
+		trace_in(rx_buf, got);
+		fprintf(stderr, "response too short for echo\n");
+		exit(1);
+	}
+	if (memcmp(rx_buf, cmd, cmd_len) ||
+	    rx_buf[cmd_len] != '\r' || rx_buf[cmd_len+1] != '\n') {
+		trace_in(rx_buf, got);
+		fprintf(stderr, "echo mismatch\n");
+		exit(1);
+	}
+
+	trace_in(rx_buf, cmd_len+2);
+
+	got -= cmd_len+2;
+	memcpy(buf, rx_buf+cmd_len+2, got);
+
+	return got;
+}
+
+
+static int autobaud(void)
+{
+	uint8_t reply[100];
+	int i, got;
+
+	for (i = 0; i != AUTOBAUD_TRIES; i++) {
+		CLR(TGT_nRESET);
+		usleep(10);	/* DS Table 9 pg 29 says min 50 ns */
+		SET(TGT_nRESET);
+
+		usleep(5*1000);	/* UM 26.3.1 pg 408 says max 3 ms */
+
+		got = swuart_trx("?", 1, reply, sizeof(reply), 1000, 100);
+		trace_in(reply, got);
+
+		if (got != strlen(SYNC)+2 || memcmp(reply, SYNC "\r\n", got))
+			continue;
+
+		got = dialog(SYNC, reply, sizeof(reply), 100);
+		trace_in(reply, got);
+
+		if (got == 4 && !memcmp(reply, "OK\r\n", 4))
+			return 1;
+	}
+	return 0;
+}
+
+
+/* ----- ISP session ------------------------------------------------------- */
+
+
 static void at_exit(void)
 {
 	ubb_close(0);
 }
 
 
-int main(int argc, char **argv)
+static void start_isp(void)
 {
 	uint8_t reply[1000];
 	int got;
@@ -80,26 +167,32 @@ int main(int argc, char **argv)
 
 	swuart_open(HOST_TX, HOST_RX, 115200);
 
-	CLR(TGT_nRESET);
-	usleep(10);	/* DS Table 9 pg 29 says min 50 ns */
-	SET(TGT_nRESET);
+	if (!autobaud()) {
+		fprintf(stderr, "target is not responding\n");
+		exit(1);
+	}
 
-	usleep(5*1000);	/* UM 26.3.1 pg 408 says max 3 ms */
+	got = dialog("12000", reply, sizeof(reply), 100);
+	trace_in(reply, got);
+	if (got != 4 || memcmp(reply, "OK\r\n", 4)) {
+		fprintf(stderr, "cannot set clock rate\n");
+		exit(1);
+	}
+}
 
-	got = swuart_trx("?", 1, reply, sizeof(reply), 1000, 100);
-	dump(reply, got);
 
-	got = swuart_trx("Synchronized\r\n", 14,
-	    reply, sizeof(reply), 1000, 100);
-	dump(reply, got);
+/* ----- Command-line processing ------------------------------------------- */
 
-	got = swuart_trx("12000\r\n", 7,
-	    reply, sizeof(reply), 1000, 100);
-	dump(reply, got);
 
-	got = swuart_trx("J\r\n", 7,
-	    reply, sizeof(reply), 1000, 100);
-	dump(reply, got);
+int main(int argc, char **argv)
+{
+	uint8_t reply[1000];
+	int got;
+
+	start_isp();
+
+	got = dialog("J", reply, sizeof(reply), 100);
+	trace_in(reply, got);
 
 	return 0;
 }