Add H4 transport for serial ports

1 files changed, 116 insertions, 4 deletions

diff --git a/tools/csr_h4.c b/tools/csr_h4.c
index 9140d30d..2a6c156f 100644
--- a/tools/csr_h4.c
+++ b/tools/csr_h4.c
@@ -27,22 +27,133 @@
 
 #include <stdio.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
 #include <stdint.h>
+#include <termios.h>
+
+#include "csr.h"
 
 static uint16_t seqnum = 0x0000;
 
+static int fd = -1;
+
 int csr_open_h4(char *device)
 {
-	fprintf(stderr, "Transport not implemented\n");
+	struct termios ti;
+
+	if (!device)
+		device = "/dev/ttyS0";
+
+	fd = open(device, O_RDWR | O_NOCTTY);
+	if (fd < 0) {
+		fprintf(stderr, "Can't open serial port: %s (%d)\n",
+						strerror(errno), errno);
+		return -1;
+	}
+
+	tcflush(fd, TCIOFLUSH);
+
+	if (tcgetattr(fd, &ti) < 0) {
+		fprintf(stderr, "Can't get port settings: %s (%d)\n",
+						strerror(errno), errno);
+		close(fd);
+		return -1;
+	}
+
+	cfmakeraw(&ti);
+
+	ti.c_cflag |= CLOCAL;
+	ti.c_cflag |= CRTSCTS;
+
+	if (tcsetattr(fd, TCSANOW, &ti) < 0) {
+		fprintf(stderr, "Can't change port settings: %s (%d)\n",
+						strerror(errno), errno);
+		close(fd);
+		return -1;
+	}
+
+	cfsetospeed(&ti, B38400);
+
+	if (tcsetattr(fd, TCSANOW, &ti) < 0) {
+		fprintf(stderr, "Can't change port settings: %s (%d)\n",
+						strerror(errno), errno);
+		close(fd);
+		return -1;
+	}
+
+	tcflush(fd, TCIOFLUSH);
 
-	return -1;
+	return 0;
 }
 
 static int do_command(uint16_t command, uint16_t seqnum, uint16_t varid, uint8_t *value, uint16_t length)
 {
-	errno = EIO;
+	unsigned char cp[254], rp[254];
+	uint8_t cmd[10];
+	uint16_t size;
+	int len, offset = 3;
+
+	size = (length < 8) ? 9 : ((length + 1) / 2) + 5;
+
+	cmd[0] = command & 0xff;
+	cmd[1] = command >> 8;
+	cmd[2] = size & 0xff;
+	cmd[3] = size >> 8;
+	cmd[4] = seqnum & 0xff;
+	cmd[5] = seqnum >> 8;
+	cmd[6] = varid & 0xff;
+	cmd[7] = varid >> 8;
+	cmd[8] = 0x00;
+	cmd[9] = 0x00;
+
+	memset(cp, 0, sizeof(cp));
+	cp[0] = 0x01;
+	cp[1] = 0x00;
+	cp[2] = 0xfc;
+	cp[3] = (size * 2) + 1;
+	cp[4] = 0xc2;
+	memcpy(cp + 5, cmd, sizeof(cmd));
+	memcpy(cp + 15, value, length);
+
+	if (write(fd, cp, (size * 2) + 5) < 0)
+		return -1;
+
+	switch (varid) {
+	case CSR_VARID_COLD_RESET:
+	case CSR_VARID_WARM_RESET:
+	case CSR_VARID_COLD_HALT:
+	case CSR_VARID_WARM_HALT:
+		return 0;
+	}
+
+	do {
+		if (read(fd, rp, 1) < 1)
+			return -1;
+	} while (rp[0] != 0x04);
+
+	if (read(fd, rp + 1, 2) < 2)
+		return -1;
+
+	do {
+		len = read(fd, rp + offset, sizeof(rp) - offset);
+		offset += len;
+	} while (offset < rp[2] + 3);
+
+	if (rp[0] != 0x04 || rp[1] != 0xff || rp[3] != 0xc2) {
+		errno = EIO;
+		return -1;
+	}
+
+	if ((rp[12] + (rp[13] << 8)) != 0) {
+		errno = ENXIO;
+		return -1;
+	}
+
+	memcpy(value, rp + 14, length);
 
-	return -1;
+	return 0;
 }
 
 int csr_read_h4(uint16_t varid, uint8_t *value, uint16_t length)
@@ -57,4 +168,5 @@ int csr_write_h4(uint16_t varid, uint8_t *value, uint16_t length)
 
 void csr_close_h4(void)
 {
+	close(fd);
 }