dediprog: add support for chip select

Thanks to the traces captured and tests done by Martin Roth, and confirmed
by tests and analysis by Joshua Zarr too, we can now use both target chips
on the Dediprog SF100.

Corresponding to flashrom svn r1673.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

dediprog.c

@@ -560,19 +560,22 @@ static int dediprog_command_b(void)
 }
 #endif
 
-/* Command C is only sent after dediprog_check_devicestring, but not after every
+/* Command Chip Select is only sent after dediprog_check_devicestring, but not after every
  * invocation of dediprog_check_devicestring. It is only sent after the first
  * dediprog_command_a(); dediprog_check_devicestring() sequence in each session.
- * I'm tempted to call this one start_SPI_engine or finish_init.
+ * Bit #1 of the value changes the chip select: 0 is target 1, 1 is target 2 and parameter target can be 1 or 2
+ * respectively. We don't know how to encode "3, Socket" and "0, reference card" yet. On SF100 the vendor
+ * software "DpCmd 6.0.4.06" selects target 2 when requesting 3 (which is unavailable on that hardware).
  */
-static int dediprog_command_c(void)
+static int dediprog_chip_select(int target)
 {
 	int ret;
-
-	ret = usb_control_msg(dediprog_handle, 0x42, 0x4, 0x0, 0x0, NULL,
+	uint16_t value = ((target - 1) & 1) << 1;
+	msg_pdbg("Selecting target chip %i\n", target);
+	ret = usb_control_msg(dediprog_handle, 0x42, 0x4, value, 0x0, NULL,
 			      0x0, DEFAULT_TIMEOUT);
 	if (ret != 0x0) {
-		msg_perr("Command C failed (%s)!\n", usb_strerror());
+		msg_perr("Command Chip Select failed (%s)!\n", usb_strerror());
 		return 1;
 	}
 	return 0;
@@ -722,7 +725,7 @@ static int parse_voltage(char *voltage)
 	return millivolt;
 }
 
-static int dediprog_setup(void)
+static int dediprog_setup(long target)
 {
 	/* URB 6. Command A. */
 	if (dediprog_command_a()) {
@@ -737,8 +740,8 @@ static int dediprog_setup(void)
 	if (dediprog_check_devicestring()) {
 		return 1;
 	}
-	/* URB 10. Command C. */
-	if (dediprog_command_c()) {
+	/* URB 10. Command Chip Select */
+	if (dediprog_chip_select(target)) {
 		return 1;
 	}
 	return 0;
@@ -785,10 +788,11 @@ static int dediprog_shutdown(void *data)
 int dediprog_init(void)
 {
 	struct usb_device *dev;
-	char *voltage, *device, *spispeed;
+	char *voltage, *device, *spispeed, *target_str;
 	int spispeed_idx = 2;
 	int millivolt = 3500;
 	long usedevice = 0;
+	long target = 1;
 	int i, ret;
 
 	msg_pspew("%s\n", __func__);
@@ -841,6 +845,30 @@ int dediprog_init(void)
 	}
 	free(device);
 
+	target_str = extract_programmer_param("target");
+	if (target_str) {
+		char *target_suffix;
+		errno = 0;
+		target = strtol(target_str, &target_suffix, 10);
+		if (errno != 0 || target_str == target_suffix) {
+			msg_perr("Error: Could not convert 'target'.\n");
+			free(target_str);
+			return 1;
+		}
+		if (target < 1 || target > 2) {
+			msg_perr("Error: Value for 'target' is out of range.\n");
+			free(target_str);
+			return 1;
+		}
+		if (strlen(target_suffix) > 0) {
+			msg_perr("Error: Garbage following 'target' value.\n");
+			free(target_str);
+			return 1;
+		}
+		msg_pinfo("Using target %li.\n", target);
+	}
+	free(target_str);
+
 	/* Here comes the USB stuff. */
 	usb_init();
 	usb_find_busses();
@@ -877,13 +905,13 @@ int dediprog_init(void)
 	dediprog_set_leds(PASS_ON|BUSY_ON|ERROR_ON);
 
 	/* Perform basic setup. */
-	if (dediprog_setup()) {
+	if (dediprog_setup(target)) {
 		dediprog_set_leds(PASS_OFF|BUSY_OFF|ERROR_ON);
 		return 1;
 	}
 
 	/* After setting voltage and speed, perform setup again. */
-	if (dediprog_set_spi_voltage(0) || dediprog_set_spi_speed(spispeed_idx) || dediprog_setup()) {
+	if (dediprog_set_spi_voltage(0) || dediprog_set_spi_speed(spispeed_idx) || dediprog_setup(target)) {
 		dediprog_set_leds(PASS_OFF|BUSY_OFF|ERROR_ON);
 		return 1;
 	}

flashrom.8

@@ -692,6 +692,18 @@ where
 can be
 .BR 375k ", " 750k ", " 1.5M ", " 2.18M ", " 3M ", " 8M ", " 12M " or " 24M
 (in Hz). The default is a frequency of 12 MHz.
+.sp
+An optional
+.B target
+parameter specifies which target chip should be used. Syntax is
+.sp
+.B "  flashrom \-p dediprog:target=value"
+.sp
+where
+.B value
+can be
+.BR 1 " or " 2
+to select target chip 1 or 2 repectively. The default is target chip 1.
 .SS
 .BR "rayer_spi " programmer
 The default I/O base address used for the parallel port is 0x378 and you can use