Implement SRST for libftdi.

Travis GCC needs -Wno-missing-field-initializers or will otherwise warn.

src/platforms/hosted/Makefile.inc

@@ -25,6 +25,7 @@ endif
 LDFLAGS += -lusb-1.0
 CFLAGS += $(shell pkg-config --cflags libftdi1)
 LDFLAGS += $(shell pkg-config --libs libftdi1)
+CFLAGS += -Wno-missing-field-initializers
 
 ifneq (, $(findstring mingw, $(SYS)))
  SRC += cmsis_dap.c dap.c hid.c

src/platforms/hosted/ftdi_bmp.c

@@ -2,6 +2,7 @@
  * This file is part of the Black Magic Debug project.
  *
  * Copyright (C) 2011  Black Sphere Technologies Ltd.
+ * Copyright (C) 2018  Uwe Bonnes(bon@elektron.ikp.physik.tu-darmstadt.de)
  * Written by Gareth McMullin <gareth@blacksphere.co.nz>
  *
  * This program is free software: you can redistribute it and/or modify
@@ -47,18 +48,32 @@ cable_desc_t cable_desc[] = {
 		.dbus_ddr  = 0x1B,
 		.bitbang_tms_in_port_cmd = GET_BITS_LOW,
 		.bitbang_tms_in_pin = MPSSE_TMS,
+		.assert_srst.data_low   = ~0x40,
+		.assert_srst.ddr_low    =  0x40,
+		.deassert_srst.data_low =  0x40,
+		.deassert_srst.ddr_low  = ~0x40,
 		.description = "FLOSS-JTAG",
 		.name = "flossjtag"
 	},
 	{
 		/* Buffered connection from FTDI to Jtag/Swd.
 		 * TCK and TMS not independant switchable!
-		 * SWD not possible. */
+		 * SWD not possible.
+		 * DBUS PIN6 : SRST readback.
+		 * CBUS PIN1 : Drive SRST
+		 * CBUS PIN4 : not tristate SRST
+		 */
 		.vendor = 0x0403,
 		.product = 0x6010,
 		.interface = INTERFACE_A,
 		.dbus_data = 0x08,
 		.dbus_ddr  = 0x1B,
+		.cbus_data = 0x1c,
+		.cbus_ddr  = 0x1f,
+		.assert_srst.data_high  =  ~0x08,
+		.deassert_srst.data_high =  0x08,
+		.srst_get_port_cmd = GET_BITS_LOW,
+		.srst_get_pin = 0x40,
 		.description = "FTDIJTAG",
 		.name = "ftdijtag"
 	},
@@ -87,6 +102,10 @@ cable_desc_t cable_desc[] = {
 		.bitbang_tms_in_port_cmd = GET_BITS_LOW,
 		.bitbang_tms_in_pin = MPSSE_TDO, /* keep bit 5 low*/
 		.bitbang_swd_dbus_read_data = 0x02,
+		.assert_srst.data_high   = ~PIN1,
+		.assert_srst.ddr_high    =  PIN1,
+		.deassert_srst.data_high =  PIN1,
+		.deassert_srst.ddr_high  = ~PIN1,
 		.name = "ftdiswd"
 	},
 	{
@@ -106,6 +125,10 @@ cable_desc_t cable_desc[] = {
 		.interface = INTERFACE_A,
 		.dbus_data = 0x08,
 		.dbus_ddr  = 0x1B,
+		.assert_srst.data_low = 0x40,
+		.deassert_srst.data_low = ~0x40,
+		.srst_get_port_cmd = GET_BITS_HIGH,
+		.srst_get_pin = 0x01,
 		.name = "turtelizer"
 	},
 	{
@@ -245,13 +268,78 @@ int ftdi_bmp_init(BMP_CL_OPTIONS_t *cl_opts, bmp_info_t *info)
 	return -1;
 }
 
-void libftdi_srst_set_val(bool assert)
+static void libftdi_set_data(data_desc_t* data)
 {
-	(void)assert;
+	uint8_t cmd[6];
-	libftdi_buffer_flush();
+	int index = 0;
+	if ((data->data_low) || (data->ddr_low)) {
+		if (data->data_low > 0)
+			active_cable->dbus_data |= (data->data_low & 0xff);
+		else
+			active_cable->dbus_data &= (data->data_low & 0xff);
+		if (data->ddr_low > 0)
+			active_cable->dbus_ddr  |= (data->ddr_low  & 0xff);
+		else
+			active_cable->dbus_ddr  &= (data->ddr_low  & 0xff);
+		cmd[index++] = SET_BITS_LOW;
+		cmd[index++] = active_cable->dbus_data;
+		cmd[index++] = active_cable->dbus_ddr;
+	}
+	if ((data->data_high) || (data->ddr_high)) {
+		if (data->data_high > 0)
+			active_cable->cbus_data |= (data->data_high & 0xff);
+		else
+			active_cable->cbus_data &= (data->data_high & 0xff);
+		if (data->ddr_high > 0)
+			active_cable->cbus_ddr  |= (data->ddr_high  & 0xff);
+		else
+			active_cable->cbus_ddr  &= (data->ddr_high  & 0xff);
+		cmd[index++] = SET_BITS_HIGH;
+		cmd[index++] = active_cable->cbus_data;
+		cmd[index++] = active_cable->cbus_ddr;
+	}
+	if (index) {
+		libftdi_buffer_write(cmd, index);
+		libftdi_buffer_flush();
+	}
 }
 
-bool libftdi_srst_get_val(void) { return false; }
+void libftdi_srst_set_val(bool assert)
+{
+	if (assert)
+		libftdi_set_data(&active_cable->assert_srst);
+	else
+		libftdi_set_data(&active_cable->deassert_srst);
+}
+
+bool libftdi_srst_get_val(void)
+{
+	uint8_t cmd[1] = {0};
+	uint8_t pin = 0;
+	if (active_cable->srst_get_port_cmd && active_cable->srst_get_pin) {
+		cmd[0]= active_cable->srst_get_port_cmd;
+		pin   =  active_cable->srst_get_pin;
+	} else if (active_cable->assert_srst.data_low &&
+			   active_cable->assert_srst.ddr_low) {
+		cmd[0]= GET_BITS_LOW;
+		pin   = active_cable->assert_srst.data_low;
+	} else if (active_cable->assert_srst.data_high &&
+			   active_cable->assert_srst.ddr_high) {
+		cmd[0]= GET_BITS_HIGH;
+		pin   = active_cable->assert_srst.data_high;
+	}else {
+		return false;
+	}
+	libftdi_buffer_write(cmd, 1);
+	uint8_t data[1];
+	libftdi_buffer_read(data, 1);
+	bool res = false;
+	if (((pin < 0x7f) || (pin == PIN7)))
+		res = data[0] & pin;
+	else
+		res = !(data[0] & ~pin);
+	return res;
+}
 
 void libftdi_buffer_flush(void)
 {

src/platforms/hosted/ftdi_bmp.h

@@ -25,6 +25,13 @@
 #include "swdptap.h"
 #include "jtagtap.h"
 
+typedef struct data_desc_s {
+	int16_t data_low;
+	int16_t ddr_low;
+	int16_t data_high;
+	int16_t ddr_high;
+}data_desc_t;
+
 typedef struct cable_desc_s {
 	int vendor;
 	int product;
@@ -36,8 +43,20 @@ typedef struct cable_desc_s {
 	uint8_t bitbang_tms_in_port_cmd;
 	uint8_t bitbang_tms_in_pin;
 	uint8_t bitbang_swd_dbus_read_data;
-	/* bitbang_swd_dbus_read_data is same as dbus_data,
+	uint8_t bitbang_swd_direct;
-	 * as long as CBUS is not involved.*/
+	/* dbus_data, dbus_ddr, cbus_data, cbus_ddr value to assert SRST.
+	 *	E.g. with CBUS Pin 1 low,
+	 *	give data_high = ~PIN1, ddr_high = PIN1 */
+	data_desc_t assert_srst;
+	/* dbus_data, dbus_ddr, cbus_data, cbus_ddr value to release SRST.
+	 *	E.g. with CBUS Pin 1 floating with internal pull up,
+	 *	give data_high = PIN1, ddr_high = ~PIN1 */
+	data_desc_t deassert_srst;
+	/* Command to read back SRST. If 0, port from assert_srst is used*/
+	uint8_t srst_get_port_cmd;
+	/* PIN to read back as SRST. if 0 port from assert_srst is ised.
+	*  Use PINX if active high, use Complement (~PINX) if active low*/
+	uint8_t srst_get_pin;
 	char *description;
 	char * name;
 }cable_desc_t;
@@ -54,8 +73,16 @@ int libftdi_buffer_write(const uint8_t *data, int size);
 int libftdi_buffer_read(uint8_t *data, int size);
 const char *libftdi_target_voltage(void);
 
+#define MPSSE_TCK 1
+#define PIN0      1
 #define MPSSE_TDI 2
+#define PIN1      2
 #define MPSSE_TDO 4
+#define PIN2      4
 #define MPSSE_TMS 8
-
+#define PIN3      8
+#define PIN4      0x10
+#define PIN5      0x20
+#define PIN6      0x40
+#define PIN7      0x80
 #endif