This is an automated email from Gerrit.
"Michael Hough <dejitaru...@gmail.com>" just uploaded a new patch set to
Gerrit, which you can find at https://review.openocd.org/c/openocd/+/6978
-- gerrit
commit f5b61fac19ed9b64d564425cb76cbed5c7323cd4
Author: Michael Hough <dejitaru...@gmail.com>
Date: Mon May 16 12:24:24 2022 -0400
topic: Add SWD support to FT232R driver
Adds SWD protocol support to the existing FT232R JTAG driver.
Implements bitbang.c/bitbang.h for backing logic; new code only needs to
toggle GPIO accordingly.
Minor clarifications in comments & code ('0' to 'NULL' when it's a pointer)
Signed-off-by: Michael Hough <dejitaru...@gmail.com>
Change-Id: Iabced6ee2b81d1f5407cde9244b7927fe7d25714
diff --git a/src/jtag/drivers/ft232r.c b/src/jtag/drivers/ft232r.c
index c930d8c4c1..e296a7e4f7 100644
--- a/src/jtag/drivers/ft232r.c
+++ b/src/jtag/drivers/ft232r.c
@@ -16,6 +16,9 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
+/* 2022-05: SWD support added by Michael Hough;
+ * strongly inspired by bcm2835gpio.c, implements bitbang.c driver */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
@@ -31,6 +34,7 @@
#include <jtag/commands.h>
#include <helper/time_support.h>
#include "libusb_helper.h"
+#include "bitbang.h"
/* system includes */
#include <string.h>
@@ -50,7 +54,7 @@
#define IN_EP 0x02
#define OUT_EP 0x81
-/* Requests */
+/* Control request types: */
#define SIO_RESET 0 /* Reset the port */
#define SIO_MODEM_CTRL 1 /* Set the modem control register */
#define SIO_SET_FLOW_CTRL 2 /* Set flow control register */
@@ -63,10 +67,16 @@
#define SIO_GET_LATENCY_TIMER 10
#define SIO_SET_BITMODE 11
#define SIO_READ_PINS 12
+
#define SIO_READ_EEPROM 0x90
#define SIO_WRITE_EEPROM 0x91
#define SIO_ERASE_EEPROM 0x92
+/* Reset requests: */
+#define SIO_RESET_SIO 0 /* Reset device */
+#define SIO_RESET_PURGE_RX 1 /* Reset USB RX (host->FT232R) buffer */
+#define SIO_RESET_PURGE_TX 2 /* Reset USB TX (FT232R->host) buffer */
+
#define FT232R_BUF_SIZE_EXTRA 4096
static uint16_t ft232r_vid = 0x0403; /* FTDI */
@@ -86,23 +96,117 @@ static char *ft232r_bit_name_array[FT232R_BIT_COUNT] = {
"RTS", /* 2: pin 3 TDO input */
"CTS", /* 3: pin 11 TMS output */
"DTR", /* 4: pin 2 /TRST output */
- "DSR", /* 5: pin 9 unused */
+ "DSR", /* 5: pin 9 SWDIO */
"DCD", /* 6: pin 10 /SYSRST output */
- "RI" /* 7: pin 6 unused */
+ "RI" /* 7: pin 6 SWCLK */
};
-static int tck_gpio; /* initialized to 0 by default */
+static int tck_gpio; /* = 0;*/
static int tdi_gpio = 1;
static int tdo_gpio = 2;
static int tms_gpio = 3;
static int ntrst_gpio = 4;
static int nsysrst_gpio = 6;
+static int swdio_gpio = 5;
+static int swclk_gpio = 7;
+/* FIXME: It might make more sense to share clock pin and put SWDIO on TMS?
+ * These protocols can not be used at the same time, and it's already sharing
reset pins. */
+
static size_t ft232r_buf_size = FT232R_BUF_SIZE_EXTRA;
-/** 0xFFFF disables restore by default, after exit serial port will not work.
- * 0x15 sets TXD RTS DTR as outputs, after exit serial port will continue to
work.
- */
+
+/* 0xFFFF disables restore by default, after exit serial port will not work.
+ * Any variant of 0x00nn should reset to default serial mode. */
static uint16_t ft232r_restore_bitmode = 0xFFFF;
+static uint32_t swd_delay = 100;
+
+static int ft232r_swdio_read(void);
+static void ft232r_swdio_drive(bool is_output);
+static int ft232r_swd_write(int swclk, int swdio);
+
+/* Only implements SWD via bitbang driver - existing JTAG implementation seems
faster. */
+static struct bitbang_interface ft232r_bitbang = {
+ .read = NULL,
+ .write = NULL,
+ .swdio_read = ft232r_swdio_read,
+ .swdio_drive = ft232r_swdio_drive,
+ .swd_write = ft232r_swd_write,
+ .blink = NULL /* Even if we had enough pins, can't blink without
messing up I/O */
+};
+
+/**
+ * Sets GPIO to synchronous bitbang mode (0x0400) with the given direction
mask.
+ * 1 is output, 0 is input.
+ */
+static int ft232r_set_dirs(unsigned char dir_mask)
+{
+ return jtag_libusb_control_transfer(adapter,
+ LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
+ SIO_SET_BITMODE, dir_mask | 0x0400,
+ 0, NULL, 0, 1000);
+}
+
+/**
+ * Sets the designated SWCLK and SWDIO pins according to provided params.
+ * (swclk and swdio are ensured as boolean 0 or 1 in bitbang.c)
+ */
+static int ft232r_swd_write(int swclk, int swdio)
+{
+ char level_mask = (swclk << swclk_gpio) | (swdio << swdio_gpio);
+
+ static int runs;
+ ++runs;
+
+ int n;
+ if (jtag_libusb_bulk_write(adapter, IN_EP, &level_mask, 1, 1000, &n) !=
ERROR_OK) {
+ LOG_ERROR("usb bulk write failed");
+ return ERROR_JTAG_DEVICE_ERROR;
+ }
+
+ struct timespec ts;
+ ts.tv_sec = 0;
+ ts.tv_nsec = swd_delay;
+ nanosleep(&ts, &ts);
+
+ if (runs > 127) {
+ /* This is needed to prevent Sync BB mode from seizing up.
+ Each write also reads to internal buffer (256 bytes); stops
when that's full.
+ Telling it to nuke buffer is much, much faster than actually
reading. */
+ jtag_libusb_control_transfer(adapter,
+ LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
+ SIO_RESET, SIO_RESET_PURGE_TX, 0, NULL, 0, 1000);
+ runs = 0;
+ }
+
+ return ERROR_OK;
+}
+
+/**
+ * Sets whether the SWDIO pin will be driven by host (output) or target (input)
+ */
+static void ft232r_swdio_drive(bool is_output)
+{
+ unsigned char dir_mask = (1<<swclk_gpio) | (is_output<<swdio_gpio);
+ ft232r_set_dirs(dir_mask);
+}
+
+/**
+ * Reads value on SWDIO pin.
+ * This uses immediate polling, bypassing device buffer.
+ * We are trusting that bitbang.c has put the pin into input mode by now.
+ */
+static int ft232r_swdio_read(void)
+{
+ unsigned char swdio_mask = (1 << swdio_gpio);
+ char data = 0;
+ jtag_libusb_control_transfer(adapter,
+ LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_IN,
+ SIO_READ_PINS, 0,
+ 0, &data, 1, 1000);
+
+ return (data & swdio_mask) != 0;
+}
+
/**
* Perform sync bitbang output/input transaction.
* Before call, an array ft232r_output[] should be filled with data to send.
@@ -210,7 +314,7 @@ static void ft232r_write(int tck, int tms, int tdi)
* Control /TRST and /SYSRST pins.
* Perform immediate bitbang transaction.
*/
-static void ft232r_reset(int trst, int srst)
+static int ft232r_reset(int trst, int srst)
{
unsigned out_value = (1<<ntrst_gpio) | (1<<nsysrst_gpio);
LOG_DEBUG("ft232r_reset(%d,%d)", trst, srst);
@@ -230,11 +334,12 @@ static void ft232r_reset(int trst, int srst)
if (ft232r_output_len >= ft232r_buf_size) {
/* FIXME: should we just execute queue here? */
LOG_ERROR("ft232r_write: buffer overflow");
- return;
+ return ERROR_JTAG_DEVICE_ERROR;
}
ft232r_output[ft232r_output_len++] = out_value;
ft232r_send_recv();
+ return ERROR_OK;
}
static int ft232r_speed(int divisor)
@@ -244,9 +349,12 @@ static int ft232r_speed(int divisor)
3000000 / divisor;
LOG_DEBUG("ft232r_speed(%d) rate %d bits/sec", divisor, baud);
+ /* Manual delay, in nanoseconds: */
+ swd_delay = 1000000 / baud;
+
if (jtag_libusb_control_transfer(adapter,
LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
- SIO_SET_BAUD_RATE, divisor, 0, 0, 0, 1000) != 0) {
+ SIO_SET_BAUD_RATE, divisor, 0, NULL, 0, 1000) != 0) {
LOG_ERROR("cannot set baud rate");
return ERROR_JTAG_DEVICE_ERROR;
}
@@ -255,6 +363,8 @@ static int ft232r_speed(int divisor)
static int ft232r_init(void)
{
+ bitbang_interface = &ft232r_bitbang;
+
uint16_t avids[] = {ft232r_vid, 0};
uint16_t apids[] = {ft232r_pid, 0};
if (jtag_libusb_open(avids, apids, &adapter, NULL)) {
@@ -263,6 +373,7 @@ static int ft232r_init(void)
ft232r_vid, ft232r_pid, (!ft232r_serial_desc) ? "[any]"
: ft232r_serial_desc);
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Device found");
if (ft232r_restore_bitmode == 0xFFFF) /* serial port will not be
restored after jtag: */
libusb_detach_kernel_driver(adapter, 0);
@@ -273,60 +384,61 @@ static int ft232r_init(void)
LOG_ERROR("unable to claim interface");
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Interface claimed");
/* Reset the device. */
if (jtag_libusb_control_transfer(adapter,
LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
- SIO_RESET, 0, 0, 0, 0, 1000) != 0) {
+ SIO_RESET, SIO_RESET_SIO, 0, NULL, 0, 1000) != 0) {
LOG_ERROR("unable to reset device");
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Device reset");
- /* Sync bit bang mode. */
- if (jtag_libusb_control_transfer(adapter,
- LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
- SIO_SET_BITMODE, (1<<tck_gpio) | (1<<tdi_gpio) | (1<<tms_gpio)
| (1<<ntrst_gpio) | (1<<nsysrst_gpio) | 0x400,
- 0, 0, 0, 1000) != 0) {
+ /* Sync bit bang mode. TDO is the only input to start. */
+ unsigned char dir_mask = ~(1<<tdo_gpio);
+ if (ft232r_set_dirs(dir_mask) != 0) {
LOG_ERROR("cannot set sync bitbang mode");
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Bitbang mode enabled");
/* Exactly 500 nsec between updates. */
unsigned divisor = 1;
unsigned char latency_timer = 1;
/* Frequency divisor is 14-bit non-zero value. */
- if (jtag_libusb_control_transfer(adapter,
- LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
- SIO_SET_BAUD_RATE, divisor,
- 0, 0, 0, 1000) != 0) {
- LOG_ERROR("cannot set baud rate");
+ if (ft232r_speed(divisor) != ERROR_OK)
return ERROR_JTAG_INIT_FAILED;
- }
+
+ LOG_DEBUG("Baud rate set");
+
if (jtag_libusb_control_transfer(adapter,
LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
- SIO_SET_LATENCY_TIMER, latency_timer, 0, 0, 0, 1000) != 0) {
+ SIO_SET_LATENCY_TIMER, latency_timer, 0, NULL, 0, 1000) != 0) {
LOG_ERROR("unable to set latency timer");
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Latency set");
ft232r_output = malloc(ft232r_buf_size);
if (!ft232r_output) {
LOG_ERROR("Unable to allocate memory for the buffer");
return ERROR_JTAG_INIT_FAILED;
}
+ LOG_DEBUG("Buffer allocated");
return ERROR_OK;
}
static int ft232r_quit(void)
{
- /* to restore serial port: set TXD RTS DTR as outputs, others as
inputs, disable sync bit bang mode. */
+ /* Disabling bit-bang mode will resume normal serial operations. */
if (ft232r_restore_bitmode != 0xFFFF) {
if (jtag_libusb_control_transfer(adapter,
LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE |
LIBUSB_ENDPOINT_OUT,
SIO_SET_BITMODE, ft232r_restore_bitmode,
- 0, 0, 0, 1000) != 0) {
+ 0, NULL, 0, 1000) != 0) {
LOG_ERROR("cannot set bitmode to restore serial port");
}
}
@@ -537,6 +649,38 @@ COMMAND_HANDLER(ft232r_handle_srst_num_command)
return ERROR_OK;
}
+COMMAND_HANDLER(ft232r_handle_swdio_num_command)
+{
+ if (CMD_ARGC == 1)
+ swdio_gpio = ft232r_bit_name_to_number(CMD_ARGV[0]);
+ else if (CMD_ARGC != 0)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ if (swdio_gpio < 0)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ command_print(CMD,
+ "FT232R num: SWDIO = %d %s", swdio_gpio,
ft232r_bit_number_to_name(swdio_gpio));
+
+ return ERROR_OK;
+}
+
+COMMAND_HANDLER(ft232r_handle_swclk_num_command)
+{
+ if (CMD_ARGC == 1)
+ swclk_gpio = ft232r_bit_name_to_number(CMD_ARGV[0]);
+ else if (CMD_ARGC != 0)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ if (swclk_gpio < 0)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ command_print(CMD,
+ "FT232R num: SWCLK = %d %s", swclk_gpio,
ft232r_bit_number_to_name(swclk_gpio));
+
+ return ERROR_OK;
+}
+
COMMAND_HANDLER(ft232r_handle_restore_serial_command)
{
if (CMD_ARGC == 1)
@@ -608,6 +752,20 @@ static const struct command_registration
ft232r_subcommand_handlers[] = {
.help = "gpio number for trst.",
.usage = "<0-7|TXD|RXD|RTS|CTS|DTR|DSR|DCD|RI>",
},
+ {
+ .name = "swdio_num",
+ .handler = ft232r_handle_swdio_num_command,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio number for swdio.",
+ .usage = "<0-7|TXD|RXD|RTS|CTS|DTR|DSR|DCD|RI>",
+ },
+ {
+ .name = "swclk_num",
+ .handler = ft232r_handle_swclk_num_command,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio number for swclk.",
+ .usage = "<0-7|TXD|RXD|RTS|CTS|DTR|DSR|DCD|RI>",
+ },
{
.name = "restore_serial",
.handler = ft232r_handle_restore_serial_command,
@@ -660,8 +818,7 @@ static void syncbb_state_move(int skip)
}
/**
- * Clock a bunch of TMS (or SWDIO) transitions, to change the JTAG
- * (or SWD) state machine.
+ * Clock a bunch of TMS transitions, to change the JTAG state machine.
*/
static int syncbb_execute_tms(struct jtag_command *cmd)
{
@@ -906,6 +1063,8 @@ static int syncbb_execute_queue(void)
return retval;
}
+static const char * const f232r_transports[] = { "jtag", "swd", NULL };
+
static struct jtag_interface ft232r_interface = {
.supported = DEBUG_CAP_TMS_SEQ,
.execute_queue = syncbb_execute_queue,
@@ -913,14 +1072,16 @@ static struct jtag_interface ft232r_interface = {
struct adapter_driver ft232r_adapter_driver = {
.name = "ft232r",
- .transports = jtag_only,
+ .transports = f232r_transports,
.commands = ft232r_command_handlers,
.init = ft232r_init,
.quit = ft232r_quit,
+ .reset = ft232r_reset,
.speed = ft232r_speed,
.khz = ft232r_khz,
.speed_div = ft232r_speed_div,
.jtag_ops = &ft232r_interface,
+ .swd_ops = &bitbang_swd,
};
--
