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Bus Pirate driver: Small assorted fixes. 

Fixes are:
- Discard any stale data from the previous connection.
- Disable CR/LF translation on the (virtual USB) serial port.
- Increase the average USB packet size. The 1 KiB buffer was underutilised.
- Option "buspirate_speed fast" now works out of the box.
- Some extra comments, error checking, etc.

Change-Id: I72c49d943a8ce9c5e5d1644ef90cb1482f93c618
Signed-off-by: R. Diez <rdiezmail-openocd@yahoo.de>
Reviewed-on: http://openocd.zylin.com/1437
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
This commit is contained in:
R. Diez 2013-06-08 16:07:28 +02:00 committed by Spencer Oliver
parent 9f1616d2b5
commit 0910f1a507
1 changed files with 168 additions and 24 deletions
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192
src/jtag/drivers/buspirate.c
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@ -1,6 +1,7 @@
/***************************************************************************
* Copyright (C) 2010 by Michal Demin *
* based on usbprog.c and arm-jtag-ew.c *
* Several fixes by R. Diez in 2013. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
@ -81,6 +82,9 @@ enum {
SERIAL_FAST = 1
};
static const cc_t SHORT_TIMEOUT = 1; /* Must be at least 1. */
static const cc_t NORMAL_TIMEOUT = 10;
static int buspirate_fd = -1;
static int buspirate_pinmode = MODE_JTAG_OD;
static int buspirate_baudrate = SERIAL_NORMAL;
@ -88,6 +92,9 @@ static int buspirate_vreg;
static int buspirate_pullup;
static char *buspirate_port;
static enum tap_state last_tap_state = TAP_RESET;
/* TAP interface */
static void buspirate_tap_init(void);
static int buspirate_tap_execute(void);
@ -109,7 +116,7 @@ static void buspirate_jtag_get_adcs(int);
/* low level HW communication interface */
static int buspirate_serial_open(char *port);
static int buspirate_serial_setspeed(int fd, char speed);
static int buspirate_serial_setspeed(int fd, char speed, cc_t timeout);
static int buspirate_serial_write(int fd, char *buf, int size);
static int buspirate_serial_read(int fd, char *buf, int size);
static void buspirate_serial_close(int fd);
@ -196,6 +203,54 @@ static int buspirate_execute_queue(void)
return buspirate_tap_execute();
}
/* Returns true if successful, false if error. */
static bool read_and_discard_all_data(const int fd)
{
/* LOG_INFO("Discarding any stale data from a previous connection..."); */
bool was_msg_already_printed = false;
for ( ; ; ) {
char buffer[1024]; /* Any size will do, it's a trade-off between stack size and performance. */
const ssize_t read_count = read(fd, buffer, sizeof(buffer));
if (read_count == 0) {
/* This is the "end of file" or "connection closed at the other end" condition. */
return true;
}
if (read_count > 0) {
if (!was_msg_already_printed) {
LOG_INFO("Some stale data from a previous connection was discarded.");
was_msg_already_printed = true;
}
continue;
}
assert(read_count == -1); /* According to the specification. */
const int errno_code = errno;
if (errno_code == EINTR)
continue;
if (errno_code == EAGAIN ||
errno_code == EWOULDBLOCK) {
/* We know that the file descriptor has been opened with O_NONBLOCK or O_NDELAY,
and these codes mean that there is no data to read at present. */
return true;
}
/* Some other error has occurred. */
return false;
}
}
static int buspirate_init(void)
{
if (buspirate_port == NULL) {
@ -209,7 +264,33 @@ static int buspirate_init(void)
return ERROR_JTAG_INIT_FAILED;
}
buspirate_serial_setspeed(buspirate_fd, SERIAL_NORMAL);
/* The Operating System or the device itself may deliver stale data from the last connection,
so discard all available bytes right after the new connection has been established.
After all, we are implementing here a master/slave protocol, so the slave should have nothing
to say until the master sends the first command.
In the past, there was a tcflush() call in buspirate_serial_setspeed(), but that
was not enough. I guess you must actively read from the serial port to trigger any
data collection from the device and/or lower USB layers. If you disable the serial port
read timeout (if you set SHORT_TIMEOUT to 0), then the discarding does not work any more.
Note that we are lowering the serial port timeout for this first read operation,
otherwise the normal initialisation would be delayed for too long. */
if (-1 == buspirate_serial_setspeed(buspirate_fd, SERIAL_NORMAL, SHORT_TIMEOUT)) {
LOG_ERROR("Error configuring the serial port.");
return ERROR_JTAG_INIT_FAILED;
}
if (!read_and_discard_all_data(buspirate_fd)) {
LOG_ERROR("Error while attempting to discard any stale data right after establishing the connection.");
return ERROR_JTAG_INIT_FAILED;
}
if (-1 == buspirate_serial_setspeed(buspirate_fd, SERIAL_NORMAL, NORMAL_TIMEOUT)) {
LOG_ERROR("Error configuring the serial port.");
return ERROR_JTAG_INIT_FAILED;
}
buspirate_jtag_enable(buspirate_fd);
@ -524,8 +605,20 @@ static void buspirate_scan(bool ir_scan, enum scan_type type,
/************************* TAP related stuff **********/
/* This buffer size matches the maximum CMD_TAP_SHIFT bit length in the Bus Pirate firmware,
look for constant 0x2000 in OpenOCD.c . */
#define BUSPIRATE_BUFFER_SIZE 1024
#define BUSPIRATE_MAX_PENDING_SCANS 32
/* The old value of 32 scans was not enough to achieve near 100% utilisation ratio
for the current BUSPIRATE_BUFFER_SIZE value of 1024.
With 128 scans I am getting full USB 2.0 high speed packets (512 bytes long) when
using the JtagDue firmware on the Arduino Due instead of the Bus Pirate, which
amounts approximately to a 10% overall speed gain. Bigger packets should also
benefit the Bus Pirate, but the speed difference is much smaller.
Unfortunately, each 512-byte packet is followed by a 329-byte one, which is not ideal.
However, increasing BUSPIRATE_BUFFER_SIZE for the benefit of the JtagDue would
make it incompatible with the Bus Pirate firmware. */
#define BUSPIRATE_MAX_PENDING_SCANS 128
static char tms_chain[BUSPIRATE_BUFFER_SIZE]; /* send */
static char tdi_chain[BUSPIRATE_BUFFER_SIZE]; /* send */
@ -551,6 +644,8 @@ static void buspirate_tap_init(void)
static int buspirate_tap_execute(void)
{
static const int CMD_TAP_SHIFT_HEADER_LEN = 3;
char tmp[4096];
uint8_t *in_buf;
int i;
@ -564,13 +659,13 @@ static int buspirate_tap_execute(void)
LOG_DEBUG("executing tap num bits = %i scans = %i",
tap_chain_index, tap_pending_scans_num);
bytes_to_send = (tap_chain_index+7) / 8;
bytes_to_send = DIV_ROUND_UP(tap_chain_index, 8);
tmp[0] = CMD_TAP_SHIFT; /* this command expects number of bits */
tmp[1] = (char)(tap_chain_index >> 8); /* high */
tmp[2] = (char)(tap_chain_index); /* low */
fill_index = 3;
fill_index = CMD_TAP_SHIFT_HEADER_LEN;
for (i = 0; i < bytes_to_send; i++) {
tmp[fill_index] = tdi_chain[i];
fill_index++;
@ -578,18 +673,26 @@ static int buspirate_tap_execute(void)
fill_index++;
}
ret = buspirate_serial_write(buspirate_fd, tmp, 3 + bytes_to_send*2);
if (ret != bytes_to_send*2+3) {
/* jlink.c calls the routine below, which may be useful for debugging purposes.
For example, enabling this allows you to compare the log outputs from jlink.c
and from this module for JTAG development or troubleshooting purposes. */
if (false) {
last_tap_state = jtag_debug_state_machine(tms_chain, tdi_chain,
tap_chain_index, last_tap_state);
}
ret = buspirate_serial_write(buspirate_fd, tmp, CMD_TAP_SHIFT_HEADER_LEN + bytes_to_send*2);
if (ret != bytes_to_send*2+CMD_TAP_SHIFT_HEADER_LEN) {
LOG_ERROR("error writing :(");
return ERROR_JTAG_DEVICE_ERROR;
}
ret = buspirate_serial_read(buspirate_fd, tmp, bytes_to_send + 3);
if (ret != bytes_to_send + 3) {
ret = buspirate_serial_read(buspirate_fd, tmp, bytes_to_send + CMD_TAP_SHIFT_HEADER_LEN);
if (ret != bytes_to_send + CMD_TAP_SHIFT_HEADER_LEN) {
LOG_ERROR("error reading");
return ERROR_FAIL;
}
in_buf = (uint8_t *)(&tmp[3]);
in_buf = (uint8_t *)(&tmp[CMD_TAP_SHIFT_HEADER_LEN]);
/* parse the scans */
for (i = 0; i < tap_pending_scans_num; i++) {
@ -609,8 +712,7 @@ static int buspirate_tap_execute(void)
free(buffer);
}
tap_pending_scans_num = 0;
tap_chain_index = 0;
buspirate_tap_init();
return ERROR_OK;
}
@ -634,6 +736,19 @@ static void buspirate_tap_append(int tms, int tdi)
int bit_index = tap_chain_index % 8;
uint8_t bit = 1 << bit_index;
if (0 == bit_index) {
/* Let's say that the TAP shift operation wants to shift 9 bits,
so we will be sending to the Bus Pirate a bit count of 9 but still
full 16 bits (2 bytes) of shift data.
If we don't clear all bits at this point, the last 7 bits will contain
random data from the last buffer contents, which is not pleasant to the eye.
Besides, the Bus Pirate (or some clone) may want to assert in debug builds
that, after consuming all significant data bits, the rest of them are zero.
Therefore, for aesthetic and for assert purposes, we clear all bits below. */
tms_chain[chain_index] = 0;
tdi_chain[chain_index] = 0;
}
if (tms)
tms_chain[chain_index] |= bit;
else
@ -645,9 +760,13 @@ static void buspirate_tap_append(int tms, int tdi)
tdi_chain[chain_index] &= ~bit;
tap_chain_index++;
} else
} else {
LOG_ERROR("tap_chain overflow, bad things will happen");
/* Exit abruptly, like jlink.c does. After a buffer overflow we don't want
to carry on, as data will be corrupt. Another option would be to return
some error code at this point. */
exit(-1);
}
}
static void buspirate_tap_append_scan(int length, uint8_t *buffer,
@ -770,7 +889,10 @@ static void buspirate_jtag_set_speed(int fd, char speed)
buspirate_jtag_command(fd, tmp, 2);
/* here the adapter changes speed, we need follow */
buspirate_serial_setspeed(fd, speed);
if (-1 == buspirate_serial_setspeed(fd, speed, NORMAL_TIMEOUT)) {
LOG_ERROR("Error configuring the serial port.");
exit(-1);
}
buspirate_serial_write(fd, ack, 2);
ret = buspirate_serial_read(fd, tmp, 2);
@ -779,7 +901,7 @@ static void buspirate_jtag_set_speed(int fd, char speed)
exit(-1);
}
if ((tmp[0] != CMD_UART_SPEED) || (tmp[1] != speed)) {
LOG_ERROR("Buspirate did not reply as expected");
LOG_ERROR("Buspirate did not reply as expected to the speed change command");
exit(-1);
}
LOG_INFO("Buspirate switched to %s mode",
@ -865,28 +987,50 @@ static int buspirate_serial_open(char *port)
return fd;
}
static int buspirate_serial_setspeed(int fd, char speed)
/* Returns -1 on error. */
static int buspirate_serial_setspeed(int fd, char speed, cc_t timeout)
{
struct termios t_opt;
speed_t baud = (speed == SERIAL_FAST) ? B1000000 : B115200;
/* set the serial port parameters */
fcntl(fd, F_SETFL, 0);
tcgetattr(fd, &t_opt);
cfsetispeed(&t_opt, baud);
cfsetospeed(&t_opt, baud);
if (0 != tcgetattr(fd, &t_opt))
return -1;
if (0 != cfsetispeed(&t_opt, baud))
return -1;
if (0 != cfsetospeed(&t_opt, baud))
return -1;
t_opt.c_cflag |= (CLOCAL | CREAD);
t_opt.c_cflag &= ~PARENB;
t_opt.c_cflag &= ~CSTOPB;
t_opt.c_cflag &= ~CSIZE;
t_opt.c_cflag |= CS8;
t_opt.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
t_opt.c_iflag &= ~(IXON | IXOFF | IXANY);
/* The serial port may have been configured for human interaction with
the Bus Pirate console, but OpenOCD is going to use a binary protocol,
so make sure to turn off any CR/LF translation and the like. */
t_opt.c_iflag &= ~(IXON | IXOFF | IXANY | INLCR | ICRNL);
t_opt.c_oflag &= ~OPOST;
t_opt.c_cc[VMIN] = 0;
t_opt.c_cc[VTIME] = 10;
tcflush(fd, TCIFLUSH);
tcsetattr(fd, TCSANOW, &t_opt);
t_opt.c_cc[VTIME] = timeout;
/* Note that, in the past, TCSANOW was used below instead of TCSADRAIN,
and CMD_UART_SPEED did not work properly then, at least with
the Bus Pirate v3.5 (USB). */
if (0 != tcsetattr(fd, TCSADRAIN, &t_opt)) {
/* According to the Linux documentation, this is actually not enough
to detect errors, you need to call tcgetattr() and check that
all changes have been performed successfully. */
return -1;
}
return 0;
}