presto.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2007 by Pavel Chromy                                    *
 *   chromy@asix.cz                                                        *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#if IS_CYGWIN == 1
#include "windows.h"
#endif
 
#include <jtag/adapter.h>
#include <jtag/interface.h>
#include <helper/time_support.h>
#include "bitq.h"
 
/* PRESTO access library includes */
#include "libftdi_helper.h"
 
/* -------------------------------------------------------------------------- */
 
#define FT_DEVICE_NAME_LEN 64
#define FT_DEVICE_SERNUM_LEN 64
 
#define PRESTO_VID_PID 0x0403f1a0
#define PRESTO_VID (0x0403)
#define PRESTO_PID (0xf1a0)
 
#define BUFFER_SIZE (64*62)
 
struct presto {
    struct ftdi_context ftdic;
    int retval;
 
    char serial[FT_DEVICE_SERNUM_LEN];
 
    uint8_t buff_out[BUFFER_SIZE];
    int buff_out_pos;
 
    uint8_t buff_in[BUFFER_SIZE];
    int buff_in_exp;/* expected in buffer length */
    int buff_in_len;/* length of data received */
    int buff_in_pos;
 
    unsigned long total_out;
    unsigned long total_in;
 
    int jtag_tms;   /* last tms state */
    int jtag_tck;   /* last tck state */
    int jtag_rst;   /* last trst state */
 
    int jtag_tdi_data;
    int jtag_tdi_count;
 
    int jtag_speed;
};
 
static struct presto presto_state;
static struct presto *presto = &presto_state;
 
static uint8_t presto_init_seq[] = {
    0x80, 0xA0, 0xA8, 0xB0, 0xC0, 0xE0
};
 
static int presto_write(uint8_t *buf, uint32_t size)
{
    uint32_t ftbytes;
    presto->retval = ftdi_write_data(&presto->ftdic, buf, size);
    if (presto->retval < 0) {
        LOG_ERROR("ftdi_write_data: %s", ftdi_get_error_string(&presto->ftdic));
        return ERROR_JTAG_DEVICE_ERROR;
    }
    ftbytes = presto->retval;
 
    if (ftbytes != size) {
        LOG_ERROR("couldn't write the requested number of bytes to PRESTO (%u < %u)",
            (unsigned)ftbytes, (unsigned)size);
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    return ERROR_OK;
}
 
static int presto_read(uint8_t *buf, uint32_t size)
{
    uint32_t ftbytes = 0;
 
    // 1 second timeout
    int64_t then = timeval_ms() + 1000;
 
    while (ftbytes < size) {
        presto->retval = ftdi_read_data(&presto->ftdic, buf + ftbytes, size - ftbytes);
        if (presto->retval < 0) {
            LOG_ERROR("ftdi_read_data: %s", ftdi_get_error_string(&presto->ftdic));
            return ERROR_JTAG_DEVICE_ERROR;
        }
        ftbytes += presto->retval;
 
        if (timeval_ms() > then)
            break;
    }
 
    if (ftbytes != size) {
        /* this is just a warning, there might have been timeout when detecting PRESTO,
         *which is not fatal */
        LOG_WARNING("couldn't read the requested number of bytes from PRESTO (%u < %u)",
            (unsigned)ftbytes, (unsigned)size);
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    return ERROR_OK;
}
 
static int presto_open_libftdi(const char *req_serial)
{
    uint8_t presto_data;
 
    LOG_DEBUG("searching for PRESTO using libftdi");
 
    /* initialize FTDI context structure */
    if (ftdi_init(&presto->ftdic) < 0) {
        LOG_ERROR("unable to init libftdi: %s", presto->ftdic.error_str);
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    /* context, vendor id, product id */
    if (ftdi_usb_open_desc(&presto->ftdic, PRESTO_VID, PRESTO_PID, NULL, req_serial) < 0) {
        LOG_ERROR("unable to open PRESTO: %s", presto->ftdic.error_str);
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    if (ftdi_usb_reset(&presto->ftdic) < 0) {
        LOG_ERROR("unable to reset PRESTO device");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    if (ftdi_set_latency_timer(&presto->ftdic, 1) < 0) {
        LOG_ERROR("unable to set latency timer");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    if (ftdi_tcioflush(&presto->ftdic) < 0) {
        LOG_ERROR("unable to flush PRESTO buffers");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    presto_data = 0xD0;
    if (presto_write(&presto_data, 1) != ERROR_OK) {
        LOG_ERROR("error writing to PRESTO");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    if (presto_read(&presto_data, 1) != ERROR_OK) {
        LOG_DEBUG("no response from PRESTO, retrying");
 
        if (ftdi_tcioflush(&presto->ftdic) < 0)
            return ERROR_JTAG_DEVICE_ERROR;
 
        presto_data = 0xD0;
        if (presto_write(&presto_data, 1) != ERROR_OK)
            return ERROR_JTAG_DEVICE_ERROR;
 
        if (presto_read(&presto_data, 1) != ERROR_OK) {
            LOG_ERROR("no response from PRESTO, giving up");
            return ERROR_JTAG_DEVICE_ERROR;
        }
    }
 
    if (presto_write(presto_init_seq, sizeof(presto_init_seq)) != ERROR_OK) {
        LOG_ERROR("error writing PRESTO init sequence");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    return ERROR_OK;
}
 
static int presto_open(const char *req_serial)
{
    presto->buff_out_pos = 0;
    presto->buff_in_pos = 0;
    presto->buff_in_len = 0;
    presto->buff_in_exp = 0;
 
    presto->total_out = 0;
    presto->total_in = 0;
 
    presto->jtag_tms = 0;
    presto->jtag_tck = 0;
    presto->jtag_rst = 0;
    presto->jtag_tdi_data = 0;
    presto->jtag_tdi_count = 0;
 
    presto->jtag_speed = 0;
 
    return presto_open_libftdi(req_serial);
}
 
static int presto_close(void)
{
 
    int result = ERROR_OK;
 
    presto->retval = ftdi_write_data(&presto->ftdic, presto_init_seq, sizeof(presto_init_seq));
    if (presto->retval != sizeof(presto_init_seq))
        result = ERROR_JTAG_DEVICE_ERROR;
 
    presto->retval = ftdi_set_latency_timer(&presto->ftdic, 16);
    if (presto->retval < 0)
        result = ERROR_JTAG_DEVICE_ERROR;
 
    presto->retval = ftdi_usb_close(&presto->ftdic);
    if (presto->retval < 0)
        result = ERROR_JTAG_DEVICE_ERROR;
    else
        ftdi_deinit(&presto->ftdic);
 
    return result;
}
 
static int presto_flush(void)
{
    if (presto->buff_out_pos == 0)
        return ERROR_OK;
 
    if (presto->retval < 0) {
        LOG_DEBUG("error in previous communication, canceling I/O operation");
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    if (presto_write(presto->buff_out, presto->buff_out_pos) != ERROR_OK) {
        presto->buff_out_pos = 0;
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    presto->total_out += presto->buff_out_pos;
    presto->buff_out_pos = 0;
 
    if (presto->buff_in_exp == 0)
        return ERROR_OK;
 
    presto->buff_in_pos = 0;
    presto->buff_in_len = 0;
 
    if (presto_read(presto->buff_in, presto->buff_in_exp) != ERROR_OK) {
        presto->buff_in_exp = 0;
        return ERROR_JTAG_DEVICE_ERROR;
    }
 
    presto->total_in += presto->buff_in_exp;
    presto->buff_in_len = presto->buff_in_exp;
    presto->buff_in_exp = 0;
 
    return ERROR_OK;
}
 
static int presto_sendbyte(int data)
{
    if (data == EOF)
        return presto_flush();
 
    if (presto->buff_out_pos < BUFFER_SIZE) {
        presto->buff_out[presto->buff_out_pos++] = (uint8_t)data;
        if (((data & 0xC0) == 0x40) || ((data & 0xD0) == 0xD0))
            presto->buff_in_exp++;
    } else
        return ERROR_JTAG_DEVICE_ERROR;
 
    /* libftdi does not do background read, be sure that USB IN buffer does not overflow (128
     *bytes only!) */
    if (presto->buff_out_pos >= BUFFER_SIZE || presto->buff_in_exp == 128)
        return presto_flush();
 
    return ERROR_OK;
}
 
#if 0
static int presto_getbyte(void)
{
    if (presto->buff_in_pos < presto->buff_in_len)
        return presto->buff_in[presto->buff_in_pos++];
 
    if (presto->buff_in_exp == 0)
        return -1;
 
    if (presto_flush() != ERROR_OK)
        return -1;
 
    if (presto->buff_in_pos < presto->buff_in_len)
        return presto->buff_in[presto->buff_in_pos++];
 
    return -1;
}
#endif
 
/* -------------------------------------------------------------------------- */
 
static int presto_tdi_flush(void)
{
    if (presto->jtag_tdi_count == 0)
        return 0;
 
    if (presto->jtag_tck == 0) {
        LOG_ERROR("BUG: unexpected TAP condition, TCK low");
        return -1;
    }
 
    presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
    presto_sendbyte(presto->jtag_tdi_data);
    presto->jtag_tdi_count = 0;
    presto->jtag_tdi_data = 0;
 
    return 0;
}
 
static int presto_tck_idle(void)
{
    if (presto->jtag_tck == 1) {
        presto_sendbyte(0xCA);
        presto->jtag_tck = 0;
    }
 
    return 0;
}
 
/* -------------------------------------------------------------------------- */
 
static int presto_bitq_out(int tms, int tdi, int tdo_req)
{
    int i;
    unsigned char cmd;
 
    if (presto->jtag_tck == 0)
        presto_sendbyte(0xA4);  /* LED indicator - JTAG active */
    else if (presto->jtag_speed == 0 && !tdo_req && tms == presto->jtag_tms) {
        presto->jtag_tdi_data |= (tdi != 0) << presto->jtag_tdi_count;
 
        if (++presto->jtag_tdi_count == 4)
            presto_tdi_flush();
 
        return 0;
    }
 
    presto_tdi_flush();
 
    cmd = tdi ? 0xCB : 0xCA;
    presto_sendbyte(cmd);
 
    if (tms != presto->jtag_tms) {
        presto_sendbyte((tms ? 0xEC : 0xE8) | (presto->jtag_rst ? 0x02 : 0));
        presto->jtag_tms = tms;
    }
 
    /* delay with TCK low */
    for (i = presto->jtag_speed; i > 1; i--)
        presto_sendbyte(cmd);
 
    cmd |= 0x04;
    presto_sendbyte(cmd | (tdo_req ? 0x10 : 0));
 
    /* delay with TCK high */
    for (i = presto->jtag_speed; i > 1; i--)
        presto_sendbyte(cmd);
 
    presto->jtag_tck = 1;
 
    return 0;
}
 
static int presto_bitq_flush(void)
{
    presto_tdi_flush();
    presto_tck_idle();
 
    presto_sendbyte(0xA0);  /* LED indicator - JTAG idle */
 
    return presto_flush();
}
 
static int presto_bitq_in_rdy(void)
{
    if (presto->buff_in_pos >= presto->buff_in_len)
        return 0;
    return presto->buff_in_len-presto->buff_in_pos;
}
 
static int presto_bitq_in(void)
{
    if (presto->buff_in_pos >= presto->buff_in_len)
        return -1;
    if (presto->buff_in[presto->buff_in_pos++]&0x08)
        return 1;
    return 0;
}
 
static int presto_bitq_sleep(unsigned long us)
{
    long waits;
 
    presto_tdi_flush();
    presto_tck_idle();
 
    if (us > 100000) {
        presto_bitq_flush();
        jtag_sleep(us);
        return 0;
    }
 
    waits = us / 170 + 2;
    while (waits--)
        presto_sendbyte(0x80);
 
    return 0;
}
 
static int presto_bitq_reset(int trst, int srst)
{
    presto_tdi_flush();
    presto_tck_idle();
 
    /* add a delay after possible TCK transition */
    presto_sendbyte(0x80);
    presto_sendbyte(0x80);
 
    presto->jtag_rst = trst || srst;
    presto_sendbyte((presto->jtag_rst ? 0xEA : 0xE8) | (presto->jtag_tms ? 0x04 : 0));
 
    return 0;
}
 
static struct bitq_interface presto_bitq = {
    .out = &presto_bitq_out,
    .flush = &presto_bitq_flush,
    .sleep = &presto_bitq_sleep,
    .reset = &presto_bitq_reset,
    .in_rdy = &presto_bitq_in_rdy,
    .in = &presto_bitq_in,
};
 
/* -------------------------------------------------------------------------- */
 
static int presto_adapter_khz(int khz, int *jtag_speed)
{
    if (khz <= 0) {
        *jtag_speed = 0;
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    if (khz >= 3000)
        *jtag_speed = 0;
    else
        *jtag_speed = (1000 + khz-1)/khz;
 
    return 0;
}
 
static int presto_jtag_speed_div(int speed, int *khz)
{
    if ((speed < 0) || (speed > 1000)) {
        *khz = 0;
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    if (speed == 0)
        *khz = 3000;
    else
        *khz = 1000/speed;
 
    return 0;
}
 
static int presto_jtag_speed(int speed)
{
    int khz;
 
    if (presto_jtag_speed_div(speed, &khz))
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    presto->jtag_speed = speed;
 
    if (khz%1000 == 0)
        LOG_INFO("setting speed to %d, max. TCK freq. is %d MHz", speed, khz/1000);
    else
        LOG_INFO("setting speed to %d, max. TCK freq. is %d kHz", speed, khz);
 
    return 0;
}
 
static int presto_jtag_init(void)
{
    const char *presto_serial = adapter_get_required_serial();
 
    if (presto_open(presto_serial) != ERROR_OK) {
        presto_close();
        if (presto_serial)
            LOG_ERROR("Cannot open PRESTO, serial number '%s'", presto_serial);
        else
            LOG_ERROR("Cannot open PRESTO");
        return ERROR_JTAG_INIT_FAILED;
    }
    LOG_INFO("PRESTO open, serial number '%s'", presto->serial);
 
    bitq_interface = &presto_bitq;
    return ERROR_OK;
}
 
static int presto_jtag_quit(void)
{
    bitq_cleanup();
    presto_close();
    LOG_INFO("PRESTO closed");
    return ERROR_OK;
}
 
static struct jtag_interface presto_interface = {
    .execute_queue = bitq_execute_queue,
};
 
struct adapter_driver presto_adapter_driver = {
    .name = "presto",
    .transport_ids = TRANSPORT_JTAG,
    .transport_preferred_id = TRANSPORT_JTAG,
 
    .init = presto_jtag_init,
    .quit = presto_jtag_quit,
    .speed = presto_jtag_speed,
    .khz = presto_adapter_khz,
    .speed_div = presto_jtag_speed_div,
 
    .jtag_ops = &presto_interface,
};