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/***************************************************************************
* Copyright (C) 2020 by Liam Fraser *
* liam@raspberrypi.com *
* *
* Based on: kitprog.c, ftdi.c, mpsse.c *
* *
* 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 *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <jtag/interface.h>
#include <jtag/swd.h>
#include <jtag/commands.h>
#include "libusb_helper.h"
#define VID 0x2E8A /* Raspberry Pi */
#define PID 0x0004 /* Picoprobe */
#define BULK_EP_OUT 4
#define BULK_EP_IN 5
#define PICOPROBE_INTERFACE 2
#define PICOPROBE_MAX_PACKET_LENGTH 512
#define LIBUSB_TIMEOUT 10000
struct picoprobe {
struct libusb_device_handle *usb_handle;
uint8_t *packet_buffer;
int freq;
};
static struct swd_cmd_queue_entry {
uint8_t cmd;
uint32_t *dst;
uint8_t trn_ack_data_parity_trn[DIV_ROUND_UP(4 + 3 + 32 + 1 + 4, 8)];
} *swd_cmd_queue;
static size_t swd_cmd_queue_length;
static size_t swd_cmd_queue_alloced;
static int queued_retval;
static struct picoprobe *picoprobe_handle;
static int picoprobe_init(void);
static int picoprobe_quit(void);
enum PROBE_CMDS {
PROBE_INVALID = 0, /* Invalid */
PROBE_WRITE_BITS = 1, /* Host wants us to write bits */
PROBE_READ_BITS = 2, /* Host wants us to read bits */
PROBE_SET_FREQ = 3, /* Set TCK freq */
PROBE_RESET = 4
};
struct __attribute__((__packed__)) probe_cmd_hdr {
uint8_t id;
uint8_t cmd;
uint32_t bits;
};
struct __attribute__((__packed__)) probe_pkt_hdr {
uint32_t total_packet_length;
};
/* Separate queue to swd_cmd_queue because we sometimes insert idle cycles not described
* there */
#define PICOPROBE_QUEUE_SIZE 64
static struct picoprobe_queue_entry {
uint8_t id;
uint8_t cmd; /* PROBE_CMDS */
unsigned bits;
unsigned offset;
const uint8_t *buf;
} *picoprobe_queue;
static size_t picoprobe_queue_length;
static size_t picoprobe_queue_alloced;
static inline unsigned packet_length(uint8_t *pkt)
{
return pkt - picoprobe_handle->packet_buffer;
}
static int picoprobe_bulk_write(struct probe_pkt_hdr *pkt_hdr, uint8_t *pkt)
{
pkt_hdr->total_packet_length = packet_length(pkt);
assert(pkt_hdr->total_packet_length <= PICOPROBE_MAX_PACKET_LENGTH);
int ret = 0;
jtag_libusb_bulk_write(picoprobe_handle->usb_handle,
BULK_EP_OUT, (char *)picoprobe_handle->packet_buffer, packet_length(pkt), LIBUSB_TIMEOUT,
&ret);
if (ret < 0)
return ERROR_JTAG_DEVICE_ERROR;
return ERROR_OK;
}
static int picoprobe_flush(void)
{
LOG_DEBUG_IO("Flush %d transactions", (int)picoprobe_queue_length);
int ret = ERROR_OK;
struct probe_pkt_hdr *pkt_hdr = (struct probe_pkt_hdr *)picoprobe_handle->packet_buffer;
/* Chain pending write and read commands together */
uint8_t *pkt = picoprobe_handle->packet_buffer + sizeof(struct probe_pkt_hdr);
unsigned total_reads = 0;
unsigned total_read_bytes = 0;
for (unsigned i = 0; i < picoprobe_queue_length; i++) {
/* Copy header regardless of read or write */
struct picoprobe_queue_entry *q = &picoprobe_queue[i];
struct probe_cmd_hdr *hdr = (struct probe_cmd_hdr *)pkt;
if (q->id != i) {
LOG_ERROR("Wrong queue id. q->id %d != %d", q->id, i);
return ERROR_JTAG_DEVICE_ERROR;
}
hdr->id = q->id;
hdr->cmd = q->cmd;
hdr->bits = q->bits;
pkt += sizeof(struct probe_cmd_hdr);
unsigned length_bytes = DIV_ROUND_UP(q->bits, 8);
if (q->cmd == PROBE_WRITE_BITS) {
/* Copy the data to write into the packet buffer */
if (q->buf) {
bit_copy(pkt, 0, q->buf, q->offset, q->bits);
} else {
/* Make sure the packet buffer is zerod to clock zeros */
assert(q->offset == 0);
memset(pkt, 0, length_bytes);
}
pkt += length_bytes;
} else if (q->cmd == PROBE_READ_BITS) {
/* Nothing to do for a read as we have already copied the header
* Will process the data later in one go */
total_reads++;
total_read_bytes += length_bytes;
} else {
/* Unexpected cmd to flush */
return ERROR_FAIL;
}
}
/* Send all read/write commands + write data */
ret = picoprobe_bulk_write(pkt_hdr, pkt);
if (ret < 0)
return ERROR_JTAG_DEVICE_ERROR;
/* If no reads we can bail */
if (total_reads == 0) {
picoprobe_queue_length = 0;
return ret;
}
/* Now get any read responses */
unsigned rx_pkt_len = sizeof(struct probe_pkt_hdr) +
(sizeof(struct probe_cmd_hdr) * total_reads) +
total_read_bytes;
jtag_libusb_bulk_read(picoprobe_handle->usb_handle,
BULK_EP_IN | LIBUSB_ENDPOINT_IN, (char *)picoprobe_handle->packet_buffer,
rx_pkt_len, LIBUSB_TIMEOUT, &ret);
if (ret < 0)
return ERROR_JTAG_DEVICE_ERROR;
/* Now time to process the rx data */
LOG_DEBUG_IO("Read %d bytes from probe", ret);
/* If we didn't get length we expected */
if ((int)rx_pkt_len != ret)
return ERROR_JTAG_DEVICE_ERROR;
struct probe_pkt_hdr *response_hdr = (struct probe_pkt_hdr *)picoprobe_handle->packet_buffer;
if (rx_pkt_len != response_hdr->total_packet_length)
return ERROR_JTAG_DEVICE_ERROR;
pkt = picoprobe_handle->packet_buffer + sizeof(struct probe_pkt_hdr);
/* Now go through read responses */
for (unsigned i = 0; i < total_reads; i++) {
struct probe_cmd_hdr *read_hdr = (struct probe_cmd_hdr *)pkt;
pkt += sizeof(struct probe_cmd_hdr);
unsigned read_bytes = DIV_ROUND_UP(read_hdr->bits, 8);
if (read_hdr->cmd != PROBE_READ_BITS)
return ERROR_JTAG_DEVICE_ERROR;
uint8_t id = read_hdr->id;
struct picoprobe_queue_entry *q = &picoprobe_queue[id];
assert(read_hdr->cmd == q->cmd);
assert(read_hdr->id == q->id);
assert(read_hdr->bits == q->bits);
LOG_DEBUG_IO("Processing read of %d bits", read_hdr->bits);
/* Copy data back to swd cmd queue */
memcpy((void *)q->buf, pkt, read_bytes);
pkt += read_bytes;
}
unsigned processed_len = (pkt - picoprobe_handle->packet_buffer);
if (processed_len != rx_pkt_len)
return ERROR_JTAG_DEVICE_ERROR;
picoprobe_queue_length = 0;
/* Keep gdb alive */
keep_alive();
return ERROR_OK;
}
static int picoprobe_read_write_bits(const uint8_t *buf, unsigned offset, unsigned length, uint8_t cmd)
{
if (picoprobe_queue_length == picoprobe_queue_alloced) {
LOG_ERROR("Picoprobe queue full");
return ERROR_BUF_TOO_SMALL;
} else {
LOG_DEBUG_IO("Picoprobe queue len %d -> %d", (int)picoprobe_queue_length,
(int)picoprobe_queue_length + 1);
}
struct picoprobe_queue_entry *q = &picoprobe_queue[picoprobe_queue_length];
q->id = picoprobe_queue_length++;
q->cmd = cmd;
q->bits = length;
q->offset = offset;
q->buf = buf;
return ERROR_OK;
}
static int picoprobe_write_bits(const uint8_t *buf, unsigned offset, unsigned length)
{
LOG_DEBUG_IO("Write %d bits @ offset %d", length, offset);
return picoprobe_read_write_bits(buf, offset, length, PROBE_WRITE_BITS);
}
static int picoprobe_read_bits(const uint8_t *buf, unsigned offset, unsigned length)
{
LOG_DEBUG_IO("Read %d bits @ offset %d", length, offset);
if (picoprobe_queue_length == picoprobe_queue_alloced)
return ERROR_BUF_TOO_SMALL;
return picoprobe_read_write_bits(buf, offset, length, PROBE_READ_BITS);
}
static int picoprobe_swd_run_queue(void)
{
LOG_DEBUG_IO("Executing %zu queued transactions", swd_cmd_queue_length);
int retval;
queued_retval = picoprobe_flush();
if (queued_retval != ERROR_OK) {
LOG_DEBUG_IO("Skipping due to previous errors: %d", queued_retval);
goto skip;
}
for (size_t i = 0; i < swd_cmd_queue_length; i++) {
if (0 == ((swd_cmd_queue[i].cmd ^ swd_cmd(false, false, DP_TARGETSEL)) &
(SWD_CMD_APNDP|SWD_CMD_RNW|SWD_CMD_A32))) {
/* Targetsel has no ack so force it */
buf_set_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1, 3, SWD_ACK_OK);
}
LOG_DEBUG_IO("trn_ack_data_parity_trn:");
for (size_t y = 0; y < sizeof(swd_cmd_queue[i].trn_ack_data_parity_trn); y++)
LOG_DEBUG_IO("BYTE %d 0x%x", (int)y, swd_cmd_queue[i].trn_ack_data_parity_trn[y]);
int ack = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1, 3);
LOG_DEBUG_IO("%s %s %s reg %X = %08"PRIx32,
ack == SWD_ACK_OK ? "OK" : ack == SWD_ACK_WAIT ? "WAIT" : ack == SWD_ACK_FAULT ? "FAULT" : "JUNK",
swd_cmd_queue[i].cmd & SWD_CMD_APNDP ? "AP" : "DP",
swd_cmd_queue[i].cmd & SWD_CMD_RNW ? "read" : "write",
(swd_cmd_queue[i].cmd & SWD_CMD_A32) >> 1,
buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn,
1 + 3 + (swd_cmd_queue[i].cmd & SWD_CMD_RNW ? 0 : 1), 32));
if (ack != SWD_ACK_OK) {
queued_retval = ack == SWD_ACK_WAIT ? ERROR_WAIT : ERROR_FAIL;
goto skip;
} else if (swd_cmd_queue[i].cmd & SWD_CMD_RNW) {
uint32_t data = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3, 32);
int parity = buf_get_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 32, 1);
if (parity != parity_u32(data)) {
LOG_ERROR("SWD Read data parity mismatch");
queued_retval = ERROR_FAIL;
goto skip;
}
if (swd_cmd_queue[i].dst != NULL)
*swd_cmd_queue[i].dst = data;
}
}
skip:
/* Defensive cleanup - seems like a bad idea to have potentially stale pointers sticking around */
for (size_t i = 0; i < swd_cmd_queue_length; i++)
swd_cmd_queue[i].dst = NULL;
swd_cmd_queue_length = 0;
retval = queued_retval;
queued_retval = ERROR_OK;
return retval;
}
static void picoprobe_swd_queue_cmd(uint8_t cmd, uint32_t *dst, uint32_t data, uint32_t ap_delay_clk)
{
if (swd_cmd_queue_length == swd_cmd_queue_alloced)
queued_retval = picoprobe_swd_run_queue();
if (queued_retval != ERROR_OK)
return;
size_t i = swd_cmd_queue_length++;
swd_cmd_queue[i].cmd = cmd | SWD_CMD_START | SWD_CMD_PARK;
picoprobe_write_bits(&swd_cmd_queue[i].cmd, 0, 8);
if (swd_cmd_queue[i].cmd & SWD_CMD_RNW) {
/* Queue a read transaction */
swd_cmd_queue[i].dst = dst;
picoprobe_read_bits(swd_cmd_queue[i].trn_ack_data_parity_trn,
0, 1 + 3 + 32 + 1 + 1);
} else {
/* Queue a write transaction */
picoprobe_read_bits(swd_cmd_queue[i].trn_ack_data_parity_trn,
0, 1 + 3 + 1);
buf_set_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 1, 32, data);
buf_set_u32(swd_cmd_queue[i].trn_ack_data_parity_trn, 1 + 3 + 1 + 32, 1, parity_u32(data));
picoprobe_write_bits(swd_cmd_queue[i].trn_ack_data_parity_trn,
1 + 3 + 1, 32 + 1);
}
/* Insert idle cycles after AP accesses to avoid WAIT */
if (cmd & SWD_CMD_APNDP) {
if (ap_delay_clk == 0)
return;
LOG_DEBUG("Add %d idle cycles", ap_delay_clk);
picoprobe_write_bits(NULL, 0, ap_delay_clk);
}
}
static void picoprobe_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay_clk)
{
assert(cmd & SWD_CMD_RNW);
picoprobe_swd_queue_cmd(cmd, value, 0, ap_delay_clk);
}
static void picoprobe_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay_clk)
{
assert(!(cmd & SWD_CMD_RNW));
picoprobe_swd_queue_cmd(cmd, NULL, value, ap_delay_clk);
}
static int_least32_t picoprobe_set_frequency(int_least32_t hz)
{
int ret;
struct probe_pkt_hdr *pkt_hdr = (struct probe_pkt_hdr *)picoprobe_handle->packet_buffer;
/* Assert this is a standalone command with nothing else queued */
assert(picoprobe_queue_length == 0);
/* Chain writes and read commands together */
uint8_t *pkt = picoprobe_handle->packet_buffer + sizeof(struct probe_pkt_hdr);
struct probe_cmd_hdr *hdr = (struct probe_cmd_hdr *)pkt;
hdr->id = 0;
hdr->cmd = PROBE_SET_FREQ;
hdr->bits = hz / 1000;
pkt += sizeof(struct probe_cmd_hdr);
/* Send all read/write commands + write data */
ret = picoprobe_bulk_write(pkt_hdr, pkt);
if (ret < 0)
return ERROR_JTAG_DEVICE_ERROR;
return hz;
}
static int_least32_t picoprobe_speed(int_least32_t hz)
{
int ret = picoprobe_set_frequency(hz);
if (ret < 0)
LOG_ERROR("Couldn't set picoprobe speed");
else
picoprobe_handle->freq = ret;
return ERROR_OK;
}
static int picoprobe_khz(int khz, int *jtag_speed)
{
*jtag_speed = khz * 1000;
return ERROR_OK;
}
static int picoprobe_speed_div(int speed, int *khz)
{
*khz = speed / 1000;
return ERROR_OK;
}
static int picoprobe_swd_init(void)
{
return ERROR_OK;
}
static int picoprobe_swd_switch_seq(enum swd_special_seq seq)
{
int ret = ERROR_OK;
switch (seq) {
case LINE_RESET:
LOG_DEBUG_IO("SWD line reset");
ret = picoprobe_write_bits(swd_seq_line_reset, 0, swd_seq_line_reset_len);
break;
case JTAG_TO_SWD:
LOG_DEBUG("JTAG-to-SWD");
ret = picoprobe_write_bits(swd_seq_jtag_to_swd, 0, swd_seq_jtag_to_swd_len);
break;
case SWD_TO_JTAG:
LOG_DEBUG("SWD-to-JTAG");
ret = picoprobe_write_bits(swd_seq_swd_to_jtag, 0, swd_seq_swd_to_jtag_len);
break;
case DORMANT_TO_SWD:
LOG_DEBUG("DORMANT-to-SWD");
ret = picoprobe_write_bits(swd_seq_dormant_to_swd, 0, swd_seq_dormant_to_swd_len);
break;
case SWD_TO_DORMANT:
LOG_DEBUG("SWD-to-DORMANT");
ret = picoprobe_write_bits(swd_seq_swd_to_dormant, 0, swd_seq_swd_to_dormant_len);
break;
default:
LOG_ERROR("Sequence %d not supported", seq);
return ERROR_FAIL;
}
return ret;
}
static int picoprobe_reset(int trst, int srst)
{
return ERROR_OK;
}
static const struct swd_driver picoprobe_swd = {
.init = picoprobe_swd_init,
.switch_seq = picoprobe_swd_switch_seq,
.read_reg = picoprobe_swd_read_reg,
.write_reg = picoprobe_swd_write_reg,
.run = picoprobe_swd_run_queue,
};
static const char * const picoprobe_transports[] = { "swd", NULL };
struct adapter_driver picoprobe_adapter_driver = {
.name = "picoprobe",
.commands = NULL,
.transports = picoprobe_transports,
.swd_ops = &picoprobe_swd,
.init = picoprobe_init,
.quit = picoprobe_quit,
.reset = picoprobe_reset,
.speed = picoprobe_speed,
.speed_div = picoprobe_speed_div,
.khz = picoprobe_khz,
};
static int picoprobe_usb_open(void)
{
const uint16_t vids[] = { VID, 0 };
const uint16_t pids[] = { PID, 0 };
if (jtag_libusb_open(vids, pids, NULL,
&picoprobe_handle->usb_handle, NULL) != ERROR_OK) {
LOG_ERROR("Failed to open or find the device");
return ERROR_FAIL;
}
if (libusb_claim_interface(picoprobe_handle->usb_handle, PICOPROBE_INTERFACE) != ERROR_OK) {
LOG_ERROR("Failed to claim picoprobe interface");
return ERROR_FAIL;
}
return ERROR_OK;
}
static void picoprobe_usb_close(void)
{
jtag_libusb_close(picoprobe_handle->usb_handle);
}
static int picoprobe_init(void)
{
picoprobe_handle = malloc(sizeof(struct picoprobe));
if (picoprobe_handle == NULL) {
LOG_ERROR("Failed to allocate memory");
return ERROR_FAIL;
}
if (picoprobe_usb_open() != ERROR_OK) {
LOG_ERROR("Can't find a picoprobe device! Please check device connections and permissions.");
return ERROR_JTAG_INIT_FAILED;
}
/* Allocate packet buffers and queues */
picoprobe_handle->packet_buffer = malloc(PICOPROBE_MAX_PACKET_LENGTH);
if (picoprobe_handle->packet_buffer == NULL) {
LOG_ERROR("Failed to allocate memory for the packet buffer");
return ERROR_FAIL;
}
picoprobe_queue_alloced = PICOPROBE_QUEUE_SIZE;
picoprobe_queue_length = 0;
picoprobe_queue = malloc(picoprobe_queue_alloced * sizeof(*picoprobe_queue));
if (picoprobe_queue == NULL)
return ERROR_FAIL;
swd_cmd_queue_alloced = 10;
swd_cmd_queue = malloc(swd_cmd_queue_alloced * sizeof(*swd_cmd_queue));
return swd_cmd_queue != NULL ? ERROR_OK : ERROR_FAIL;
}
static int picoprobe_quit(void)
{
picoprobe_usb_close();
return ERROR_OK;
}
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