dirtyjtag: Add DirtyJTAG programmer

Add a new programmer driver for the DirtyJTAG project (a USB-JTAG
firmware for STM32 MCUs).

Successfully tested with DirtyJTAG 1.4 running on an Olimex STM32-H103
development board and a SST25VF020B SPI flash chip.

Change-Id: Ic43e9a014ed7d04e429e73b30c9dcfdde1a78913
Signed-off-by: Jean THOMAS <virgule@jeanthomas.me>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/67878
Original-Reviewed-by: Felix Singer <felixsinger@posteo.net>
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71492
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/dirtyjtag_spi.c b/dirtyjtag_spi.c
new file mode 100644
index 0000000..5b08952
--- /dev/null
+++ b/dirtyjtag_spi.c
@@ -0,0 +1,326 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2021-2022 Jean THOMAS <virgule@jeanthomas.me>
+ *
+ * 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.
+ */
+
+/*
+ * Driver for the DirtyJTAG project.
+ * See https://github.com/jeanthom/dirtyjtag for more info.
+ *
+ *  SPI-JTAG Pin Mapping
+ * |=========|==========|
+ * | SPI pin | JTAG pin |
+ * |=========|==========|
+ * | #CS     | TMS      |
+ * | #WP     | SRST     |
+ * | #HOLD   | TRST     |
+ * | MISO    | TDO      |
+ * | MOSI    | TDI      |
+ * | CLK     | TCK      |
+ * |=========|==========|
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <libusb.h>
+#include "programmer.h"
+
+struct dirtyjtag_spi_data {
+	struct libusb_context *libusb_ctx;
+	struct libusb_device_handle *libusb_handle;
+};
+
+static const struct dev_entry devs_dirtyjtag_spi[] = {
+	{ 0x1209, 0xc0ca, OK, "DirtyJTAG", "JTAG probe" },
+	{ 0 },
+};
+
+static const char dirtyjtag_write_endpoint = 0x01;
+static const char dirtyjtag_read_endpoint = 0x82;
+static const int dirtyjtag_timeout = 100 * 10; /* 100 ms */
+
+enum dirtyjtag_command_identifier {
+	CMD_STOP = 0x00,
+	CMD_INFO = 0x01,
+	CMD_FREQ = 0x02,
+	CMD_XFER = 0x03,
+	CMD_SETSIG = 0x04,
+	CMD_GETSIG = 0x05,
+	CMD_CLK = 0x06
+};
+
+enum dirtyjtag_signal_identifier {
+	SIG_TCK = 1 << 1,
+	SIG_TDI = 1 << 2,
+	SIG_TDO = 1 << 3,
+	SIG_TMS = 1 << 4,
+	SIG_TRST = 1 << 5,
+	SIG_SRST = 1 << 6
+};
+
+static int dirtyjtag_send(struct dirtyjtag_spi_data *djtag_data, uint8_t *data, size_t len)
+{
+	int transferred;
+	int ret = libusb_bulk_transfer(djtag_data->libusb_handle,
+		dirtyjtag_write_endpoint,
+		data,
+		len,
+		&transferred,
+		dirtyjtag_timeout);
+	if (ret != 0) {
+		msg_perr("%s: failed to send query command\n", __func__);
+		return -1;
+	}
+	if (transferred != (int)len) {
+		msg_perr("%s: failed to send whole packet\n", __func__);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int dirtyjtag_receive(struct dirtyjtag_spi_data *djtag_data, uint8_t *data, size_t buffer_len, int expected)
+{
+	int transferred;
+	int ret = libusb_bulk_transfer(djtag_data->libusb_handle,
+		dirtyjtag_read_endpoint,
+		data,
+		buffer_len,
+		&transferred,
+		dirtyjtag_timeout);
+	if (ret != 0) {
+		msg_perr("%s: Failed to read SPI commands\n", __func__);
+		return -1;
+	}
+
+	if (expected != -1 && transferred != expected) {
+		msg_perr("%s: failed to meet expected\n", __func__);
+		return -1;
+	}
+
+	return transferred;
+}
+
+static int dirtyjtag_spi_shutdown(void *data)
+{
+	struct dirtyjtag_spi_data *djtag_data = (struct dirtyjtag_spi_data*)data;
+	libusb_release_interface(djtag_data->libusb_handle, 0);
+	libusb_attach_kernel_driver(djtag_data->libusb_handle, 0);
+	libusb_close(djtag_data->libusb_handle);
+	libusb_exit(djtag_data->libusb_ctx);
+	free(data);
+	return 0;
+}
+
+static int dirtyjtag_djtag1_spi_send_command(struct dirtyjtag_spi_data *context,
+					     unsigned int writecnt, unsigned int readcnt,
+					     const unsigned char *writearr, unsigned char *readarr)
+{
+	const size_t max_xfer_size = 30; // max transfer size in DJTAG1
+	size_t len = writecnt + readcnt;
+	size_t num_xfer = (len + max_xfer_size - 1 ) / max_xfer_size; // ceil(len/max_xfer_size)
+	size_t i;
+
+	uint8_t *rxtx_buffer = malloc(max_xfer_size * num_xfer);
+	if (!rxtx_buffer) {
+		msg_perr("%s: Failed rxtx_buffer allocation\n", __func__);
+		return -1;
+	}
+
+	memcpy(rxtx_buffer, writearr, writecnt);
+	for (i = 0; i < num_xfer; i++) {
+		const size_t xfer_offset = i * max_xfer_size;
+		size_t txn_size = max_xfer_size;
+		if (i == num_xfer-1 && len % max_xfer_size != 0)
+			txn_size = len % max_xfer_size;
+
+		uint8_t transfer_buffer[32] = {
+			CMD_XFER,
+			txn_size * 8
+		};
+		memcpy(transfer_buffer + 2, rxtx_buffer + xfer_offset, txn_size);
+
+		if (dirtyjtag_send(context, transfer_buffer, sizeof(transfer_buffer)))
+			goto cleanup_fail;
+
+		if (dirtyjtag_receive(context, transfer_buffer, sizeof(transfer_buffer), 32) < 0)
+			goto cleanup_fail;
+
+		memcpy(rxtx_buffer + xfer_offset, transfer_buffer, txn_size);
+	}
+	memcpy(readarr, rxtx_buffer + writecnt, readcnt);
+
+	free(rxtx_buffer);
+
+	uint8_t tms_reset_buffer[] = {
+		CMD_SETSIG,
+		SIG_TMS,
+		SIG_TMS,
+
+		CMD_STOP,
+	};
+	dirtyjtag_send(context, tms_reset_buffer, sizeof(tms_reset_buffer));
+
+	return 0;
+
+cleanup_fail:
+	free(rxtx_buffer);
+	return -1;
+}
+
+static int dirtyjtag_spi_spi_send_command(const struct flashctx *flash,
+					  unsigned int writecnt, unsigned int readcnt,
+					  const unsigned char *writearr, unsigned char *readarr)
+{
+	struct dirtyjtag_spi_data *djtag_data = flash->mst->spi.data;
+	return dirtyjtag_djtag1_spi_send_command(djtag_data, writecnt, readcnt, writearr, readarr);
+}
+
+static struct spi_master spi_master_dirtyjtag_spi = {
+	.features	= SPI_MASTER_4BA,
+	.max_data_read	= MAX_DATA_READ_UNLIMITED,
+	.max_data_write	= MAX_DATA_WRITE_UNLIMITED,
+	.command	= dirtyjtag_spi_spi_send_command,
+	.multicommand	= default_spi_send_multicommand,
+	.read		= default_spi_read,
+	.write_256	= default_spi_write_256,
+	.write_aai	= default_spi_write_aai,
+};
+
+static int dirtyjtag_spi_init(void)
+{
+	struct libusb_device_handle *handle = NULL;
+	struct dirtyjtag_spi_data *djtag_data = NULL;
+
+	djtag_data = calloc(1, sizeof(struct dirtyjtag_spi_data));
+	if (djtag_data == NULL) {
+		msg_perr("%s: failed to allocate internal driver data structure\n", __func__);
+		return -1;
+	}
+
+	int ret = libusb_init(&djtag_data->libusb_ctx);
+	if (ret < 0) {
+		msg_perr("%s: couldn't initialize libusb!\n", __func__);
+		goto cleanup_djtag_struct;
+	}
+
+#if LIBUSB_API_VERSION < 0x01000106
+	libusb_set_debug(djtag_data->libusb_ctx, 3);
+#else
+	libusb_set_option(djtag_data->libusb_ctx, LIBUSB_OPTION_LOG_LEVEL, LIBUSB_LOG_LEVEL_INFO);
+#endif
+
+	uint16_t vid = devs_dirtyjtag_spi[0].vendor_id;
+	uint16_t pid = devs_dirtyjtag_spi[0].device_id;
+	handle = libusb_open_device_with_vid_pid(djtag_data->libusb_ctx, vid, pid);
+	if (handle == NULL) {
+		msg_perr("%s: couldn't open device %04x:%04x.\n", __func__, vid, pid);
+		goto cleanup_libusb_ctx;
+	}
+
+	ret = libusb_detach_kernel_driver(handle, 0);
+	if (ret != 0 && ret != LIBUSB_ERROR_NOT_FOUND) {
+		msg_pwarn("Cannot detach the existing USB driver. Claiming the interface may fail. %s\n",
+			libusb_error_name(ret));
+	}
+
+	ret = libusb_claim_interface(handle, 0);
+	if (ret != 0) {
+		msg_perr("%s: failed to claim interface 0: '%s'\n", __func__, libusb_error_name(ret));
+		goto cleanup_libusb_handle;
+	}
+
+	djtag_data->libusb_handle = handle;
+
+	unsigned long int freq = 100;
+	char *tmp = extract_programmer_param("spispeed");
+	if (tmp) {
+		char *units = tmp;
+
+		errno = 0;
+		freq = strtoul(tmp, &units, 0);
+		if (errno) {
+			msg_perr("Invalid frequency \"%s\", %s\n", tmp, strerror(errno));
+			free(tmp);
+			goto cleanup_libusb_handle;
+		}
+
+		if (!strcasecmp(units, "hz")) {
+			freq /= 1000;
+		} else if (!strcasecmp(units, "khz")) {
+			/* Do nothing, already in the right unit */
+		} else if (!strcasecmp(units, "mhz")) {
+			freq *= 1000;
+		} else {
+			msg_perr("Invalid unit: %s, use hz, khz or mhz\n", units);
+			free(tmp);
+			goto cleanup_libusb_handle;
+		}
+
+		if (freq > UINT16_MAX) {
+			msg_perr("%s: Frequency set above DJTAG1 limits (%d kHz)", __func__, UINT16_MAX);
+			free(tmp);
+			goto cleanup_libusb_handle;
+		}
+
+		msg_pinfo("%s: programmer speed set to %lu kHz\n", __func__, freq);
+	}
+	free(tmp);
+
+	uint8_t commands[] = {
+		CMD_SETSIG, /* Set TDI/TCK to low, SRST/TRST/TMS to high */
+		SIG_TDI | SIG_TMS | SIG_TCK | SIG_SRST | SIG_TRST,
+		SIG_SRST | SIG_TRST | SIG_TMS,
+
+		CMD_FREQ, /* Set frequency */
+		(freq >> 8) & 0xff,
+		freq & 0xff,
+
+		CMD_STOP,
+	};
+	ret = dirtyjtag_send(djtag_data, commands, sizeof(commands));
+	if (ret != 0) {
+		msg_perr("%s: failed to configure DirtyJTAG into initialized state\n", __func__);
+		goto cleanup_libusb_handle;
+	}
+
+	if (register_shutdown(dirtyjtag_spi_shutdown, djtag_data))
+		goto cleanup_libusb_handle;
+
+	spi_master_dirtyjtag_spi.data = djtag_data;
+	return register_spi_master(&spi_master_dirtyjtag_spi);
+
+cleanup_libusb_handle:
+	libusb_attach_kernel_driver(handle, 0);
+	libusb_close(handle);
+
+cleanup_libusb_ctx:
+	libusb_exit(djtag_data->libusb_ctx);
+
+cleanup_djtag_struct:
+	free(djtag_data);
+	return -1;
+}
+
+const struct programmer_entry programmer_dirtyjtag_spi = {
+	.name			= "dirtyjtag_spi",
+	.type			= USB,
+	.devs.dev		= devs_dirtyjtag_spi,
+	.init			= dirtyjtag_spi_init,
+	.map_flash_region	= fallback_map,
+	.unmap_flash_region	= fallback_unmap,
+	.delay			= internal_delay,
+};