digilent_spi: add a driver for the iCEblink40 development board

This is driver that supports the Lattice iCE40 evaluation kits. On the
board is a SPI flash memory chip labeled ST 25P10VP.

Tested to work read/write/erase with "-p digilent_spi -c M25P10" or
with a patch that resets the part beforehands (in which case it gets
detected as a M25P10-A and is way faster due to paged writes).

Change-Id: I7ffcd9a2db4395816f0e8b6ce6c3b0d8e930c9e6
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-on: https://review.coreboot.org/23338
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 453 insertions, 0 deletions

diff --git a/digilent_spi.c b/digilent_spi.c
new file mode 100644
index 000000000..458e1b637
--- /dev/null
+++ b/digilent_spi.c
@@ -0,0 +1,453 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2018 Lubomir Rintel <lkundrak@v3.sk>
+ *
+ * Based on ft2232_spi.c:
+ *
+ * Copyright (C) 2011 asbokid <ballymunboy@gmail.com>
+ * Copyright (C) 2014 Pluto Yang <yangyj.ee@gmail.com>
+ * Copyright (C) 2015-2016 Stefan Tauner
+ * Copyright (C) 2015 Urja Rannikko <urjaman@gmail.com>
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+/*
+ * The reverse-engineered protocol description was obtained from the
+ * iceBurn project <https://github.com/davidcarne/iceBurn> by
+ * David Carne <davidcarne@gmail.com>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <libusb.h>
+#include "programmer.h"
+
+/* This is pretty much arbitrarily chosen. After one second without a
+ * response we can be pretty sure we're not going to succeed. */
+#define USB_TIMEOUT		1000
+
+#define	CMD_WRITE_EP		0x01
+#define	CMD_READ_EP		0x82
+#define	DATA_WRITE_EP		0x03
+#define	DATA_READ_EP		0x84
+
+static struct libusb_device_handle *handle = NULL;
+static bool reset_board;
+
+#define DIGILENT_VID		0x1443
+#define DIGILENT_JTAG_PID	0x0007
+
+const struct dev_entry devs_digilent_spi[] = {
+	{ DIGILENT_VID, DIGILENT_JTAG_PID, OK, "Digilent", "Development board JTAG" },
+	{ 0 },
+};
+
+/* Control endpoint commands. */
+enum {
+	GET_BOARD_TYPE		= 0xe2,
+	GET_BOARD_SERIAL	= 0xe4,
+};
+
+/* Command bulk endpoint command groups. */
+enum {
+	CMD_GPIO		= 0x03,
+	CMD_BOARD		= 0x04,
+	CMD_SPI			= 0x06,
+};
+
+/* GPIO subcommands. */
+enum {
+	CMD_GPIO_OPEN		= 0x00,
+	CMD_GPIO_CLOSE		= 0x01,
+	CMD_GPIO_SET_DIR	= 0x04,
+	CMD_GPIO_SET_VAL	= 0x06,
+};
+
+/* Board subcommands. */
+enum {
+	CMD_BOARD_OPEN		= 0x00,
+	CMD_BOARD_CLOSE		= 0x01,
+	CMD_BOARD_SET_REG	= 0x04,
+	CMD_BOARD_GET_REG	= 0x05,
+	CMD_BOARD_PL_STAT	= 0x85,
+};
+
+/* SPI subcommands. */
+enum {
+	CMD_SPI_OPEN		= 0x00,
+	CMD_SPI_CLOSE		= 0x01,
+	CMD_SPI_SET_SPEED	= 0x03,
+	CMD_SPI_SET_MODE	= 0x05,
+	CMD_SPI_SET_CS		= 0x06,
+	CMD_SPI_START_IO	= 0x07,
+	CMD_SPI_TX_END		= 0x87,
+};
+
+static int do_command(uint8_t *req, int req_len, uint8_t *res, int res_len)
+{
+	int tx_len = 0;
+	int ret;
+
+	req[0] = req_len - 1;
+	ret = libusb_bulk_transfer(handle, CMD_WRITE_EP, req, req_len, &tx_len, USB_TIMEOUT);
+	if (ret) {
+		msg_perr("Failed to issue a command: '%s'\n", libusb_error_name(ret));
+		return -1;
+	}
+
+	if (tx_len != req_len) {
+		msg_perr("Short write issuing a command\n");
+		return -1;
+	}
+
+	ret = libusb_bulk_transfer(handle, CMD_READ_EP, res, res_len, &tx_len, USB_TIMEOUT);
+	if (ret) {
+		msg_perr("Failed to get a response: '%s'\n", libusb_error_name(ret));
+		return -1;
+	}
+
+	if (tx_len != res_len) {
+		msg_perr("Short read getting a response\n");
+		return -1;
+	}
+
+	if (res[0] != res_len -1) {
+		msg_perr("Response indicates incorrect length.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int gpio_open(void)
+{
+	uint8_t req[] = { 0x00, CMD_GPIO, CMD_GPIO_OPEN, 0x00 };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int gpio_set_dir(uint8_t direction)
+{
+	uint8_t req[] = { 0x00, CMD_GPIO, CMD_GPIO_SET_DIR, 0x00,
+			  direction, 0x00, 0x00, 0x00 };
+	uint8_t res[6];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int gpio_set_value(uint8_t value)
+{
+	uint8_t req[] = { 0x00, CMD_GPIO, CMD_GPIO_SET_VAL, 0x00,
+			  value, 0x00, 0x00, 0x00 };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int spi_open(void)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_OPEN, 0x00 };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int spi_set_speed(uint32_t speed)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_SET_SPEED, 0x00,
+			  (speed) & 0xff,
+			  (speed >> 8) & 0xff,
+			  (speed >> 16) & 0xff,
+			  (speed >> 24) & 0xff };
+	uint8_t res[6];
+	uint32_t real_speed;
+	int ret;
+
+	ret = do_command(req, sizeof(req), res, sizeof(res));
+	if (ret)
+		return ret;
+
+	real_speed = (res[5] << 24) | (res[4] << 16) | (res[3] << 8) | res[2];
+	if (real_speed != speed)
+		msg_pwarn("SPI speed set to %d instead of %d\n", real_speed, speed);
+
+	return 0;
+}
+
+static int spi_set_mode(uint8_t mode)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_SET_MODE, 0x00, mode };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int spi_set_cs(uint8_t cs)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_SET_CS, 0x00, cs };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int spi_start_io(uint8_t read_follows, uint32_t write_len)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_START_IO, 0x00,
+			  0x00, 0x00, /* meaning unknown */
+			  read_follows,
+			  (write_len) & 0xff,
+			  (write_len >> 8) & 0xff,
+			  (write_len >> 16) & 0xff,
+			  (write_len >> 24) & 0xff };
+	uint8_t res[2];
+
+	return do_command(req, sizeof(req), res, sizeof(res));
+}
+
+static int spi_tx_end(uint8_t read_follows, uint32_t tx_len)
+{
+	uint8_t req[] = { 0x00, CMD_SPI, CMD_SPI_TX_END, 0x00 };
+	uint8_t res[read_follows ? 10 : 6];
+	int ret;
+	uint32_t count;
+
+	ret = do_command(req, sizeof(req), res, sizeof(res));
+	if (ret != 0)
+		return ret;
+
+	if ((res[1] & 0x80) == 0) {
+		msg_perr("%s: response missing a write count\n", __func__);
+		return -1;
+	}
+
+	count = res[2] | (res[3] << 8) | (res[4] << 16) | res[5] << 24;
+	if (count != tx_len) {
+		msg_perr("%s: wrote only %d bytes instead of %d\n", __func__, count, tx_len);
+		return -1;
+	}
+
+	if (read_follows) {
+		if ((res[1] & 0x40) == 0) {
+			msg_perr("%s: response missing a read count\n", __func__);
+			return -1;
+		}
+
+		count = res[6] | (res[7] << 8) | (res[8] << 16) | res[9] << 24;
+		if (count != tx_len) {
+			msg_perr("%s: read only %d bytes instead of %d\n", __func__, count, tx_len);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int digilent_spi_send_command(struct flashctx *flash, unsigned int writecnt, unsigned int readcnt,
+				     const unsigned char *writearr, unsigned char *readarr)
+{
+	int ret;
+	int len = writecnt + readcnt;
+	int tx_len = 0;
+	uint8_t buf[len];
+	uint8_t read_follows = readcnt > 0 ? 1 : 0;
+
+	memcpy(buf, writearr, writecnt);
+	memset(buf + writecnt, 0xff, readcnt);
+
+	ret = spi_set_cs(0);
+	if (ret != 0)
+		return ret;
+
+	ret = spi_start_io(read_follows, writecnt);
+	if (ret != 0)
+		return ret;
+
+	ret = libusb_bulk_transfer(handle, DATA_WRITE_EP, buf, len, &tx_len, USB_TIMEOUT);
+	if (ret != 0) {
+		msg_perr("%s: failed to write data: '%s'\n", __func__, libusb_error_name(ret));
+		return -1;
+	}
+	if (tx_len != len) {
+		msg_perr("%s: short write\n", __func__);
+		return -1;
+	}
+
+	if (read_follows) {
+		ret = libusb_bulk_transfer(handle, DATA_READ_EP, buf, len, &tx_len, USB_TIMEOUT);
+		if (ret != 0) {
+			msg_perr("%s: failed to read data: '%s'\n", __func__, libusb_error_name(ret));
+			return -1;
+		}
+		if (tx_len != len) {
+			msg_perr("%s: short read\n", __func__);
+			return -1;
+		}
+	}
+
+	ret = spi_tx_end(read_follows, len);
+	if (ret != 0)
+		return ret;
+
+	ret = spi_set_cs(1);
+	if (ret != 0)
+		return ret;
+
+	memcpy(readarr, &buf[writecnt], readcnt);
+
+	return 0;
+}
+
+static const struct spi_master spi_master_digilent_spi = {
+	.type		= SPI_CONTROLLER_DIGILENT_SPI,
+	.features	= SPI_MASTER_4BA,
+	.max_data_read	= 252,
+	.max_data_write	= 252,
+	.command	= digilent_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 digilent_spi_shutdown(void *data)
+{
+	if (reset_board)
+		gpio_set_dir(0);
+
+	libusb_close(handle);
+	handle = NULL;
+
+	return 0;
+}
+
+static bool default_reset(void)
+{
+	char board[17];
+
+	libusb_control_transfer(handle, LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR,
+	                        GET_BOARD_TYPE, 0, 0,
+	                        (unsigned char *)board, sizeof(board) - 1, USB_TIMEOUT);
+	board[sizeof(board) -1] = '\0';
+
+	if (strcmp(board, "iCE40") == 0)
+		return true;
+
+	msg_pwarn("%s: unknown board '%s' not attempting a reset. "
+	          "Override with '-p digilent_spi=reset=1'.\n", __func__, board);
+	return false;
+}
+
+struct digilent_spispeeds {
+        const char *const name;
+        const int speed;
+};
+
+static const struct digilent_spispeeds spispeeds[] = {
+	{ "4M",		4000000 },
+	{ "2M",		2000000 },
+	{ "1M",		1000000 },
+	{ "500k",	500000 },
+	{ "250k",	250000 },
+	{ "125k",	125000 },
+	{ "62.5k",	62500 },
+	{ NULL,		0 },
+};
+
+int digilent_spi_init(void)
+{
+	char *p;
+	uint32_t speed_hz = spispeeds[0].speed;
+	int i;
+
+	if (handle != NULL) {
+		msg_cerr("%s: handle already set! Please report a bug at flashrom@flashrom.org\n", __func__);
+		return -1;
+	}
+
+	int32_t ret = libusb_init(NULL);
+	if (ret < 0) {
+		msg_perr("%s: couldn't initialize libusb!\n", __func__);
+		return -1;
+	}
+
+	libusb_set_debug(NULL, 3);
+
+	uint16_t vid = devs_digilent_spi[0].vendor_id;
+	uint16_t pid = devs_digilent_spi[0].device_id;
+	handle = libusb_open_device_with_vid_pid(NULL, vid, pid);
+	if (handle == NULL) {
+		msg_perr("%s: couldn't open device %04x:%04x.\n", __func__, vid, pid);
+		return -1;
+	}
+
+	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 close_handle;
+	}
+
+	p = extract_programmer_param("spispeed");
+	if (p) {
+		for (i = 0; spispeeds[i].name; ++i) {
+			if (!strcasecmp(spispeeds[i].name, p)) {
+				speed_hz = spispeeds[i].speed;
+				break;
+			}
+		}
+		if (!spispeeds[i].name) {
+			msg_perr("Error: Invalid spispeed value: '%s'.\n", p);
+			free(p);
+			goto close_handle;
+		}
+		free(p);
+	}
+
+	p = extract_programmer_param("reset");
+	if (p && strlen(p))
+		reset_board = (p[0] == '1');
+	else
+		reset_board = default_reset();
+	free(p);
+
+	if (reset_board) {
+		if (gpio_open() != 0)
+			goto close_handle;
+		if (gpio_set_dir(1) != 0)
+			goto close_handle;
+		if (gpio_set_value(0) != 0)
+			goto close_handle;
+	}
+
+	if (spi_open() != 0)
+		goto close_handle;
+	if (spi_set_speed(speed_hz) != 0)
+		goto close_handle;
+	if (spi_set_mode(0x00) != 0)
+		goto close_handle;
+
+	register_shutdown(digilent_spi_shutdown, NULL);
+	register_spi_master(&spi_master_digilent_spi);
+
+	return 0;
+
+close_handle:
+	libusb_close(handle);
+	handle = NULL;
+	return -1;
+}