Add support for the Linux SPI subsystem (spidev)

See http://www.kernel.org/doc/Documentation/spi/spidev for an introduction.

Usage is as follows:

  flashrom -p linux_spi:dev=/dev/spidevX.Y

where X is the bus number, and Y device. It accepts an optional parameter
'speed' which allows to set the SPI clock speed in kHz.

Tested on an Atmel AVR32AP7000 board (NGW100 Network Gateway Kit), see
below, which was used to program a ThinkPad X60, but it should work on every
other Linux system, too.
  
  http://www.atmel.com/dyn/products/tools_card.asp?tool_id=4102)

Corresponding to flashrom svn r1427.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>

1 files changed, 139 insertions, 0 deletions

diff --git a/linux_spi.c b/linux_spi.c
new file mode 100644
index 0000000..fa6ec17
--- /dev/null
+++ b/linux_spi.c
@@ -0,0 +1,139 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2011 Sven Schnelle <svens@stackframe.org>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <linux/spi/spidev.h>
+#include <sys/ioctl.h>
+#include "flash.h"
+#include "chipdrivers.h"
+#include "programmer.h"
+#include "spi.h"
+
+static int fd = -1;
+
+static int linux_spi_shutdown(void *data);
+static int linux_spi_send_command(unsigned int writecnt, unsigned int readcnt,
+			const unsigned char *txbuf, unsigned char *rxbuf);
+static int linux_spi_read(struct flashchip *flash, uint8_t *buf, int start,
+			  int len);
+static int linux_spi_write_256(struct flashchip *flash, uint8_t *buf,
+			       int start, int len);
+
+static const struct spi_programmer spi_programmer_linux = {
+	.type		= SPI_CONTROLLER_LINUX,
+	.max_data_read	= MAX_DATA_UNSPECIFIED, /* TODO? */
+	.max_data_write	= MAX_DATA_UNSPECIFIED, /* TODO? */
+	.command	= linux_spi_send_command,
+	.multicommand	= default_spi_send_multicommand,
+	.read		= linux_spi_read,
+	.write_256	= linux_spi_write_256,
+};
+
+int linux_spi_init(void)
+{
+	char *p, *endp, *dev;
+	int speed = 0;
+
+	dev = extract_programmer_param("dev");
+	if (!dev || !strlen(dev)) {
+		msg_perr("No SPI device given. Use flashrom -p "
+			 "linux_spi:dev=/dev/spidevX.Y\n");
+		return 1;
+	}
+
+	p = extract_programmer_param("speed");
+	if (p && strlen(p)) {
+		speed = strtoul(p, &endp, 10) * 1024;
+		if (p == endp) {
+			msg_perr("%s: invalid clock: %s kHz\n", __func__, p);
+			return 1;
+		}
+	}
+
+	if ((fd = open(dev, O_RDWR)) == -1) {
+		msg_perr("%s: failed to open %s: %s\n", __func__,
+			 dev, strerror(errno));
+		return 1;
+	}
+
+	if (speed > 0 && ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed) == -1) {
+		msg_perr("%s: failed to set speed %dHz: %s\n",
+			 __func__, speed, strerror(errno));
+		close(fd);
+		return 1;
+	}
+
+	if (register_shutdown(linux_spi_shutdown, NULL))
+		return 1;
+
+	register_spi_programmer(&spi_programmer_linux);
+
+	return 0;
+}
+
+static int linux_spi_shutdown(void *data)
+{
+	if (fd != -1) {
+		close(fd);
+		fd = -1;
+	}
+	return 0;
+}
+
+static int linux_spi_send_command(unsigned int writecnt, unsigned int readcnt,
+			const unsigned char *txbuf, unsigned char *rxbuf)
+{
+	struct spi_ioc_transfer msg[2] = {
+		{
+			.tx_buf = (uint64_t)txbuf,
+			.len = writecnt,
+		},
+		{
+			.rx_buf = (uint64_t)rxbuf,
+			.len = readcnt,
+		},
+	};
+
+	if (fd == -1)
+		return -1;
+
+	if (ioctl(fd, SPI_IOC_MESSAGE(2), msg) == -1) {
+		msg_cerr("%s: ioctl: %s\n", __func__, strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+static int linux_spi_read(struct flashchip *flash, uint8_t *buf, int start,
+			  int len)
+{
+	return spi_read_chunked(flash, buf, start, len, getpagesize());
+}
+
+static int linux_spi_write_256(struct flashchip *flash, uint8_t *buf,
+			       int start, int len)
+{
+	return spi_write_chunked(flash, buf, start, len, getpagesize() - 4);
+}