This is the bitbanging SPI driver infrastructure

If you want support for a particular piece of hardware, just fill in
a few functions in spi_bitbang_master_table. That's it.
On top of this, the RayeR SPI flasher should be supportable in ~20 LOC.

Tested, trace looks OK.

Corresponding to flashrom svn r736.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>

Makefile

@@ -68,6 +68,9 @@ SVNDEF := -D'FLASHROM_VERSION="$(VERSION)"'
 # Always enable serprog for now. Needs to be disabled on Windows.
 CONFIG_SERPROG ?= yes
 
+# Bitbanging SPI infrastructure is not used yet.
+CONFIG_BITBANG_SPI ?= no
+
 # Always enable 3Com NICs for now.
 CONFIG_NIC3COM ?= yes
 
@@ -94,6 +97,11 @@ LIBS += -lsocket
 endif
 endif
 
+ifeq ($(CONFIG_BITBANG_SPI), yes)
+FEATURE_CFLAGS += -D'BITBANG_SPI_SUPPORT=1'
+OBJS += bitbang_spi.o
+endif
+
 ifeq ($(CONFIG_NIC3COM), yes)
 FEATURE_CFLAGS += -D'NIC3COM_SUPPORT=1'
 OBJS += nic3com.o

bitbang_spi.c

@@ -0,0 +1,161 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2009 Carl-Daniel Hailfinger
+ *
+ * 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 <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include "flash.h"
+#include "spi.h"
+
+/* Length of half a clock period in usecs */
+int bitbang_half_period = 0;
+
+enum spi_bitbang_master spi_bitbang_master = SPI_BITBANG_INVALID;
+
+const struct spi_bitbang_master_entry spi_bitbang_master_table[] = {
+	{}, /* This entry corresponds to SPI_BITBANG_INVALID. */
+};
+
+const int spi_bitbang_master_count = ARRAY_SIZE(spi_bitbang_master_table);
+
+void bitbang_set_cs(int val)
+{
+	spi_bitbang_master_table[spi_bitbang_master].set_cs(val);
+}
+
+void bitbang_set_sck(int val)
+{
+	spi_bitbang_master_table[spi_bitbang_master].set_sck(val);
+}
+
+void bitbang_set_mosi(int val)
+{
+	spi_bitbang_master_table[spi_bitbang_master].set_mosi(val);
+}
+
+int bitbang_get_miso(void)
+{
+	return spi_bitbang_master_table[spi_bitbang_master].get_miso();
+}
+
+int bitbang_spi_init(void)
+{
+	bitbang_set_cs(1);
+	bitbang_set_sck(0);
+	buses_supported = CHIP_BUSTYPE_SPI;
+	return 0;
+}
+
+uint8_t bitbang_spi_readwrite_byte(uint8_t val)
+{
+	uint8_t ret = 0;
+	int i;
+
+	for (i = 7; i >= 0; i--) {
+		bitbang_set_mosi((val >> i) & 1);
+		programmer_delay(bitbang_half_period);
+		bitbang_set_sck(1);
+		ret <<= 1;
+		ret |= bitbang_get_miso();
+		programmer_delay(bitbang_half_period);
+		bitbang_set_sck(0);
+	}
+	return ret;
+}
+
+int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt,
+		const unsigned char *writearr, unsigned char *readarr)
+{
+	static unsigned char *bufout = NULL;
+	static unsigned char *bufin = NULL;
+	static int oldbufsize = 0;
+	int bufsize = max(writecnt + readcnt, 260);
+	int i;
+
+	/* Arbitrary size limitation here. We're only constrained by memory. */
+	if (writecnt > 65536 || readcnt > 65536)
+		return SPI_INVALID_LENGTH;
+
+	if (bufsize != oldbufsize) {
+		bufout = realloc(bufout, bufsize);
+		if (!bufout) {
+			fprintf(stderr, "Out of memory!\n");
+			if (bufin)
+				free(bufin);
+			exit(1);
+		}
+		bufin = realloc(bufout, bufsize);
+		if (!bufin) {
+			fprintf(stderr, "Out of memory!\n");
+			if (bufout)
+				free(bufout);
+			exit(1);
+		}
+	}
+		
+	memcpy(bufout, writearr, writecnt);
+	/* Shift out 0x00 while reading data. */
+	memset(bufout + writecnt, 0x00, readcnt);
+	/* Make sure any non-read data is 0xff. */
+	memset(bufin + writecnt, 0xff, readcnt);
+
+	bitbang_set_cs(0);
+	for (i = 0; i < readcnt + writecnt; i++) {
+		bufin[i] = bitbang_spi_readwrite_byte(bufout[i]);
+	}
+	programmer_delay(bitbang_half_period);
+	bitbang_set_cs(1);
+	programmer_delay(bitbang_half_period);
+	memcpy(readarr, bufin + writecnt, readcnt);
+
+	return 0;
+}
+
+int bitbang_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len)
+{
+	/* Maximum read length is unlimited, use 64k bytes. */
+	return spi_read_chunked(flash, buf, start, len, 64 * 1024);
+}
+
+int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf)
+{
+	int total_size = 1024 * flash->total_size;
+	int i;
+
+	printf_debug("total_size is %d\n", total_size);
+	for (i = 0; i < total_size; i += 256) {
+		int l, r;
+		if (i + 256 <= total_size)
+			l = 256;
+		else
+			l = total_size - i;
+
+		if ((r = spi_nbyte_program(i, &buf[i], l))) {
+			fprintf(stderr, "%s: write fail %d\n", __FUNCTION__, r);
+			return 1;
+		}
+		
+		while (spi_read_status_register() & JEDEC_RDSR_BIT_WIP)
+			/* loop */;
+	}
+
+	return 0;
+}

flash.h

@@ -145,6 +145,21 @@ uint32_t chip_readl(const chipaddr addr);
 void chip_readn(uint8_t *buf, const chipaddr addr, size_t len);
 void programmer_delay(int usecs);
 
+enum spi_bitbang_master {
+	SPI_BITBANG_INVALID /* This must always be the last entry. */
+};
+
+extern const int spi_bitbang_master_count;
+
+extern enum spi_bitbang_master spi_bitbang_master;
+
+struct spi_bitbang_master_entry {
+	void (*set_cs) (int val);
+	void (*set_sck) (int val);
+	void (*set_mosi) (int val);
+	int (*get_miso) (void);
+};
+
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
 enum chipbustype {
@@ -444,6 +459,14 @@ int ft2232_spi_send_command(unsigned int writecnt, unsigned int readcnt, const u
 int ft2232_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len);
 int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf);
 
+/* bitbang_spi.c */
+extern int bitbang_half_period;
+extern const struct spi_bitbang_master_entry spi_bitbang_master_table[];
+int bitbang_spi_init(void);
+int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr);
+int bitbang_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len);
+int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf);
+
 /* flashrom.c */
 extern char *programmer_param;
 extern int verbose;

flashrom.c

@@ -693,6 +693,12 @@ int main(int argc, char *argv[])
 		fprintf(stderr, "SPI programmer table miscompilation!\n");
 		exit(1);
 	}
+#if BITBANG_SPI_SUPPORT == 1
+	if (spi_bitbang_master_count - 1 != SPI_BITBANG_INVALID) {
+		fprintf(stderr, "Bitbanging SPI master table miscompilation!\n");
+		exit(1);
+	}
+#endif
 
 	setbuf(stdout, NULL);
 	while ((opt = getopt_long(argc, argv, optstring,