sf: add driver for SST flashes

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

drivers/mtd/spi/Makefile

@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi_flash.a
 COBJS-$(CONFIG_SPI_FLASH)	+= spi_flash.o
 COBJS-$(CONFIG_SPI_FLASH_ATMEL)	+= atmel.o
 COBJS-$(CONFIG_SPI_FLASH_SPANSION)	+= spansion.o
+COBJS-$(CONFIG_SPI_FLASH_SST)	+= sst.o
 COBJS-$(CONFIG_SPI_FLASH_STMICRO)	+= stmicro.o
 
 COBJS	:= $(COBJS-y)

drivers/mtd/spi/spi_flash.c

@@ -138,6 +138,11 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 	case 0x20:
 		flash = spi_flash_probe_stmicro(spi, idcode);
 		break;
+#endif
+#ifdef CONFIG_SPI_FLASH_SST
+	case 0xBF:
+		flash = spi_flash_probe_sst(spi, idcode);
+		break;
 #endif
 	default:
 		debug("SF: Unsupported manufacturer %02X\n", idcode[0]);

drivers/mtd/spi/spi_flash_internal.h

@@ -43,4 +43,5 @@ int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
 /* Manufacturer-specific probe functions */
 struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode);
 struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode);
+struct spi_flash *spi_flash_probe_sst(struct spi_slave *spi, u8 *idcode);
 struct spi_flash *spi_flash_probe_stmicro(struct spi_slave *spi, u8 *idcode);

drivers/mtd/spi/sst.c

@@ -0,0 +1,358 @@
+/*
+ * Driver for SST serial flashes
+ *
+ * (C) Copyright 2000-2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ * Copyright 2008, Network Appliance Inc.
+ * Jason McMullan <mcmullan@netapp.com>
+ * Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
+ * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
+ * Copyright (c) 2008-2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi_flash.h>
+
+#include "spi_flash_internal.h"
+
+#define CMD_SST_WREN		0x06	/* Write Enable */
+#define CMD_SST_WRDI		0x04	/* Write Disable */
+#define CMD_SST_RDSR		0x05	/* Read Status Register */
+#define CMD_SST_WRSR		0x01	/* Write Status Register */
+#define CMD_SST_READ		0x03	/* Read Data Bytes */
+#define CMD_SST_FAST_READ	0x0b	/* Read Data Bytes at Higher Speed */
+#define CMD_SST_BP		0x02	/* Byte Program */
+#define CMD_SST_AAI_WP		0xAD	/* Auto Address Increment Word Program */
+#define CMD_SST_SE		0x20	/* Sector Erase */
+
+#define SST_SR_WIP		(1 << 0)	/* Write-in-Progress */
+#define SST_SR_WEL		(1 << 1)	/* Write enable */
+#define SST_SR_BP0		(1 << 2)	/* Block Protection 0 */
+#define SST_SR_BP1		(1 << 3)	/* Block Protection 1 */
+#define SST_SR_BP2		(1 << 4)	/* Block Protection 2 */
+#define SST_SR_AAI		(1 << 6)	/* Addressing mode */
+#define SST_SR_BPL		(1 << 7)	/* BP bits lock */
+
+struct sst_spi_flash_params {
+	u8 idcode1;
+	u16 nr_sectors;
+	const char *name;
+};
+
+struct sst_spi_flash {
+	struct spi_flash flash;
+	const struct sst_spi_flash_params *params;
+};
+
+static inline struct sst_spi_flash *to_sst_spi_flash(struct spi_flash *flash)
+{
+	return container_of(flash, struct sst_spi_flash, flash);
+}
+
+#define SST_SECTOR_SIZE (4 * 1024)
+static const struct sst_spi_flash_params sst_spi_flash_table[] = {
+	{
+		.idcode1 = 0x01,
+		.nr_sectors = 128,
+		.name = "SST25WF512",
+	},{
+		.idcode1 = 0x02,
+		.nr_sectors = 256,
+		.name = "SST25WF010",
+	},{
+		.idcode1 = 0x03,
+		.nr_sectors = 512,
+		.name = "SST25WF020",
+	},{
+		.idcode1 = 0x04,
+		.nr_sectors = 1024,
+		.name = "SST25WF040",
+	},
+};
+
+static int
+sst_wait_ready(struct spi_flash *flash, unsigned long timeout)
+{
+	struct spi_slave *spi = flash->spi;
+	unsigned long timebase;
+	int ret;
+	u8 byte = CMD_SST_RDSR;
+
+	ret = spi_xfer(spi, sizeof(byte) * 8, &byte, NULL, SPI_XFER_BEGIN);
+	if (ret) {
+		debug("SF: Failed to send command %02x: %d\n", byte, ret);
+		return ret;
+	}
+
+	timebase = get_timer(0);
+	do {
+		ret = spi_xfer(spi, sizeof(byte) * 8, NULL, &byte, 0);
+		if (ret)
+			break;
+
+		if ((byte & SST_SR_WIP) == 0)
+			break;
+
+	} while (get_timer(timebase) < timeout);
+
+	spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
+
+	if (!ret && (byte & SST_SR_WIP) != 0)
+		ret = -1;
+
+	if (ret)
+		debug("SF: sst wait for ready timed out\n");
+	return ret;
+}
+
+static int
+sst_enable_writing(struct spi_flash *flash)
+{
+	int ret = spi_flash_cmd(flash->spi, CMD_SST_WREN, NULL, 0);
+	if (ret)
+		debug("SF: Enabling Write failed\n");
+	return ret;
+}
+
+static int
+sst_disable_writing(struct spi_flash *flash)
+{
+	int ret = spi_flash_cmd(flash->spi, CMD_SST_WRDI, NULL, 0);
+	if (ret)
+		debug("SF: Disabling Write failed\n");
+	return ret;
+}
+
+static int
+sst_read_fast(struct spi_flash *flash, u32 offset, size_t len, void *buf)
+{
+	u8 cmd[5] = {
+		CMD_READ_ARRAY_FAST,
+		offset >> 16,
+		offset >> 8,
+		offset,
+		0x00,
+	};
+	return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
+}
+
+static int
+sst_byte_write(struct spi_flash *flash, u32 offset, const void *buf)
+{
+	int ret;
+	u8 cmd[4] = {
+		CMD_SST_BP,
+		offset >> 16,
+		offset >> 8,
+		offset,
+	};
+
+	debug("BP[%02x]: 0x%p => cmd = { 0x%02x 0x%06x }\n",
+		spi_w8r8(flash->spi, CMD_SST_RDSR), buf, cmd[0], offset);
+
+	ret = sst_enable_writing(flash);
+	if (ret)
+		return ret;
+
+	ret = spi_flash_cmd_write(flash->spi, cmd, sizeof(cmd), buf, 1);
+	if (ret)
+		return ret;
+
+	return sst_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+}
+
+static int
+sst_write(struct spi_flash *flash, u32 offset, size_t len, const void *buf)
+{
+	size_t actual, cmd_len;
+	int ret;
+	u8 cmd[4];
+
+	ret = spi_claim_bus(flash->spi);
+	if (ret) {
+		debug("SF: Unable to claim SPI bus\n");
+		return ret;
+	}
+
+	/* If the data is not word aligned, write out leading single byte */
+	actual = offset % 2;
+	if (actual) {
+		ret = sst_byte_write(flash, offset, buf);
+		if (ret)
+			goto done;
+	}
+	offset += actual;
+
+	ret = sst_enable_writing(flash);
+	if (ret)
+		goto done;
+
+	cmd_len = 4;
+	cmd[0] = CMD_SST_AAI_WP;
+	cmd[1] = offset >> 16;
+	cmd[2] = offset >> 8;
+	cmd[3] = offset;
+
+	for (; actual < len - 1; actual += 2) {
+		debug("WP[%02x]: 0x%p => cmd = { 0x%02x 0x%06x }\n",
+		     spi_w8r8(flash->spi, CMD_SST_RDSR), buf + actual, cmd[0],
+		     offset);
+
+		ret = spi_flash_cmd_write(flash->spi, cmd, cmd_len,
+		                          buf + actual, 2);
+		if (ret) {
+			debug("SF: sst word program failed\n");
+			break;
+		}
+
+		ret = sst_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+		if (ret)
+			break;
+
+		cmd_len = 1;
+		offset += 2;
+	}
+
+	if (!ret)
+		ret = sst_disable_writing(flash);
+
+	/* If there is a single trailing byte, write it out */
+	if (!ret && actual != len)
+		ret = sst_byte_write(flash, offset, buf + actual);
+
+ done:
+	debug("SF: sst: program %s %zu bytes @ 0x%zx\n",
+	      ret ? "failure" : "success", len, offset - actual);
+
+	spi_release_bus(flash->spi);
+	return ret;
+}
+
+int
+sst_erase(struct spi_flash *flash, u32 offset, size_t len)
+{
+	unsigned long sector_size;
+	u32 start, end;
+	int ret;
+	u8 cmd[4];
+
+	/*
+	 * This function currently uses sector erase only.
+	 * Probably speed things up by using bulk erase
+	 * when possible.
+	 */
+
+	sector_size = SST_SECTOR_SIZE;
+
+	if (offset % sector_size) {
+		debug("SF: Erase offset not multiple of sector size\n");
+		return -1;
+	}
+
+	ret = spi_claim_bus(flash->spi);
+	if (ret) {
+		debug("SF: Unable to claim SPI bus\n");
+		return ret;
+	}
+
+	cmd[0] = CMD_SST_SE;
+	cmd[3] = 0;
+	start = offset;
+	end = start + len;
+
+	ret = 0;
+	while (offset < end) {
+		cmd[1] = offset >> 16;
+		cmd[2] = offset >> 8;
+		offset += sector_size;
+
+		debug("SF: erase %2x %2x %2x %2x (%x)\n", cmd[0], cmd[1],
+		      cmd[2], cmd[3], offset);
+
+		ret = sst_enable_writing(flash);
+		if (ret)
+			break;
+
+		ret = spi_flash_cmd_write(flash->spi, cmd, sizeof(cmd), NULL, 0);
+		if (ret) {
+			debug("SF: sst page erase failed\n");
+			break;
+		}
+
+		ret = sst_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
+		if (ret)
+			break;
+	}
+
+	debug("SF: sst: Successfully erased %lu bytes @ 0x%x\n",
+	      len * sector_size, start);
+
+	spi_release_bus(flash->spi);
+	return ret;
+}
+
+static int
+sst_unlock(struct spi_flash *flash)
+{
+	int ret;
+	u8 cmd, status;
+
+	ret = sst_enable_writing(flash);
+	if (ret)
+		return ret;
+
+	cmd = CMD_SST_WRSR;
+	status = 0;
+	ret = spi_flash_cmd_write(flash->spi, &cmd, 1, &status, 1);
+	if (ret)
+		debug("SF: Unable to set status byte\n");
+
+	debug("SF: sst: status = %x\n", spi_w8r8(flash->spi, CMD_SST_RDSR));
+
+	return ret;
+}
+
+struct spi_flash *
+spi_flash_probe_sst(struct spi_slave *spi, u8 *idcode)
+{
+	const struct sst_spi_flash_params *params;
+	struct sst_spi_flash *stm;
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(sst_spi_flash_table); ++i) {
+		params = &sst_spi_flash_table[i];
+		if (params->idcode1 == idcode[2])
+			break;
+	}
+
+	if (i == ARRAY_SIZE(sst_spi_flash_table)) {
+		debug("SF: Unsupported SST ID %02x\n", idcode[1]);
+		return NULL;
+	}
+
+	stm = malloc(sizeof(*stm));
+	if (!stm) {
+		debug("SF: Failed to allocate memory\n");
+		return NULL;
+	}
+
+	stm->params = params;
+	stm->flash.spi = spi;
+	stm->flash.name = params->name;
+
+	stm->flash.write = sst_write;
+	stm->flash.erase = sst_erase;
+	stm->flash.read = sst_read_fast;
+	stm->flash.size = SST_SECTOR_SIZE * params->nr_sectors;
+
+	debug("SF: Detected %s with page size %u, total %u bytes\n",
+	      params->name, SST_SECTOR_SIZE, stm->flash.size);
+
+	/* Flash powers up read-only, so clear BP# bits */
+	sst_unlock(&stm->flash);
+
+	return &stm->flash;
+}