sf: new driver for Winbond W25X16/32/64 devices

Signed-off-by: Jason McMullan <jason.mcmullan@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 332 insertions, 0 deletions

diff --git a/drivers/mtd/spi/winbond.c b/drivers/mtd/spi/winbond.c
new file mode 100644
index 0000000..b8da923
--- /dev/null
+++ b/drivers/mtd/spi/winbond.c
@@ -0,0 +1,332 @@
+/*
+ * Copyright 2008, Network Appliance Inc.
+ * Author: Jason McMullan <mcmullan <at> netapp.com>
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi_flash.h>
+
+#include "spi_flash_internal.h"
+
+/* M25Pxx-specific commands */
+#define CMD_W25_WREN		0x06	/* Write Enable */
+#define CMD_W25_WRDI		0x04	/* Write Disable */
+#define CMD_W25_RDSR		0x05	/* Read Status Register */
+#define CMD_W25_WRSR		0x01	/* Write Status Register */
+#define CMD_W25_READ		0x03	/* Read Data Bytes */
+#define CMD_W25_FAST_READ	0x0b	/* Read Data Bytes at Higher Speed */
+#define CMD_W25_PP		0x02	/* Page Program */
+#define CMD_W25_SE		0x20	/* Sector (4K) Erase */
+#define CMD_W25_BE		0xd8	/* Block (64K) Erase */
+#define CMD_W25_CE		0xc7	/* Chip Erase */
+#define CMD_W25_DP		0xb9	/* Deep Power-down */
+#define CMD_W25_RES		0xab	/* Release from DP, and Read Signature */
+
+#define WINBOND_ID_W25X16		0x3015
+#define WINBOND_ID_W25X32		0x3016
+#define WINBOND_ID_W25X64		0x3017
+
+#define WINBOND_SR_WIP		(1 << 0)	/* Write-in-Progress */
+
+struct winbond_spi_flash_params {
+	uint16_t	id;
+	/* Log2 of page size in power-of-two mode */
+	uint8_t		l2_page_size;
+	uint16_t	pages_per_sector;
+	uint16_t	sectors_per_block;
+	uint8_t		nr_blocks;
+	const char	*name;
+};
+
+/* spi_flash needs to be first so upper layers can free() it */
+struct winbond_spi_flash {
+	struct spi_flash flash;
+	const struct winbond_spi_flash_params *params;
+};
+
+static inline struct winbond_spi_flash *
+to_winbond_spi_flash(struct spi_flash *flash)
+{
+	return container_of(flash, struct winbond_spi_flash, flash);
+}
+
+static const struct winbond_spi_flash_params winbond_spi_flash_table[] = {
+	{
+		.id			= WINBOND_ID_W25X16,
+		.l2_page_size		= 8,
+		.pages_per_sector	= 16,
+		.sectors_per_block	= 16,
+		.nr_blocks		= 32,
+		.name			= "W25X16",
+	},
+	{
+		.id			= WINBOND_ID_W25X32,
+		.l2_page_size		= 8,
+		.pages_per_sector	= 16,
+		.sectors_per_block	= 16,
+		.nr_blocks		= 64,
+		.name			= "W25X32",
+	},
+	{
+		.id			= WINBOND_ID_W25X64,
+		.l2_page_size		= 8,
+		.pages_per_sector	= 16,
+		.sectors_per_block	= 16,
+		.nr_blocks		= 128,
+		.name			= "W25X64",
+	},
+};
+
+static int winbond_wait_ready(struct spi_flash *flash, unsigned long timeout)
+{
+	struct spi_slave *spi = flash->spi;
+	unsigned long timebase;
+	int ret;
+	u8 status;
+	u8 cmd[4] = { CMD_W25_RDSR, 0xff, 0xff, 0xff };
+
+	ret = spi_xfer(spi, 32, &cmd[0], NULL, SPI_XFER_BEGIN);
+	if (ret) {
+		debug("SF: Failed to send command %02x: %d\n", cmd, ret);
+		return ret;
+	}
+
+	timebase = get_timer(0);
+	do {
+		ret = spi_xfer(spi, 8, NULL, &status, 0);
+		if (ret) {
+			debug("SF: Failed to get status for cmd %02x: %d\n", cmd, ret);
+			return -1;
+		}
+
+		if ((status & WINBOND_SR_WIP) == 0)
+			break;
+
+	} while (get_timer(timebase) < timeout);
+
+	spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
+
+	if ((status & WINBOND_SR_WIP) == 0)
+		return 0;
+
+	debug("SF: Timed out on command %02x: %d\n", cmd, ret);
+	/* Timed out */
+	return -1;
+}
+
+/*
+ * Assemble the address part of a command for Winbond devices in
+ * non-power-of-two page size mode.
+ */
+static void winbond_build_address(struct winbond_spi_flash *stm, u8 *cmd, u32 offset)
+{
+	unsigned long page_addr;
+	unsigned long byte_addr;
+	unsigned long page_size;
+	unsigned int page_shift;
+
+	/*
+	 * The "extra" space per page is the power-of-two page size
+	 * divided by 32.
+	 */
+	page_shift = stm->params->l2_page_size;
+	page_size = (1 << page_shift);
+	page_addr = offset / page_size;
+	byte_addr = offset % page_size;
+
+	cmd[0] = page_addr >> (16 - page_shift);
+	cmd[1] = page_addr << (page_shift - 8) | (byte_addr >> 8);
+	cmd[2] = byte_addr;
+}
+
+static int winbond_read_fast(struct spi_flash *flash,
+		u32 offset, size_t len, void *buf)
+{
+	struct winbond_spi_flash *stm = to_winbond_spi_flash(flash);
+	u8 cmd[5];
+
+	cmd[0] = CMD_READ_ARRAY_FAST;
+	winbond_build_address(stm, cmd + 1, offset);
+	cmd[4] = 0x00;
+
+	return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
+}
+
+static int winbond_write(struct spi_flash *flash,
+		u32 offset, size_t len, const void *buf)
+{
+	struct winbond_spi_flash *stm = to_winbond_spi_flash(flash);
+	unsigned long page_addr;
+	unsigned long byte_addr;
+	unsigned long page_size;
+	unsigned int page_shift;
+	size_t chunk_len;
+	size_t actual;
+	int ret;
+	u8 cmd[4];
+
+	page_shift = stm->params->l2_page_size;
+	page_size = (1 << page_shift);
+	page_addr = offset / page_size;
+	byte_addr = offset % page_size;
+
+	ret = spi_claim_bus(flash->spi);
+	if (ret) {
+		debug("SF: Unable to claim SPI bus\n");
+		return ret;
+	}
+
+	for (actual = 0; actual < len; actual += chunk_len) {
+		chunk_len = min(len - actual, page_size - byte_addr);
+
+		cmd[0] = CMD_W25_PP;
+		cmd[1] = page_addr >> (16 - page_shift);
+		cmd[2] = page_addr << (page_shift - 8) | (byte_addr >> 8);
+		cmd[3] = byte_addr;
+		debug("PP: 0x%p => cmd = { 0x%02x 0x%02x%02x%02x } chunk_len = %d\n",
+			buf + actual,
+			cmd[0], cmd[1], cmd[2], cmd[3], chunk_len);
+
+		ret = spi_flash_cmd(flash->spi, CMD_W25_WREN, NULL, 0);
+		if (ret < 0) {
+			debug("SF: Enabling Write failed\n");
+			goto out;
+		}
+
+		ret = spi_flash_cmd_write(flash->spi, cmd, 4,
+				buf + actual, chunk_len);
+		if (ret < 0) {
+			debug("SF: Winbond Page Program failed\n");
+			goto out;
+		}
+
+		ret = winbond_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+		if (ret < 0) {
+			debug("SF: Winbond page programming timed out\n");
+			goto out;
+		}
+
+		page_addr++;
+		byte_addr = 0;
+	}
+
+	debug("SF: Winbond: Successfully programmed %u bytes @ 0x%x\n",
+			len, offset);
+	ret = 0;
+
+out:
+	spi_release_bus(flash->spi);
+	return ret;
+}
+
+int winbond_erase(struct spi_flash *flash, u32 offset, size_t len)
+{
+	struct winbond_spi_flash *stm = to_winbond_spi_flash(flash);
+	unsigned long sector_size;
+	unsigned int page_shift;
+	size_t actual;
+	int ret;
+	u8 cmd[4];
+
+	/*
+	 * This function currently uses sector erase only.
+	 * probably speed things up by using bulk erase
+	 * when possible.
+	 */
+
+	page_shift = stm->params->l2_page_size;
+	sector_size = (1 << page_shift) * stm->params->pages_per_sector;
+
+	if (offset % sector_size || len % sector_size) {
+		debug("SF: Erase offset/length not multiple of sector size\n");
+		return -1;
+	}
+
+	len /= sector_size;
+	cmd[0] = CMD_W25_SE;
+
+	ret = spi_claim_bus(flash->spi);
+	if (ret) {
+		debug("SF: Unable to claim SPI bus\n");
+		return ret;
+	}
+
+	for (actual = 0; actual < len; actual++) {
+		winbond_build_address(stm, &cmd[1], offset + actual * sector_size);
+		printf("Erase: %02x %02x %02x %02x\n",
+				cmd[0], cmd[1], cmd[2], cmd[3]);
+
+		ret = spi_flash_cmd(flash->spi, CMD_W25_WREN, NULL, 0);
+		if (ret < 0) {
+			debug("SF: Enabling Write failed\n");
+			goto out;
+		}
+
+		ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
+		if (ret < 0) {
+			debug("SF: Winbond sector erase failed\n");
+			goto out;
+		}
+
+		ret = winbond_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
+		if (ret < 0) {
+			debug("SF: Winbond sector erase timed out\n");
+			goto out;
+		}
+	}
+
+	debug("SF: Winbond: Successfully erased %u bytes @ 0x%x\n",
+			len * sector_size, offset);
+	ret = 0;
+
+out:
+	spi_release_bus(flash->spi);
+	return ret;
+}
+
+struct spi_flash *spi_flash_probe_winbond(struct spi_slave *spi, u8 *idcode)
+{
+	const struct winbond_spi_flash_params *params;
+	unsigned long page_size;
+	struct winbond_spi_flash *stm;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(winbond_spi_flash_table); i++) {
+		params = &winbond_spi_flash_table[i];
+		if (params->id == ((idcode[1] << 8) | idcode[2]))
+			break;
+	}
+
+	if (i == ARRAY_SIZE(winbond_spi_flash_table)) {
+		debug("SF: Unsupported Winbond ID %02x%02x\n",
+				idcode[1], idcode[2]);
+		return NULL;
+	}
+
+	stm = malloc(sizeof(struct winbond_spi_flash));
+	if (!stm) {
+		debug("SF: Failed to allocate memory\n");
+		return NULL;
+	}
+
+	stm->params = params;
+	stm->flash.spi = spi;
+	stm->flash.name = params->name;
+
+	/* Assuming power-of-two page size initially. */
+	page_size = 1 << params->l2_page_size;
+
+	stm->flash.write = winbond_write;
+	stm->flash.erase = winbond_erase;
+	stm->flash.read = winbond_read_fast;
+	stm->flash.size = page_size * params->pages_per_sector
+				* params->sectors_per_block
+				* params->nr_blocks;
+
+	debug("SF: Detected %s with page size %u, total %u bytes\n",
+			params->name, page_size, stm->flash.size);
+
+	return &stm->flash;
+}