[PATCH] spi: mtd dataflash driver (1d6432fe) · Commits · 戴 / test

drivers/mtd/devices/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -47,6 +47,14 @@ config MTD_MS02NV
		accelerator. Say Y here if you have a DECstation 5000/2x0 or a
		DECsystem 5900 equipped with such a module.

		config MTD_DATAFLASH
		tristate "Support for AT45xxx DataFlash"
		depends on MTD && SPI_MASTER && EXPERIMENTAL
		help
		This enables access to AT45xxx DataFlash chips, using SPI.
		Sometimes DataFlash chips are packaged inside MMC-format
		cards; at this writing, the MMC stack won't handle those.

		config MTD_SLRAM
		tristate "Uncached system RAM"
		depends on MTD

drivers/mtd/devices/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -23,3 +23,4 @@ obj-$(CONFIG_MTD_MTDRAM) += mtdram.o
		obj-$(CONFIG_MTD_LART) += lart.o
		obj-$(CONFIG_MTD_BLKMTD) += blkmtd.o
		obj-$(CONFIG_MTD_BLOCK2MTD) += block2mtd.o
		obj-$(CONFIG_MTD_DATAFLASH) += mtd_dataflash.o

drivers/mtd/devices/mtd_dataflash.c

0 → 100644

+623 −0

Original line number	Diff line number	Diff line
		/*
		* Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
		*
		* Largely derived from at91_dataflash.c:
		* Copyright (C) 2003-2005 SAN People (Pty) Ltd
		*
		* 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.
		*/
		#include <linux/config.h>
		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/slab.h>
		#include <linux/delay.h>
		#include <linux/device.h>
		#include <linux/spi/spi.h>
		#include <linux/spi/flash.h>

		#include <linux/mtd/mtd.h>
		#include <linux/mtd/partitions.h>


		/*
		* DataFlash is a kind of SPI flash. Most AT45 chips have two buffers in
		* each chip, which may be used for double buffered I/O; but this driver
		* doesn't (yet) use these for any kind of i/o overlap or prefetching.
		*
		* Sometimes DataFlash is packaged in MMC-format cards, although the
		* MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash
		* protocols during enumeration.
		*/

		#define CONFIG_DATAFLASH_WRITE_VERIFY

		/* reads can bypass the buffers */
		#define OP_READ_CONTINUOUS 0xE8
		#define OP_READ_PAGE 0xD2

		/* group B requests can run even while status reports "busy" */
		#define OP_READ_STATUS 0xD7 /* group B */

		/* move data between host and buffer */
		#define OP_READ_BUFFER1 0xD4 /* group B */
		#define OP_READ_BUFFER2 0xD6 /* group B */
		#define OP_WRITE_BUFFER1 0x84 /* group B */
		#define OP_WRITE_BUFFER2 0x87 /* group B */

		/* erasing flash */
		#define OP_ERASE_PAGE 0x81
		#define OP_ERASE_BLOCK 0x50

		/* move data between buffer and flash */
		#define OP_TRANSFER_BUF1 0x53
		#define OP_TRANSFER_BUF2 0x55
		#define OP_MREAD_BUFFER1 0xD4
		#define OP_MREAD_BUFFER2 0xD6
		#define OP_MWERASE_BUFFER1 0x83
		#define OP_MWERASE_BUFFER2 0x86
		#define OP_MWRITE_BUFFER1 0x88 /* sector must be pre-erased */
		#define OP_MWRITE_BUFFER2 0x89 /* sector must be pre-erased */

		/* write to buffer, then write-erase to flash */
		#define OP_PROGRAM_VIA_BUF1 0x82
		#define OP_PROGRAM_VIA_BUF2 0x85

		/* compare buffer to flash */
		#define OP_COMPARE_BUF1 0x60
		#define OP_COMPARE_BUF2 0x61

		/* read flash to buffer, then write-erase to flash */
		#define OP_REWRITE_VIA_BUF1 0x58
		#define OP_REWRITE_VIA_BUF2 0x59

		/* newer chips report JEDEC manufacturer and device IDs; chip
		* serial number and OTP bits; and per-sector writeprotect.
		*/
		#define OP_READ_ID 0x9F
		#define OP_READ_SECURITY 0x77
		#define OP_WRITE_SECURITY 0x9A /* OTP bits */


		struct dataflash {
		u8 command[4];
		char name[24];

		unsigned partitioned:1;

		unsigned short page_offset; /* offset in flash address */
		unsigned int page_size; /* of bytes per page */

		struct semaphore lock;
		struct spi_device *spi;

		struct mtd_info mtd;
		};

		#ifdef CONFIG_MTD_PARTITIONS
		#define mtd_has_partitions() (1)
		#else
		#define mtd_has_partitions() (0)
		#endif

		/* ......................................................................... */

		/*
		* Return the status of the DataFlash device.
		*/
		static inline int dataflash_status(struct spi_device *spi)
		{
		/* NOTE: at45db321c over 25 MHz wants to write
		* a dummy byte after the opcode...
		*/
		return spi_w8r8(spi, OP_READ_STATUS);
		}

		/*
		* Poll the DataFlash device until it is READY.
		* This usually takes 5-20 msec or so; more for sector erase.
		*/
		static int dataflash_waitready(struct spi_device *spi)
		{
		int status;

		for (;;) {
		status = dataflash_status(spi);
		if (status < 0) {
		DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
		spi->dev.bus_id, status);
		status = 0;
		}

		if (status & (1 << 7)) /* RDY/nBSY */
		return status;

		msleep(3);
		}
		}

		/* ......................................................................... */

		/*
		* Erase pages of flash.
		*/
		static int dataflash_erase(struct mtd_info mtd, struct erase_info instr)
		{
		struct dataflash priv = (struct dataflash )mtd->priv;
		struct spi_device *spi = priv->spi;
		struct spi_transfer x[1] = { { .tx_dma = 0, }, };
		struct spi_message msg;
		unsigned blocksize = priv->page_size << 3;
		u8 *command;

		DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n",
		spi->dev.bus_id,
		instr->addr, instr->len);

		/* Sanity checks */
		if ((instr->addr + instr->len) > mtd->size
		\|\| (instr->len % priv->page_size) != 0
		\|\| (instr->addr % priv->page_size) != 0)
		return -EINVAL;

		x[0].tx_buf = command = priv->command;
		x[0].len = 4;
		msg.transfers = x;
		msg.n_transfer = 1;

		down(&priv->lock);
		while (instr->len > 0) {
		unsigned int pageaddr;
		int status;
		int do_block;

		/* Calculate flash page address; use block erase (for speed) if
		* we're at a block boundary and need to erase the whole block.
		*/
		pageaddr = instr->addr / priv->page_size;
		do_block = (pageaddr & 0x7) == 0 && instr->len <= blocksize;
		pageaddr = pageaddr << priv->page_offset;

		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
		command[1] = (u8)(pageaddr >> 16);
		command[2] = (u8)(pageaddr >> 8);
		command[3] = 0;

		DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
		do_block ? "block" : "page",
		command[0], command[1], command[2], command[3],
		pageaddr);

		status = spi_sync(spi, &msg);
		(void) dataflash_waitready(spi);

		if (status < 0) {
		printk(KERN_ERR "%s: erase %x, err %d\n",
		spi->dev.bus_id, pageaddr, status);
		/* REVISIT: can retry instr->retries times; or
		* giveup and instr->fail_addr = instr->addr;
		*/
		continue;
		}

		if (do_block) {
		instr->addr += blocksize;
		instr->len -= blocksize;
		} else {
		instr->addr += priv->page_size;
		instr->len -= priv->page_size;
		}
		}
		up(&priv->lock);

		/* Inform MTD subsystem that erase is complete */
		instr->state = MTD_ERASE_DONE;
		mtd_erase_callback(instr);

		return 0;
		}

		/*
		* Read from the DataFlash device.
		* from : Start offset in flash device
		* len : Amount to read
		* retlen : About of data actually read
		* buf : Buffer containing the data
		*/
		static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t retlen, u_char buf)
		{
		struct dataflash priv = (struct dataflash )mtd->priv;
		struct spi_transfer x[2] = { { .tx_dma = 0, }, };
		struct spi_message msg;
		unsigned int addr;
		u8 *command;
		int status;

		DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
		priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len));

		*retlen = 0;

		/* Sanity checks */
		if (!len)
		return 0;
		if (from + len > mtd->size)
		return -EINVAL;

		/* Calculate flash page/byte address */
		addr = (((unsigned)from / priv->page_size) << priv->page_offset)
		+ ((unsigned)from % priv->page_size);

		command = priv->command;

		DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
		command[0], command[1], command[2], command[3]);

		x[0].tx_buf = command;
		x[0].len = 8;
		x[1].rx_buf = buf;
		x[1].len = len;
		msg.transfers = x;
		msg.n_transfer = 2;

		down(&priv->lock);

		/* Continuous read, max clock = f(car) which may be less than
		* the peak rate available. Some chips support commands with
		* fewer "don't care" bytes. Both buffers stay unchanged.
		*/
		command[0] = OP_READ_CONTINUOUS;
		command[1] = (u8)(addr >> 16);
		command[2] = (u8)(addr >> 8);
		command[3] = (u8)(addr >> 0);
		/* plus 4 "don't care" bytes */

		status = spi_sync(priv->spi, &msg);
		up(&priv->lock);

		if (status >= 0) {
		*retlen = msg.actual_length - 8;
		status = 0;
		} else
		DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
		priv->spi->dev.bus_id,
		(unsigned)from, (unsigned)(from + len),
		status);
		return status;
		}

		/*
		* Write to the DataFlash device.
		* to : Start offset in flash device
		* len : Amount to write
		* retlen : Amount of data actually written
		* buf : Buffer containing the data
		*/
		static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t * retlen, const u_char * buf)
		{
		struct dataflash priv = (struct dataflash )mtd->priv;
		struct spi_device *spi = priv->spi;
		struct spi_transfer x[2] = { { .tx_dma = 0, }, };
		struct spi_message msg;
		unsigned int pageaddr, addr, offset, writelen;
		size_t remaining = len;
		u_char writebuf = (u_char ) buf;
		int status = -EINVAL;
		u8 *command;

		DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
		spi->dev.bus_id, (unsigned)to, (unsigned)(to + len));

		*retlen = 0;

		/* Sanity checks */
		if (!len)
		return 0;
		if ((to + len) > mtd->size)
		return -EINVAL;

		x[0].tx_buf = command = priv->command;
		x[0].len = 4;
		msg.transfers = x;

		pageaddr = ((unsigned)to / priv->page_size);
		offset = ((unsigned)to % priv->page_size);
		if (offset + len > priv->page_size)
		writelen = priv->page_size - offset;
		else
		writelen = len;

		down(&priv->lock);
		while (remaining > 0) {
		DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
		pageaddr, offset, writelen);

		/* REVISIT:
		* (a) each page in a sector must be rewritten at least
		* once every 10K sibling erase/program operations.
		* (b) for pages that are already erased, we could
		* use WRITE+MWRITE not PROGRAM for ~30% speedup.
		* (c) WRITE to buffer could be done while waiting for
		* a previous MWRITE/MWERASE to complete ...
		* (d) error handling here seems to be mostly missing.
		*
		* Two persistent bits per page, plus a per-sector counter,
		* could support (a) and (b) ... we might consider using
		* the second half of sector zero, which is just one block,
		* to track that state. (On AT91, that sector should also
		* support boot-from-DataFlash.)
		*/

		addr = pageaddr << priv->page_offset;

		/* (1) Maybe transfer partial page to Buffer1 */
		if (writelen != priv->page_size) {
		command[0] = OP_TRANSFER_BUF1;
		command[1] = (addr & 0x00FF0000) >> 16;
		command[2] = (addr & 0x0000FF00) >> 8;
		command[3] = 0;

		DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
		command[0], command[1], command[2], command[3]);

		msg.n_transfer = 1;
		status = spi_sync(spi, &msg);
		if (status < 0)
		DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
		spi->dev.bus_id, addr, status);

		(void) dataflash_waitready(priv->spi);
		}

		/* (2) Program full page via Buffer1 */
		addr += offset;
		command[0] = OP_PROGRAM_VIA_BUF1;
		command[1] = (addr & 0x00FF0000) >> 16;
		command[2] = (addr & 0x0000FF00) >> 8;
		command[3] = (addr & 0x000000FF);

		DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
		command[0], command[1], command[2], command[3]);

		x[1].tx_buf = writebuf;
		x[1].len = writelen;
		msg.n_transfer = 2;
		status = spi_sync(spi, &msg);
		if (status < 0)
		DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
		spi->dev.bus_id, addr, writelen, status);

		(void) dataflash_waitready(priv->spi);

		#ifdef CONFIG_DATAFLASH_WRITE_VERIFY

		/* (3) Compare to Buffer1 */
		addr = pageaddr << priv->page_offset;
		command[0] = OP_COMPARE_BUF1;
		command[1] = (addr & 0x00FF0000) >> 16;
		command[2] = (addr & 0x0000FF00) >> 8;
		command[3] = 0;

		DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
		command[0], command[1], command[2], command[3]);

		msg.n_transfer = 1;
		status = spi_sync(spi, &msg);
		if (status < 0)
		DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
		spi->dev.bus_id, addr, status);

		status = dataflash_waitready(priv->spi);

		/* Check result of the compare operation */
		if ((status & (1 << 6)) == 1) {
		printk(KERN_ERR "%s: compare page %u, err %d\n",
		spi->dev.bus_id, pageaddr, status);
		remaining = 0;
		status = -EIO;
		break;
		} else
		status = 0;

		#endif /* CONFIG_DATAFLASH_WRITE_VERIFY */

		remaining = remaining - writelen;
		pageaddr++;
		offset = 0;
		writebuf += writelen;
		*retlen += writelen;

		if (remaining > priv->page_size)
		writelen = priv->page_size;
		else
		writelen = remaining;
		}
		up(&priv->lock);

		return status;
		}

		/* ......................................................................... */

		/*
		* Register DataFlash device with MTD subsystem.
		*/
		static int __devinit
		add_dataflash(struct spi_device spi, char name,
		int nr_pages, int pagesize, int pageoffset)
		{
		struct dataflash *priv;
		struct mtd_info *device;
		struct flash_platform_data *pdata = spi->dev.platform_data;

		priv = (struct dataflash ) kzalloc(sizeof priv, GFP_KERNEL);
		if (!priv)
		return -ENOMEM;

		init_MUTEX(&priv->lock);
		priv->spi = spi;
		priv->page_size = pagesize;
		priv->page_offset = pageoffset;

		/* name must be usable with cmdlinepart */
		sprintf(priv->name, "spi%d.%d-%s",
		spi->master->bus_num, spi->chip_select,
		name);

		device = &priv->mtd;
		device->name = (pdata && pdata->name) ? pdata->name : priv->name;
		device->size = nr_pages * pagesize;
		device->erasesize = pagesize;
		device->owner = THIS_MODULE;
		device->type = MTD_DATAFLASH;
		device->flags = MTD_CAP_NORFLASH;
		device->erase = dataflash_erase;
		device->read = dataflash_read;
		device->write = dataflash_write;
		device->priv = priv;

		dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024);
		dev_set_drvdata(&spi->dev, priv);

		if (mtd_has_partitions()) {
		struct mtd_partition *parts;
		int nr_parts = 0;

		#ifdef CONFIG_MTD_CMDLINE_PARTS
		static const char *part_probes[] = { "cmdlinepart", NULL, };

		nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0);
		#endif

		if (nr_parts <= 0 && pdata && pdata->parts) {
		parts = pdata->parts;
		nr_parts = pdata->nr_parts;
		}

		if (nr_parts > 0) {
		priv->partitioned = 1;
		return add_mtd_partitions(device, parts, nr_parts);
		}
		} else if (pdata->nr_parts)
		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
		pdata->nr_parts, device->name);

		return add_mtd_device(device) == 1 ? -ENODEV : 0;
		}

		/*
		* Detect and initialize DataFlash device:
		*
		* Device Density ID code #Pages PageSize Offset
		* AT45DB011B 1Mbit (128K) xx0011xx (0x0c) 512 264 9
		* AT45DB021B 2Mbit (256K) xx0101xx (0x14) 1025 264 9
		* AT45DB041B 4Mbit (512K) xx0111xx (0x1c) 2048 264 9
		* AT45DB081B 8Mbit (1M) xx1001xx (0x24) 4096 264 9
		* AT45DB0161B 16Mbit (2M) xx1011xx (0x2c) 4096 528 10
		* AT45DB0321B 32Mbit (4M) xx1101xx (0x34) 8192 528 10
		* AT45DB0642 64Mbit (8M) xx111xxx (0x3c) 8192 1056 11
		* AT45DB1282 128Mbit (16M) xx0100xx (0x10) 16384 1056 11
		*/
		static int __devinit dataflash_probe(struct spi_device *spi)
		{
		int status;

		status = dataflash_status(spi);
		if (status <= 0 \|\| status == 0xff) {
		DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
		spi->dev.bus_id, status);
		if (status == 0xff)
		status = -ENODEV;
		return status;
		}

		/* if there's a device there, assume it's dataflash.
		* board setup should have set spi->max_speed_max to
		* match f(car) for continuous reads, mode 0 or 3.
		*/
		switch (status & 0x3c) {
		case 0x0c: /* 0 0 1 1 x x */
		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
		break;
		case 0x14: /* 0 1 0 1 x x */
		status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9);
		break;
		case 0x1c: /* 0 1 1 1 x x */
		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
		break;
		case 0x24: /* 1 0 0 1 x x */
		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
		break;
		case 0x2c: /* 1 0 1 1 x x */
		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
		break;
		case 0x34: /* 1 1 0 1 x x */
		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
		break;
		case 0x38: /* 1 1 1 x x x */
		case 0x3c:
		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
		break;
		/* obsolete AT45DB1282 not (yet?) supported */
		default:
		DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
		spi->dev.bus_id, status & 0x3c);
		status = -ENODEV;
		}

		if (status < 0)
		DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
		spi->dev.bus_id, status);

		return status;
		}

		static int __devexit dataflash_remove(struct spi_device *spi)
		{
		struct dataflash *flash = dev_get_drvdata(&spi->dev);
		int status;

		DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id);

		if (mtd_has_partitions() && flash->partitioned)
		status = del_mtd_partitions(&flash->mtd);
		else
		status = del_mtd_device(&flash->mtd);
		if (status == 0)
		kfree(flash);
		return status;
		}

		static struct spi_driver dataflash_driver = {
		.driver = {
		.name = "mtd_dataflash",
		.bus = &spi_bus_type,
		.owner = THIS_MODULE,
		},

		.probe = dataflash_probe,
		.remove = __devexit_p(dataflash_remove),

		/* FIXME: investigate suspend and resume... */
		};

		static int __init dataflash_init(void)
		{
		return spi_register_driver(&dataflash_driver);
		}
		module_init(dataflash_init);

		static void __exit dataflash_exit(void)
		{
		spi_unregister_driver(&dataflash_driver);
		}
		module_exit(dataflash_exit);


		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Andrew Victor, David Brownell");
		MODULE_DESCRIPTION("MTD DataFlash driver");

include/linux/spi/flash.h

0 → 100644

+27 −0

Original line number	Diff line number	Diff line
		#ifndef LINUX_SPI_FLASH_H
		#define LINUX_SPI_FLASH_H

		struct mtd_partition;

		/**
		* struct flash_platform_data: board-specific flash data
		* @name: optional flash device name (eg, as used with mtdparts=)
		* @parts: optional array of mtd_partitions for static partitioning
		* @nr_parts: number of mtd_partitions for static partitoning
		*
		* Board init code (in arch/.../mach-xxx/board-yyy.c files) can
		* provide information about SPI flash parts (such as DataFlash) to
		* help set up the device and its appropriate default partitioning.
		*
		* Note that for DataFlash, sizes for pages, blocks, and sectors are
		* rarely powers of two; and partitions should be sector-aligned.
		*/
		struct flash_platform_data {
		char *name;
		struct mtd_partition *parts;
		unsigned int nr_parts;

		/* we'll likely add more ... use JEDEC IDs, etc */
		};

		#endif

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