Re: [PATCH 2.6-git 2/3] SPI core refresh: MTD dataflash driver
From: Vitaly Wool
Date: Thu Dec 15 2005 - 05:00:41 EST
Signed-off-by: Dmitry Pervushin <dpervushin@xxxxxxxxx>
Signed-off-by: Vitaly Wool <vwool@xxxxxxxxxxxxx>
drivers/mtd/devices/Kconfig | 8
drivers/mtd/devices/Makefile | 1
drivers/mtd/devices/mtd_dataflash.c | 601 ++++++++++++++++++++++++++++++++++++
include/linux/spi/flash.h | 27 +
4 files changed, 637 insertions(+)
Index: linux-2.6.orig/drivers/mtd/devices/Kconfig
===================================================================
--- linux-2.6.orig.orig/drivers/mtd/devices/Kconfig
+++ linux-2.6.orig/drivers/mtd/devices/Kconfig
@@ -255,5 +255,13 @@ config MTD_DOCPROBE_55AA
LinuxBIOS or if you need to recover a DiskOnChip Millennium on which
you have managed to wipe the first block.
+config MTD_DATAFLASH
+ tristate "Support for AT45xxx DataFlash"
+ depends on MTD && SPI && 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.
+
endmenu
Index: linux-2.6.orig/drivers/mtd/devices/Makefile
===================================================================
--- linux-2.6.orig.orig/drivers/mtd/devices/Makefile
+++ linux-2.6.orig/drivers/mtd/devices/Makefile
@@ -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
Index: linux-2.6.orig/drivers/mtd/devices/mtd_dataflash.c
===================================================================
--- /dev/null
+++ linux-2.6.orig/drivers/mtd/devices/mtd_dataflash.c
@@ -0,0 +1,601 @@
+/*
+ * 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.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. This driver does
+ * not (yet) expect to be hotplugged through MMC or SPI. That's fair,
+ * since the MMC stack can't even use SPI (yet), much less 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 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;
+};
+
+/* ......................................................................... */
+
+/*
+ * 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;
+ u8 *command;
+
+ DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=%x len %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;
+
+ command = priv->command;
+
+ down(&priv->lock);
+ while (instr->len > 0) {
+ unsigned int pageaddr;
+ int status;
+
+ /* Calculate flash page address */
+ // REVISIT: pageaddr == instr->addr, yes???
+ pageaddr = (instr->addr / priv->page_size) << priv->page_offset;
+
+ /* REVISIT block erase is faster, if this page is at a block
+ * boundary and the next eight pages must all be erased ...
+ */
+ command[0] = OP_ERASE_PAGE;
+ command[1] = (u8)(pageaddr >> 16);
+ command[2] = (u8)(pageaddr >> 8);
+ command[3] = 0;
+
+ DEBUG(MTD_DEBUG_LEVEL3, "ERASE: (%x) %x %x %x [%i]\n",
+ command[0], command[1], command[2], command[3],
+ pageaddr);
+
+ status = spi_write (spi, SPI_M_CS | SPI_M_CSREL, command, 4);
+ (void) dataflash_waitready(spi);
+
+ if (status < 0) {
+ printk(KERN_ERR "%s: erase %x, err %d\n",
+ spi->dev.bus_id, pageaddr, status);
+ continue;
+ }
+
+ instr->addr += priv->page_size; /* next page */
+ 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;
+ unsigned int addr;
+ u8 *command;
+ int status = 0;
+ struct spi_msg *msg;
+
+ DEBUG(MTD_DEBUG_LEVEL2, "%s: read %x..%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]);
+
+ 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 */
+
+ msg = spimsg_alloc(priv->spi,
+ SPI_M_RD | SPI_M_CS,
+ command,
+ 8,
+ NULL);
+ if (!msg) {
+ status = -ENOMEM;
+ goto out;
+ }
+ if (!spimsg_chain(msg,
+ SPI_M_RD | SPI_M_CSREL,
+ buf,
+ len,
+ NULL)) {
+ status = -ENOMEM;
+ goto out;
+ }
+ status = spi_transfer(msg, NULL);
+
+ spimsg_free(msg);
+
+ up(&priv->lock);
+
+ if (status >= 0) {
+ *retlen = status;
+ status = 0;
+ } else
+ DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
+ priv->spi->dev.bus_id,
+ (unsigned)from, (unsigned)(from + len),
+ status);
+out:
+ 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;
+ unsigned int pageaddr, addr, offset, writelen;
+ size_t remaining = len;
+ u_char *writebuf = (u_char *) buf;
+ int status = -EINVAL;
+ u8 *command = priv->command;
+ struct spi_msg *msg;
+
+ DEBUG(MTD_DEBUG_LEVEL2, "%s: write %x..%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;
+
+ 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]);
+
+ spi_write (spi, SPI_M_CS | SPI_M_CSREL, command, 4);
+ 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]);
+
+ msg = spimsg_alloc(spi,
+ SPI_M_WR | SPI_M_CS,
+ command,
+ 4,
+ NULL);
+ if (!msg)
+ return -ENOMEM;
+ if (!spimsg_chain(msg,
+ SPI_M_WR | SPI_M_CSREL,
+ writebuf,
+ writelen,
+ NULL))
+ return -ENOMEM;
+
+ status = spi_transfer(msg, NULL);
+ spimsg_free(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]);
+
+ status = spi_write (spi, SPI_M_CS | SPI_M_CSREL, command, 4);
+ 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 __init
+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, "mtd-%s",
+ spi->dev.parent->bus_id); /* mtd-spipnx0 */
+
+ 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);
+
+#ifdef CONFIG_MTD_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)
+ return add_mtd_partitions(device, parts, nr_parts);
+ }
+#endif
+ return add_mtd_device(device);
+}
+
+/*
+ * 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 __init dataflash_probe(struct spi_device *spi)
+{
+ int 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.
+ */
+ status = dataflash_status(spi);
+ if (status > 0 && status != 0xff) {
+ 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, "AT45DB041B",
+ 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:
+ printk(KERN_WARNING "%s: unsupported device (%x)\n",
+ spi->dev.bus_id, status & 0x3c);
+ status = -EINVAL;
+ }
+ }
+
+ return status;
+}
+
+static int __exit dataflash_remove(struct spi_device *spi)
+{
+ // struct dataflash *flash = dev_get_drvdata(dev);
+
+ dev_warn(&spi->dev, "implement remove!\n");
+ return -EINVAL;
+}
+
+static struct spi_driver dataflash_driver = {
+ .probe = dataflash_probe,
+ .remove = __exit_p(dataflash_remove),
+
+ /* FIXME: investigate suspend and resume... */
+};
+
+static int __init dataflash_init(void)
+{
+ return spi_driver_add(&dataflash_driver);
+}
+module_init(dataflash_init);
+
+#if 0
+static void __exit dataflash_exit(void)
+{
+ driver_unregister(&dataflash_driver);
+}
+module_exit(dataflash_exit);
+#endif
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Victor, David Brownell");
+MODULE_DESCRIPTION("MTD DataFlash driver");
Index: linux-2.6.orig/include/linux/spi/flash.h
===================================================================
--- /dev/null
+++ linux-2.6.orig/include/linux/spi/flash.h
@@ -0,0 +1,27 @@
+#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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