+++ /dev/null
-/*
- * Atmel DataFlash driver for Atmel AT91RM9200 (Thunder)
- * This is a largely modified version of at91_dataflash.c that
- * supports AT26xxx dataflash chips. The original driver supports
- * AT45xxx chips.
- *
- * Note: This driver was only tested with an AT26F004. It should be
- * easy to make it work with other AT26xxx dataflash devices, though.
- *
- * Copyright (C) 2007 Hans J. Koch <hjk@linutronix.de>
- * original Copyright (C) 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
- * version 2 as published by the Free Software Foundation.
-*/
-
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/mtd/mtd.h>
-
-#include <asm/arch/at91_spi.h>
-
-#define DATAFLASH_MAX_DEVICES 4 /* max number of dataflash devices */
-
-#define MANUFACTURER_ID_ATMEL 0x1F
-
-/* command codes */
-
-#define AT26_OP_READ_STATUS 0x05
-#define AT26_OP_READ_DEV_ID 0x9F
-#define AT26_OP_ERASE_PAGE_4K 0x20
-#define AT26_OP_READ_ARRAY_FAST 0x0B
-#define AT26_OP_SEQUENTIAL_WRITE 0xAF
-#define AT26_OP_WRITE_ENABLE 0x06
-#define AT26_OP_WRITE_DISABLE 0x04
-#define AT26_OP_SECTOR_PROTECT 0x36
-#define AT26_OP_SECTOR_UNPROTECT 0x39
-
-/* status register bits */
-
-#define AT26_STATUS_BUSY 0x01
-#define AT26_STATUS_WRITE_ENABLE 0x02
-
-struct dataflash_local
-{
- int spi; /* SPI chip-select number */
- unsigned int page_size; /* number of bytes per page */
-};
-
-
-/* Detected DataFlash devices */
-static struct mtd_info* mtd_devices[DATAFLASH_MAX_DEVICES];
-static int nr_devices = 0;
-
-/* Allocate a single SPI transfer descriptor. We're assuming that if multiple
- SPI transfers occur at the same time, spi_access_bus() will serialize them.
- If this is not valid, then either (i) each dataflash 'priv' structure
- needs it's own transfer descriptor, (ii) we lock this one, or (iii) use
- another mechanism. */
-static struct spi_transfer_list* spi_transfer_desc;
-
-/*
- * Perform a SPI transfer to access the DataFlash device.
- */
-static int do_spi_transfer(int nr, char* tx, int tx_len, char* rx, int rx_len,
- char* txnext, int txnext_len, char* rxnext, int rxnext_len)
-{
- struct spi_transfer_list* list = spi_transfer_desc;
-
- list->tx[0] = tx; list->txlen[0] = tx_len;
- list->rx[0] = rx; list->rxlen[0] = rx_len;
-
- list->tx[1] = txnext; list->txlen[1] = txnext_len;
- list->rx[1] = rxnext; list->rxlen[1] = rxnext_len;
-
- list->nr_transfers = nr;
- /* Note: spi_transfer() always returns 0, there are no error checks */
- return spi_transfer(list);
-}
-
-/*
- * Return the status of the DataFlash device.
- */
-static unsigned char at91_dataflash26_status(void)
-{
- unsigned char command[2];
-
- command[0] = AT26_OP_READ_STATUS;
- command[1] = 0;
-
- do_spi_transfer(1, command, 2, command, 2, NULL, 0, NULL, 0);
-
- return command[1];
-}
-
-/*
- * Poll the DataFlash device until it is READY.
- */
-static unsigned char at91_dataflash26_waitready(void)
-{
- unsigned char status;
-
- while (1) {
- status = at91_dataflash26_status();
- if (!(status & AT26_STATUS_BUSY))
- return status;
- }
-}
-
-/*
- * Enable/disable write access
- */
- static void at91_dataflash26_write_enable(int enable)
-{
- unsigned char cmd[2];
-
- DEBUG(MTD_DEBUG_LEVEL3, "write_enable: enable=%i\n", enable);
-
- if (enable)
- cmd[0] = AT26_OP_WRITE_ENABLE;
- else
- cmd[0] = AT26_OP_WRITE_DISABLE;
- cmd[1] = 0;
-
- do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);
-}
-
-/*
- * Protect/unprotect sector
- */
- static void at91_dataflash26_sector_protect(loff_t addr, int protect)
-{
- unsigned char cmd[4];
-
- DEBUG(MTD_DEBUG_LEVEL3, "sector_protect: addr=0x%06x prot=%d\n",
- addr, protect);
-
- if (protect)
- cmd[0] = AT26_OP_SECTOR_PROTECT;
- else
- cmd[0] = AT26_OP_SECTOR_UNPROTECT;
- cmd[1] = (addr & 0x00FF0000) >> 16;
- cmd[2] = (addr & 0x0000FF00) >> 8;
- cmd[3] = (addr & 0x000000FF);
-
- do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);
-}
-
-/*
- * Erase blocks of flash.
- */
-static int at91_dataflash26_erase(struct mtd_info *mtd,
- struct erase_info *instr)
-{
- struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
- unsigned char cmd[4];
-
- DEBUG(MTD_DEBUG_LEVEL1, "dataflash_erase: addr=0x%06x len=%i\n",
- instr->addr, instr->len);
-
- /* Sanity checks */
- if (priv->page_size != 4096)
- return -EINVAL; /* Can't handle other sizes at the moment */
-
- if ( ((instr->len % mtd->erasesize) != 0)
- || ((instr->len % priv->page_size) != 0)
- || ((instr->addr % priv->page_size) != 0)
- || ((instr->addr + instr->len) > mtd->size))
- return -EINVAL;
-
- spi_access_bus(priv->spi);
-
- while (instr->len > 0) {
- at91_dataflash26_write_enable(1);
- at91_dataflash26_sector_protect(instr->addr, 0);
- at91_dataflash26_write_enable(1);
- cmd[0] = AT26_OP_ERASE_PAGE_4K;
- cmd[1] = (instr->addr & 0x00FF0000) >> 16;
- cmd[2] = (instr->addr & 0x0000FF00) >> 8;
- cmd[3] = (instr->addr & 0x000000FF);
-
- DEBUG(MTD_DEBUG_LEVEL3, "ERASE: (0x%02x) 0x%02x 0x%02x"
- "0x%02x\n",
- cmd[0], cmd[1], cmd[2], cmd[3]);
-
- do_spi_transfer(1, cmd, 4, cmd, 4, NULL, 0, NULL, 0);
- at91_dataflash26_waitready();
-
- instr->addr += priv->page_size; /* next page */
- instr->len -= priv->page_size;
- }
-
- at91_dataflash26_write_enable(0);
- spi_release_bus(priv->spi);
-
- /* Inform MTD subsystem that erase is complete */
- instr->state = MTD_ERASE_DONE;
- if (instr->callback)
- instr->callback(instr);
-
- return 0;
-}
-
-/*
- * Read from the DataFlash device.
- * from : Start offset in flash device
- * len : Number of bytes to read
- * retlen : Number of bytes actually read
- * buf : Buffer that will receive data
- */
-static int at91_dataflash26_read(struct mtd_info *mtd, loff_t from, size_t len,
- size_t *retlen, u_char *buf)
-{
- struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
- unsigned char cmd[5];
-
- DEBUG(MTD_DEBUG_LEVEL1, "dataflash_read: %lli .. %lli\n",
- from, from+len);
-
- *retlen = 0;
-
- /* Sanity checks */
- if (!len)
- return 0;
- if (from + len > mtd->size)
- return -EINVAL;
-
- cmd[0] = AT26_OP_READ_ARRAY_FAST;
- cmd[1] = (from & 0x00FF0000) >> 16;
- cmd[2] = (from & 0x0000FF00) >> 8;
- cmd[3] = (from & 0x000000FF);
- /* cmd[4] is a "Don't care" byte */
-
- DEBUG(MTD_DEBUG_LEVEL3, "READ: (0x%02x) 0x%02x 0x%02x 0x%02x\n",
- cmd[0], cmd[1], cmd[2], cmd[3]);
-
- spi_access_bus(priv->spi);
- do_spi_transfer(2, cmd, 5, cmd, 5, buf, len, buf, len);
- spi_release_bus(priv->spi);
-
- *retlen = len;
- return 0;
-}
-
-/*
- * Write to the DataFlash device.
- * to : Start offset in flash device
- * len : Number of bytes to write
- * retlen : Number of bytes actually written
- * buf : Buffer containing the data
- */
-static int at91_dataflash26_write(struct mtd_info *mtd, loff_t to, size_t len,
- size_t *retlen, const u_char *buf)
-{
- struct dataflash_local *priv = (struct dataflash_local *) mtd->priv;
- unsigned int addr, buf_index = 0;
- int ret = -EIO, sector, last_sector;
- unsigned char status, cmd[5];
-
- DEBUG(MTD_DEBUG_LEVEL1, "dataflash_write: %lli .. %lli\n", to, to+len);
-
- *retlen = 0;
-
- /* Sanity checks */
- if (!len)
- return 0;
- if (to + len > mtd->size)
- return -EINVAL;
-
- spi_access_bus(priv->spi);
-
- addr = to;
- last_sector = -1;
-
- while (buf_index < len) {
- sector = addr / priv->page_size;
- /* Write first byte if a new sector begins */
- if (sector != last_sector) {
- at91_dataflash26_write_enable(1);
- at91_dataflash26_sector_protect(addr, 0);
- at91_dataflash26_write_enable(1);
-
- /* Program first byte of a new sector */
- cmd[0] = AT26_OP_SEQUENTIAL_WRITE;
- cmd[1] = (addr & 0x00FF0000) >> 16;
- cmd[2] = (addr & 0x0000FF00) >> 8;
- cmd[3] = (addr & 0x000000FF);
- cmd[4] = buf[buf_index++];
- do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);
- status = at91_dataflash26_waitready();
- addr++;
- /* On write errors, the chip resets the write enable
- flag. This also happens after the last byte of a
- sector is successfully programmed. */
- if ( ( !(status & AT26_STATUS_WRITE_ENABLE))
- && ((addr % priv->page_size) != 0) ) {
- DEBUG(MTD_DEBUG_LEVEL1,
- "write error1: addr=0x%06x, "
- "status=0x%02x\n", addr, status);
- goto write_err;
- }
- (*retlen)++;
- last_sector = sector;
- }
-
- /* Write subsequent bytes in the same sector */
- cmd[0] = AT26_OP_SEQUENTIAL_WRITE;
- cmd[1] = buf[buf_index++];
- do_spi_transfer(1, cmd, 2, cmd, 2, NULL, 0, NULL, 0);
- status = at91_dataflash26_waitready();
- addr++;
-
- if ( ( !(status & AT26_STATUS_WRITE_ENABLE))
- && ((addr % priv->page_size) != 0) ) {
- DEBUG(MTD_DEBUG_LEVEL1, "write error2: addr=0x%06x, "
- "status=0x%02x\n", addr, status);
- goto write_err;
- }
-
- (*retlen)++;
- }
-
- ret = 0;
- at91_dataflash26_write_enable(0);
-write_err:
- spi_release_bus(priv->spi);
- return ret;
-}
-
-/*
- * Initialize and register DataFlash device with MTD subsystem.
- */
-static int __init add_dataflash(int channel, char *name, int nr_pages,
- int pagesize)
-{
- struct mtd_info *device;
- struct dataflash_local *priv;
-
- if (nr_devices >= DATAFLASH_MAX_DEVICES) {
- printk(KERN_ERR "at91_dataflash26: Too many devices "
- "detected\n");
- return 0;
- }
-
- device = kzalloc(sizeof(struct mtd_info) + strlen(name) + 8,
- GFP_KERNEL);
- if (!device)
- return -ENOMEM;
-
- device->name = (char *)&device[1];
- sprintf(device->name, "%s.spi%d", name, channel);
- device->size = nr_pages * pagesize;
- device->erasesize = pagesize;
- device->owner = THIS_MODULE;
- device->type = MTD_DATAFLASH;
- device->flags = MTD_CAP_NORFLASH;
- device->erase = at91_dataflash26_erase;
- device->read = at91_dataflash26_read;
- device->write = at91_dataflash26_write;
-
- priv = (struct dataflash_local *)kzalloc(sizeof(struct dataflash_local),
- GFP_KERNEL);
- if (!priv) {
- kfree(device);
- return -ENOMEM;
- }
-
- priv->spi = channel;
- priv->page_size = pagesize;
- device->priv = priv;
-
- mtd_devices[nr_devices] = device;
- nr_devices++;
- printk(KERN_INFO "at91_dataflash26: %s detected [spi%i] (%i bytes)\n",
- name, channel, device->size);
-
- return add_mtd_device(device);
-}
-
-/*
- * Detect and initialize DataFlash device connected to specified SPI channel.
- *
- */
-
-struct dataflash26_types {
- unsigned char id0;
- unsigned char id1;
- char *name;
- int pagesize;
- int nr_pages;
-};
-
-struct dataflash26_types df26_types[] = {
- {
- .id0 = 0x04,
- .id1 = 0x00,
- .name = "AT26F004",
- .pagesize = 4096,
- .nr_pages = 128,
- },
- {
- .id0 = 0x45,
- .id1 = 0x01,
- .name = "AT26DF081A", /* Not tested ! */
- .pagesize = 4096,
- .nr_pages = 256,
- },
-};
-
-static int __init at91_dataflash26_detect(int channel)
-{
- unsigned char status, cmd[5];
- int i;
-
- spi_access_bus(channel);
- status = at91_dataflash26_status();
-
- if (status == 0 || status == 0xff) {
- printk(KERN_ERR "at91_dataflash26_detect: status error %d\n",
- status);
- spi_release_bus(channel);
- return -ENODEV;
- }
-
- cmd[0] = AT26_OP_READ_DEV_ID;
- do_spi_transfer(1, cmd, 5, cmd, 5, NULL, 0, NULL, 0);
- spi_release_bus(channel);
-
- if (cmd[1] != MANUFACTURER_ID_ATMEL)
- return -ENODEV;
-
- for (i = 0; i < ARRAY_SIZE(df26_types); i++) {
- if ( cmd[2] == df26_types[i].id0
- && cmd[3] == df26_types[i].id1)
- return add_dataflash(channel,
- df26_types[i].name,
- df26_types[i].nr_pages,
- df26_types[i].pagesize);
- }
-
- printk(KERN_ERR "at91_dataflash26_detect: Unsupported device "
- "(0x%02x/0x%02x)\n", cmd[2], cmd[3]);
- return -ENODEV;
-}
-
-static int __init at91_dataflash26_init(void)
-{
- spi_transfer_desc = kmalloc(sizeof(struct spi_transfer_list),
- GFP_KERNEL);
- if (!spi_transfer_desc)
- return -ENOMEM;
-
- /* DataFlash (SPI chip select 0) */
- at91_dataflash26_detect(0);
-
-#ifdef CONFIG_MTD_AT91_DATAFLASH_CARD
- /* DataFlash card (SPI chip select 3) */
- at91_dataflash26_detect(3);
-#endif
- return 0;
-}
-
-static void __exit at91_dataflash26_exit(void)
-{
- int i;
-
- for (i = 0; i < DATAFLASH_MAX_DEVICES; i++) {
- if (mtd_devices[i]) {
- del_mtd_device(mtd_devices[i]);
- kfree(mtd_devices[i]->priv);
- kfree(mtd_devices[i]);
- }
- }
- nr_devices = 0;
- kfree(spi_transfer_desc);
-}
-
-module_init(at91_dataflash26_init);
-module_exit(at91_dataflash26_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Hans J. Koch");
-MODULE_DESCRIPTION("DataFlash AT26xxx driver for Atmel AT91RM9200");
projects / platform / kernel / linux-rpi.git / commitdiff