--- /dev/null
+
+/*
+ * MTD driver for the SPI Flash Memory support.
+ *
+ * Copyright (c) 2005-2006 Atheros Communications Inc.
+ * Copyright (C) 2006 FON Technology, SL.
+ * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org>
+ * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This code 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.
+ *
+ */
+
+/*===========================================================================
+** !!!! VERY IMPORTANT NOTICE !!!! FLASH DATA STORED IN LITTLE ENDIAN FORMAT
+**
+** This module contains the Serial Flash access routines for the Atheros SOC.
+** The Atheros SOC integrates a SPI flash controller that is used to access
+** serial flash parts. The SPI flash controller executes in "Little Endian"
+** mode. THEREFORE, all WRITES and READS from the MIPS CPU must be
+** BYTESWAPPED! The SPI Flash controller hardware by default performs READ
+** ONLY byteswapping when accessed via the SPI Flash Alias memory region
+** (Physical Address 0x0800_0000 - 0x0fff_ffff). The data stored in the
+** flash sectors is stored in "Little Endian" format.
+**
+** The spiflash_write() routine performs byteswapping on all write
+** operations.
+**===========================================================================*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/version.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/platform_device.h>
+#include <linux/squashfs_fs.h>
+#include <linux/root_dev.h>
+#include <asm/delay.h>
+#include <asm/io.h>
+#include "spiflash.h"
+
+/* debugging */
+/* #define SPIFLASH_DEBUG */
+
+#ifndef __BIG_ENDIAN
+#error This driver currently only works with big endian CPU.
+#endif
+
+#define MAX_PARTS 32
+
+static char module_name[] = "spiflash";
+
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+#define FALSE 0
+#define TRUE 1
+
+#define ROOTFS_NAME "rootfs"
+
+static __u32 spiflash_regread32(int reg);
+static void spiflash_regwrite32(int reg, __u32 data);
+static __u32 spiflash_sendcmd (int op);
+
+int __init spiflash_init (void);
+void __exit spiflash_exit (void);
+static int spiflash_probe_chip (void);
+static int spiflash_erase (struct mtd_info *mtd,struct erase_info *instr);
+static int spiflash_read (struct mtd_info *mtd, loff_t from,size_t len,size_t *retlen,u_char *buf);
+static int spiflash_write (struct mtd_info *mtd,loff_t to,size_t len,size_t *retlen,const u_char *buf);
+
+/* Flash configuration table */
+struct flashconfig {
+ __u32 byte_cnt;
+ __u32 sector_cnt;
+ __u32 sector_size;
+ __u32 cs_addrmask;
+} flashconfig_tbl[MAX_FLASH] =
+ {
+ { 0, 0, 0, 0},
+ { STM_1MB_BYTE_COUNT, STM_1MB_SECTOR_COUNT, STM_1MB_SECTOR_SIZE, 0x0},
+ { STM_2MB_BYTE_COUNT, STM_2MB_SECTOR_COUNT, STM_2MB_SECTOR_SIZE, 0x0},
+ { STM_4MB_BYTE_COUNT, STM_4MB_SECTOR_COUNT, STM_4MB_SECTOR_SIZE, 0x0},
+ { STM_8MB_BYTE_COUNT, STM_8MB_SECTOR_COUNT, STM_8MB_SECTOR_SIZE, 0x0}
+ };
+
+/* Mapping of generic opcodes to STM serial flash opcodes */
+struct opcodes {
+ __u16 code;
+ __s8 tx_cnt;
+ __s8 rx_cnt;
+} stm_opcodes[] = {
+ {STM_OP_WR_ENABLE, 1, 0},
+ {STM_OP_WR_DISABLE, 1, 0},
+ {STM_OP_RD_STATUS, 1, 1},
+ {STM_OP_WR_STATUS, 1, 0},
+ {STM_OP_RD_DATA, 4, 4},
+ {STM_OP_FAST_RD_DATA, 1, 0},
+ {STM_OP_PAGE_PGRM, 8, 0},
+ {STM_OP_SECTOR_ERASE, 4, 0},
+ {STM_OP_BULK_ERASE, 1, 0},
+ {STM_OP_DEEP_PWRDOWN, 1, 0},
+ {STM_OP_RD_SIG, 4, 1}
+};
+
+/* Driver private data structure */
+struct spiflash_data {
+ struct mtd_info *mtd;
+ struct mtd_partition *parsed_parts; /* parsed partitions */
+ void *spiflash_readaddr; /* memory mapped data for read */
+ void *spiflash_mmraddr; /* memory mapped register space */
+ spinlock_t mutex;
+};
+
+static struct spiflash_data *spidata;
+
+extern int parse_redboot_partitions(struct mtd_info *master, struct mtd_partition **pparts);
+
+/***************************************************************************************************/
+
+static __u32
+spiflash_regread32(int reg)
+{
+ volatile __u32 *data = (__u32 *)(spidata->spiflash_mmraddr + reg);
+
+ return (*data);
+}
+
+static void
+spiflash_regwrite32(int reg, __u32 data)
+{
+ volatile __u32 *addr = (__u32 *)(spidata->spiflash_mmraddr + reg);
+
+ *addr = data;
+ return;
+}
+
+static __u32
+spiflash_sendcmd (int op)
+{
+ __u32 reg;
+ __u32 mask;
+ struct opcodes *ptr_opcode;
+
+ ptr_opcode = &stm_opcodes[op];
+
+ do {
+ reg = spiflash_regread32(SPI_FLASH_CTL);
+ } while (reg & SPI_CTL_BUSY);
+
+ spiflash_regwrite32(SPI_FLASH_OPCODE, ptr_opcode->code);
+
+ reg = (reg & ~SPI_CTL_TX_RX_CNT_MASK) | ptr_opcode->tx_cnt |
+ (ptr_opcode->rx_cnt << 4) | SPI_CTL_START;
+
+ spiflash_regwrite32(SPI_FLASH_CTL, reg);
+
+ if (ptr_opcode->rx_cnt > 0) {
+ do {
+ reg = spiflash_regread32(SPI_FLASH_CTL);
+ } while (reg & SPI_CTL_BUSY);
+
+ reg = (__u32) spiflash_regread32(SPI_FLASH_DATA);
+
+ switch (ptr_opcode->rx_cnt) {
+ case 1:
+ mask = 0x000000ff;
+ break;
+ case 2:
+ mask = 0x0000ffff;
+ break;
+ case 3:
+ mask = 0x00ffffff;
+ break;
+ default:
+ mask = 0xffffffff;
+ break;
+ }
+
+ reg &= mask;
+ }
+ else {
+ reg = 0;
+ }
+
+ return reg;
+}
+
+/* Probe SPI flash device
+ * Function returns 0 for failure.
+ * and flashconfig_tbl array index for success.
+ */
+static int
+spiflash_probe_chip (void)
+{
+ __u32 sig;
+ int flash_size;
+
+ /* Read the signature on the flash device */
+ sig = spiflash_sendcmd(SPI_RD_SIG);
+
+ switch (sig) {
+ case STM_8MBIT_SIGNATURE:
+ flash_size = FLASH_1MB;
+ break;
+ case STM_16MBIT_SIGNATURE:
+ flash_size = FLASH_2MB;
+ break;
+ case STM_32MBIT_SIGNATURE:
+ flash_size = FLASH_4MB;
+ break;
+ case STM_64MBIT_SIGNATURE:
+ flash_size = FLASH_8MB;
+ break;
+ default:
+ printk (KERN_WARNING "%s: Read of flash device signature failed!\n", module_name);
+ return (0);
+ }
+
+ return (flash_size);
+}
+
+
+static int
+spiflash_erase (struct mtd_info *mtd,struct erase_info *instr)
+{
+ struct opcodes *ptr_opcode;
+ __u32 temp, reg;
+ int finished = FALSE;
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "%s(addr = 0x%.8x, len = %d)\n",__FUNCTION__,instr->addr,instr->len);
+#endif
+
+ /* sanity checks */
+ if (instr->addr + instr->len > mtd->size) return (-EINVAL);
+
+ ptr_opcode = &stm_opcodes[SPI_SECTOR_ERASE];
+
+ temp = ((__u32)instr->addr << 8) | (__u32)(ptr_opcode->code);
+ spin_lock(&spidata->mutex);
+ spiflash_sendcmd(SPI_WRITE_ENABLE);
+ do {
+ schedule();
+ reg = spiflash_regread32(SPI_FLASH_CTL);
+ } while (reg & SPI_CTL_BUSY);
+
+ spiflash_regwrite32(SPI_FLASH_OPCODE, temp);
+
+ reg = (reg & ~SPI_CTL_TX_RX_CNT_MASK) | ptr_opcode->tx_cnt | SPI_CTL_START;
+ spiflash_regwrite32(SPI_FLASH_CTL, reg);
+
+ do {
+ schedule();
+ reg = spiflash_sendcmd(SPI_RD_STATUS);
+ if (!(reg & SPI_STATUS_WIP)) {
+ finished = TRUE;
+ }
+ } while (!finished);
+ spin_unlock(&spidata->mutex);
+
+ instr->state = MTD_ERASE_DONE;
+ if (instr->callback) instr->callback (instr);
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "%s return\n",__FUNCTION__);
+#endif
+ return (0);
+}
+
+static int
+spiflash_read (struct mtd_info *mtd, loff_t from,size_t len,size_t *retlen,u_char *buf)
+{
+ u_char *read_addr;
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "%s(from = 0x%.8x, len = %d)\n",__FUNCTION__,(__u32) from,(int)len);
+#endif
+
+ /* sanity checks */
+ if (!len) return (0);
+ if (from + len > mtd->size) return (-EINVAL);
+
+
+ /* we always read len bytes */
+ *retlen = len;
+
+ read_addr = (u_char *)(spidata->spiflash_readaddr + from);
+ spin_lock(&spidata->mutex);
+ memcpy(buf, read_addr, len);
+ spin_unlock(&spidata->mutex);
+
+ return (0);
+}
+
+static int
+spiflash_write (struct mtd_info *mtd,loff_t to,size_t len,size_t *retlen,const u_char *buf)
+{
+ int done = FALSE, page_offset, bytes_left, finished;
+ __u32 xact_len, spi_data = 0, opcode, reg;
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "%s(to = 0x%.8x, len = %d)\n",__FUNCTION__,(__u32) to,len);
+#endif
+
+ *retlen = 0;
+
+ /* sanity checks */
+ if (!len) return (0);
+ if (to + len > mtd->size) return (-EINVAL);
+
+ opcode = stm_opcodes[SPI_PAGE_PROGRAM].code;
+ bytes_left = len;
+
+ while (done == FALSE) {
+ xact_len = MIN(bytes_left, sizeof(__u32));
+
+ /* 32-bit writes cannot span across a page boundary
+ * (256 bytes). This types of writes require two page
+ * program operations to handle it correctly. The STM part
+ * will write the overflow data to the beginning of the
+ * current page as opposed to the subsequent page.
+ */
+ page_offset = (to & (STM_PAGE_SIZE - 1)) + xact_len;
+
+ if (page_offset > STM_PAGE_SIZE) {
+ xact_len -= (page_offset - STM_PAGE_SIZE);
+ }
+
+ spin_lock(&spidata->mutex);
+ spiflash_sendcmd(SPI_WRITE_ENABLE);
+
+ do {
+ schedule();
+ reg = spiflash_regread32(SPI_FLASH_CTL);
+ } while (reg & SPI_CTL_BUSY);
+
+ switch (xact_len) {
+ case 1:
+ spi_data = (u32) ((u8) *buf);
+ break;
+ case 2:
+ spi_data = (buf[1] << 8) | buf[0];
+ break;
+ case 3:
+ spi_data = (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ break;
+ case 4:
+ spi_data = (buf[3] << 24) | (buf[2] << 16) |
+ (buf[1] << 8) | buf[0];
+ break;
+ default:
+ printk("spiflash_write: default case\n");
+ break;
+ }
+
+ spiflash_regwrite32(SPI_FLASH_DATA, spi_data);
+ opcode = (opcode & SPI_OPCODE_MASK) | ((__u32)to << 8);
+ spiflash_regwrite32(SPI_FLASH_OPCODE, opcode);
+
+ reg = (reg & ~SPI_CTL_TX_RX_CNT_MASK) | (xact_len + 4) | SPI_CTL_START;
+ spiflash_regwrite32(SPI_FLASH_CTL, reg);
+ finished = FALSE;
+
+ do {
+ schedule();
+ reg = spiflash_sendcmd(SPI_RD_STATUS);
+ if (!(reg & SPI_STATUS_WIP)) {
+ finished = TRUE;
+ }
+ } while (!finished);
+ spin_unlock(&spidata->mutex);
+
+ bytes_left -= xact_len;
+ to += xact_len;
+ buf += xact_len;
+
+ *retlen += xact_len;
+
+ if (bytes_left == 0) {
+ done = TRUE;
+ }
+ }
+
+ return (0);
+}
+
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
+#endif
+
+
+static int spiflash_probe(struct platform_device *pdev)
+{
+ int result = -1, i, j;
+ u32 len;
+ int index, num_parts;
+ struct mtd_info *mtd;
+ struct mtd_partition *mtd_parts;
+ char *buf;
+ struct mtd_partition *part;
+ struct squashfs_super_block *sb;
+ u32 config_start;
+
+ spidata->spiflash_mmraddr = ioremap_nocache(SPI_FLASH_MMR, SPI_FLASH_MMR_SIZE);
+
+ if (!spidata->spiflash_mmraddr) {
+ printk (KERN_WARNING "%s: Failed to map flash device\n", module_name);
+ kfree(spidata);
+ spidata = NULL;
+ }
+
+ mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+ if (!mtd) {
+ kfree(spidata);
+ return (-ENXIO);
+ }
+
+ printk ("MTD driver for SPI flash.\n");
+ printk ("%s: Probing for Serial flash ...\n", module_name);
+ if (!(index = spiflash_probe_chip())) {
+ printk (KERN_WARNING "%s: Found no serial flash device\n", module_name);
+ kfree(mtd);
+ kfree(spidata);
+ return (-ENXIO);
+ }
+
+ printk ("%s: Found SPI serial Flash.\n", module_name);
+
+ spidata->spiflash_readaddr = ioremap_nocache(SPI_FLASH_READ, flashconfig_tbl[index].byte_cnt);
+ if (!spidata->spiflash_readaddr) {
+ printk (KERN_WARNING "%s: Failed to map flash device\n", module_name);
+ kfree(mtd);
+ kfree(spidata);
+ return (-ENXIO);
+ }
+
+ mtd->name = module_name;
+ mtd->type = MTD_NORFLASH;
+ mtd->flags = (MTD_CAP_NORFLASH|MTD_WRITEABLE);
+ mtd->size = flashconfig_tbl[index].byte_cnt;
+ mtd->erasesize = flashconfig_tbl[index].sector_size;
+ mtd->writesize = 1;
+ mtd->numeraseregions = 0;
+ mtd->eraseregions = NULL;
+ mtd->erase = spiflash_erase;
+ mtd->read = spiflash_read;
+ mtd->write = spiflash_write;
+ mtd->owner = THIS_MODULE;
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG
+ "mtd->name = %s\n"
+ "mtd->size = 0x%.8x (%uM)\n"
+ "mtd->erasesize = 0x%.8x (%uK)\n"
+ "mtd->numeraseregions = %d\n",
+ mtd->name,
+ mtd->size, mtd->size / (1024*1024),
+ mtd->erasesize, mtd->erasesize / 1024,
+ mtd->numeraseregions);
+
+ if (mtd->numeraseregions) {
+ for (result = 0; result < mtd->numeraseregions; result++) {
+ printk (KERN_DEBUG
+ "\n\n"
+ "mtd->eraseregions[%d].offset = 0x%.8x\n"
+ "mtd->eraseregions[%d].erasesize = 0x%.8x (%uK)\n"
+ "mtd->eraseregions[%d].numblocks = %d\n",
+ result,mtd->eraseregions[result].offset,
+ result,mtd->eraseregions[result].erasesize,mtd->eraseregions[result].erasesize / 1024,
+ result,mtd->eraseregions[result].numblocks);
+ }
+ }
+#endif
+
+ /* parse redboot partitions */
+ num_parts = parse_mtd_partitions(mtd, part_probe_types, &spidata->parsed_parts, 0);
+
+ mtd_parts = kzalloc(sizeof(struct mtd_partition) * MAX_PARTS, GFP_KERNEL);
+ buf = kmalloc(mtd->erasesize, GFP_KERNEL);
+ sb = (struct squashfs_super_block *) buf;
+ for (i = j = 0; i < num_parts; i++, j++) {
+ part = &mtd_parts[j];
+ memcpy(part, &spidata->parsed_parts[i], sizeof(struct mtd_partition));
+
+ if (!strcmp(part->name, ROOTFS_NAME)) {
+ /* create the root device */
+ ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, i);
+
+ part->size -= mtd->erasesize;
+ config_start = part->offset + part->size;
+
+ while ((mtd->read(mtd, part->offset, mtd->erasesize, &len, buf) == 0) &&
+ (len == mtd->erasesize) &&
+ (*((u32 *) buf) == SQUASHFS_MAGIC) &&
+ (sb->bytes_used > 0)) {
+
+ /* this is squashfs, allocate another partition starting from the end of filesystem data */
+ memcpy(&mtd_parts[j + 1], part, sizeof(struct mtd_partition));
+
+ len = (u32) sb->bytes_used;
+ len += (part->offset & 0x000fffff);
+ len += (mtd->erasesize - 1);
+ len &= ~(mtd->erasesize - 1);
+ len -= (part->offset & 0x000fffff);
+
+ if (len + mtd->erasesize > part->size)
+ break;
+
+ part = &mtd_parts[++j];
+
+ part->offset += len;
+ part->size -= len;
+
+ part->name = kmalloc(10, GFP_KERNEL);
+ sprintf(part->name, "rootfs%d", j - i);
+ }
+ }
+ if (!strcmp(part->name, "RedBoot config")) {
+ /* add anoterh partition for the board config data */
+ memcpy(&mtd_parts[j + 1], part, sizeof(struct mtd_partition));
+ j++;
+ part = &mtd_parts[j];
+ part->offset += part->size;
+ part->size = mtd->erasesize;
+
+ part->name = kmalloc(16, GFP_KERNEL);
+ sprintf(part->name, "board_config");
+ }
+ }
+ num_parts += j - i;
+ kfree(buf);
+
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "Found %d redboot partitions\n", num_parts);
+#endif
+ if (num_parts) {
+ result = add_mtd_partitions(mtd, mtd_parts, num_parts);
+ } else {
+#ifdef SPIFLASH_DEBUG
+ printk (KERN_DEBUG "Did not find any redboot partitions\n");
+#endif
+ kfree(mtd);
+ kfree(spidata);
+ return (-ENXIO);
+ }
+
+ spidata->mtd = mtd;
+
+ return (result);
+}
+
+static int spiflash_remove (struct platform_device *pdev)
+{
+ del_mtd_partitions (spidata->mtd);
+ kfree(spidata->mtd);
+
+ return 0;
+}
+
+struct platform_driver spiflash_driver = {
+ .driver.name = "spiflash",
+ .probe = spiflash_probe,
+ .remove = spiflash_remove,
+};
+
+int __init
+spiflash_init (void)
+{
+ spidata = kmalloc(sizeof(struct spiflash_data), GFP_KERNEL);
+ if (!spidata)
+ return (-ENXIO);
+
+ spin_lock_init(&spidata->mutex);
+ platform_driver_register(&spiflash_driver);
+
+ return 0;
+}
+
+void __exit
+spiflash_exit (void)
+{
+ kfree(spidata);
+}
+
+module_init (spiflash_init);
+module_exit (spiflash_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Atheros Communications Inc");
+MODULE_DESCRIPTION("MTD driver for SPI Flash on Atheros SOC");
+
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