release/src-rt-6.x.4708/linux/linux-2.6.36/arch/cris/arch-v32/drivers/mach-fs/nandflash.c

   1 /*
   2  *  arch/cris/arch-v32/drivers/nandflash.c
   3  *
   4  *  Copyright (c) 2004
   5  *
   6  *  Derived from drivers/mtd/nand/spia.c
   7  *        Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/nand.h>
  20 #include <linux/mtd/partitions.h>
  21 #include <arch/memmap.h>
  22 #include <hwregs/reg_map.h>
  23 #include <hwregs/reg_rdwr.h>
  24 #include <hwregs/gio_defs.h>
  25 #include <hwregs/bif_core_defs.h>
  26 #include <asm/io.h>
  27
  28 #define CE_BIT 4
  29 #define CLE_BIT 5
  30 #define ALE_BIT 6
  31 #define BY_BIT 7
  32
  33 struct mtd_info_wrapper {
  34         struct mtd_info info;
  35         struct nand_chip chip;
  36 };
  37
  38 /* Bitmask for control pins */
  39 #define PIN_BITMASK ((1 << CE_BIT) | (1 << CLE_BIT) | (1 << ALE_BIT))
  40
  41 /* Bitmask for mtd nand control bits */
  42 #define CTRL_BITMASK (NAND_NCE | NAND_CLE | NAND_ALE)
  43
  44
  45 static struct mtd_info *crisv32_mtd;
  46 /*
  47  *      hardware specific access to control-lines
  48  */
  49 static void crisv32_hwcontrol(struct mtd_info *mtd, int cmd,
  50                               unsigned int ctrl)
  51 {
  52         unsigned long flags;
  53         reg_gio_rw_pa_dout dout;
  54         struct nand_chip *this = mtd->priv;
  55
  56         local_irq_save(flags);
  57
  58         /* control bits change */
  59         if (ctrl & NAND_CTRL_CHANGE) {
  60                 dout = REG_RD(gio, regi_gio, rw_pa_dout);
  61                 dout.data &= ~PIN_BITMASK;
  62
  63 #if (CE_BIT == 4 && NAND_NCE == CLE_BIT == 5 && NAND_CLE == 2 && ALE_BIT == 6 && \
  64         NAND_ALE == 4)
  65                 /* Pins in same order as control bits, but shifted.
  66                  * Optimize for this case; works for 2.6.18 */
  67                 dout.data |= ((ctrl & CTRL_BITMASK) ^ NAND_NCE) << CE_BIT;
  68 #else
  69                 /* the slow way */
  70                 if (!(ctrl & NAND_NCE))
  71                         dout.data |= (1 << CE_BIT);
  72                 if (ctrl & NAND_CLE)
  73                         dout.data |= (1 << CLE_BIT);
  74                 if (ctrl & NAND_ALE)
  75                         dout.data |= (1 << ALE_BIT);
  76 #endif
  77                 REG_WR(gio, regi_gio, rw_pa_dout, dout);
  78         }
  79
  80         /* command to chip */
  81         if (cmd != NAND_CMD_NONE)
  82                 writeb(cmd, this->IO_ADDR_W);
  83
  84         local_irq_restore(flags);
  85 }
  86
  87 /*
  88 *       read device ready pin
  89 */
  90 static int crisv32_device_ready(struct mtd_info *mtd)
  91 {
  92         reg_gio_r_pa_din din = REG_RD(gio, regi_gio, r_pa_din);
  93         return ((din.data & (1 << BY_BIT)) >> BY_BIT);
  94 }
  95
  96 /*
  97  * Main initialization routine
  98  */
  99 struct mtd_info *__init crisv32_nand_flash_probe(void)
 100 {
 101         void __iomem *read_cs;
 102         void __iomem *write_cs;
 103
 104         reg_bif_core_rw_grp3_cfg bif_cfg = REG_RD(bif_core, regi_bif_core,
 105                 rw_grp3_cfg);
 106         reg_gio_rw_pa_oe pa_oe = REG_RD(gio, regi_gio, rw_pa_oe);
 107         struct mtd_info_wrapper *wrapper;
 108         struct nand_chip *this;
 109         int err = 0;
 110
 111         /* Allocate memory for MTD device structure and private data */
 112         wrapper = kzalloc(sizeof(struct mtd_info_wrapper), GFP_KERNEL);
 113         if (!wrapper) {
 114                 printk(KERN_ERR "Unable to allocate CRISv32 NAND MTD "
 115                         "device structure.\n");
 116                 err = -ENOMEM;
 117                 return NULL;
 118         }
 119
 120         read_cs = ioremap(MEM_CSP0_START | MEM_NON_CACHEABLE, 8192);
 121         write_cs = ioremap(MEM_CSP1_START | MEM_NON_CACHEABLE, 8192);
 122
 123         if (!read_cs || !write_cs) {
 124                 printk(KERN_ERR "CRISv32 NAND ioremap failed\n");
 125                 err = -EIO;
 126                 goto out_mtd;
 127         }
 128
 129         /* Get pointer to private data */
 130         this = &wrapper->chip;
 131         crisv32_mtd = &wrapper->info;
 132
 133         pa_oe.oe |= 1 << CE_BIT;
 134         pa_oe.oe |= 1 << ALE_BIT;
 135         pa_oe.oe |= 1 << CLE_BIT;
 136         pa_oe.oe &= ~(1 << BY_BIT);
 137         REG_WR(gio, regi_gio, rw_pa_oe, pa_oe);
 138
 139         bif_cfg.gated_csp0 = regk_bif_core_rd;
 140         bif_cfg.gated_csp1 = regk_bif_core_wr;
 141         REG_WR(bif_core, regi_bif_core, rw_grp3_cfg, bif_cfg);
 142
 143         /* Link the private data with the MTD structure */
 144         crisv32_mtd->priv = this;
 145
 146         /* Set address of NAND IO lines */
 147         this->IO_ADDR_R = read_cs;
 148         this->IO_ADDR_W = write_cs;
 149         this->cmd_ctrl = crisv32_hwcontrol;
 150         this->dev_ready = crisv32_device_ready;
 151         /* 20 us command delay time */
 152         this->chip_delay = 20;
 153         this->ecc.mode = NAND_ECC_SOFT;
 154
 155         /* Enable the following for a flash based bad block table */
 156         /* this->options = NAND_USE_FLASH_BBT; */
 157
 158         /* Scan to find existance of the device */
 159         if (nand_scan(crisv32_mtd, 1)) {
 160                 err = -ENXIO;
 161                 goto out_ior;
 162         }
 163
 164         return crisv32_mtd;
 165
 166 out_ior:
 167         iounmap((void *)read_cs);
 168         iounmap((void *)write_cs);
 169 out_mtd:
 170         kfree(wrapper);
 171         return NULL;
 172 }