release/src-rt-6.x.4708/linux/linux-2.6.36/arch/cris/arch-v32/drivers/mach-a3/nandflash.c

   1 /*
   2  *  arch/cris/arch-v32/drivers/nandflash.c
   3  *
   4  *  Copyright (c) 2007
   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/pio_defs.h>
  25 #include <pinmux.h>
  26 #include <asm/io.h>
  27
  28 #define MANUAL_ALE_CLE_CONTROL 1
  29
  30 #define regf_ALE        a0
  31 #define regf_CLE        a1
  32 #define regf_NCE        ce0_n
  33
  34 #define CLE_BIT 10
  35 #define ALE_BIT 11
  36 #define CE_BIT 12
  37
  38 struct mtd_info_wrapper {
  39         struct mtd_info info;
  40         struct nand_chip chip;
  41 };
  42
  43 /* Bitmask for control pins */
  44 #define PIN_BITMASK ((1 << CE_BIT) | (1 << CLE_BIT) | (1 << ALE_BIT))
  45
  46 static struct mtd_info *crisv32_mtd;
  47 /*
  48  *      hardware specific access to control-lines
  49  */
  50 static void crisv32_hwcontrol(struct mtd_info *mtd, int cmd,
  51                               unsigned int ctrl)
  52 {
  53         unsigned long flags;
  54         reg_pio_rw_dout dout;
  55         struct nand_chip *this = mtd->priv;
  56
  57         local_irq_save(flags);
  58
  59         /* control bits change */
  60         if (ctrl & NAND_CTRL_CHANGE) {
  61                 dout = REG_RD(pio, regi_pio, rw_dout);
  62                 dout.regf_NCE = (ctrl & NAND_NCE) ? 0 : 1;
  63
  64 #if !MANUAL_ALE_CLE_CONTROL
  65                 if (ctrl & NAND_ALE) {
  66                         /* A0 = ALE high */
  67                         this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
  68                                 regi_pio, rw_io_access1);
  69                 } else if (ctrl & NAND_CLE) {
  70                         /* A1 = CLE high */
  71                         this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
  72                                 regi_pio, rw_io_access2);
  73                 } else {
  74                         /* A1 = CLE and A0 = ALE low */
  75                         this->IO_ADDR_W = (void __iomem *)REG_ADDR(pio,
  76                                 regi_pio, rw_io_access0);
  77                 }
  78 #else
  79
  80                 dout.regf_CLE = (ctrl & NAND_CLE) ? 1 : 0;
  81                 dout.regf_ALE = (ctrl & NAND_ALE) ? 1 : 0;
  82 #endif
  83                 REG_WR(pio, regi_pio, rw_dout, dout);
  84         }
  85
  86         /* command to chip */
  87         if (cmd != NAND_CMD_NONE)
  88                 writeb(cmd, this->IO_ADDR_W);
  89
  90         local_irq_restore(flags);
  91 }
  92
  93 /*
  94 *       read device ready pin
  95 */
  96 static int crisv32_device_ready(struct mtd_info *mtd)
  97 {
  98         reg_pio_r_din din = REG_RD(pio, regi_pio, r_din);
  99         return din.rdy;
 100 }
 101
 102 /*
 103  * Main initialization routine
 104  */
 105 struct mtd_info *__init crisv32_nand_flash_probe(void)
 106 {
 107         void __iomem *read_cs;
 108         void __iomem *write_cs;
 109
 110         struct mtd_info_wrapper *wrapper;
 111         struct nand_chip *this;
 112         int err = 0;
 113
 114         reg_pio_rw_man_ctrl man_ctrl = {
 115                 .regf_NCE = regk_pio_yes,
 116 #if MANUAL_ALE_CLE_CONTROL
 117                 .regf_ALE = regk_pio_yes,
 118                 .regf_CLE = regk_pio_yes
 119 #endif
 120         };
 121         reg_pio_rw_oe oe = {
 122                 .regf_NCE = regk_pio_yes,
 123 #if MANUAL_ALE_CLE_CONTROL
 124                 .regf_ALE = regk_pio_yes,
 125                 .regf_CLE = regk_pio_yes
 126 #endif
 127         };
 128         reg_pio_rw_dout dout = { .regf_NCE = 1 };
 129
 130         /* Allocate pio pins to pio */
 131         crisv32_pinmux_alloc_fixed(pinmux_pio);
 132         /* Set up CE, ALE, CLE (ce0_n, a0, a1) for manual control and output */
 133         REG_WR(pio, regi_pio, rw_man_ctrl, man_ctrl);
 134         REG_WR(pio, regi_pio, rw_dout, dout);
 135         REG_WR(pio, regi_pio, rw_oe, oe);
 136
 137         /* Allocate memory for MTD device structure and private data */
 138         wrapper = kzalloc(sizeof(struct mtd_info_wrapper), GFP_KERNEL);
 139         if (!wrapper) {
 140                 printk(KERN_ERR "Unable to allocate CRISv32 NAND MTD "
 141                         "device structure.\n");
 142                 err = -ENOMEM;
 143                 return NULL;
 144         }
 145
 146         read_cs = write_cs = (void __iomem *)REG_ADDR(pio, regi_pio,
 147                 rw_io_access0);
 148
 149         /* Get pointer to private data */
 150         this = &wrapper->chip;
 151         crisv32_mtd = &wrapper->info;
 152
 153         /* Link the private data with the MTD structure */
 154         crisv32_mtd->priv = this;
 155
 156         /* Set address of NAND IO lines */
 157         this->IO_ADDR_R = read_cs;
 158         this->IO_ADDR_W = write_cs;
 159         this->cmd_ctrl = crisv32_hwcontrol;
 160         this->dev_ready = crisv32_device_ready;
 161         /* 20 us command delay time */
 162         this->chip_delay = 20;
 163         this->ecc.mode = NAND_ECC_SOFT;
 164
 165         /* Enable the following for a flash based bad block table */
 166         /* this->options = NAND_USE_FLASH_BBT; */
 167
 168         /* Scan to find existance of the device */
 169         if (nand_scan(crisv32_mtd, 1)) {
 170                 err = -ENXIO;
 171                 goto out_mtd;
 172         }
 173
 174         return crisv32_mtd;
 175
 176 out_mtd:
 177         kfree(wrapper);
 178         return NULL;
 179 }