drivers/mtd/nand/at91_nand.c

   1 /*
   2  * drivers/mtd/nand/at91_nand.c
   3  *
   4  *  Copyright (C) 2003 Rick Bronson
   5  *
   6  *  Derived from drivers/mtd/nand/autcpu12.c
   7  *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
   8  *
   9  *  Derived from drivers/mtd/spia.c
  10  *       Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  */
  17
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/nand.h>
  23 #include <linux/mtd/partitions.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/sizes.h>
  27
  28 #include <asm/hardware.h>
  29 #include <asm/arch/board.h>
  30 #include <asm/arch/gpio.h>
  31
  32 struct at91_nand_host {
  33         struct nand_chip        nand_chip;
  34         struct mtd_info         mtd;
  35         void __iomem            *io_base;
  36         struct at91_nand_data   *board;
  37 };
  38
  39 /*
  40  * Hardware specific access to control-lines
  41  */
  42 static void at91_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  43 {
  44         struct nand_chip *nand_chip = mtd->priv;
  45         struct at91_nand_host *host = nand_chip->priv;
  46
  47         if (cmd == NAND_CMD_NONE)
  48                 return;
  49
  50         if (ctrl & NAND_CLE)
  51                 writeb(cmd, host->io_base + (1 << host->board->cle));
  52         else
  53                 writeb(cmd, host->io_base + (1 << host->board->ale));
  54 }
  55
  56 /*
  57  * Read the Device Ready pin.
  58  */
  59 static int at91_nand_device_ready(struct mtd_info *mtd)
  60 {
  61         struct nand_chip *nand_chip = mtd->priv;
  62         struct at91_nand_host *host = nand_chip->priv;
  63
  64         return at91_get_gpio_value(host->board->rdy_pin);
  65 }
  66
  67 /*
  68  * Enable NAND.
  69  */
  70 static void at91_nand_enable(struct at91_nand_host *host)
  71 {
  72         if (host->board->enable_pin)
  73                 at91_set_gpio_value(host->board->enable_pin, 0);
  74 }
  75
  76 /*
  77  * Disable NAND.
  78  */
  79 static void at91_nand_disable(struct at91_nand_host *host)
  80 {
  81         if (host->board->enable_pin)
  82                 at91_set_gpio_value(host->board->enable_pin, 1);
  83 }
  84
  85 #ifdef CONFIG_MTD_PARTITIONS
  86 const char *part_probes[] = { "cmdlinepart", NULL };
  87 #endif
  88
  89 /*
  90  * Probe for the NAND device.
  91  */
  92 static int __init at91_nand_probe(struct platform_device *pdev)
  93 {
  94         struct at91_nand_host *host;
  95         struct mtd_info *mtd;
  96         struct nand_chip *nand_chip;
  97         int res;
  98
  99 #ifdef CONFIG_MTD_PARTITIONS
 100         struct mtd_partition *partitions = NULL;
 101         int num_partitions = 0;
 102 #endif
 103
 104         /* Allocate memory for the device structure (and zero it) */
 105         host = kzalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
 106         if (!host) {
 107                 printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
 108                 return -ENOMEM;
 109         }
 110
 111         host->io_base = ioremap(pdev->resource[0].start,
 112                                 pdev->resource[0].end - pdev->resource[0].start + 1);
 113         if (host->io_base == NULL) {
 114                 printk(KERN_ERR "at91_nand: ioremap failed\n");
 115                 kfree(host);
 116                 return -EIO;
 117         }
 118
 119         mtd = &host->mtd;
 120         nand_chip = &host->nand_chip;
 121         host->board = pdev->dev.platform_data;
 122
 123         nand_chip->priv = host;         /* link the private data structures */
 124         mtd->priv = nand_chip;
 125         mtd->owner = THIS_MODULE;
 126
 127         /* Set address of NAND IO lines */
 128         nand_chip->IO_ADDR_R = host->io_base;
 129         nand_chip->IO_ADDR_W = host->io_base;
 130         nand_chip->cmd_ctrl = at91_nand_cmd_ctrl;
 131         nand_chip->dev_ready = at91_nand_device_ready;
 132         nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
 133         nand_chip->chip_delay = 20;             /* 20us command delay time */
 134
 135         if (host->board->bus_width_16)          /* 16-bit bus width */
 136                 nand_chip->options |= NAND_BUSWIDTH_16;
 137
 138         platform_set_drvdata(pdev, host);
 139         at91_nand_enable(host);
 140
 141         if (host->board->det_pin) {
 142                 if (at91_get_gpio_value(host->board->det_pin)) {
 143                         printk ("No SmartMedia card inserted.\n");
 144                         res = ENXIO;
 145                         goto out;
 146                 }
 147         }
 148
 149         /* Scan to find existance of the device */
 150         if (nand_scan(mtd, 1)) {
 151                 res = -ENXIO;
 152                 goto out;
 153         }
 154
 155 #ifdef CONFIG_MTD_PARTITIONS
 156         if (host->board->partition_info)
 157                 partitions = host->board->partition_info(mtd->size, &num_partitions);
 158 #ifdef CONFIG_MTD_CMDLINE_PARTS
 159         else {
 160                 mtd->name = "at91_nand";
 161                 num_partitions = parse_mtd_partitions(mtd, part_probes, &partitions, 0);
 162         }
 163 #endif
 164
 165         if ((!partitions) || (num_partitions == 0)) {
 166                 printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
 167                 res = ENXIO;
 168                 goto release;
 169         }
 170
 171         res = add_mtd_partitions(mtd, partitions, num_partitions);
 172 #else
 173         res = add_mtd_device(mtd);
 174 #endif
 175
 176         if (!res)
 177                 return res;
 178
 179 release:
 180         nand_release(mtd);
 181 out:
 182         at91_nand_disable(host);
 183         platform_set_drvdata(pdev, NULL);
 184         iounmap(host->io_base);
 185         kfree(host);
 186         return res;
 187 }
 188
 189 /*
 190  * Remove a NAND device.
 191  */
 192 static int __devexit at91_nand_remove(struct platform_device *pdev)
 193 {
 194         struct at91_nand_host *host = platform_get_drvdata(pdev);
 195         struct mtd_info *mtd = &host->mtd;
 196
 197         nand_release(mtd);
 198
 199         at91_nand_disable(host);
 200
 201         iounmap(host->io_base);
 202         kfree(host);
 203
 204         return 0;
 205 }
 206
 207 static struct platform_driver at91_nand_driver = {
 208         .probe          = at91_nand_probe,
 209         .remove         = at91_nand_remove,
 210         .driver         = {
 211                 .name   = "at91_nand",
 212                 .owner  = THIS_MODULE,
 213         },
 214 };
 215
 216 static int __init at91_nand_init(void)
 217 {
 218         return platform_driver_register(&at91_nand_driver);
 219 }
 220
 221
 222 static void __exit at91_nand_exit(void)
 223 {
 224         platform_driver_unregister(&at91_nand_driver);
 225 }
 226
 227
 228 module_init(at91_nand_init);
 229 module_exit(at91_nand_exit);
 230
 231 MODULE_LICENSE("GPL");
 232 MODULE_AUTHOR("Rick Bronson");
 233 MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");