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 /*
  86  * Probe for the NAND device.
  87  */
  88 static int __init at91_nand_probe(struct platform_device *pdev)
  89 {
  90         struct at91_nand_host *host;
  91         struct mtd_info *mtd;
  92         struct nand_chip *nand_chip;
  93         int res;
  94
  95 #ifdef CONFIG_MTD_PARTITIONS
  96         struct mtd_partition *partitions = NULL;
  97         int num_partitions = 0;
  98 #endif
  99
 100         /* Allocate memory for the device structure (and zero it) */
 101         host = kzalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
 102         if (!host) {
 103                 printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
 104                 return -ENOMEM;
 105         }
 106
 107         host->io_base = ioremap(pdev->resource[0].start,
 108                                 pdev->resource[0].end - pdev->resource[0].start + 1);
 109         if (host->io_base == NULL) {
 110                 printk(KERN_ERR "at91_nand: ioremap failed\n");
 111                 kfree(host);
 112                 return -EIO;
 113         }
 114
 115         mtd = &host->mtd;
 116         nand_chip = &host->nand_chip;
 117         host->board = pdev->dev.platform_data;
 118
 119         nand_chip->priv = host;         /* link the private data structures */
 120         mtd->priv = nand_chip;
 121         mtd->owner = THIS_MODULE;
 122
 123         /* Set address of NAND IO lines */
 124         nand_chip->IO_ADDR_R = host->io_base;
 125         nand_chip->IO_ADDR_W = host->io_base;
 126         nand_chip->cmd_ctrl = at91_nand_cmd_ctrl;
 127         nand_chip->dev_ready = at91_nand_device_ready;
 128         nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
 129         nand_chip->chip_delay = 20;             /* 20us command delay time */
 130
 131         if (host->board->bus_width_16)          /* 16-bit bus width */
 132                 nand_chip->options |= NAND_BUSWIDTH_16;
 133
 134         platform_set_drvdata(pdev, host);
 135         at91_nand_enable(host);
 136
 137         if (host->board->det_pin) {
 138                 if (at91_get_gpio_value(host->board->det_pin)) {
 139                         printk ("No SmartMedia card inserted.\n");
 140                         res = ENXIO;
 141                         goto out;
 142                 }
 143         }
 144
 145         /* Scan to find existance of the device */
 146         if (nand_scan(mtd, 1)) {
 147                 res = -ENXIO;
 148                 goto out;
 149         }
 150
 151 #ifdef CONFIG_MTD_PARTITIONS
 152         if (host->board->partition_info)
 153                 partitions = host->board->partition_info(mtd->size, &num_partitions);
 154
 155         if ((!partitions) || (num_partitions == 0)) {
 156                 printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
 157                 res = ENXIO;
 158                 goto release;
 159         }
 160
 161         res = add_mtd_partitions(mtd, partitions, num_partitions);
 162 #else
 163         res = add_mtd_device(mtd);
 164 #endif
 165
 166         if (!res)
 167                 return res;
 168
 169 release:
 170         nand_release(mtd);
 171 out:
 172         at91_nand_disable(host);
 173         platform_set_drvdata(pdev, NULL);
 174         iounmap(host->io_base);
 175         kfree(host);
 176         return res;
 177 }
 178
 179 /*
 180  * Remove a NAND device.
 181  */
 182 static int __devexit at91_nand_remove(struct platform_device *pdev)
 183 {
 184         struct at91_nand_host *host = platform_get_drvdata(pdev);
 185         struct mtd_info *mtd = &host->mtd;
 186
 187         nand_release(mtd);
 188
 189         at91_nand_disable(host);
 190
 191         iounmap(host->io_base);
 192         kfree(host);
 193
 194         return 0;
 195 }
 196
 197 static struct platform_driver at91_nand_driver = {
 198         .probe          = at91_nand_probe,
 199         .remove         = at91_nand_remove,
 200         .driver         = {
 201                 .name   = "at91_nand",
 202                 .owner  = THIS_MODULE,
 203         },
 204 };
 205
 206 static int __init at91_nand_init(void)
 207 {
 208         return platform_driver_register(&at91_nand_driver);
 209 }
 210
 211
 212 static void __exit at91_nand_exit(void)
 213 {
 214         platform_driver_unregister(&at91_nand_driver);
 215 }
 216
 217
 218 module_init(at91_nand_init);
 219 module_exit(at91_nand_exit);
 220
 221 MODULE_LICENSE("GPL");
 222 MODULE_AUTHOR("Rick Bronson");
 223 MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91RM9200");