drivers/mtd/nand/excite_nandflash.c

   1 /*
   2 *  Copyright (C) 2005 - 2007 by Basler Vision Technologies AG
   3 *  Author: Thomas Koeller <thomas.koeller.qbaslerweb.com>
   4 *  Original code by Thies Moeller <thies.moeller@baslerweb.com>
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License as published by
   8 *  the Free Software Foundation; either version 2 of the License, or
   9 *  (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to the Free Software
  18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/string.h>
  26 #include <linux/ioport.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/delay.h>
  29 #include <linux/err.h>
  30
  31 #include <linux/mtd/mtd.h>
  32 #include <linux/mtd/nand.h>
  33 #include <linux/mtd/nand_ecc.h>
  34 #include <linux/mtd/partitions.h>
  35
  36 #include <asm/io.h>
  37 #include <asm/rm9k-ocd.h>
  38
  39 #include <excite_nandflash.h>
  40
  41 #define EXCITE_NANDFLASH_VERSION "0.1"
  42
  43 /* I/O register offsets */
  44 #define EXCITE_NANDFLASH_DATA_BYTE   0x00
  45 #define EXCITE_NANDFLASH_STATUS_BYTE 0x0c
  46 #define EXCITE_NANDFLASH_ADDR_BYTE   0x10
  47 #define EXCITE_NANDFLASH_CMD_BYTE    0x14
  48
  49 /* prefix for debug output */
  50 static const char module_id[] = "excite_nandflash";
  51
  52 /*
  53  * partition definition
  54  */
  55 static const struct mtd_partition partition_info[] = {
  56         {
  57                 .name = "eXcite RootFS",
  58                 .offset = 0,
  59                 .size = MTDPART_SIZ_FULL
  60         }
  61 };
  62
  63 static inline const struct resource *
  64 excite_nand_get_resource(struct platform_device *d, unsigned long flags,
  65                          const char *basename)
  66 {
  67         char buf[80];
  68
  69         if (snprintf(buf, sizeof buf, "%s_%u", basename, d->id) >= sizeof buf)
  70                 return NULL;
  71         return platform_get_resource_byname(d, flags, buf);
  72 }
  73
  74 static inline void __iomem *
  75 excite_nand_map_regs(struct platform_device *d, const char *basename)
  76 {
  77         void *result = NULL;
  78         const struct resource *const r =
  79             excite_nand_get_resource(d, IORESOURCE_MEM, basename);
  80
  81         if (r)
  82                 result = ioremap_nocache(r->start, r->end + 1 - r->start);
  83         return result;
  84 }
  85
  86 /* controller and mtd information */
  87 struct excite_nand_drvdata {
  88         struct mtd_info board_mtd;
  89         struct nand_chip board_chip;
  90         void __iomem *regs;
  91         void __iomem *tgt;
  92 };
  93
  94 /* Control function */
  95 static void excite_nand_control(struct mtd_info *mtd, int cmd,
  96                                        unsigned int ctrl)
  97 {
  98         struct excite_nand_drvdata * const d =
  99             container_of(mtd, struct excite_nand_drvdata, board_mtd);
 100
 101         switch (ctrl) {
 102         case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
 103                 d->tgt = d->regs + EXCITE_NANDFLASH_CMD_BYTE;
 104                 break;
 105         case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
 106                 d->tgt = d->regs + EXCITE_NANDFLASH_ADDR_BYTE;
 107                 break;
 108         case NAND_CTRL_CHANGE | NAND_NCE:
 109                 d->tgt = d->regs + EXCITE_NANDFLASH_DATA_BYTE;
 110                 break;
 111         }
 112
 113         if (cmd != NAND_CMD_NONE)
 114                 __raw_writeb(cmd, d->tgt);
 115 }
 116
 117 /* Return 0 if flash is busy, 1 if ready */
 118 static int excite_nand_devready(struct mtd_info *mtd)
 119 {
 120         struct excite_nand_drvdata * const drvdata =
 121             container_of(mtd, struct excite_nand_drvdata, board_mtd);
 122
 123         return __raw_readb(drvdata->regs + EXCITE_NANDFLASH_STATUS_BYTE);
 124 }
 125
 126 /*
 127  * Called by device layer to remove the driver.
 128  * The binding to the mtd and all allocated
 129  * resources are released.
 130  */
 131 static int __exit excite_nand_remove(struct device *dev)
 132 {
 133         struct excite_nand_drvdata * const this = dev_get_drvdata(dev);
 134
 135         dev_set_drvdata(dev, NULL);
 136
 137         if (unlikely(!this)) {
 138                 printk(KERN_ERR "%s: called %s without private data!!",
 139                        module_id, __func__);
 140                 return -EINVAL;
 141         }
 142
 143         /* first thing we need to do is release our mtd
 144          * then go through freeing the resource used
 145          */
 146         nand_release(&this->board_mtd);
 147
 148         /* free the common resources */
 149         iounmap(this->regs);
 150         kfree(this);
 151
 152         DEBUG(MTD_DEBUG_LEVEL1, "%s: removed\n", module_id);
 153         return 0;
 154 }
 155
 156 /*
 157  * Called by device layer when it finds a device matching
 158  * one our driver can handle. This code checks to see if
 159  * it can allocate all necessary resources then calls the
 160  * nand layer to look for devices.
 161 */
 162 static int __init excite_nand_probe(struct device *dev)
 163 {
 164         struct platform_device * const pdev = to_platform_device(dev);
 165         struct excite_nand_drvdata *drvdata;    /* private driver data */
 166         struct nand_chip *board_chip;   /* private flash chip data */
 167         struct mtd_info *board_mtd;     /* mtd info for this board */
 168         int scan_res;
 169
 170         drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
 171         if (unlikely(!drvdata)) {
 172                 printk(KERN_ERR "%s: no memory for drvdata\n",
 173                        module_id);
 174                 return -ENOMEM;
 175         }
 176
 177         /* bind private data into driver */
 178         dev_set_drvdata(dev, drvdata);
 179
 180         /* allocate and map the resource */
 181         drvdata->regs =
 182                 excite_nand_map_regs(pdev, EXCITE_NANDFLASH_RESOURCE_REGS);
 183
 184         if (unlikely(!drvdata->regs)) {
 185                 printk(KERN_ERR "%s: cannot reserve register region\n",
 186                        module_id);
 187                 kfree(drvdata);
 188                 return -ENXIO;
 189         }
 190
 191         drvdata->tgt = drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
 192
 193         /* initialise our chip */
 194         board_chip = &drvdata->board_chip;
 195         board_chip->IO_ADDR_R = board_chip->IO_ADDR_W =
 196                 drvdata->regs + EXCITE_NANDFLASH_DATA_BYTE;
 197         board_chip->cmd_ctrl = excite_nand_control;
 198         board_chip->dev_ready = excite_nand_devready;
 199         board_chip->chip_delay = 25;
 200         board_chip->ecc.mode = NAND_ECC_SOFT;
 201
 202         /* link chip to mtd */
 203         board_mtd = &drvdata->board_mtd;
 204         board_mtd->priv = board_chip;
 205
 206         DEBUG(MTD_DEBUG_LEVEL2, "%s: device scan\n", module_id);
 207         scan_res = nand_scan(&drvdata->board_mtd, 1);
 208
 209         if (likely(!scan_res)) {
 210                 DEBUG(MTD_DEBUG_LEVEL2, "%s: register partitions\n", module_id);
 211                 add_mtd_partitions(&drvdata->board_mtd, partition_info,
 212                                    sizeof partition_info / sizeof partition_info[0]);
 213         } else {
 214                 iounmap(drvdata->regs);
 215                 kfree(drvdata);
 216                 printk(KERN_ERR "%s: device scan failed\n", module_id);
 217                 return -EIO;
 218         }
 219         return 0;
 220 }
 221
 222 static struct device_driver excite_nand_driver = {
 223         .name = "excite_nand",
 224         .bus = &platform_bus_type,
 225         .probe = excite_nand_probe,
 226         .remove = __exit_p(excite_nand_remove)
 227 };
 228
 229 static int __init excite_nand_init(void)
 230 {
 231         pr_info("Basler eXcite nand flash driver Version "
 232                 EXCITE_NANDFLASH_VERSION "\n");
 233         return driver_register(&excite_nand_driver);
 234 }
 235
 236 static void __exit excite_nand_exit(void)
 237 {
 238         driver_unregister(&excite_nand_driver);
 239 }
 240
 241 module_init(excite_nand_init);
 242 module_exit(excite_nand_exit);
 243
 244 MODULE_AUTHOR("Thomas Koeller <thomas.koeller@baslerweb.com>");
 245 MODULE_DESCRIPTION("Basler eXcite NAND-Flash driver");
 246 MODULE_LICENSE("GPL");
 247 MODULE_VERSION(EXCITE_NANDFLASH_VERSION)