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