drivers/mtd/nand/omap-nand-flash.c

   1 /*
   2  * drivers/mtd/nand/omap-nand-flash.c
   3  *
   4  * Copyright (c) 2004 Texas Instruments, Jian Zhang <jzhang@ti.com>
   5  * Copyright (c) 2004 David Brownell
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/ioport.h>
  14 #include <linux/delay.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/types.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/nand.h>
  21 #include <linux/mtd/partitions.h>
  22
  23 #include <asm/io.h>
  24 #include <mach/hardware.h>
  25 #include <asm/mach-types.h>
  26 #include <asm/mach/flash.h>
  27 #include <mach/tc.h>
  28
  29 #include <mach/nand.h>
  30
  31 #define DRIVER_NAME     "omapnand"
  32
  33 #ifdef CONFIG_MTD_PARTITIONS
  34 static const char *part_probes[] = { "cmdlinepart", NULL };
  35 #endif
  36
  37 struct omap_nand_info {
  38         struct omap_nand_platform_data *pdata;
  39         struct mtd_partition    *parts;
  40         struct mtd_info         mtd;
  41         struct nand_chip        nand;
  42 };
  43
  44 /*
  45  *      hardware specific access to control-lines
  46  *      NOTE:  boards may use different bits for these!!
  47  *
  48  *      ctrl:
  49  *      NAND_NCE: bit 0 - don't care
  50  *      NAND_CLE: bit 1 -> bit 1  (0x0002)
  51  *      NAND_ALE: bit 2 -> bit 2  (0x0004)
  52  */
  53
  54 static void omap_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  55 {
  56         struct nand_chip *chip = mtd->priv;
  57         unsigned long mask;
  58
  59         if (cmd == NAND_CMD_NONE)
  60                 return;
  61
  62         mask = (ctrl & NAND_CLE) ? 0x02 : 0;
  63         if (ctrl & NAND_ALE)
  64                 mask |= 0x04;
  65         writeb(cmd, (unsigned long)chip->IO_ADDR_W | mask);
  66 }
  67
  68 static int omap_nand_dev_ready(struct mtd_info *mtd)
  69 {
  70         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd);
  71
  72         return info->pdata->dev_ready(info->pdata);
  73 }
  74
  75 static int __devinit omap_nand_probe(struct platform_device *pdev)
  76 {
  77         struct omap_nand_info           *info;
  78         struct omap_nand_platform_data  *pdata = pdev->dev.platform_data;
  79         struct resource                 *res = pdev->resource;
  80         unsigned long                   size = res->end - res->start + 1;
  81         int                             err;
  82
  83         info = kzalloc(sizeof(struct omap_nand_info), GFP_KERNEL);
  84         if (!info)
  85                 return -ENOMEM;
  86
  87         if (!request_mem_region(res->start, size, pdev->dev.driver->name)) {
  88                 err = -EBUSY;
  89                 goto out_free_info;
  90         }
  91
  92         info->nand.IO_ADDR_R = ioremap(res->start, size);
  93         if (!info->nand.IO_ADDR_R) {
  94                 err = -ENOMEM;
  95                 goto out_release_mem_region;
  96         }
  97         info->nand.IO_ADDR_W = info->nand.IO_ADDR_R;
  98         info->nand.cmd_ctrl = omap_nand_hwcontrol;
  99         info->nand.ecc.mode = NAND_ECC_SOFT;
 100         info->nand.options = pdata->options;
 101         if (pdata->dev_ready)
 102                 info->nand.dev_ready = omap_nand_dev_ready;
 103         else
 104                 info->nand.chip_delay = 20;
 105
 106         info->mtd.name = dev_name(&pdev->dev);
 107         info->mtd.priv = &info->nand;
 108
 109         info->pdata = pdata;
 110
 111         /* DIP switches on H2 and some other boards change between 8 and 16 bit
 112          * bus widths for flash.  Try the other width if the first try fails.
 113          */
 114         if (nand_scan(&info->mtd, 1)) {
 115                 info->nand.options ^= NAND_BUSWIDTH_16;
 116                 if (nand_scan(&info->mtd, 1)) {
 117                         err = -ENXIO;
 118                         goto out_iounmap;
 119                 }
 120         }
 121         info->mtd.owner = THIS_MODULE;
 122
 123 #ifdef CONFIG_MTD_PARTITIONS
 124         err = parse_mtd_partitions(&info->mtd, part_probes, &info->parts, 0);
 125         if (err > 0)
 126                 add_mtd_partitions(&info->mtd, info->parts, err);
 127         else if (err < 0 && pdata->parts)
 128                 add_mtd_partitions(&info->mtd, pdata->parts, pdata->nr_parts);
 129         else
 130 #endif
 131                 add_mtd_device(&info->mtd);
 132
 133         platform_set_drvdata(pdev, info);
 134
 135         return 0;
 136
 137 out_iounmap:
 138         iounmap(info->nand.IO_ADDR_R);
 139 out_release_mem_region:
 140         release_mem_region(res->start, size);
 141 out_free_info:
 142         kfree(info);
 143
 144         return err;
 145 }
 146
 147 static int omap_nand_remove(struct platform_device *pdev)
 148 {
 149         struct omap_nand_info *info = platform_get_drvdata(pdev);
 150
 151         platform_set_drvdata(pdev, NULL);
 152         /* Release NAND device, its internal structures and partitions */
 153         nand_release(&info->mtd);
 154         iounmap(info->nand.IO_ADDR_R);
 155         kfree(info);
 156         return 0;
 157 }
 158
 159 static struct platform_driver omap_nand_driver = {
 160         .probe          = omap_nand_probe,
 161         .remove         = omap_nand_remove,
 162         .driver         = {
 163                 .name   = DRIVER_NAME,
 164         },
 165 };
 166 MODULE_ALIAS(DRIVER_NAME);
 167
 168 static int __init omap_nand_init(void)
 169 {
 170         return platform_driver_register(&omap_nand_driver);
 171 }
 172
 173 static void __exit omap_nand_exit(void)
 174 {
 175         platform_driver_unregister(&omap_nand_driver);
 176 }
 177
 178 module_init(omap_nand_init);
 179 module_exit(omap_nand_exit);
 180
 181 MODULE_LICENSE("GPL");
 182 MODULE_AUTHOR("Jian Zhang <jzhang@ti.com> (and others)");
 183 MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");
 184