drivers/mtd/nand/ams-delta.c

   1 /*
   2  *  drivers/mtd/nand/ams-delta.c
   3  *
   4  *  Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
   5  *
   6  *  Derived from drivers/mtd/toto.c
   7  *  Converted to platform driver by Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
   8  *  Partially stolen from drivers/mtd/nand/plat_nand.c
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  *  Overview:
  15  *   This is a device driver for the NAND flash device found on the
  16  *   Amstrad E3 (Delta).
  17  */
  18
  19 #include <linux/slab.h>
  20 #include <linux/init.h>
  21 #include <linux/module.h>
  22 #include <linux/delay.h>
  23 #include <linux/mtd/mtd.h>
  24 #include <linux/mtd/nand.h>
  25 #include <linux/mtd/partitions.h>
  26 #include <asm/io.h>
  27 #include <mach/hardware.h>
  28 #include <asm/sizes.h>
  29 #include <asm/gpio.h>
  30 #include <plat/board-ams-delta.h>
  31
  32 /*
  33  * MTD structure for E3 (Delta)
  34  */
  35 static struct mtd_info *ams_delta_mtd = NULL;
  36
  37 #define NAND_MASK (AMS_DELTA_LATCH2_NAND_NRE | AMS_DELTA_LATCH2_NAND_NWE | AMS_DELTA_LATCH2_NAND_CLE | AMS_DELTA_LATCH2_NAND_ALE | AMS_DELTA_LATCH2_NAND_NCE | AMS_DELTA_LATCH2_NAND_NWP)
  38
  39 /*
  40  * Define partitions for flash devices
  41  */
  42
  43 static struct mtd_partition partition_info[] = {
  44         { .name         = "Kernel",
  45           .offset       = 0,
  46           .size         = 3 * SZ_1M + SZ_512K },
  47         { .name         = "u-boot",
  48           .offset       = 3 * SZ_1M + SZ_512K,
  49           .size         = SZ_256K },
  50         { .name         = "u-boot params",
  51           .offset       = 3 * SZ_1M + SZ_512K + SZ_256K,
  52           .size         = SZ_256K },
  53         { .name         = "Amstrad LDR",
  54           .offset       = 4 * SZ_1M,
  55           .size         = SZ_256K },
  56         { .name         = "File system",
  57           .offset       = 4 * SZ_1M + 1 * SZ_256K,
  58           .size         = 27 * SZ_1M },
  59         { .name         = "PBL reserved",
  60           .offset       = 32 * SZ_1M - 3 * SZ_256K,
  61           .size         =  3 * SZ_256K },
  62 };
  63
  64 static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
  65 {
  66         struct nand_chip *this = mtd->priv;
  67         void __iomem *io_base = this->priv;
  68
  69         writew(0, io_base + OMAP_MPUIO_IO_CNTL);
  70         writew(byte, this->IO_ADDR_W);
  71         ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, 0);
  72         ndelay(40);
  73         ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE,
  74                                AMS_DELTA_LATCH2_NAND_NWE);
  75 }
  76
  77 static u_char ams_delta_read_byte(struct mtd_info *mtd)
  78 {
  79         u_char res;
  80         struct nand_chip *this = mtd->priv;
  81         void __iomem *io_base = this->priv;
  82
  83         ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, 0);
  84         ndelay(40);
  85         writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
  86         res = readw(this->IO_ADDR_R);
  87         ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE,
  88                                AMS_DELTA_LATCH2_NAND_NRE);
  89
  90         return res;
  91 }
  92
  93 static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
  94                                 int len)
  95 {
  96         int i;
  97
  98         for (i=0; i<len; i++)
  99                 ams_delta_write_byte(mtd, buf[i]);
 100 }
 101
 102 static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 103 {
 104         int i;
 105
 106         for (i=0; i<len; i++)
 107                 buf[i] = ams_delta_read_byte(mtd);
 108 }
 109
 110 static int ams_delta_verify_buf(struct mtd_info *mtd, const u_char *buf,
 111                                 int len)
 112 {
 113         int i;
 114
 115         for (i=0; i<len; i++)
 116                 if (buf[i] != ams_delta_read_byte(mtd))
 117                         return -EFAULT;
 118
 119         return 0;
 120 }
 121
 122 /*
 123  * Command control function
 124  *
 125  * ctrl:
 126  * NAND_NCE: bit 0 -> bit 2
 127  * NAND_CLE: bit 1 -> bit 7
 128  * NAND_ALE: bit 2 -> bit 6
 129  */
 130 static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
 131                                 unsigned int ctrl)
 132 {
 133
 134         if (ctrl & NAND_CTRL_CHANGE) {
 135                 unsigned long bits;
 136
 137                 bits = (~ctrl & NAND_NCE) ? AMS_DELTA_LATCH2_NAND_NCE : 0;
 138                 bits |= (ctrl & NAND_CLE) ? AMS_DELTA_LATCH2_NAND_CLE : 0;
 139                 bits |= (ctrl & NAND_ALE) ? AMS_DELTA_LATCH2_NAND_ALE : 0;
 140
 141                 ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_CLE |
 142                                 AMS_DELTA_LATCH2_NAND_ALE |
 143                                 AMS_DELTA_LATCH2_NAND_NCE, bits);
 144         }
 145
 146         if (cmd != NAND_CMD_NONE)
 147                 ams_delta_write_byte(mtd, cmd);
 148 }
 149
 150 static int ams_delta_nand_ready(struct mtd_info *mtd)
 151 {
 152         return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
 153 }
 154
 155 /*
 156  * Main initialization routine
 157  */
 158 static int __devinit ams_delta_init(struct platform_device *pdev)
 159 {
 160         struct nand_chip *this;
 161         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 162         void __iomem *io_base;
 163         int err = 0;
 164
 165         if (!res)
 166                 return -ENXIO;
 167
 168         /* Allocate memory for MTD device structure and private data */
 169         ams_delta_mtd = kmalloc(sizeof(struct mtd_info) +
 170                                 sizeof(struct nand_chip), GFP_KERNEL);
 171         if (!ams_delta_mtd) {
 172                 printk (KERN_WARNING "Unable to allocate E3 NAND MTD device structure.\n");
 173                 err = -ENOMEM;
 174                 goto out;
 175         }
 176
 177         ams_delta_mtd->owner = THIS_MODULE;
 178
 179         /* Get pointer to private data */
 180         this = (struct nand_chip *) (&ams_delta_mtd[1]);
 181
 182         /* Initialize structures */
 183         memset(ams_delta_mtd, 0, sizeof(struct mtd_info));
 184         memset(this, 0, sizeof(struct nand_chip));
 185
 186         /* Link the private data with the MTD structure */
 187         ams_delta_mtd->priv = this;
 188
 189         if (!request_mem_region(res->start, resource_size(res),
 190                         dev_name(&pdev->dev))) {
 191                 dev_err(&pdev->dev, "request_mem_region failed\n");
 192                 err = -EBUSY;
 193                 goto out_free;
 194         }
 195
 196         io_base = ioremap(res->start, resource_size(res));
 197         if (io_base == NULL) {
 198                 dev_err(&pdev->dev, "ioremap failed\n");
 199                 err = -EIO;
 200                 goto out_release_io;
 201         }
 202
 203         this->priv = io_base;
 204
 205         /* Set address of NAND IO lines */
 206         this->IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
 207         this->IO_ADDR_W = io_base + OMAP_MPUIO_OUTPUT;
 208         this->read_byte = ams_delta_read_byte;
 209         this->write_buf = ams_delta_write_buf;
 210         this->read_buf = ams_delta_read_buf;
 211         this->verify_buf = ams_delta_verify_buf;
 212         this->cmd_ctrl = ams_delta_hwcontrol;
 213         if (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
 214                 this->dev_ready = ams_delta_nand_ready;
 215         } else {
 216                 this->dev_ready = NULL;
 217                 printk(KERN_NOTICE "Couldn't request gpio for Delta NAND ready.\n");
 218         }
 219         /* 25 us command delay time */
 220         this->chip_delay = 30;
 221         this->ecc.mode = NAND_ECC_SOFT;
 222
 223         platform_set_drvdata(pdev, io_base);
 224
 225         /* Set chip enabled, but  */
 226         ams_delta_latch2_write(NAND_MASK, AMS_DELTA_LATCH2_NAND_NRE |
 227                                           AMS_DELTA_LATCH2_NAND_NWE |
 228                                           AMS_DELTA_LATCH2_NAND_NCE |
 229                                           AMS_DELTA_LATCH2_NAND_NWP);
 230
 231         /* Scan to find existence of the device */
 232         if (nand_scan(ams_delta_mtd, 1)) {
 233                 err = -ENXIO;
 234                 goto out_mtd;
 235         }
 236
 237         /* Register the partitions */
 238         mtd_device_register(ams_delta_mtd, partition_info,
 239                             ARRAY_SIZE(partition_info));
 240
 241         goto out;
 242
 243  out_mtd:
 244         platform_set_drvdata(pdev, NULL);
 245         iounmap(io_base);
 246 out_release_io:
 247         release_mem_region(res->start, resource_size(res));
 248 out_free:
 249         kfree(ams_delta_mtd);
 250  out:
 251         return err;
 252 }
 253
 254 /*
 255  * Clean up routine
 256  */
 257 static int __devexit ams_delta_cleanup(struct platform_device *pdev)
 258 {
 259         void __iomem *io_base = platform_get_drvdata(pdev);
 260         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 261
 262         /* Release resources, unregister device */
 263         nand_release(ams_delta_mtd);
 264
 265         iounmap(io_base);
 266         release_mem_region(res->start, resource_size(res));
 267
 268         /* Free the MTD device structure */
 269         kfree(ams_delta_mtd);
 270
 271         return 0;
 272 }
 273
 274 static struct platform_driver ams_delta_nand_driver = {
 275         .probe          = ams_delta_init,
 276         .remove         = __devexit_p(ams_delta_cleanup),
 277         .driver         = {
 278                 .name   = "ams-delta-nand",
 279                 .owner  = THIS_MODULE,
 280         },
 281 };
 282
 283 module_platform_driver(ams_delta_nand_driver);
 284
 285 MODULE_LICENSE("GPL");
 286 MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
 287 MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");