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/module.h>
  21 #include <linux/delay.h>
  22 #include <linux/mtd/mtd.h>
  23 #include <linux/mtd/nand.h>
  24 #include <linux/mtd/partitions.h>
  25 #include <linux/gpio.h>
  26 #include <linux/platform_data/gpio-omap.h>
  27
  28 #include <asm/io.h>
  29 #include <asm/sizes.h>
  30
  31 #include <mach/board-ams-delta.h>
  32
  33 #include <mach/hardware.h>
  34
  35 /*
  36  * MTD structure for E3 (Delta)
  37  */
  38 static struct mtd_info *ams_delta_mtd = NULL;
  39
  40 /*
  41  * Define partitions for flash devices
  42  */
  43
  44 static struct mtd_partition partition_info[] = {
  45         { .name         = "Kernel",
  46           .offset       = 0,
  47           .size         = 3 * SZ_1M + SZ_512K },
  48         { .name         = "u-boot",
  49           .offset       = 3 * SZ_1M + SZ_512K,
  50           .size         = SZ_256K },
  51         { .name         = "u-boot params",
  52           .offset       = 3 * SZ_1M + SZ_512K + SZ_256K,
  53           .size         = SZ_256K },
  54         { .name         = "Amstrad LDR",
  55           .offset       = 4 * SZ_1M,
  56           .size         = SZ_256K },
  57         { .name         = "File system",
  58           .offset       = 4 * SZ_1M + 1 * SZ_256K,
  59           .size         = 27 * SZ_1M },
  60         { .name         = "PBL reserved",
  61           .offset       = 32 * SZ_1M - 3 * SZ_256K,
  62           .size         =  3 * SZ_256K },
  63 };
  64
  65 static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
  66 {
  67         struct nand_chip *this = mtd_to_nand(mtd);
  68         void __iomem *io_base = (void __iomem *)nand_get_controller_data(this);
  69
  70         writew(0, io_base + OMAP_MPUIO_IO_CNTL);
  71         writew(byte, this->IO_ADDR_W);
  72         gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 0);
  73         ndelay(40);
  74         gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 1);
  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_to_nand(mtd);
  81         void __iomem *io_base = (void __iomem *)nand_get_controller_data(this);
  82
  83         gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 0);
  84         ndelay(40);
  85         writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
  86         res = readw(this->IO_ADDR_R);
  87         gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 1);
  88
  89         return res;
  90 }
  91
  92 static void ams_delta_write_buf(struct mtd_info *mtd, const u_char *buf,
  93                                 int len)
  94 {
  95         int i;
  96
  97         for (i=0; i<len; i++)
  98                 ams_delta_write_byte(mtd, buf[i]);
  99 }
 100
 101 static void ams_delta_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 102 {
 103         int i;
 104
 105         for (i=0; i<len; i++)
 106                 buf[i] = ams_delta_read_byte(mtd);
 107 }
 108
 109 /*
 110  * Command control function
 111  *
 112  * ctrl:
 113  * NAND_NCE: bit 0 -> bit 2
 114  * NAND_CLE: bit 1 -> bit 7
 115  * NAND_ALE: bit 2 -> bit 6
 116  */
 117 static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
 118                                 unsigned int ctrl)
 119 {
 120
 121         if (ctrl & NAND_CTRL_CHANGE) {
 122                 gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NCE,
 123                                 (ctrl & NAND_NCE) == 0);
 124                 gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_CLE,
 125                                 (ctrl & NAND_CLE) != 0);
 126                 gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_ALE,
 127                                 (ctrl & NAND_ALE) != 0);
 128         }
 129
 130         if (cmd != NAND_CMD_NONE)
 131                 ams_delta_write_byte(mtd, cmd);
 132 }
 133
 134 static int ams_delta_nand_ready(struct mtd_info *mtd)
 135 {
 136         return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
 137 }
 138
 139 static const struct gpio _mandatory_gpio[] = {
 140         {
 141                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_NCE,
 142                 .flags  = GPIOF_OUT_INIT_HIGH,
 143                 .label  = "nand_nce",
 144         },
 145         {
 146                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_NRE,
 147                 .flags  = GPIOF_OUT_INIT_HIGH,
 148                 .label  = "nand_nre",
 149         },
 150         {
 151                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_NWP,
 152                 .flags  = GPIOF_OUT_INIT_HIGH,
 153                 .label  = "nand_nwp",
 154         },
 155         {
 156                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_NWE,
 157                 .flags  = GPIOF_OUT_INIT_HIGH,
 158                 .label  = "nand_nwe",
 159         },
 160         {
 161                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_ALE,
 162                 .flags  = GPIOF_OUT_INIT_LOW,
 163                 .label  = "nand_ale",
 164         },
 165         {
 166                 .gpio   = AMS_DELTA_GPIO_PIN_NAND_CLE,
 167                 .flags  = GPIOF_OUT_INIT_LOW,
 168                 .label  = "nand_cle",
 169         },
 170 };
 171
 172 /*
 173  * Main initialization routine
 174  */
 175 static int ams_delta_init(struct platform_device *pdev)
 176 {
 177         struct nand_chip *this;
 178         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 179         void __iomem *io_base;
 180         int err = 0;
 181
 182         if (!res)
 183                 return -ENXIO;
 184
 185         /* Allocate memory for MTD device structure and private data */
 186         this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
 187         if (!this) {
 188                 printk (KERN_WARNING "Unable to allocate E3 NAND MTD device structure.\n");
 189                 err = -ENOMEM;
 190                 goto out;
 191         }
 192
 193         ams_delta_mtd = nand_to_mtd(this);
 194         ams_delta_mtd->owner = THIS_MODULE;
 195
 196         /*
 197          * Don't try to request the memory region from here,
 198          * it should have been already requested from the
 199          * gpio-omap driver and requesting it again would fail.
 200          */
 201
 202         io_base = ioremap(res->start, resource_size(res));
 203         if (io_base == NULL) {
 204                 dev_err(&pdev->dev, "ioremap failed\n");
 205                 err = -EIO;
 206                 goto out_free;
 207         }
 208
 209         nand_set_controller_data(this, (void *)io_base);
 210
 211         /* Set address of NAND IO lines */
 212         this->IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
 213         this->IO_ADDR_W = io_base + OMAP_MPUIO_OUTPUT;
 214         this->read_byte = ams_delta_read_byte;
 215         this->write_buf = ams_delta_write_buf;
 216         this->read_buf = ams_delta_read_buf;
 217         this->cmd_ctrl = ams_delta_hwcontrol;
 218         if (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
 219                 this->dev_ready = ams_delta_nand_ready;
 220         } else {
 221                 this->dev_ready = NULL;
 222                 printk(KERN_NOTICE "Couldn't request gpio for Delta NAND ready.\n");
 223         }
 224         /* 25 us command delay time */
 225         this->chip_delay = 30;
 226         this->ecc.mode = NAND_ECC_SOFT;
 227         this->ecc.algo = NAND_ECC_HAMMING;
 228
 229         platform_set_drvdata(pdev, io_base);
 230
 231         /* Set chip enabled, but  */
 232         err = gpio_request_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
 233         if (err)
 234                 goto out_gpio;
 235
 236         /* Scan to find existence of the device */
 237         err = nand_scan(ams_delta_mtd, 1);
 238         if (err)
 239                 goto out_mtd;
 240
 241         /* Register the partitions */
 242         mtd_device_register(ams_delta_mtd, partition_info,
 243                             ARRAY_SIZE(partition_info));
 244
 245         goto out;
 246
 247  out_mtd:
 248         gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
 249 out_gpio:
 250         gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
 251         iounmap(io_base);
 252 out_free:
 253         kfree(this);
 254  out:
 255         return err;
 256 }
 257
 258 /*
 259  * Clean up routine
 260  */
 261 static int ams_delta_cleanup(struct platform_device *pdev)
 262 {
 263         void __iomem *io_base = platform_get_drvdata(pdev);
 264
 265         /* Release resources, unregister device */
 266         nand_release(ams_delta_mtd);
 267
 268         gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
 269         gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
 270         iounmap(io_base);
 271
 272         /* Free the MTD device structure */
 273         kfree(mtd_to_nand(ams_delta_mtd));
 274
 275         return 0;
 276 }
 277
 278 static struct platform_driver ams_delta_nand_driver = {
 279         .probe          = ams_delta_init,
 280         .remove         = ams_delta_cleanup,
 281         .driver         = {
 282                 .name   = "ams-delta-nand",
 283         },
 284 };
 285
 286 module_platform_driver(ams_delta_nand_driver);
 287
 288 MODULE_LICENSE("GPL");
 289 MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
 290 MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");