drivers/mtd/nand/cmx270_nand.c

   1 /*
   2  *  linux/drivers/mtd/nand/cmx270-nand.c
   3  *
   4  *  Copyright (C) 2006 Compulab, Ltd.
   5  *  Mike Rapoport <mike@compulab.co.il>
   6  *
   7  *  Derived from drivers/mtd/nand/h1910.c
   8  *       Copyright (C) 2002 Marius Gröger (mag@sysgo.de)
   9  *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
  10  *
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  *  Overview:
  17  *   This is a device driver for the NAND flash device found on the
  18  *   CM-X270 board.
  19  */
  20
  21 #include <linux/mtd/nand.h>
  22 #include <linux/mtd/partitions.h>
  23 #include <linux/slab.h>
  24 #include <linux/gpio.h>
  25 #include <linux/module.h>
  26
  27 #include <asm/io.h>
  28 #include <asm/irq.h>
  29 #include <asm/mach-types.h>
  30
  31 #include <mach/pxa2xx-regs.h>
  32
  33 #define GPIO_NAND_CS    (11)
  34 #define GPIO_NAND_RB    (89)
  35
  36 /* MTD structure for CM-X270 board */
  37 static struct mtd_info *cmx270_nand_mtd;
  38
  39 /* remaped IO address of the device */
  40 static void __iomem *cmx270_nand_io;
  41
  42 /*
  43  * Define static partitions for flash device
  44  */
  45 static struct mtd_partition partition_info[] = {
  46         [0] = {
  47                 .name   = "cmx270-0",
  48                 .offset = 0,
  49                 .size   = MTDPART_SIZ_FULL
  50         }
  51 };
  52 #define NUM_PARTITIONS (ARRAY_SIZE(partition_info))
  53
  54 const char *part_probes[] = { "cmdlinepart", NULL };
  55
  56 static u_char cmx270_read_byte(struct mtd_info *mtd)
  57 {
  58         struct nand_chip *this = mtd->priv;
  59
  60         return (readl(this->IO_ADDR_R) >> 16);
  61 }
  62
  63 static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  64 {
  65         int i;
  66         struct nand_chip *this = mtd->priv;
  67
  68         for (i=0; i<len; i++)
  69                 writel((*buf++ << 16), this->IO_ADDR_W);
  70 }
  71
  72 static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)
  73 {
  74         int i;
  75         struct nand_chip *this = mtd->priv;
  76
  77         for (i=0; i<len; i++)
  78                 *buf++ = readl(this->IO_ADDR_R) >> 16;
  79 }
  80
  81 static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
  82 {
  83         int i;
  84         struct nand_chip *this = mtd->priv;
  85
  86         for (i=0; i<len; i++)
  87                 if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16))
  88                         return -EFAULT;
  89
  90         return 0;
  91 }
  92
  93 static inline void nand_cs_on(void)
  94 {
  95         gpio_set_value(GPIO_NAND_CS, 0);
  96 }
  97
  98 static void nand_cs_off(void)
  99 {
 100         dsb();
 101
 102         gpio_set_value(GPIO_NAND_CS, 1);
 103 }
 104
 105 /*
 106  *      hardware specific access to control-lines
 107  */
 108 static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,
 109                              unsigned int ctrl)
 110 {
 111         struct nand_chip* this = mtd->priv;
 112         unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
 113
 114         dsb();
 115
 116         if (ctrl & NAND_CTRL_CHANGE) {
 117                 if ( ctrl & NAND_ALE )
 118                         nandaddr |=  (1 << 3);
 119                 else
 120                         nandaddr &= ~(1 << 3);
 121                 if ( ctrl & NAND_CLE )
 122                         nandaddr |=  (1 << 2);
 123                 else
 124                         nandaddr &= ~(1 << 2);
 125                 if ( ctrl & NAND_NCE )
 126                         nand_cs_on();
 127                 else
 128                         nand_cs_off();
 129         }
 130
 131         dsb();
 132         this->IO_ADDR_W = (void __iomem*)nandaddr;
 133         if (dat != NAND_CMD_NONE)
 134                 writel((dat << 16), this->IO_ADDR_W);
 135
 136         dsb();
 137 }
 138
 139 /*
 140  *      read device ready pin
 141  */
 142 static int cmx270_device_ready(struct mtd_info *mtd)
 143 {
 144         dsb();
 145
 146         return (gpio_get_value(GPIO_NAND_RB));
 147 }
 148
 149 /*
 150  * Main initialization routine
 151  */
 152 static int __init cmx270_init(void)
 153 {
 154         struct nand_chip *this;
 155         const char *part_type;
 156         struct mtd_partition *mtd_parts;
 157         int mtd_parts_nb = 0;
 158         int ret;
 159
 160         if (!(machine_is_armcore() && cpu_is_pxa27x()))
 161                 return -ENODEV;
 162
 163         ret = gpio_request(GPIO_NAND_CS, "NAND CS");
 164         if (ret) {
 165                 pr_warning("CM-X270: failed to request NAND CS gpio\n");
 166                 return ret;
 167         }
 168
 169         gpio_direction_output(GPIO_NAND_CS, 1);
 170
 171         ret = gpio_request(GPIO_NAND_RB, "NAND R/B");
 172         if (ret) {
 173                 pr_warning("CM-X270: failed to request NAND R/B gpio\n");
 174                 goto err_gpio_request;
 175         }
 176
 177         gpio_direction_input(GPIO_NAND_RB);
 178
 179         /* Allocate memory for MTD device structure and private data */
 180         cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) +
 181                                   sizeof(struct nand_chip),
 182                                   GFP_KERNEL);
 183         if (!cmx270_nand_mtd) {
 184                 pr_debug("Unable to allocate CM-X270 NAND MTD device structure.\n");
 185                 ret = -ENOMEM;
 186                 goto err_kzalloc;
 187         }
 188
 189         cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);
 190         if (!cmx270_nand_io) {
 191                 pr_debug("Unable to ioremap NAND device\n");
 192                 ret = -EINVAL;
 193                 goto err_ioremap;
 194         }
 195
 196         /* Get pointer to private data */
 197         this = (struct nand_chip *)(&cmx270_nand_mtd[1]);
 198
 199         /* Link the private data with the MTD structure */
 200         cmx270_nand_mtd->owner = THIS_MODULE;
 201         cmx270_nand_mtd->priv = this;
 202
 203         /* insert callbacks */
 204         this->IO_ADDR_R = cmx270_nand_io;
 205         this->IO_ADDR_W = cmx270_nand_io;
 206         this->cmd_ctrl = cmx270_hwcontrol;
 207         this->dev_ready = cmx270_device_ready;
 208
 209         /* 15 us command delay time */
 210         this->chip_delay = 20;
 211         this->ecc.mode = NAND_ECC_SOFT;
 212
 213         /* read/write functions */
 214         this->read_byte = cmx270_read_byte;
 215         this->read_buf = cmx270_read_buf;
 216         this->write_buf = cmx270_write_buf;
 217         this->verify_buf = cmx270_verify_buf;
 218
 219         /* Scan to find existence of the device */
 220         if (nand_scan (cmx270_nand_mtd, 1)) {
 221                 pr_notice("No NAND device\n");
 222                 ret = -ENXIO;
 223                 goto err_scan;
 224         }
 225
 226 #ifdef CONFIG_MTD_CMDLINE_PARTS
 227         mtd_parts_nb = parse_mtd_partitions(cmx270_nand_mtd, part_probes,
 228                                             &mtd_parts, 0);
 229         if (mtd_parts_nb > 0)
 230                 part_type = "command line";
 231         else
 232                 mtd_parts_nb = 0;
 233 #endif
 234         if (!mtd_parts_nb) {
 235                 mtd_parts = partition_info;
 236                 mtd_parts_nb = NUM_PARTITIONS;
 237                 part_type = "static";
 238         }
 239
 240         /* Register the partitions */
 241         pr_notice("Using %s partition definition\n", part_type);
 242         ret = mtd_device_register(cmx270_nand_mtd, mtd_parts, mtd_parts_nb);
 243         if (ret)
 244                 goto err_scan;
 245
 246         /* Return happy */
 247         return 0;
 248
 249 err_scan:
 250         iounmap(cmx270_nand_io);
 251 err_ioremap:
 252         kfree(cmx270_nand_mtd);
 253 err_kzalloc:
 254         gpio_free(GPIO_NAND_RB);
 255 err_gpio_request:
 256         gpio_free(GPIO_NAND_CS);
 257
 258         return ret;
 259
 260 }
 261 module_init(cmx270_init);
 262
 263 /*
 264  * Clean up routine
 265  */
 266 static void __exit cmx270_cleanup(void)
 267 {
 268         /* Release resources, unregister device */
 269         nand_release(cmx270_nand_mtd);
 270
 271         gpio_free(GPIO_NAND_RB);
 272         gpio_free(GPIO_NAND_CS);
 273
 274         iounmap(cmx270_nand_io);
 275
 276         /* Free the MTD device structure */
 277         kfree (cmx270_nand_mtd);
 278 }
 279 module_exit(cmx270_cleanup);
 280
 281 MODULE_LICENSE("GPL");
 282 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
 283 MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");