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 static u_char cmx270_read_byte(struct mtd_info *mtd)
  55 {
  56         struct nand_chip *this = mtd->priv;
  57
  58         return (readl(this->IO_ADDR_R) >> 16);
  59 }
  60
  61 static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  62 {
  63         int i;
  64         struct nand_chip *this = mtd->priv;
  65
  66         for (i=0; i<len; i++)
  67                 writel((*buf++ << 16), this->IO_ADDR_W);
  68 }
  69
  70 static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)
  71 {
  72         int i;
  73         struct nand_chip *this = mtd->priv;
  74
  75         for (i=0; i<len; i++)
  76                 *buf++ = readl(this->IO_ADDR_R) >> 16;
  77 }
  78
  79 static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
  80 {
  81         int i;
  82         struct nand_chip *this = mtd->priv;
  83
  84         for (i=0; i<len; i++)
  85                 if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16))
  86                         return -EFAULT;
  87
  88         return 0;
  89 }
  90
  91 static inline void nand_cs_on(void)
  92 {
  93         gpio_set_value(GPIO_NAND_CS, 0);
  94 }
  95
  96 static void nand_cs_off(void)
  97 {
  98         dsb();
  99
 100         gpio_set_value(GPIO_NAND_CS, 1);
 101 }
 102
 103 /*
 104  *      hardware specific access to control-lines
 105  */
 106 static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,
 107                              unsigned int ctrl)
 108 {
 109         struct nand_chip* this = mtd->priv;
 110         unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
 111
 112         dsb();
 113
 114         if (ctrl & NAND_CTRL_CHANGE) {
 115                 if ( ctrl & NAND_ALE )
 116                         nandaddr |=  (1 << 3);
 117                 else
 118                         nandaddr &= ~(1 << 3);
 119                 if ( ctrl & NAND_CLE )
 120                         nandaddr |=  (1 << 2);
 121                 else
 122                         nandaddr &= ~(1 << 2);
 123                 if ( ctrl & NAND_NCE )
 124                         nand_cs_on();
 125                 else
 126                         nand_cs_off();
 127         }
 128
 129         dsb();
 130         this->IO_ADDR_W = (void __iomem*)nandaddr;
 131         if (dat != NAND_CMD_NONE)
 132                 writel((dat << 16), this->IO_ADDR_W);
 133
 134         dsb();
 135 }
 136
 137 /*
 138  *      read device ready pin
 139  */
 140 static int cmx270_device_ready(struct mtd_info *mtd)
 141 {
 142         dsb();
 143
 144         return (gpio_get_value(GPIO_NAND_RB));
 145 }
 146
 147 /*
 148  * Main initialization routine
 149  */
 150 static int __init cmx270_init(void)
 151 {
 152         struct nand_chip *this;
 153         int ret;
 154
 155         if (!(machine_is_armcore() && cpu_is_pxa27x()))
 156                 return -ENODEV;
 157
 158         ret = gpio_request(GPIO_NAND_CS, "NAND CS");
 159         if (ret) {
 160                 pr_warning("CM-X270: failed to request NAND CS gpio\n");
 161                 return ret;
 162         }
 163
 164         gpio_direction_output(GPIO_NAND_CS, 1);
 165
 166         ret = gpio_request(GPIO_NAND_RB, "NAND R/B");
 167         if (ret) {
 168                 pr_warning("CM-X270: failed to request NAND R/B gpio\n");
 169                 goto err_gpio_request;
 170         }
 171
 172         gpio_direction_input(GPIO_NAND_RB);
 173
 174         /* Allocate memory for MTD device structure and private data */
 175         cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) +
 176                                   sizeof(struct nand_chip),
 177                                   GFP_KERNEL);
 178         if (!cmx270_nand_mtd) {
 179                 pr_debug("Unable to allocate CM-X270 NAND MTD device structure.\n");
 180                 ret = -ENOMEM;
 181                 goto err_kzalloc;
 182         }
 183
 184         cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);
 185         if (!cmx270_nand_io) {
 186                 pr_debug("Unable to ioremap NAND device\n");
 187                 ret = -EINVAL;
 188                 goto err_ioremap;
 189         }
 190
 191         /* Get pointer to private data */
 192         this = (struct nand_chip *)(&cmx270_nand_mtd[1]);
 193
 194         /* Link the private data with the MTD structure */
 195         cmx270_nand_mtd->owner = THIS_MODULE;
 196         cmx270_nand_mtd->priv = this;
 197
 198         /* insert callbacks */
 199         this->IO_ADDR_R = cmx270_nand_io;
 200         this->IO_ADDR_W = cmx270_nand_io;
 201         this->cmd_ctrl = cmx270_hwcontrol;
 202         this->dev_ready = cmx270_device_ready;
 203
 204         /* 15 us command delay time */
 205         this->chip_delay = 20;
 206         this->ecc.mode = NAND_ECC_SOFT;
 207
 208         /* read/write functions */
 209         this->read_byte = cmx270_read_byte;
 210         this->read_buf = cmx270_read_buf;
 211         this->write_buf = cmx270_write_buf;
 212         this->verify_buf = cmx270_verify_buf;
 213
 214         /* Scan to find existence of the device */
 215         if (nand_scan (cmx270_nand_mtd, 1)) {
 216                 pr_notice("No NAND device\n");
 217                 ret = -ENXIO;
 218                 goto err_scan;
 219         }
 220
 221         /* Register the partitions */
 222         ret = mtd_device_parse_register(cmx270_nand_mtd, NULL, 0,
 223                                         partition_info, NUM_PARTITIONS);
 224         if (ret)
 225                 goto err_scan;
 226
 227         /* Return happy */
 228         return 0;
 229
 230 err_scan:
 231         iounmap(cmx270_nand_io);
 232 err_ioremap:
 233         kfree(cmx270_nand_mtd);
 234 err_kzalloc:
 235         gpio_free(GPIO_NAND_RB);
 236 err_gpio_request:
 237         gpio_free(GPIO_NAND_CS);
 238
 239         return ret;
 240
 241 }
 242 module_init(cmx270_init);
 243
 244 /*
 245  * Clean up routine
 246  */
 247 static void __exit cmx270_cleanup(void)
 248 {
 249         /* Release resources, unregister device */
 250         nand_release(cmx270_nand_mtd);
 251
 252         gpio_free(GPIO_NAND_RB);
 253         gpio_free(GPIO_NAND_CS);
 254
 255         iounmap(cmx270_nand_io);
 256
 257         /* Free the MTD device structure */
 258         kfree (cmx270_nand_mtd);
 259 }
 260 module_exit(cmx270_cleanup);
 261
 262 MODULE_LICENSE("GPL");
 263 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
 264 MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");