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