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