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
  24 #include <asm/io.h>
  25 #include <asm/irq.h>
  26
  27 #include <asm/arch/hardware.h>
  28 #include <asm/arch/pxa-regs.h>
  29
  30 #define GPIO_NAND_CS    (11)
  31 #define GPIO_NAND_RB    (89)
  32
  33 /* This macro needed to ensure in-order operation of GPIO and local
  34  * bus. Without both asm command and dummy uncached read there're
  35  * states when NAND access is broken. I've looked for such macro(s) in
  36  * include/asm-arm but found nothing approptiate.
  37  * dmac_clean_range is close, but is makes cache invalidation
  38  * unnecessary here and it cannot be used in module
  39  */
  40 #define DRAIN_WB() \
  41         do { \
  42                 unsigned char dummy; \
  43                 asm volatile ("mcr p15, 0, r0, c7, c10, 4":::"r0"); \
  44                 dummy=*((unsigned char*)UNCACHED_ADDR); \
  45         } while(0)
  46
  47 /* MTD structure for CM-X270 board */
  48 static struct mtd_info *cmx270_nand_mtd;
  49
  50 /* remaped IO address of the device */
  51 static void __iomem *cmx270_nand_io;
  52
  53 /*
  54  * Define static partitions for flash device
  55  */
  56 static struct mtd_partition partition_info[] = {
  57         [0] = {
  58                 .name   = "cmx270-0",
  59                 .offset = 0,
  60                 .size   = MTDPART_SIZ_FULL
  61         }
  62 };
  63 #define NUM_PARTITIONS (ARRAY_SIZE(partition_info))
  64
  65 const char *part_probes[] = { "cmdlinepart", NULL };
  66
  67 static u_char cmx270_read_byte(struct mtd_info *mtd)
  68 {
  69         struct nand_chip *this = mtd->priv;
  70
  71         return (readl(this->IO_ADDR_R) >> 16);
  72 }
  73
  74 static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
  75 {
  76         int i;
  77         struct nand_chip *this = mtd->priv;
  78
  79         for (i=0; i<len; i++)
  80                 writel((*buf++ << 16), this->IO_ADDR_W);
  81 }
  82
  83 static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)
  84 {
  85         int i;
  86         struct nand_chip *this = mtd->priv;
  87
  88         for (i=0; i<len; i++)
  89                 *buf++ = readl(this->IO_ADDR_R) >> 16;
  90 }
  91
  92 static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
  93 {
  94         int i;
  95         struct nand_chip *this = mtd->priv;
  96
  97         for (i=0; i<len; i++)
  98                 if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16))
  99                         return -EFAULT;
 100
 101         return 0;
 102 }
 103
 104 static inline void nand_cs_on(void)
 105 {
 106         GPCR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);
 107 }
 108
 109 static void nand_cs_off(void)
 110 {
 111         DRAIN_WB();
 112
 113         GPSR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);
 114 }
 115
 116 /*
 117  *      hardware specific access to control-lines
 118  */
 119 static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,
 120                              unsigned int ctrl)
 121 {
 122         struct nand_chip* this = mtd->priv;
 123         unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
 124
 125         DRAIN_WB();
 126
 127         if (ctrl & NAND_CTRL_CHANGE) {
 128                 if ( ctrl & NAND_ALE )
 129                         nandaddr |=  (1 << 3);
 130                 else
 131                         nandaddr &= ~(1 << 3);
 132                 if ( ctrl & NAND_CLE )
 133                         nandaddr |=  (1 << 2);
 134                 else
 135                         nandaddr &= ~(1 << 2);
 136                 if ( ctrl & NAND_NCE )
 137                         nand_cs_on();
 138                 else
 139                         nand_cs_off();
 140         }
 141
 142         DRAIN_WB();
 143         this->IO_ADDR_W = (void __iomem*)nandaddr;
 144         if (dat != NAND_CMD_NONE)
 145                 writel((dat << 16), this->IO_ADDR_W);
 146
 147         DRAIN_WB();
 148 }
 149
 150 /*
 151  *      read device ready pin
 152  */
 153 static int cmx270_device_ready(struct mtd_info *mtd)
 154 {
 155         DRAIN_WB();
 156
 157         return (GPLR(GPIO_NAND_RB) & GPIO_bit(GPIO_NAND_RB));
 158 }
 159
 160 /*
 161  * Main initialization routine
 162  */
 163 static int cmx270_init(void)
 164 {
 165         struct nand_chip *this;
 166         const char *part_type;
 167         struct mtd_partition *mtd_parts;
 168         int mtd_parts_nb = 0;
 169         int ret;
 170
 171         /* Allocate memory for MTD device structure and private data */
 172         cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) +
 173                                   sizeof(struct nand_chip),
 174                                   GFP_KERNEL);
 175         if (!cmx270_nand_mtd) {
 176                 printk("Unable to allocate CM-X270 NAND MTD device structure.\n");
 177                 return -ENOMEM;
 178         }
 179
 180         cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);
 181         if (!cmx270_nand_io) {
 182                 printk("Unable to ioremap NAND device\n");
 183                 ret = -EINVAL;
 184                 goto err1;
 185         }
 186
 187         /* Get pointer to private data */
 188         this = (struct nand_chip *)(&cmx270_nand_mtd[1]);
 189
 190         /* Link the private data with the MTD structure */
 191         cmx270_nand_mtd->owner = THIS_MODULE;
 192         cmx270_nand_mtd->priv = this;
 193
 194         /* insert callbacks */
 195         this->IO_ADDR_R = cmx270_nand_io;
 196         this->IO_ADDR_W = cmx270_nand_io;
 197         this->cmd_ctrl = cmx270_hwcontrol;
 198         this->dev_ready = cmx270_device_ready;
 199
 200         /* 15 us command delay time */
 201         this->chip_delay = 20;
 202         this->ecc.mode = NAND_ECC_SOFT;
 203
 204         /* read/write functions */
 205         this->read_byte = cmx270_read_byte;
 206         this->read_buf = cmx270_read_buf;
 207         this->write_buf = cmx270_write_buf;
 208         this->verify_buf = cmx270_verify_buf;
 209
 210         /* Scan to find existence of the device */
 211         if (nand_scan (cmx270_nand_mtd, 1)) {
 212                 printk(KERN_NOTICE "No NAND device\n");
 213                 ret = -ENXIO;
 214                 goto err2;
 215         }
 216
 217 #ifdef CONFIG_MTD_CMDLINE_PARTS
 218         mtd_parts_nb = parse_mtd_partitions(cmx270_nand_mtd, part_probes,
 219                                             &mtd_parts, 0);
 220         if (mtd_parts_nb > 0)
 221                 part_type = "command line";
 222         else
 223                 mtd_parts_nb = 0;
 224 #endif
 225         if (!mtd_parts_nb) {
 226                 mtd_parts = partition_info;
 227                 mtd_parts_nb = NUM_PARTITIONS;
 228                 part_type = "static";
 229         }
 230
 231         /* Register the partitions */
 232         printk(KERN_NOTICE "Using %s partition definition\n", part_type);
 233         ret = add_mtd_partitions(cmx270_nand_mtd, mtd_parts, mtd_parts_nb);
 234         if (ret)
 235                 goto err2;
 236
 237         /* Return happy */
 238         return 0;
 239
 240 err2:
 241         iounmap(cmx270_nand_io);
 242 err1:
 243         kfree(cmx270_nand_mtd);
 244
 245         return ret;
 246
 247 }
 248 module_init(cmx270_init);
 249
 250 /*
 251  * Clean up routine
 252  */
 253 static void cmx270_cleanup(void)
 254 {
 255         /* Release resources, unregister device */
 256         nand_release(cmx270_nand_mtd);
 257
 258         iounmap(cmx270_nand_io);
 259
 260         /* Free the MTD device structure */
 261         kfree (cmx270_nand_mtd);
 262 }
 263 module_exit(cmx270_cleanup);
 264
 265 MODULE_LICENSE("GPL");
 266 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
 267 MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");