kernel/drivers/mtd/nand/ndfc.c

   1 /*
   2  *  drivers/mtd/ndfc.c
   3  *
   4  *  Overview:
   5  *   Platform independent driver for NDFC (NanD Flash Controller)
   6  *   integrated into EP440 cores
   7  *
   8  *   Ported to an OF platform driver by Sean MacLennan
   9  *
  10  *   The NDFC supports multiple chips, but this driver only supports a
  11  *   single chip since I do not have access to any boards with
  12  *   multiple chips.
  13  *
  14  *  Author: Thomas Gleixner
  15  *
  16  *  Copyright 2006 IBM
  17  *  Copyright 2008 PIKA Technologies
  18  *    Sean MacLennan <smaclennan@pikatech.com>
  19  *
  20  *  This program is free software; you can redistribute  it and/or modify it
  21  *  under  the terms of  the GNU General  Public License as published by the
  22  *  Free Software Foundation;  either version 2 of the  License, or (at your
  23  *  option) any later version.
  24  *
  25  */
  26 #include <linux/module.h>
  27 #include <linux/mtd/nand.h>
  28 #include <linux/mtd/nand_ecc.h>
  29 #include <linux/mtd/partitions.h>
  30 #include <linux/mtd/ndfc.h>
  31 #include <linux/slab.h>
  32 #include <linux/mtd/mtd.h>
  33 #include <linux/of_address.h>
  34 #include <linux/of_platform.h>
  35 #include <asm/io.h>
  36
  37 #define NDFC_MAX_CS    4
  38
  39 struct ndfc_controller {
  40         struct platform_device *ofdev;
  41         void __iomem *ndfcbase;
  42         struct mtd_info mtd;
  43         struct nand_chip chip;
  44         int chip_select;
  45         struct nand_hw_control ndfc_control;
  46 };
  47
  48 static struct ndfc_controller ndfc_ctrl[NDFC_MAX_CS];
  49
  50 static void ndfc_select_chip(struct mtd_info *mtd, int chip)
  51 {
  52         uint32_t ccr;
  53         struct nand_chip *nchip = mtd->priv;
  54         struct ndfc_controller *ndfc = nchip->priv;
  55
  56         ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
  57         if (chip >= 0) {
  58                 ccr &= ~NDFC_CCR_BS_MASK;
  59                 ccr |= NDFC_CCR_BS(chip + ndfc->chip_select);
  60         } else
  61                 ccr |= NDFC_CCR_RESET_CE;
  62         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
  63 }
  64
  65 static void ndfc_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
  66 {
  67         struct nand_chip *chip = mtd->priv;
  68         struct ndfc_controller *ndfc = chip->priv;
  69
  70         if (cmd == NAND_CMD_NONE)
  71                 return;
  72
  73         if (ctrl & NAND_CLE)
  74                 writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_CMD);
  75         else
  76                 writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_ALE);
  77 }
  78
  79 static int ndfc_ready(struct mtd_info *mtd)
  80 {
  81         struct nand_chip *chip = mtd->priv;
  82         struct ndfc_controller *ndfc = chip->priv;
  83
  84         return in_be32(ndfc->ndfcbase + NDFC_STAT) & NDFC_STAT_IS_READY;
  85 }
  86
  87 static void ndfc_enable_hwecc(struct mtd_info *mtd, int mode)
  88 {
  89         uint32_t ccr;
  90         struct nand_chip *chip = mtd->priv;
  91         struct ndfc_controller *ndfc = chip->priv;
  92
  93         ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
  94         ccr |= NDFC_CCR_RESET_ECC;
  95         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
  96         wmb();
  97 }
  98
  99 static int ndfc_calculate_ecc(struct mtd_info *mtd,
 100                               const u_char *dat, u_char *ecc_code)
 101 {
 102         struct nand_chip *chip = mtd->priv;
 103         struct ndfc_controller *ndfc = chip->priv;
 104         uint32_t ecc;
 105         uint8_t *p = (uint8_t *)&ecc;
 106
 107         wmb();
 108         ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
 109         /* The NDFC uses Smart Media (SMC) bytes order */
 110         ecc_code[0] = p[1];
 111         ecc_code[1] = p[2];
 112         ecc_code[2] = p[3];
 113
 114         return 0;
 115 }
 116
 117 /*
 118  * Speedups for buffer read/write/verify
 119  *
 120  * NDFC allows 32bit read/write of data. So we can speed up the buffer
 121  * functions. No further checking, as nand_base will always read/write
 122  * page aligned.
 123  */
 124 static void ndfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 125 {
 126         struct nand_chip *chip = mtd->priv;
 127         struct ndfc_controller *ndfc = chip->priv;
 128         uint32_t *p = (uint32_t *) buf;
 129
 130         for(;len > 0; len -= 4)
 131                 *p++ = in_be32(ndfc->ndfcbase + NDFC_DATA);
 132 }
 133
 134 static void ndfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 135 {
 136         struct nand_chip *chip = mtd->priv;
 137         struct ndfc_controller *ndfc = chip->priv;
 138         uint32_t *p = (uint32_t *) buf;
 139
 140         for(;len > 0; len -= 4)
 141                 out_be32(ndfc->ndfcbase + NDFC_DATA, *p++);
 142 }
 143
 144 /*
 145  * Initialize chip structure
 146  */
 147 static int ndfc_chip_init(struct ndfc_controller *ndfc,
 148                           struct device_node *node)
 149 {
 150         struct device_node *flash_np;
 151         struct nand_chip *chip = &ndfc->chip;
 152         struct mtd_part_parser_data ppdata;
 153         int ret;
 154
 155         chip->IO_ADDR_R = ndfc->ndfcbase + NDFC_DATA;
 156         chip->IO_ADDR_W = ndfc->ndfcbase + NDFC_DATA;
 157         chip->cmd_ctrl = ndfc_hwcontrol;
 158         chip->dev_ready = ndfc_ready;
 159         chip->select_chip = ndfc_select_chip;
 160         chip->chip_delay = 50;
 161         chip->controller = &ndfc->ndfc_control;
 162         chip->read_buf = ndfc_read_buf;
 163         chip->write_buf = ndfc_write_buf;
 164         chip->ecc.correct = nand_correct_data;
 165         chip->ecc.hwctl = ndfc_enable_hwecc;
 166         chip->ecc.calculate = ndfc_calculate_ecc;
 167         chip->ecc.mode = NAND_ECC_HW;
 168         chip->ecc.size = 256;
 169         chip->ecc.bytes = 3;
 170         chip->ecc.strength = 1;
 171         chip->priv = ndfc;
 172
 173         ndfc->mtd.priv = chip;
 174         ndfc->mtd.owner = THIS_MODULE;
 175
 176         flash_np = of_get_next_child(node, NULL);
 177         if (!flash_np)
 178                 return -ENODEV;
 179
 180         ppdata.of_node = flash_np;
 181         ndfc->mtd.name = kasprintf(GFP_KERNEL, "%s.%s",
 182                         dev_name(&ndfc->ofdev->dev), flash_np->name);
 183         if (!ndfc->mtd.name) {
 184                 ret = -ENOMEM;
 185                 goto err;
 186         }
 187
 188         ret = nand_scan(&ndfc->mtd, 1);
 189         if (ret)
 190                 goto err;
 191
 192         ret = mtd_device_parse_register(&ndfc->mtd, NULL, &ppdata, NULL, 0);
 193
 194 err:
 195         of_node_put(flash_np);
 196         if (ret)
 197                 kfree(ndfc->mtd.name);
 198         return ret;
 199 }
 200
 201 static int ndfc_probe(struct platform_device *ofdev)
 202 {
 203         struct ndfc_controller *ndfc;
 204         const __be32 *reg;
 205         u32 ccr;
 206         u32 cs;
 207         int err, len;
 208
 209         /* Read the reg property to get the chip select */
 210         reg = of_get_property(ofdev->dev.of_node, "reg", &len);
 211         if (reg == NULL || len != 12) {
 212                 dev_err(&ofdev->dev, "unable read reg property (%d)\n", len);
 213                 return -ENOENT;
 214         }
 215
 216         cs = be32_to_cpu(reg[0]);
 217         if (cs >= NDFC_MAX_CS) {
 218                 dev_err(&ofdev->dev, "invalid CS number (%d)\n", cs);
 219                 return -EINVAL;
 220         }
 221
 222         ndfc = &ndfc_ctrl[cs];
 223         ndfc->chip_select = cs;
 224
 225         spin_lock_init(&ndfc->ndfc_control.lock);
 226         init_waitqueue_head(&ndfc->ndfc_control.wq);
 227         ndfc->ofdev = ofdev;
 228         dev_set_drvdata(&ofdev->dev, ndfc);
 229
 230         ndfc->ndfcbase = of_iomap(ofdev->dev.of_node, 0);
 231         if (!ndfc->ndfcbase) {
 232                 dev_err(&ofdev->dev, "failed to get memory\n");
 233                 return -EIO;
 234         }
 235
 236         ccr = NDFC_CCR_BS(ndfc->chip_select);
 237
 238         /* It is ok if ccr does not exist - just default to 0 */
 239         reg = of_get_property(ofdev->dev.of_node, "ccr", NULL);
 240         if (reg)
 241                 ccr |= be32_to_cpup(reg);
 242
 243         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
 244
 245         /* Set the bank settings if given */
 246         reg = of_get_property(ofdev->dev.of_node, "bank-settings", NULL);
 247         if (reg) {
 248                 int offset = NDFC_BCFG0 + (ndfc->chip_select << 2);
 249                 out_be32(ndfc->ndfcbase + offset, be32_to_cpup(reg));
 250         }
 251
 252         err = ndfc_chip_init(ndfc, ofdev->dev.of_node);
 253         if (err) {
 254                 iounmap(ndfc->ndfcbase);
 255                 return err;
 256         }
 257
 258         return 0;
 259 }
 260
 261 static int ndfc_remove(struct platform_device *ofdev)
 262 {
 263         struct ndfc_controller *ndfc = dev_get_drvdata(&ofdev->dev);
 264
 265         nand_release(&ndfc->mtd);
 266         kfree(ndfc->mtd.name);
 267
 268         return 0;
 269 }
 270
 271 static const struct of_device_id ndfc_match[] = {
 272         { .compatible = "ibm,ndfc", },
 273         {}
 274 };
 275 MODULE_DEVICE_TABLE(of, ndfc_match);
 276
 277 static struct platform_driver ndfc_driver = {
 278         .driver = {
 279                 .name = "ndfc",
 280                 .of_match_table = ndfc_match,
 281         },
 282         .probe = ndfc_probe,
 283         .remove = ndfc_remove,
 284 };
 285
 286 module_platform_driver(ndfc_driver);
 287
 288 MODULE_LICENSE("GPL");
 289 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
 290 MODULE_DESCRIPTION("OF Platform driver for NDFC");