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