drivers/mtd/nand/ndfc.c

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