drivers/mtd/nand/raw/ndfc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Overview:
   4  *   Platform independent driver for NDFC (NanD Flash Controller)
   5  *   integrated into EP440 cores
   6  *
   7  *   Ported to an OF platform driver by Sean MacLennan
   8  *
   9  *   The NDFC supports multiple chips, but this driver only supports a
  10  *   single chip since I do not have access to any boards with
  11  *   multiple chips.
  12  *
  13  *  Author: Thomas Gleixner
  14  *
  15  *  Copyright 2006 IBM
  16  *  Copyright 2008 PIKA Technologies
  17  *    Sean MacLennan <smaclennan@pikatech.com>
  18  */
  19 #include <linux/module.h>
  20 #include <linux/mtd/rawnand.h>
  21 #include <linux/mtd/partitions.h>
  22 #include <linux/mtd/ndfc.h>
  23 #include <linux/slab.h>
  24 #include <linux/mtd/mtd.h>
  25 #include <linux/of_address.h>
  26 #include <linux/of_platform.h>
  27 #include <asm/io.h>
  28
  29 #define NDFC_MAX_CS    4
  30
  31 struct ndfc_controller {
  32         struct platform_device *ofdev;
  33         void __iomem *ndfcbase;
  34         struct nand_chip chip;
  35         int chip_select;
  36         struct nand_controller ndfc_control;
  37 };
  38
  39 static struct ndfc_controller ndfc_ctrl[NDFC_MAX_CS];
  40
  41 static void ndfc_select_chip(struct nand_chip *nchip, int chip)
  42 {
  43         uint32_t ccr;
  44         struct ndfc_controller *ndfc = nand_get_controller_data(nchip);
  45
  46         ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
  47         if (chip >= 0) {
  48                 ccr &= ~NDFC_CCR_BS_MASK;
  49                 ccr |= NDFC_CCR_BS(chip + ndfc->chip_select);
  50         } else
  51                 ccr |= NDFC_CCR_RESET_CE;
  52         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
  53 }
  54
  55 static void ndfc_hwcontrol(struct nand_chip *chip, int cmd, unsigned int ctrl)
  56 {
  57         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
  58
  59         if (cmd == NAND_CMD_NONE)
  60                 return;
  61
  62         if (ctrl & NAND_CLE)
  63                 writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_CMD);
  64         else
  65                 writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_ALE);
  66 }
  67
  68 static int ndfc_ready(struct nand_chip *chip)
  69 {
  70         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
  71
  72         return in_be32(ndfc->ndfcbase + NDFC_STAT) & NDFC_STAT_IS_READY;
  73 }
  74
  75 static void ndfc_enable_hwecc(struct nand_chip *chip, int mode)
  76 {
  77         uint32_t ccr;
  78         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
  79
  80         ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
  81         ccr |= NDFC_CCR_RESET_ECC;
  82         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
  83         wmb();
  84 }
  85
  86 static int ndfc_calculate_ecc(struct nand_chip *chip,
  87                               const u_char *dat, u_char *ecc_code)
  88 {
  89         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
  90         uint32_t ecc;
  91         uint8_t *p = (uint8_t *)&ecc;
  92
  93         wmb();
  94         ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
  95         /* The NDFC uses Smart Media (SMC) bytes order */
  96         ecc_code[0] = p[1];
  97         ecc_code[1] = p[2];
  98         ecc_code[2] = p[3];
  99
 100         return 0;
 101 }
 102
 103 /*
 104  * Speedups for buffer read/write/verify
 105  *
 106  * NDFC allows 32bit read/write of data. So we can speed up the buffer
 107  * functions. No further checking, as nand_base will always read/write
 108  * page aligned.
 109  */
 110 static void ndfc_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
 111 {
 112         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
 113         uint32_t *p = (uint32_t *) buf;
 114
 115         for(;len > 0; len -= 4)
 116                 *p++ = in_be32(ndfc->ndfcbase + NDFC_DATA);
 117 }
 118
 119 static void ndfc_write_buf(struct nand_chip *chip, const uint8_t *buf, int len)
 120 {
 121         struct ndfc_controller *ndfc = nand_get_controller_data(chip);
 122         uint32_t *p = (uint32_t *) buf;
 123
 124         for(;len > 0; len -= 4)
 125                 out_be32(ndfc->ndfcbase + NDFC_DATA, *p++);
 126 }
 127
 128 /*
 129  * Initialize chip structure
 130  */
 131 static int ndfc_chip_init(struct ndfc_controller *ndfc,
 132                           struct device_node *node)
 133 {
 134         struct device_node *flash_np;
 135         struct nand_chip *chip = &ndfc->chip;
 136         struct mtd_info *mtd = nand_to_mtd(chip);
 137         int ret;
 138
 139         chip->legacy.IO_ADDR_R = ndfc->ndfcbase + NDFC_DATA;
 140         chip->legacy.IO_ADDR_W = ndfc->ndfcbase + NDFC_DATA;
 141         chip->legacy.cmd_ctrl = ndfc_hwcontrol;
 142         chip->legacy.dev_ready = ndfc_ready;
 143         chip->legacy.select_chip = ndfc_select_chip;
 144         chip->legacy.chip_delay = 50;
 145         chip->controller = &ndfc->ndfc_control;
 146         chip->legacy.read_buf = ndfc_read_buf;
 147         chip->legacy.write_buf = ndfc_write_buf;
 148         chip->ecc.correct = rawnand_sw_hamming_correct;
 149         chip->ecc.hwctl = ndfc_enable_hwecc;
 150         chip->ecc.calculate = ndfc_calculate_ecc;
 151         chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
 152         chip->ecc.size = 256;
 153         chip->ecc.bytes = 3;
 154         chip->ecc.strength = 1;
 155         nand_set_controller_data(chip, ndfc);
 156
 157         mtd->dev.parent = &ndfc->ofdev->dev;
 158
 159         flash_np = of_get_next_child(node, NULL);
 160         if (!flash_np)
 161                 return -ENODEV;
 162         nand_set_flash_node(chip, flash_np);
 163
 164         mtd->name = kasprintf(GFP_KERNEL, "%s.%pOFn", dev_name(&ndfc->ofdev->dev),
 165                               flash_np);
 166         if (!mtd->name) {
 167                 ret = -ENOMEM;
 168                 goto err;
 169         }
 170
 171         ret = nand_scan(chip, 1);
 172         if (ret)
 173                 goto err;
 174
 175         ret = mtd_device_register(mtd, NULL, 0);
 176
 177 err:
 178         of_node_put(flash_np);
 179         if (ret)
 180                 kfree(mtd->name);
 181         return ret;
 182 }
 183
 184 static int ndfc_probe(struct platform_device *ofdev)
 185 {
 186         struct ndfc_controller *ndfc;
 187         const __be32 *reg;
 188         u32 ccr;
 189         u32 cs;
 190         int err, len;
 191
 192         /* Read the reg property to get the chip select */
 193         reg = of_get_property(ofdev->dev.of_node, "reg", &len);
 194         if (reg == NULL || len != 12) {
 195                 dev_err(&ofdev->dev, "unable read reg property (%d)\n", len);
 196                 return -ENOENT;
 197         }
 198
 199         cs = be32_to_cpu(reg[0]);
 200         if (cs >= NDFC_MAX_CS) {
 201                 dev_err(&ofdev->dev, "invalid CS number (%d)\n", cs);
 202                 return -EINVAL;
 203         }
 204
 205         ndfc = &ndfc_ctrl[cs];
 206         ndfc->chip_select = cs;
 207
 208         nand_controller_init(&ndfc->ndfc_control);
 209         ndfc->ofdev = ofdev;
 210         dev_set_drvdata(&ofdev->dev, ndfc);
 211
 212         ndfc->ndfcbase = of_iomap(ofdev->dev.of_node, 0);
 213         if (!ndfc->ndfcbase) {
 214                 dev_err(&ofdev->dev, "failed to get memory\n");
 215                 return -EIO;
 216         }
 217
 218         ccr = NDFC_CCR_BS(ndfc->chip_select);
 219
 220         /* It is ok if ccr does not exist - just default to 0 */
 221         reg = of_get_property(ofdev->dev.of_node, "ccr", NULL);
 222         if (reg)
 223                 ccr |= be32_to_cpup(reg);
 224
 225         out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
 226
 227         /* Set the bank settings if given */
 228         reg = of_get_property(ofdev->dev.of_node, "bank-settings", NULL);
 229         if (reg) {
 230                 int offset = NDFC_BCFG0 + (ndfc->chip_select << 2);
 231                 out_be32(ndfc->ndfcbase + offset, be32_to_cpup(reg));
 232         }
 233
 234         err = ndfc_chip_init(ndfc, ofdev->dev.of_node);
 235         if (err) {
 236                 iounmap(ndfc->ndfcbase);
 237                 return err;
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int ndfc_remove(struct platform_device *ofdev)
 244 {
 245         struct ndfc_controller *ndfc = dev_get_drvdata(&ofdev->dev);
 246         struct nand_chip *chip = &ndfc->chip;
 247         struct mtd_info *mtd = nand_to_mtd(chip);
 248         int ret;
 249
 250         ret = mtd_device_unregister(mtd);
 251         WARN_ON(ret);
 252         nand_cleanup(chip);
 253         kfree(mtd->name);
 254
 255         return 0;
 256 }
 257
 258 static const struct of_device_id ndfc_match[] = {
 259         { .compatible = "ibm,ndfc", },
 260         {}
 261 };
 262 MODULE_DEVICE_TABLE(of, ndfc_match);
 263
 264 static struct platform_driver ndfc_driver = {
 265         .driver = {
 266                 .name = "ndfc",
 267                 .of_match_table = ndfc_match,
 268         },
 269         .probe = ndfc_probe,
 270         .remove = ndfc_remove,
 271 };
 272
 273 module_platform_driver(ndfc_driver);
 274
 275 MODULE_LICENSE("GPL");
 276 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
 277 MODULE_DESCRIPTION("OF Platform driver for NDFC");