drivers/mtd/nand/jz4780_nand.c

   1 /*
   2  * JZ4780 NAND driver
   3  *
   4  * Copyright (c) 2015 Imagination Technologies
   5  * Author: Alex Smith <alex.smith@imgtec.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published
   9  * by the Free Software Foundation.
  10  */
  11
  12 #include <linux/delay.h>
  13 #include <linux/init.h>
  14 #include <linux/io.h>
  15 #include <linux/list.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/slab.h>
  22 #include <linux/mtd/mtd.h>
  23 #include <linux/mtd/nand.h>
  24 #include <linux/mtd/partitions.h>
  25
  26 #include <linux/jz4780-nemc.h>
  27
  28 #include "jz4780_bch.h"
  29
  30 #define DRV_NAME        "jz4780-nand"
  31
  32 #define OFFSET_DATA     0x00000000
  33 #define OFFSET_CMD      0x00400000
  34 #define OFFSET_ADDR     0x00800000
  35
  36 /* Command delay when there is no R/B pin. */
  37 #define RB_DELAY_US     100
  38
  39 struct jz4780_nand_cs {
  40         unsigned int bank;
  41         void __iomem *base;
  42 };
  43
  44 struct jz4780_nand_controller {
  45         struct device *dev;
  46         struct jz4780_bch *bch;
  47         struct nand_hw_control controller;
  48         unsigned int num_banks;
  49         struct list_head chips;
  50         int selected;
  51         struct jz4780_nand_cs cs[];
  52 };
  53
  54 struct jz4780_nand_chip {
  55         struct nand_chip chip;
  56         struct list_head chip_list;
  57
  58         struct gpio_desc *busy_gpio;
  59         struct gpio_desc *wp_gpio;
  60         unsigned int reading: 1;
  61 };
  62
  63 static inline struct jz4780_nand_chip *to_jz4780_nand_chip(struct mtd_info *mtd)
  64 {
  65         return container_of(mtd_to_nand(mtd), struct jz4780_nand_chip, chip);
  66 }
  67
  68 static inline struct jz4780_nand_controller *to_jz4780_nand_controller(struct nand_hw_control *ctrl)
  69 {
  70         return container_of(ctrl, struct jz4780_nand_controller, controller);
  71 }
  72
  73 static void jz4780_nand_select_chip(struct mtd_info *mtd, int chipnr)
  74 {
  75         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
  76         struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
  77         struct jz4780_nand_cs *cs;
  78
  79         /* Ensure the currently selected chip is deasserted. */
  80         if (chipnr == -1 && nfc->selected >= 0) {
  81                 cs = &nfc->cs[nfc->selected];
  82                 jz4780_nemc_assert(nfc->dev, cs->bank, false);
  83         }
  84
  85         nfc->selected = chipnr;
  86 }
  87
  88 static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
  89                                  unsigned int ctrl)
  90 {
  91         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
  92         struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
  93         struct jz4780_nand_cs *cs;
  94
  95         if (WARN_ON(nfc->selected < 0))
  96                 return;
  97
  98         cs = &nfc->cs[nfc->selected];
  99
 100         jz4780_nemc_assert(nfc->dev, cs->bank, ctrl & NAND_NCE);
 101
 102         if (cmd == NAND_CMD_NONE)
 103                 return;
 104
 105         if (ctrl & NAND_ALE)
 106                 writeb(cmd, cs->base + OFFSET_ADDR);
 107         else if (ctrl & NAND_CLE)
 108                 writeb(cmd, cs->base + OFFSET_CMD);
 109 }
 110
 111 static int jz4780_nand_dev_ready(struct mtd_info *mtd)
 112 {
 113         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
 114
 115         return !gpiod_get_value_cansleep(nand->busy_gpio);
 116 }
 117
 118 static void jz4780_nand_ecc_hwctl(struct mtd_info *mtd, int mode)
 119 {
 120         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
 121
 122         nand->reading = (mode == NAND_ECC_READ);
 123 }
 124
 125 static int jz4780_nand_ecc_calculate(struct mtd_info *mtd, const u8 *dat,
 126                                      u8 *ecc_code)
 127 {
 128         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
 129         struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
 130         struct jz4780_bch_params params;
 131
 132         /*
 133          * Don't need to generate the ECC when reading, BCH does it for us as
 134          * part of decoding/correction.
 135          */
 136         if (nand->reading)
 137                 return 0;
 138
 139         params.size = nand->chip.ecc.size;
 140         params.bytes = nand->chip.ecc.bytes;
 141         params.strength = nand->chip.ecc.strength;
 142
 143         return jz4780_bch_calculate(nfc->bch, &params, dat, ecc_code);
 144 }
 145
 146 static int jz4780_nand_ecc_correct(struct mtd_info *mtd, u8 *dat,
 147                                    u8 *read_ecc, u8 *calc_ecc)
 148 {
 149         struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
 150         struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
 151         struct jz4780_bch_params params;
 152
 153         params.size = nand->chip.ecc.size;
 154         params.bytes = nand->chip.ecc.bytes;
 155         params.strength = nand->chip.ecc.strength;
 156
 157         return jz4780_bch_correct(nfc->bch, &params, dat, read_ecc);
 158 }
 159
 160 static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *dev)
 161 {
 162         struct nand_chip *chip = &nand->chip;
 163         struct mtd_info *mtd = nand_to_mtd(chip);
 164         struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
 165         int eccbytes;
 166
 167         chip->ecc.bytes = fls((1 + 8) * chip->ecc.size) *
 168                                 (chip->ecc.strength / 8);
 169
 170         switch (chip->ecc.mode) {
 171         case NAND_ECC_HW:
 172                 if (!nfc->bch) {
 173                         dev_err(dev, "HW BCH selected, but BCH controller not found\n");
 174                         return -ENODEV;
 175                 }
 176
 177                 chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
 178                 chip->ecc.calculate = jz4780_nand_ecc_calculate;
 179                 chip->ecc.correct = jz4780_nand_ecc_correct;
 180                 /* fall through */
 181         case NAND_ECC_SOFT:
 182                 dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
 183                         (nfc->bch) ? "hardware BCH" : "software ECC",
 184                         chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
 185                 break;
 186         case NAND_ECC_NONE:
 187                 dev_info(dev, "not using ECC\n");
 188                 break;
 189         default:
 190                 dev_err(dev, "ECC mode %d not supported\n", chip->ecc.mode);
 191                 return -EINVAL;
 192         }
 193
 194         /* The NAND core will generate the ECC layout for SW ECC */
 195         if (chip->ecc.mode != NAND_ECC_HW)
 196                 return 0;
 197
 198         /* Generate ECC layout. ECC codes are right aligned in the OOB area. */
 199         eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
 200
 201         if (eccbytes > mtd->oobsize - 2) {
 202                 dev_err(dev,
 203                         "invalid ECC config: required %d ECC bytes, but only %d are available",
 204                         eccbytes, mtd->oobsize - 2);
 205                 return -EINVAL;
 206         }
 207
 208         mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
 209
 210         return 0;
 211 }
 212
 213 static int jz4780_nand_init_chip(struct platform_device *pdev,
 214                                 struct jz4780_nand_controller *nfc,
 215                                 struct device_node *np,
 216                                 unsigned int chipnr)
 217 {
 218         struct device *dev = &pdev->dev;
 219         struct jz4780_nand_chip *nand;
 220         struct jz4780_nand_cs *cs;
 221         struct resource *res;
 222         struct nand_chip *chip;
 223         struct mtd_info *mtd;
 224         const __be32 *reg;
 225         int ret = 0;
 226
 227         cs = &nfc->cs[chipnr];
 228
 229         reg = of_get_property(np, "reg", NULL);
 230         if (!reg)
 231                 return -EINVAL;
 232
 233         cs->bank = be32_to_cpu(*reg);
 234
 235         jz4780_nemc_set_type(nfc->dev, cs->bank, JZ4780_NEMC_BANK_NAND);
 236
 237         res = platform_get_resource(pdev, IORESOURCE_MEM, chipnr);
 238         cs->base = devm_ioremap_resource(dev, res);
 239         if (IS_ERR(cs->base))
 240                 return PTR_ERR(cs->base);
 241
 242         nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
 243         if (!nand)
 244                 return -ENOMEM;
 245
 246         nand->busy_gpio = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
 247
 248         if (IS_ERR(nand->busy_gpio)) {
 249                 ret = PTR_ERR(nand->busy_gpio);
 250                 dev_err(dev, "failed to request busy GPIO: %d\n", ret);
 251                 return ret;
 252         } else if (nand->busy_gpio) {
 253                 nand->chip.dev_ready = jz4780_nand_dev_ready;
 254         }
 255
 256         nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
 257
 258         if (IS_ERR(nand->wp_gpio)) {
 259                 ret = PTR_ERR(nand->wp_gpio);
 260                 dev_err(dev, "failed to request WP GPIO: %d\n", ret);
 261                 return ret;
 262         }
 263
 264         chip = &nand->chip;
 265         mtd = nand_to_mtd(chip);
 266         mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev),
 267                                    cs->bank);
 268         if (!mtd->name)
 269                 return -ENOMEM;
 270         mtd->dev.parent = dev;
 271
 272         chip->IO_ADDR_R = cs->base + OFFSET_DATA;
 273         chip->IO_ADDR_W = cs->base + OFFSET_DATA;
 274         chip->chip_delay = RB_DELAY_US;
 275         chip->options = NAND_NO_SUBPAGE_WRITE;
 276         chip->select_chip = jz4780_nand_select_chip;
 277         chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
 278         chip->ecc.mode = NAND_ECC_HW;
 279         chip->controller = &nfc->controller;
 280         nand_set_flash_node(chip, np);
 281
 282         ret = nand_scan_ident(mtd, 1, NULL);
 283         if (ret)
 284                 return ret;
 285
 286         ret = jz4780_nand_init_ecc(nand, dev);
 287         if (ret)
 288                 return ret;
 289
 290         ret = nand_scan_tail(mtd);
 291         if (ret)
 292                 return ret;
 293
 294         ret = mtd_device_register(mtd, NULL, 0);
 295         if (ret) {
 296                 nand_release(mtd);
 297                 return ret;
 298         }
 299
 300         list_add_tail(&nand->chip_list, &nfc->chips);
 301
 302         return 0;
 303 }
 304
 305 static void jz4780_nand_cleanup_chips(struct jz4780_nand_controller *nfc)
 306 {
 307         struct jz4780_nand_chip *chip;
 308
 309         while (!list_empty(&nfc->chips)) {
 310                 chip = list_first_entry(&nfc->chips, struct jz4780_nand_chip, chip_list);
 311                 nand_release(nand_to_mtd(&chip->chip));
 312                 list_del(&chip->chip_list);
 313         }
 314 }
 315
 316 static int jz4780_nand_init_chips(struct jz4780_nand_controller *nfc,
 317                                   struct platform_device *pdev)
 318 {
 319         struct device *dev = &pdev->dev;
 320         struct device_node *np;
 321         int i = 0;
 322         int ret;
 323         int num_chips = of_get_child_count(dev->of_node);
 324
 325         if (num_chips > nfc->num_banks) {
 326                 dev_err(dev, "found %d chips but only %d banks\n", num_chips, nfc->num_banks);
 327                 return -EINVAL;
 328         }
 329
 330         for_each_child_of_node(dev->of_node, np) {
 331                 ret = jz4780_nand_init_chip(pdev, nfc, np, i);
 332                 if (ret) {
 333                         jz4780_nand_cleanup_chips(nfc);
 334                         return ret;
 335                 }
 336
 337                 i++;
 338         }
 339
 340         return 0;
 341 }
 342
 343 static int jz4780_nand_probe(struct platform_device *pdev)
 344 {
 345         struct device *dev = &pdev->dev;
 346         unsigned int num_banks;
 347         struct jz4780_nand_controller *nfc;
 348         int ret;
 349
 350         num_banks = jz4780_nemc_num_banks(dev);
 351         if (num_banks == 0) {
 352                 dev_err(dev, "no banks found\n");
 353                 return -ENODEV;
 354         }
 355
 356         nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
 357         if (!nfc)
 358                 return -ENOMEM;
 359
 360         /*
 361          * Check for BCH HW before we call nand_scan_ident, to prevent us from
 362          * having to call it again if the BCH driver returns -EPROBE_DEFER.
 363          */
 364         nfc->bch = of_jz4780_bch_get(dev->of_node);
 365         if (IS_ERR(nfc->bch))
 366                 return PTR_ERR(nfc->bch);
 367
 368         nfc->dev = dev;
 369         nfc->num_banks = num_banks;
 370
 371         nand_hw_control_init(&nfc->controller);
 372         INIT_LIST_HEAD(&nfc->chips);
 373
 374         ret = jz4780_nand_init_chips(nfc, pdev);
 375         if (ret) {
 376                 if (nfc->bch)
 377                         jz4780_bch_release(nfc->bch);
 378                 return ret;
 379         }
 380
 381         platform_set_drvdata(pdev, nfc);
 382         return 0;
 383 }
 384
 385 static int jz4780_nand_remove(struct platform_device *pdev)
 386 {
 387         struct jz4780_nand_controller *nfc = platform_get_drvdata(pdev);
 388
 389         if (nfc->bch)
 390                 jz4780_bch_release(nfc->bch);
 391
 392         jz4780_nand_cleanup_chips(nfc);
 393
 394         return 0;
 395 }
 396
 397 static const struct of_device_id jz4780_nand_dt_match[] = {
 398         { .compatible = "ingenic,jz4780-nand" },
 399         {},
 400 };
 401 MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
 402
 403 static struct platform_driver jz4780_nand_driver = {
 404         .probe          = jz4780_nand_probe,
 405         .remove         = jz4780_nand_remove,
 406         .driver = {
 407                 .name   = DRV_NAME,
 408                 .of_match_table = of_match_ptr(jz4780_nand_dt_match),
 409         },
 410 };
 411 module_platform_driver(jz4780_nand_driver);
 412
 413 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
 414 MODULE_AUTHOR("Harvey Hunt <harveyhuntnexus@gmail.com>");
 415 MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
 416 MODULE_LICENSE("GPL v2");