linux/drivers/mtd/nand/raw/jz4780_nand.c
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   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/rawnand.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
  39struct jz4780_nand_cs {
  40        unsigned int bank;
  41        void __iomem *base;
  42};
  43
  44struct 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
  54struct 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
  63static 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
  68static 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
  73static 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
  88static 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
 111static 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
 118static 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
 125static 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
 146static 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
 160static 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
 213static 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
 305static 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
 316static 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
 343static 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
 385static 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
 397static const struct of_device_id jz4780_nand_dt_match[] = {
 398        { .compatible = "ingenic,jz4780-nand" },
 399        {},
 400};
 401MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
 402
 403static 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};
 411module_platform_driver(jz4780_nand_driver);
 412
 413MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
 414MODULE_AUTHOR("Harvey Hunt <harveyhuntnexus@gmail.com>");
 415MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
 416MODULE_LICENSE("GPL v2");
 417