target/linux/ath79/files/drivers/mtd/nand/raw/nand_rb4xx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * NAND driver for the MikroTik RouterBoard 4xx series
   4  *
   5  * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
   6  * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   7  * Copyright (C) 2015 Bert Vermeulen <bert@biot.com>
   8  * Copyright (C) 2020 Christopher Hill <ch6574@gmail.com>
   9  *
  10  * This file was based on the driver for Linux 2.6.22 published by
  11  * MikroTik for their RouterBoard 4xx series devices.
  12  *
  13  * N.B. driver probe reports "DMA mask not set" warnings which are
  14  * an artifact of using a platform_driver as an MFD device child.
  15  * See conversation here https://lkml.org/lkml/2020/4/28/675
  16  */
  17 #include <linux/platform_device.h>
  18 #include <linux/mtd/rawnand.h>
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/module.h>
  21 #include <linux/of_device.h>
  22 #include <linux/version.h>
  23
  24 #include <mfd/rb4xx-cpld.h>
  25
  26 struct rb4xx_nand {
  27         struct rb4xx_cpld *cpld;
  28         struct device *dev;
  29
  30         struct nand_chip chip;
  31         struct gpio_desc *ale;
  32         struct gpio_desc *cle;
  33         struct gpio_desc *nce;
  34         struct gpio_desc *rdy;
  35 };
  36
  37 static int rb4xx_ooblayout_ecc(struct mtd_info *mtd, int section,
  38                                struct mtd_oob_region *oobregion)
  39 {
  40         switch (section) {
  41         case 0:
  42                 oobregion->offset = 8;
  43                 oobregion->length = 3;
  44                 return 0;
  45         case 1:
  46                 oobregion->offset = 13;
  47                 oobregion->length = 3;
  48                 return 0;
  49         default:
  50                 return -ERANGE;
  51         }
  52 }
  53
  54 static int rb4xx_ooblayout_free(struct mtd_info *mtd, int section,
  55                                 struct mtd_oob_region *oobregion)
  56 {
  57         switch (section) {
  58         case 0:
  59                 oobregion->offset = 0;
  60                 oobregion->length = 4;
  61                 return 0;
  62         case 1:
  63                 oobregion->offset = 4;
  64                 oobregion->length = 1;
  65                 return 0;
  66         case 2:
  67                 oobregion->offset = 6;
  68                 oobregion->length = 2;
  69                 return 0;
  70         case 3:
  71                 oobregion->offset = 11;
  72                 oobregion->length = 2;
  73                 return 0;
  74         default:
  75                 return -ERANGE;
  76         }
  77 }
  78
  79 static const struct mtd_ooblayout_ops rb4xx_nand_ecclayout_ops = {
  80         .ecc = rb4xx_ooblayout_ecc,
  81         .free = rb4xx_ooblayout_free,
  82 };
  83
  84 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
  85 static uint8_t rb4xx_nand_read_byte(struct mtd_info *mtd)
  86 {
  87         struct rb4xx_nand *nand = mtd->priv;
  88 #else
  89 static u8 rb4xx_nand_read_byte(struct nand_chip *chip)
  90 {
  91         struct rb4xx_nand *nand = chip->priv;
  92 #endif
  93         struct rb4xx_cpld *cpld = nand->cpld;
  94         u8 data;
  95         int ret;
  96
  97         ret = cpld->read_nand(cpld, &data, 1);
  98         if (unlikely(ret))
  99                 return 0xff;
 100
 101         return data;
 102 }
 103
 104 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 105 static void rb4xx_nand_write_buf(struct mtd_info *mtd, const uint8_t *buf,
 106                                  int len)
 107 {
 108         struct rb4xx_nand *nand = mtd->priv;
 109 #else
 110 static void rb4xx_nand_write_buf(struct nand_chip *chip, const u8 *buf, int len)
 111 {
 112         struct rb4xx_nand *nand = chip->priv;
 113 #endif
 114         struct rb4xx_cpld *cpld = nand->cpld;
 115
 116         cpld->write_nand(cpld, buf, len);
 117 }
 118
 119 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 120 static void rb4xx_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 121 {
 122         struct rb4xx_nand *nand = mtd->priv;
 123 #else
 124 static void rb4xx_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
 125 {
 126         struct rb4xx_nand *nand = chip->priv;
 127 #endif
 128         struct rb4xx_cpld *cpld = nand->cpld;
 129
 130         cpld->read_nand(cpld, buf, len);
 131 }
 132
 133 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 134 static void rb4xx_nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
 135 {
 136         struct rb4xx_nand *nand = mtd->priv;
 137 #else
 138 static void rb4xx_nand_cmd_ctrl(struct nand_chip *chip, int dat,
 139                                 unsigned int ctrl)
 140 {
 141         struct rb4xx_nand *nand = chip->priv;
 142 #endif
 143         struct rb4xx_cpld *cpld = nand->cpld;
 144         u8 data = dat;
 145
 146         if (ctrl & NAND_CTRL_CHANGE) {
 147                 gpiod_set_value_cansleep(nand->cle, !!(ctrl & NAND_CLE));
 148                 gpiod_set_value_cansleep(nand->ale, !!(ctrl & NAND_ALE));
 149                 gpiod_set_value_cansleep(nand->nce,  !(ctrl & NAND_NCE));
 150         }
 151
 152         if (dat != NAND_CMD_NONE)
 153                 cpld->write_nand(cpld, &data, 1);
 154 }
 155
 156 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 157 static int rb4xx_nand_dev_ready(struct mtd_info *mtd)
 158 {
 159         struct rb4xx_nand *nand = mtd->priv;
 160 #else
 161 static int rb4xx_nand_dev_ready(struct nand_chip *chip)
 162 {
 163         struct rb4xx_nand *nand = chip->priv;
 164 #endif
 165
 166         return gpiod_get_value_cansleep(nand->rdy);
 167 }
 168
 169 static int rb4xx_nand_probe(struct platform_device *pdev)
 170 {
 171         struct device *dev = &pdev->dev;
 172         struct device *parent = dev->parent;
 173         struct rb4xx_nand *nand;
 174         struct mtd_info *mtd;
 175         int ret;
 176
 177         if (!parent)
 178                 return -ENODEV;
 179
 180         nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
 181         if (!nand)
 182                 return -ENOMEM;
 183
 184         platform_set_drvdata(pdev, nand);
 185         nand->cpld      = dev_get_drvdata(parent);
 186         nand->dev       = dev;
 187
 188         nand->ale = devm_gpiod_get_index(dev, NULL, 0, GPIOD_OUT_LOW);
 189         if (IS_ERR(nand->ale))
 190                 dev_err(dev, "missing gpio ALE: %ld\n", PTR_ERR(nand->ale));
 191
 192         nand->cle = devm_gpiod_get_index(dev, NULL, 1, GPIOD_OUT_LOW);
 193         if (IS_ERR(nand->cle))
 194                 dev_err(dev, "missing gpio CLE: %ld\n", PTR_ERR(nand->cle));
 195
 196         nand->nce = devm_gpiod_get_index(dev, NULL, 2, GPIOD_OUT_LOW);
 197         if (IS_ERR(nand->nce))
 198                 dev_err(dev, "missing gpio nCE: %ld\n", PTR_ERR(nand->nce));
 199
 200         nand->rdy = devm_gpiod_get_index(dev, NULL, 3, GPIOD_IN);
 201         if (IS_ERR(nand->rdy))
 202                 dev_err(dev, "missing gpio RDY: %ld\n", PTR_ERR(nand->rdy));
 203
 204         if (IS_ERR(nand->ale) || IS_ERR(nand->cle) ||
 205             IS_ERR(nand->nce) || IS_ERR(nand->rdy))
 206                 return -ENOENT;
 207
 208         gpiod_set_consumer_name(nand->ale, "mikrotik:nand:ALE");
 209         gpiod_set_consumer_name(nand->cle, "mikrotik:nand:CLE");
 210         gpiod_set_consumer_name(nand->nce, "mikrotik:nand:nCE");
 211         gpiod_set_consumer_name(nand->rdy, "mikrotik:nand:RDY");
 212
 213         mtd = nand_to_mtd(&nand->chip);
 214         mtd->priv       = nand;
 215         mtd->owner      = THIS_MODULE;
 216         mtd->dev.parent = dev;
 217         mtd_set_of_node(mtd, dev->of_node);
 218
 219         if (mtd->writesize == 512)
 220                 mtd_set_ooblayout(mtd, &rb4xx_nand_ecclayout_ops);
 221
 222         nand->chip.ecc.mode     = NAND_ECC_SOFT;
 223         nand->chip.ecc.algo     = NAND_ECC_HAMMING;
 224         nand->chip.options      = NAND_NO_SUBPAGE_WRITE;
 225         nand->chip.priv         = nand;
 226
 227 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 228         nand->chip.read_byte    = rb4xx_nand_read_byte;
 229         nand->chip.write_buf    = rb4xx_nand_write_buf;
 230         nand->chip.read_buf     = rb4xx_nand_read_buf;
 231         nand->chip.cmd_ctrl     = rb4xx_nand_cmd_ctrl;
 232         nand->chip.dev_ready    = rb4xx_nand_dev_ready;
 233         nand->chip.chip_delay   = 25;
 234
 235         ret = nand_scan(mtd, 1);
 236 #else
 237         nand->chip.legacy.read_byte     = rb4xx_nand_read_byte;
 238         nand->chip.legacy.write_buf     = rb4xx_nand_write_buf;
 239         nand->chip.legacy.read_buf      = rb4xx_nand_read_buf;
 240         nand->chip.legacy.cmd_ctrl      = rb4xx_nand_cmd_ctrl;
 241         nand->chip.legacy.dev_ready     = rb4xx_nand_dev_ready;
 242         nand->chip.legacy.chip_delay    = 25;
 243
 244         ret = nand_scan(&nand->chip, 1);
 245 #endif
 246         if (ret)
 247                 return -ENXIO;
 248
 249         ret = mtd_device_register(mtd, NULL, 0);
 250         if (ret) {
 251 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 252                 nand_release(mtd);
 253 #else
 254                 nand_release(&nand->chip);
 255 #endif
 256                 return ret;
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int rb4xx_nand_remove(struct platform_device *pdev)
 263 {
 264         struct rb4xx_nand *nand = platform_get_drvdata(pdev);
 265
 266 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
 267         nand_release(nand_to_mtd(&nand->chip));
 268 #else
 269         nand_release(&nand->chip);
 270 #endif
 271
 272         return 0;
 273 }
 274
 275 static const struct platform_device_id rb4xx_nand_id_table[] = {
 276         { "mikrotik,rb4xx-nand", },
 277         { },
 278 };
 279 MODULE_DEVICE_TABLE(platform, rb4xx_nand_id_table);
 280
 281 static struct platform_driver rb4xx_nand_driver = {
 282         .probe = rb4xx_nand_probe,
 283         .remove = rb4xx_nand_remove,
 284         .id_table = rb4xx_nand_id_table,
 285         .driver = {
 286                 .name = "rb4xx-nand",
 287         },
 288 };
 289
 290 module_platform_driver(rb4xx_nand_driver);
 291
 292 MODULE_DESCRIPTION("Mikrotik RB4xx NAND driver");
 293 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 294 MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
 295 MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
 296 MODULE_AUTHOR("Christopher Hill <ch6574@gmail.com");
 297 MODULE_LICENSE("GPL v2");