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 static u8 rb4xx_nand_read_byte(struct nand_chip *chip)
  85 {
  86         struct rb4xx_nand *nand = chip->priv;
  87         struct rb4xx_cpld *cpld = nand->cpld;
  88         u8 data;
  89         int ret;
  90
  91         ret = cpld->read_nand(cpld, &data, 1);
  92         if (unlikely(ret))
  93                 return 0xff;
  94
  95         return data;
  96 }
  97
  98 static void rb4xx_nand_write_buf(struct nand_chip *chip, const u8 *buf, int len)
  99 {
 100         struct rb4xx_nand *nand = chip->priv;
 101         struct rb4xx_cpld *cpld = nand->cpld;
 102
 103         cpld->write_nand(cpld, buf, len);
 104 }
 105
 106 static void rb4xx_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
 107 {
 108         struct rb4xx_nand *nand = chip->priv;
 109         struct rb4xx_cpld *cpld = nand->cpld;
 110
 111         cpld->read_nand(cpld, buf, len);
 112 }
 113
 114 static void rb4xx_nand_cmd_ctrl(struct nand_chip *chip, int dat,
 115                                 unsigned int ctrl)
 116 {
 117         struct rb4xx_nand *nand = chip->priv;
 118         struct rb4xx_cpld *cpld = nand->cpld;
 119         u8 data = dat;
 120
 121         if (ctrl & NAND_CTRL_CHANGE) {
 122                 gpiod_set_value_cansleep(nand->cle, !!(ctrl & NAND_CLE));
 123                 gpiod_set_value_cansleep(nand->ale, !!(ctrl & NAND_ALE));
 124                 gpiod_set_value_cansleep(nand->nce,  !(ctrl & NAND_NCE));
 125         }
 126
 127         if (dat != NAND_CMD_NONE)
 128                 cpld->write_nand(cpld, &data, 1);
 129 }
 130
 131 static int rb4xx_nand_dev_ready(struct nand_chip *chip)
 132 {
 133         struct rb4xx_nand *nand = chip->priv;
 134
 135         return gpiod_get_value_cansleep(nand->rdy);
 136 }
 137
 138 static int rb4xx_nand_probe(struct platform_device *pdev)
 139 {
 140         struct device *dev = &pdev->dev;
 141         struct device *parent = dev->parent;
 142         struct rb4xx_nand *nand;
 143         struct mtd_info *mtd;
 144         int ret;
 145
 146         if (!parent)
 147                 return -ENODEV;
 148
 149         nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
 150         if (!nand)
 151                 return -ENOMEM;
 152
 153         platform_set_drvdata(pdev, nand);
 154         nand->cpld      = dev_get_drvdata(parent);
 155         nand->dev       = dev;
 156
 157         nand->ale = devm_gpiod_get_index(dev, NULL, 0, GPIOD_OUT_LOW);
 158         if (IS_ERR(nand->ale))
 159                 dev_err(dev, "missing gpio ALE: %ld\n", PTR_ERR(nand->ale));
 160
 161         nand->cle = devm_gpiod_get_index(dev, NULL, 1, GPIOD_OUT_LOW);
 162         if (IS_ERR(nand->cle))
 163                 dev_err(dev, "missing gpio CLE: %ld\n", PTR_ERR(nand->cle));
 164
 165         nand->nce = devm_gpiod_get_index(dev, NULL, 2, GPIOD_OUT_LOW);
 166         if (IS_ERR(nand->nce))
 167                 dev_err(dev, "missing gpio nCE: %ld\n", PTR_ERR(nand->nce));
 168
 169         nand->rdy = devm_gpiod_get_index(dev, NULL, 3, GPIOD_IN);
 170         if (IS_ERR(nand->rdy))
 171                 dev_err(dev, "missing gpio RDY: %ld\n", PTR_ERR(nand->rdy));
 172
 173         if (IS_ERR(nand->ale) || IS_ERR(nand->cle) ||
 174             IS_ERR(nand->nce) || IS_ERR(nand->rdy))
 175                 return -ENOENT;
 176
 177         gpiod_set_consumer_name(nand->ale, "mikrotik:nand:ALE");
 178         gpiod_set_consumer_name(nand->cle, "mikrotik:nand:CLE");
 179         gpiod_set_consumer_name(nand->nce, "mikrotik:nand:nCE");
 180         gpiod_set_consumer_name(nand->rdy, "mikrotik:nand:RDY");
 181
 182         mtd = nand_to_mtd(&nand->chip);
 183         mtd->priv       = nand;
 184         mtd->owner      = THIS_MODULE;
 185         mtd->dev.parent = dev;
 186         mtd_set_of_node(mtd, dev->of_node);
 187
 188         if (mtd->writesize == 512)
 189                 mtd_set_ooblayout(mtd, &rb4xx_nand_ecclayout_ops);
 190
 191         nand->chip.ecc.mode     = NAND_ECC_SOFT;
 192         nand->chip.ecc.algo     = NAND_ECC_HAMMING;
 193         nand->chip.options      = NAND_NO_SUBPAGE_WRITE;
 194         nand->chip.priv         = nand;
 195
 196         nand->chip.legacy.read_byte     = rb4xx_nand_read_byte;
 197         nand->chip.legacy.write_buf     = rb4xx_nand_write_buf;
 198         nand->chip.legacy.read_buf      = rb4xx_nand_read_buf;
 199         nand->chip.legacy.cmd_ctrl      = rb4xx_nand_cmd_ctrl;
 200         nand->chip.legacy.dev_ready     = rb4xx_nand_dev_ready;
 201         nand->chip.legacy.chip_delay    = 25;
 202
 203         ret = nand_scan(&nand->chip, 1);
 204         if (ret)
 205                 return -ENXIO;
 206
 207         ret = mtd_device_register(mtd, NULL, 0);
 208         if (ret) {
 209                 nand_release(&nand->chip);
 210                 return ret;
 211         }
 212
 213         return 0;
 214 }
 215
 216 static int rb4xx_nand_remove(struct platform_device *pdev)
 217 {
 218         struct rb4xx_nand *nand = platform_get_drvdata(pdev);
 219
 220         nand_release(&nand->chip);
 221
 222         return 0;
 223 }
 224
 225 static const struct platform_device_id rb4xx_nand_id_table[] = {
 226         { "mikrotik,rb4xx-nand", },
 227         { },
 228 };
 229 MODULE_DEVICE_TABLE(platform, rb4xx_nand_id_table);
 230
 231 static struct platform_driver rb4xx_nand_driver = {
 232         .probe = rb4xx_nand_probe,
 233         .remove = rb4xx_nand_remove,
 234         .id_table = rb4xx_nand_id_table,
 235         .driver = {
 236                 .name = "rb4xx-nand",
 237         },
 238 };
 239
 240 module_platform_driver(rb4xx_nand_driver);
 241
 242 MODULE_DESCRIPTION("Mikrotik RB4xx NAND driver");
 243 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 244 MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
 245 MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
 246 MODULE_AUTHOR("Christopher Hill <ch6574@gmail.com");
 247 MODULE_LICENSE("GPL v2");