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