root/drivers/mtd/nand/raw/ams-delta.c

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DEFINITIONS

This source file includes following definitions.
  1. ams_delta_write_commit
  2. ams_delta_io_write
  3. ams_delta_dir_output
  4. ams_delta_io_read
  5. ams_delta_dir_input
  6. ams_delta_write_buf
  7. ams_delta_read_buf
  8. ams_delta_ctrl_cs
  9. ams_delta_exec_op
  10. ams_delta_init
  11. ams_delta_cleanup

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
   4  *
   5  *  Derived from drivers/mtd/nand/toto.c (removed in v2.6.28)
   6  *    Copyright (c) 2003 Texas Instruments
   7  *    Copyright (c) 2002 Thomas Gleixner <tgxl@linutronix.de>
   8  *
   9  *  Converted to platform driver by Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
  10  *  Partially stolen from plat_nand.c
  11  *
  12  *  Overview:
  13  *   This is a device driver for the NAND flash device found on the
  14  *   Amstrad E3 (Delta).
  15  */
  16 
  17 #include <linux/slab.h>
  18 #include <linux/module.h>
  19 #include <linux/delay.h>
  20 #include <linux/gpio/consumer.h>
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/rawnand.h>
  23 #include <linux/mtd/partitions.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/sizes.h>
  26 
  27 /*
  28  * MTD structure for E3 (Delta)
  29  */
  30 struct ams_delta_nand {
  31         struct nand_controller  base;
  32         struct nand_chip        nand_chip;
  33         struct gpio_desc        *gpiod_rdy;
  34         struct gpio_desc        *gpiod_nce;
  35         struct gpio_desc        *gpiod_nre;
  36         struct gpio_desc        *gpiod_nwp;
  37         struct gpio_desc        *gpiod_nwe;
  38         struct gpio_desc        *gpiod_ale;
  39         struct gpio_desc        *gpiod_cle;
  40         struct gpio_descs       *data_gpiods;
  41         bool                    data_in;
  42 };
  43 
  44 /*
  45  * Define partitions for flash devices
  46  */
  47 
  48 static const struct mtd_partition partition_info[] = {
  49         { .name         = "Kernel",
  50           .offset       = 0,
  51           .size         = 3 * SZ_1M + SZ_512K },
  52         { .name         = "u-boot",
  53           .offset       = 3 * SZ_1M + SZ_512K,
  54           .size         = SZ_256K },
  55         { .name         = "u-boot params",
  56           .offset       = 3 * SZ_1M + SZ_512K + SZ_256K,
  57           .size         = SZ_256K },
  58         { .name         = "Amstrad LDR",
  59           .offset       = 4 * SZ_1M,
  60           .size         = SZ_256K },
  61         { .name         = "File system",
  62           .offset       = 4 * SZ_1M + 1 * SZ_256K,
  63           .size         = 27 * SZ_1M },
  64         { .name         = "PBL reserved",
  65           .offset       = 32 * SZ_1M - 3 * SZ_256K,
  66           .size         =  3 * SZ_256K },
  67 };
  68 
  69 static void ams_delta_write_commit(struct ams_delta_nand *priv)
  70 {
  71         gpiod_set_value(priv->gpiod_nwe, 0);
  72         ndelay(40);
  73         gpiod_set_value(priv->gpiod_nwe, 1);
  74 }
  75 
  76 static void ams_delta_io_write(struct ams_delta_nand *priv, u8 byte)
  77 {
  78         struct gpio_descs *data_gpiods = priv->data_gpiods;
  79         DECLARE_BITMAP(values, BITS_PER_TYPE(byte)) = { byte, };
  80 
  81         gpiod_set_raw_array_value(data_gpiods->ndescs, data_gpiods->desc,
  82                                   data_gpiods->info, values);
  83 
  84         ams_delta_write_commit(priv);
  85 }
  86 
  87 static void ams_delta_dir_output(struct ams_delta_nand *priv, u8 byte)
  88 {
  89         struct gpio_descs *data_gpiods = priv->data_gpiods;
  90         DECLARE_BITMAP(values, BITS_PER_TYPE(byte)) = { byte, };
  91         int i;
  92 
  93         for (i = 0; i < data_gpiods->ndescs; i++)
  94                 gpiod_direction_output_raw(data_gpiods->desc[i],
  95                                            test_bit(i, values));
  96 
  97         ams_delta_write_commit(priv);
  98 
  99         priv->data_in = false;
 100 }
 101 
 102 static u8 ams_delta_io_read(struct ams_delta_nand *priv)
 103 {
 104         u8 res;
 105         struct gpio_descs *data_gpiods = priv->data_gpiods;
 106         DECLARE_BITMAP(values, BITS_PER_TYPE(res)) = { 0, };
 107 
 108         gpiod_set_value(priv->gpiod_nre, 0);
 109         ndelay(40);
 110 
 111         gpiod_get_raw_array_value(data_gpiods->ndescs, data_gpiods->desc,
 112                                   data_gpiods->info, values);
 113 
 114         gpiod_set_value(priv->gpiod_nre, 1);
 115 
 116         res = values[0];
 117         return res;
 118 }
 119 
 120 static void ams_delta_dir_input(struct ams_delta_nand *priv)
 121 {
 122         struct gpio_descs *data_gpiods = priv->data_gpiods;
 123         int i;
 124 
 125         for (i = 0; i < data_gpiods->ndescs; i++)
 126                 gpiod_direction_input(data_gpiods->desc[i]);
 127 
 128         priv->data_in = true;
 129 }
 130 
 131 static void ams_delta_write_buf(struct ams_delta_nand *priv, const u8 *buf,
 132                                 int len)
 133 {
 134         int i = 0;
 135 
 136         if (len > 0 && priv->data_in)
 137                 ams_delta_dir_output(priv, buf[i++]);
 138 
 139         while (i < len)
 140                 ams_delta_io_write(priv, buf[i++]);
 141 }
 142 
 143 static void ams_delta_read_buf(struct ams_delta_nand *priv, u8 *buf, int len)
 144 {
 145         int i;
 146 
 147         if (!priv->data_in)
 148                 ams_delta_dir_input(priv);
 149 
 150         for (i = 0; i < len; i++)
 151                 buf[i] = ams_delta_io_read(priv);
 152 }
 153 
 154 static void ams_delta_ctrl_cs(struct ams_delta_nand *priv, bool assert)
 155 {
 156         gpiod_set_value(priv->gpiod_nce, assert ? 0 : 1);
 157 }
 158 
 159 static int ams_delta_exec_op(struct nand_chip *this,
 160                              const struct nand_operation *op, bool check_only)
 161 {
 162         struct ams_delta_nand *priv = nand_get_controller_data(this);
 163         const struct nand_op_instr *instr;
 164         int ret = 0;
 165 
 166         if (check_only)
 167                 return 0;
 168 
 169         ams_delta_ctrl_cs(priv, 1);
 170 
 171         for (instr = op->instrs; instr < op->instrs + op->ninstrs; instr++) {
 172                 switch (instr->type) {
 173                 case NAND_OP_CMD_INSTR:
 174                         gpiod_set_value(priv->gpiod_cle, 1);
 175                         ams_delta_write_buf(priv, &instr->ctx.cmd.opcode, 1);
 176                         gpiod_set_value(priv->gpiod_cle, 0);
 177                         break;
 178 
 179                 case NAND_OP_ADDR_INSTR:
 180                         gpiod_set_value(priv->gpiod_ale, 1);
 181                         ams_delta_write_buf(priv, instr->ctx.addr.addrs,
 182                                             instr->ctx.addr.naddrs);
 183                         gpiod_set_value(priv->gpiod_ale, 0);
 184                         break;
 185 
 186                 case NAND_OP_DATA_IN_INSTR:
 187                         ams_delta_read_buf(priv, instr->ctx.data.buf.in,
 188                                            instr->ctx.data.len);
 189                         break;
 190 
 191                 case NAND_OP_DATA_OUT_INSTR:
 192                         ams_delta_write_buf(priv, instr->ctx.data.buf.out,
 193                                             instr->ctx.data.len);
 194                         break;
 195 
 196                 case NAND_OP_WAITRDY_INSTR:
 197                         ret = priv->gpiod_rdy ?
 198                               nand_gpio_waitrdy(this, priv->gpiod_rdy,
 199                                                 instr->ctx.waitrdy.timeout_ms) :
 200                               nand_soft_waitrdy(this,
 201                                                 instr->ctx.waitrdy.timeout_ms);
 202                         break;
 203                 }
 204 
 205                 if (ret)
 206                         break;
 207         }
 208 
 209         ams_delta_ctrl_cs(priv, 0);
 210 
 211         return ret;
 212 }
 213 
 214 static const struct nand_controller_ops ams_delta_ops = {
 215         .exec_op = ams_delta_exec_op,
 216 };
 217 
 218 /*
 219  * Main initialization routine
 220  */
 221 static int ams_delta_init(struct platform_device *pdev)
 222 {
 223         struct ams_delta_nand *priv;
 224         struct nand_chip *this;
 225         struct mtd_info *mtd;
 226         struct gpio_descs *data_gpiods;
 227         int err = 0;
 228 
 229         /* Allocate memory for MTD device structure and private data */
 230         priv = devm_kzalloc(&pdev->dev, sizeof(struct ams_delta_nand),
 231                             GFP_KERNEL);
 232         if (!priv)
 233                 return -ENOMEM;
 234 
 235         this = &priv->nand_chip;
 236 
 237         mtd = nand_to_mtd(this);
 238         mtd->dev.parent = &pdev->dev;
 239 
 240         nand_set_controller_data(this, priv);
 241 
 242         priv->gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
 243         if (IS_ERR(priv->gpiod_rdy)) {
 244                 err = PTR_ERR(priv->gpiod_rdy);
 245                 dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n", err);
 246                 return err;
 247         }
 248 
 249         this->ecc.mode = NAND_ECC_SOFT;
 250         this->ecc.algo = NAND_ECC_HAMMING;
 251 
 252         platform_set_drvdata(pdev, priv);
 253 
 254         /* Set chip enabled, but  */
 255         priv->gpiod_nwp = devm_gpiod_get(&pdev->dev, "nwp", GPIOD_OUT_HIGH);
 256         if (IS_ERR(priv->gpiod_nwp)) {
 257                 err = PTR_ERR(priv->gpiod_nwp);
 258                 dev_err(&pdev->dev, "NWP GPIO request failed (%d)\n", err);
 259                 return err;
 260         }
 261 
 262         priv->gpiod_nce = devm_gpiod_get(&pdev->dev, "nce", GPIOD_OUT_HIGH);
 263         if (IS_ERR(priv->gpiod_nce)) {
 264                 err = PTR_ERR(priv->gpiod_nce);
 265                 dev_err(&pdev->dev, "NCE GPIO request failed (%d)\n", err);
 266                 return err;
 267         }
 268 
 269         priv->gpiod_nre = devm_gpiod_get(&pdev->dev, "nre", GPIOD_OUT_HIGH);
 270         if (IS_ERR(priv->gpiod_nre)) {
 271                 err = PTR_ERR(priv->gpiod_nre);
 272                 dev_err(&pdev->dev, "NRE GPIO request failed (%d)\n", err);
 273                 return err;
 274         }
 275 
 276         priv->gpiod_nwe = devm_gpiod_get(&pdev->dev, "nwe", GPIOD_OUT_HIGH);
 277         if (IS_ERR(priv->gpiod_nwe)) {
 278                 err = PTR_ERR(priv->gpiod_nwe);
 279                 dev_err(&pdev->dev, "NWE GPIO request failed (%d)\n", err);
 280                 return err;
 281         }
 282 
 283         priv->gpiod_ale = devm_gpiod_get(&pdev->dev, "ale", GPIOD_OUT_LOW);
 284         if (IS_ERR(priv->gpiod_ale)) {
 285                 err = PTR_ERR(priv->gpiod_ale);
 286                 dev_err(&pdev->dev, "ALE GPIO request failed (%d)\n", err);
 287                 return err;
 288         }
 289 
 290         priv->gpiod_cle = devm_gpiod_get(&pdev->dev, "cle", GPIOD_OUT_LOW);
 291         if (IS_ERR(priv->gpiod_cle)) {
 292                 err = PTR_ERR(priv->gpiod_cle);
 293                 dev_err(&pdev->dev, "CLE GPIO request failed (%d)\n", err);
 294                 return err;
 295         }
 296 
 297         /* Request array of data pins, initialize them as input */
 298         data_gpiods = devm_gpiod_get_array(&pdev->dev, "data", GPIOD_IN);
 299         if (IS_ERR(data_gpiods)) {
 300                 err = PTR_ERR(data_gpiods);
 301                 dev_err(&pdev->dev, "data GPIO request failed: %d\n", err);
 302                 return err;
 303         }
 304         priv->data_gpiods = data_gpiods;
 305         priv->data_in = true;
 306 
 307         /* Initialize the NAND controller object embedded in ams_delta_nand. */
 308         priv->base.ops = &ams_delta_ops;
 309         nand_controller_init(&priv->base);
 310         this->controller = &priv->base;
 311 
 312         /* Scan to find existence of the device */
 313         err = nand_scan(this, 1);
 314         if (err)
 315                 return err;
 316 
 317         /* Register the partitions */
 318         err = mtd_device_register(mtd, partition_info,
 319                                   ARRAY_SIZE(partition_info));
 320         if (err)
 321                 goto err_nand_cleanup;
 322 
 323         return 0;
 324 
 325 err_nand_cleanup:
 326         nand_cleanup(this);
 327 
 328         return err;
 329 }
 330 
 331 /*
 332  * Clean up routine
 333  */
 334 static int ams_delta_cleanup(struct platform_device *pdev)
 335 {
 336         struct ams_delta_nand *priv = platform_get_drvdata(pdev);
 337         struct mtd_info *mtd = nand_to_mtd(&priv->nand_chip);
 338 
 339         /* Unregister device */
 340         nand_release(mtd_to_nand(mtd));
 341 
 342         return 0;
 343 }
 344 
 345 static struct platform_driver ams_delta_nand_driver = {
 346         .probe          = ams_delta_init,
 347         .remove         = ams_delta_cleanup,
 348         .driver         = {
 349                 .name   = "ams-delta-nand",
 350         },
 351 };
 352 
 353 module_platform_driver(ams_delta_nand_driver);
 354 
 355 MODULE_LICENSE("GPL v2");
 356 MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
 357 MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");

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