LXR linux/drivers/mtd/lpddr/lpddr2

   1/*
   2 * LPDDR2-NVM MTD driver. This module provides read, write, erase, lock/unlock
   3 * support for LPDDR2-NVM PCM memories
   4 *
   5 * Copyright © 2012 Micron Technology, Inc.
   6 *
   7 * Vincenzo Aliberti <vincenzo.aliberti@gmail.com>
   8 * Domenico Manna <domenico.manna@gmail.com>
   9 * Many thanks to Andrea Vigilante for initial enabling
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public License
  13 * as published by the Free Software Foundation; either version 2
  14 * of the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 */
  21
  22#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
  23
  24#include <linux/init.h>
  25#include <linux/io.h>
  26#include <linux/module.h>
  27#include <linux/kernel.h>
  28#include <linux/mtd/map.h>
  29#include <linux/mtd/mtd.h>
  30#include <linux/mtd/partitions.h>
  31#include <linux/slab.h>
  32#include <linux/platform_device.h>
  33#include <linux/ioport.h>
  34#include <linux/err.h>
  35
  36/* Parameters */
  37#define ERASE_BLOCKSIZE                 (0x00020000/2)  /* in Word */
  38#define WRITE_BUFFSIZE                  (0x00000400/2)  /* in Word */
  39#define OW_BASE_ADDRESS                 0x00000000      /* OW offset */
  40#define BUS_WIDTH                       0x00000020      /* x32 devices */
  41
  42/* PFOW symbols address offset */
  43#define PFOW_QUERY_STRING_P             (0x0000/2)      /* in Word */
  44#define PFOW_QUERY_STRING_F             (0x0002/2)      /* in Word */
  45#define PFOW_QUERY_STRING_O             (0x0004/2)      /* in Word */
  46#define PFOW_QUERY_STRING_W             (0x0006/2)      /* in Word */
  47
  48/* OW registers address */
  49#define CMD_CODE_OFS                    (0x0080/2)      /* in Word */
  50#define CMD_DATA_OFS                    (0x0084/2)      /* in Word */
  51#define CMD_ADD_L_OFS                   (0x0088/2)      /* in Word */
  52#define CMD_ADD_H_OFS                   (0x008A/2)      /* in Word */
  53#define MPR_L_OFS                       (0x0090/2)      /* in Word */
  54#define MPR_H_OFS                       (0x0092/2)      /* in Word */
  55#define CMD_EXEC_OFS                    (0x00C0/2)      /* in Word */
  56#define STATUS_REG_OFS                  (0x00CC/2)      /* in Word */
  57#define PRG_BUFFER_OFS                  (0x0010/2)      /* in Word */
  58
  59/* Datamask */
  60#define MR_CFGMASK                      0x8000
  61#define SR_OK_DATAMASK                  0x0080
  62
  63/* LPDDR2-NVM Commands */
  64#define LPDDR2_NVM_LOCK                 0x0061
  65#define LPDDR2_NVM_UNLOCK               0x0062
  66#define LPDDR2_NVM_SW_PROGRAM           0x0041
  67#define LPDDR2_NVM_SW_OVERWRITE         0x0042
  68#define LPDDR2_NVM_BUF_PROGRAM          0x00E9
  69#define LPDDR2_NVM_BUF_OVERWRITE        0x00EA
  70#define LPDDR2_NVM_ERASE                0x0020
  71
  72/* LPDDR2-NVM Registers offset */
  73#define LPDDR2_MODE_REG_DATA            0x0040
  74#define LPDDR2_MODE_REG_CFG             0x0050
  75
  76/*
  77 * Internal Type Definitions
  78 * pcm_int_data contains memory controller details:
  79 * @reg_data : LPDDR2_MODE_REG_DATA register address after remapping
  80 * @reg_cfg  : LPDDR2_MODE_REG_CFG register address after remapping
  81 * &bus_width: memory bus-width (eg: x16 2 Bytes, x32 4 Bytes)
  82 */
  83struct pcm_int_data {
  84        void __iomem *ctl_regs;
  85        int bus_width;
  86};
  87
  88static DEFINE_MUTEX(lpdd2_nvm_mutex);
  89
  90/*
  91 * Build a map_word starting from an u_long
  92 */
  93static inline map_word build_map_word(u_long myword)
  94{
  95        map_word val = { {0} };
  96        val.x[0] = myword;
  97        return val;
  98}
  99
 100/*
 101 * Build Mode Register Configuration DataMask based on device bus-width
 102 */
 103static inline u_int build_mr_cfgmask(u_int bus_width)
 104{
 105        u_int val = MR_CFGMASK;
 106
 107        if (bus_width == 0x0004)                /* x32 device */
 108                val = val << 16;
 109
 110        return val;
 111}
 112
 113/*
 114 * Build Status Register OK DataMask based on device bus-width
 115 */
 116static inline u_int build_sr_ok_datamask(u_int bus_width)
 117{
 118        u_int val = SR_OK_DATAMASK;
 119
 120        if (bus_width == 0x0004)                /* x32 device */
 121                val = (val << 16)+val;
 122
 123        return val;
 124}
 125
 126/*
 127 * Evaluates Overlay Window Control Registers address
 128 */
 129static inline u_long ow_reg_add(struct map_info *map, u_long offset)
 130{
 131        u_long val = 0;
 132        struct pcm_int_data *pcm_data = map->fldrv_priv;
 133
 134        val = map->pfow_base + offset*pcm_data->bus_width;
 135
 136        return val;
 137}
 138
 139/*
 140 * Enable lpddr2-nvm Overlay Window
 141 * Overlay Window is a memory mapped area containing all LPDDR2-NVM registers
 142 * used by device commands as well as uservisible resources like Device Status
 143 * Register, Device ID, etc
 144 */
 145static inline void ow_enable(struct map_info *map)
 146{
 147        struct pcm_int_data *pcm_data = map->fldrv_priv;
 148
 149        writel_relaxed(build_mr_cfgmask(pcm_data->bus_width) | 0x18,
 150                pcm_data->ctl_regs + LPDDR2_MODE_REG_CFG);
 151        writel_relaxed(0x01, pcm_data->ctl_regs + LPDDR2_MODE_REG_DATA);
 152}
 153
 154/*
 155 * Disable lpddr2-nvm Overlay Window
 156 * Overlay Window is a memory mapped area containing all LPDDR2-NVM registers
 157 * used by device commands as well as uservisible resources like Device Status
 158 * Register, Device ID, etc
 159 */
 160static inline void ow_disable(struct map_info *map)
 161{
 162        struct pcm_int_data *pcm_data = map->fldrv_priv;
 163
 164        writel_relaxed(build_mr_cfgmask(pcm_data->bus_width) | 0x18,
 165                pcm_data->ctl_regs + LPDDR2_MODE_REG_CFG);
 166        writel_relaxed(0x02, pcm_data->ctl_regs + LPDDR2_MODE_REG_DATA);
 167}
 168
 169/*
 170 * Execute lpddr2-nvm operations
 171 */
 172static int lpddr2_nvm_do_op(struct map_info *map, u_long cmd_code,
 173        u_long cmd_data, u_long cmd_add, u_long cmd_mpr, u_char *buf)
 174{
 175        map_word add_l = { {0} }, add_h = { {0} }, mpr_l = { {0} },
 176                mpr_h = { {0} }, data_l = { {0} }, cmd = { {0} },
 177                exec_cmd = { {0} }, sr;
 178        map_word data_h = { {0} };      /* only for 2x x16 devices stacked */
 179        u_long i, status_reg, prg_buff_ofs;
 180        struct pcm_int_data *pcm_data = map->fldrv_priv;
 181        u_int sr_ok_datamask = build_sr_ok_datamask(pcm_data->bus_width);
 182
 183        /* Builds low and high words for OW Control Registers */
 184        add_l.x[0]      = cmd_add & 0x0000FFFF;
 185        add_h.x[0]      = (cmd_add >> 16) & 0x0000FFFF;
 186        mpr_l.x[0]      = cmd_mpr & 0x0000FFFF;
 187        mpr_h.x[0]      = (cmd_mpr >> 16) & 0x0000FFFF;
 188        cmd.x[0]        = cmd_code & 0x0000FFFF;
 189        exec_cmd.x[0]   = 0x0001;
 190        data_l.x[0]     = cmd_data & 0x0000FFFF;
 191        data_h.x[0]     = (cmd_data >> 16) & 0x0000FFFF; /* only for 2x x16 */
 192
 193        /* Set Overlay Window Control Registers */
 194        map_write(map, cmd, ow_reg_add(map, CMD_CODE_OFS));
 195        map_write(map, data_l, ow_reg_add(map, CMD_DATA_OFS));
 196        map_write(map, add_l, ow_reg_add(map, CMD_ADD_L_OFS));
 197        map_write(map, add_h, ow_reg_add(map, CMD_ADD_H_OFS));
 198        map_write(map, mpr_l, ow_reg_add(map, MPR_L_OFS));
 199        map_write(map, mpr_h, ow_reg_add(map, MPR_H_OFS));
 200        if (pcm_data->bus_width == 0x0004) {    /* 2x16 devices stacked */
 201                map_write(map, cmd, ow_reg_add(map, CMD_CODE_OFS) + 2);
 202                map_write(map, data_h, ow_reg_add(map, CMD_DATA_OFS) + 2);
 203                map_write(map, add_l, ow_reg_add(map, CMD_ADD_L_OFS) + 2);
 204                map_write(map, add_h, ow_reg_add(map, CMD_ADD_H_OFS) + 2);
 205                map_write(map, mpr_l, ow_reg_add(map, MPR_L_OFS) + 2);
 206                map_write(map, mpr_h, ow_reg_add(map, MPR_H_OFS) + 2);
 207        }
 208
 209        /* Fill Program Buffer */
 210        if ((cmd_code == LPDDR2_NVM_BUF_PROGRAM) ||
 211                (cmd_code == LPDDR2_NVM_BUF_OVERWRITE)) {
 212                prg_buff_ofs = (map_read(map,
 213                        ow_reg_add(map, PRG_BUFFER_OFS))).x[0];
 214                for (i = 0; i < cmd_mpr; i++) {
 215                        map_write(map, build_map_word(buf[i]), map->pfow_base +
 216                        prg_buff_ofs + i);
 217                }
 218        }
 219
 220        /* Command Execute */
 221        map_write(map, exec_cmd, ow_reg_add(map, CMD_EXEC_OFS));
 222        if (pcm_data->bus_width == 0x0004)      /* 2x16 devices stacked */
 223                map_write(map, exec_cmd, ow_reg_add(map, CMD_EXEC_OFS) + 2);
 224
 225        /* Status Register Check */
 226        do {
 227                sr = map_read(map, ow_reg_add(map, STATUS_REG_OFS));
 228                status_reg = sr.x[0];
 229                if (pcm_data->bus_width == 0x0004) {/* 2x16 devices stacked */
 230                        sr = map_read(map, ow_reg_add(map,
 231                                STATUS_REG_OFS) + 2);
 232                        status_reg += sr.x[0] << 16;
 233                }
 234        } while ((status_reg & sr_ok_datamask) != sr_ok_datamask);
 235
 236        return (((status_reg & sr_ok_datamask) == sr_ok_datamask) ? 0 : -EIO);
 237}
 238
 239/*
 240 * Execute lpddr2-nvm operations @ block level
 241 */
 242static int lpddr2_nvm_do_block_op(struct mtd_info *mtd, loff_t start_add,
 243        uint64_t len, u_char block_op)
 244{
 245        struct map_info *map = mtd->priv;
 246        u_long add, end_add;
 247        int ret = 0;
 248
 249        mutex_lock(&lpdd2_nvm_mutex);
 250
 251        ow_enable(map);
 252
 253        add = start_add;
 254        end_add = add + len;
 255
 256        do {
 257                ret = lpddr2_nvm_do_op(map, block_op, 0x00, add, add, NULL);
 258                if (ret)
 259                        goto out;
 260                add += mtd->erasesize;
 261        } while (add < end_add);
 262
 263out:
 264        ow_disable(map);
 265        mutex_unlock(&lpdd2_nvm_mutex);
 266        return ret;
 267}
 268
 269/*
 270 * verify presence of PFOW string
 271 */
 272static int lpddr2_nvm_pfow_present(struct map_info *map)
 273{
 274        map_word pfow_val[4];
 275        unsigned int found = 1;
 276
 277        mutex_lock(&lpdd2_nvm_mutex);
 278
 279        ow_enable(map);
 280
 281        /* Load string from array */
 282        pfow_val[0] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_P));
 283        pfow_val[1] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_F));
 284        pfow_val[2] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_O));
 285        pfow_val[3] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_W));
 286
 287        /* Verify the string loaded vs expected */
 288        if (!map_word_equal(map, build_map_word('P'), pfow_val[0]))
 289                found = 0;
 290        if (!map_word_equal(map, build_map_word('F'), pfow_val[1]))
 291                found = 0;
 292        if (!map_word_equal(map, build_map_word('O'), pfow_val[2]))
 293                found = 0;
 294        if (!map_word_equal(map, build_map_word('W'), pfow_val[3]))
 295                found = 0;
 296
 297        ow_disable(map);
 298
 299        mutex_unlock(&lpdd2_nvm_mutex);
 300
 301        return found;
 302}
 303
 304/*
 305 * lpddr2_nvm driver read method
 306 */
 307static int lpddr2_nvm_read(struct mtd_info *mtd, loff_t start_add,
 308                                size_t len, size_t *retlen, u_char *buf)
 309{
 310        struct map_info *map = mtd->priv;
 311
 312        mutex_lock(&lpdd2_nvm_mutex);
 313
 314        *retlen = len;
 315
 316        map_copy_from(map, buf, start_add, *retlen);
 317
 318        mutex_unlock(&lpdd2_nvm_mutex);
 319        return 0;
 320}
 321
 322/*
 323 * lpddr2_nvm driver write method
 324 */
 325static int lpddr2_nvm_write(struct mtd_info *mtd, loff_t start_add,
 326                                size_t len, size_t *retlen, const u_char *buf)
 327{
 328        struct map_info *map = mtd->priv;
 329        struct pcm_int_data *pcm_data = map->fldrv_priv;
 330        u_long add, current_len, tot_len, target_len, my_data;
 331        u_char *write_buf = (u_char *)buf;
 332        int ret = 0;
 333
 334        mutex_lock(&lpdd2_nvm_mutex);
 335
 336        ow_enable(map);
 337
 338        /* Set start value for the variables */
 339        add = start_add;
 340        target_len = len;
 341        tot_len = 0;
 342
 343        while (tot_len < target_len) {
 344                if (!(IS_ALIGNED(add, mtd->writesize))) { /* do sw program */
 345                        my_data = write_buf[tot_len];
 346                        my_data += (write_buf[tot_len+1]) << 8;
 347                        if (pcm_data->bus_width == 0x0004) {/* 2x16 devices */
 348                                my_data += (write_buf[tot_len+2]) << 16;
 349                                my_data += (write_buf[tot_len+3]) << 24;
 350                        }
 351                        ret = lpddr2_nvm_do_op(map, LPDDR2_NVM_SW_OVERWRITE,
 352                                my_data, add, 0x00, NULL);
 353                        if (ret)
 354                                goto out;
 355
 356                        add += pcm_data->bus_width;
 357                        tot_len += pcm_data->bus_width;
 358                } else {                /* do buffer program */
 359                        current_len = min(target_len - tot_len,
 360                                (u_long) mtd->writesize);
 361                        ret = lpddr2_nvm_do_op(map, LPDDR2_NVM_BUF_OVERWRITE,
 362                                0x00, add, current_len, write_buf + tot_len);
 363                        if (ret)
 364                                goto out;
 365
 366                        add += current_len;
 367                        tot_len += current_len;
 368                }
 369        }
 370
 371out:
 372        *retlen = tot_len;
 373        ow_disable(map);
 374        mutex_unlock(&lpdd2_nvm_mutex);
 375        return ret;
 376}
 377
 378/*
 379 * lpddr2_nvm driver erase method
 380 */
 381static int lpddr2_nvm_erase(struct mtd_info *mtd, struct erase_info *instr)
 382{
 383        int ret = lpddr2_nvm_do_block_op(mtd, instr->addr, instr->len,
 384                LPDDR2_NVM_ERASE);
 385        if (!ret) {
 386                instr->state = MTD_ERASE_DONE;
 387                mtd_erase_callback(instr);
 388        }
 389
 390        return ret;
 391}
 392
 393/*
 394 * lpddr2_nvm driver unlock method
 395 */
 396static int lpddr2_nvm_unlock(struct mtd_info *mtd, loff_t start_add,
 397        uint64_t len)
 398{
 399        return lpddr2_nvm_do_block_op(mtd, start_add, len, LPDDR2_NVM_UNLOCK);
 400}
 401
 402/*
 403 * lpddr2_nvm driver lock method
 404 */
 405static int lpddr2_nvm_lock(struct mtd_info *mtd, loff_t start_add,
 406        uint64_t len)
 407{
 408        return lpddr2_nvm_do_block_op(mtd, start_add, len, LPDDR2_NVM_LOCK);
 409}
 410
 411/*
 412 * lpddr2_nvm driver probe method
 413 */
 414static int lpddr2_nvm_probe(struct platform_device *pdev)
 415{
 416        struct map_info *map;
 417        struct mtd_info *mtd;
 418        struct resource *add_range;
 419        struct resource *control_regs;
 420        struct pcm_int_data *pcm_data;
 421
 422        /* Allocate memory control_regs data structures */
 423        pcm_data = devm_kzalloc(&pdev->dev, sizeof(*pcm_data), GFP_KERNEL);
 424        if (!pcm_data)
 425                return -ENOMEM;
 426
 427        pcm_data->bus_width = BUS_WIDTH;
 428
 429        /* Allocate memory for map_info & mtd_info data structures */
 430        map = devm_kzalloc(&pdev->dev, sizeof(*map), GFP_KERNEL);
 431        if (!map)
 432                return -ENOMEM;
 433
 434        mtd = devm_kzalloc(&pdev->dev, sizeof(*mtd), GFP_KERNEL);
 435        if (!mtd)
 436                return -ENOMEM;
 437
 438        /* lpddr2_nvm address range */
 439        add_range = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 440
 441        /* Populate map_info data structure */
 442        *map = (struct map_info) {
 443                .virt           = devm_ioremap_resource(&pdev->dev, add_range),
 444                .name           = pdev->dev.init_name,
 445                .phys           = add_range->start,
 446                .size           = resource_size(add_range),
 447                .bankwidth      = pcm_data->bus_width / 2,
 448                .pfow_base      = OW_BASE_ADDRESS,
 449                .fldrv_priv     = pcm_data,
 450        };
 451        if (IS_ERR(map->virt))
 452                return PTR_ERR(map->virt);
 453
 454        simple_map_init(map);   /* fill with default methods */
 455
 456        control_regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 457        pcm_data->ctl_regs = devm_ioremap_resource(&pdev->dev, control_regs);
 458        if (IS_ERR(pcm_data->ctl_regs))
 459                return PTR_ERR(pcm_data->ctl_regs);
 460
 461        /* Populate mtd_info data structure */
 462        *mtd = (struct mtd_info) {
 463                .name           = pdev->dev.init_name,
 464                .type           = MTD_RAM,
 465                .priv           = map,
 466                .size           = resource_size(add_range),
 467                .erasesize      = ERASE_BLOCKSIZE * pcm_data->bus_width,
 468                .writesize      = 1,
 469                .writebufsize   = WRITE_BUFFSIZE * pcm_data->bus_width,
 470                .flags          = (MTD_CAP_NVRAM | MTD_POWERUP_LOCK),
 471                ._read          = lpddr2_nvm_read,
 472                ._write         = lpddr2_nvm_write,
 473                ._erase         = lpddr2_nvm_erase,
 474                ._unlock        = lpddr2_nvm_unlock,
 475                ._lock          = lpddr2_nvm_lock,
 476        };
 477
 478        /* Verify the presence of the device looking for PFOW string */
 479        if (!lpddr2_nvm_pfow_present(map)) {
 480                pr_err("device not recognized\n");
 481                return -EINVAL;
 482        }
 483        /* Parse partitions and register the MTD device */
 484        return mtd_device_parse_register(mtd, NULL, NULL, NULL, 0);
 485}
 486
 487/*
 488 * lpddr2_nvm driver remove method
 489 */
 490static int lpddr2_nvm_remove(struct platform_device *pdev)
 491{
 492        return mtd_device_unregister(dev_get_drvdata(&pdev->dev));
 493}
 494
 495/* Initialize platform_driver data structure for lpddr2_nvm */
 496static struct platform_driver lpddr2_nvm_drv = {
 497        .driver         = {
 498                .name   = "lpddr2_nvm",
 499        },
 500        .probe          = lpddr2_nvm_probe,
 501        .remove         = lpddr2_nvm_remove,
 502};
 503
 504module_platform_driver(lpddr2_nvm_drv);
 505MODULE_LICENSE("GPL");
 506MODULE_AUTHOR("Vincenzo Aliberti <vincenzo.aliberti@gmail.com>");
 507MODULE_DESCRIPTION("MTD driver for LPDDR2-NVM PCM memories");
 508