linux/drivers/mtd/spi-nor/mtk-quadspi.c
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   1/*
   2 * Copyright (c) 2015 MediaTek Inc.
   3 * Author: Bayi Cheng <bayi.cheng@mediatek.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 */
  14
  15#include <linux/clk.h>
  16#include <linux/delay.h>
  17#include <linux/device.h>
  18#include <linux/init.h>
  19#include <linux/io.h>
  20#include <linux/iopoll.h>
  21#include <linux/ioport.h>
  22#include <linux/math64.h>
  23#include <linux/module.h>
  24#include <linux/mutex.h>
  25#include <linux/of.h>
  26#include <linux/of_device.h>
  27#include <linux/pinctrl/consumer.h>
  28#include <linux/platform_device.h>
  29#include <linux/slab.h>
  30#include <linux/mtd/mtd.h>
  31#include <linux/mtd/partitions.h>
  32#include <linux/mtd/spi-nor.h>
  33
  34#define MTK_NOR_CMD_REG                 0x00
  35#define MTK_NOR_CNT_REG                 0x04
  36#define MTK_NOR_RDSR_REG                0x08
  37#define MTK_NOR_RDATA_REG               0x0c
  38#define MTK_NOR_RADR0_REG               0x10
  39#define MTK_NOR_RADR1_REG               0x14
  40#define MTK_NOR_RADR2_REG               0x18
  41#define MTK_NOR_WDATA_REG               0x1c
  42#define MTK_NOR_PRGDATA0_REG            0x20
  43#define MTK_NOR_PRGDATA1_REG            0x24
  44#define MTK_NOR_PRGDATA2_REG            0x28
  45#define MTK_NOR_PRGDATA3_REG            0x2c
  46#define MTK_NOR_PRGDATA4_REG            0x30
  47#define MTK_NOR_PRGDATA5_REG            0x34
  48#define MTK_NOR_SHREG0_REG              0x38
  49#define MTK_NOR_SHREG1_REG              0x3c
  50#define MTK_NOR_SHREG2_REG              0x40
  51#define MTK_NOR_SHREG3_REG              0x44
  52#define MTK_NOR_SHREG4_REG              0x48
  53#define MTK_NOR_SHREG5_REG              0x4c
  54#define MTK_NOR_SHREG6_REG              0x50
  55#define MTK_NOR_SHREG7_REG              0x54
  56#define MTK_NOR_SHREG8_REG              0x58
  57#define MTK_NOR_SHREG9_REG              0x5c
  58#define MTK_NOR_CFG1_REG                0x60
  59#define MTK_NOR_CFG2_REG                0x64
  60#define MTK_NOR_CFG3_REG                0x68
  61#define MTK_NOR_STATUS0_REG             0x70
  62#define MTK_NOR_STATUS1_REG             0x74
  63#define MTK_NOR_STATUS2_REG             0x78
  64#define MTK_NOR_STATUS3_REG             0x7c
  65#define MTK_NOR_FLHCFG_REG              0x84
  66#define MTK_NOR_TIME_REG                0x94
  67#define MTK_NOR_PP_DATA_REG             0x98
  68#define MTK_NOR_PREBUF_STUS_REG         0x9c
  69#define MTK_NOR_DELSEL0_REG             0xa0
  70#define MTK_NOR_DELSEL1_REG             0xa4
  71#define MTK_NOR_INTRSTUS_REG            0xa8
  72#define MTK_NOR_INTREN_REG              0xac
  73#define MTK_NOR_CHKSUM_CTL_REG          0xb8
  74#define MTK_NOR_CHKSUM_REG              0xbc
  75#define MTK_NOR_CMD2_REG                0xc0
  76#define MTK_NOR_WRPROT_REG              0xc4
  77#define MTK_NOR_RADR3_REG               0xc8
  78#define MTK_NOR_DUAL_REG                0xcc
  79#define MTK_NOR_DELSEL2_REG             0xd0
  80#define MTK_NOR_DELSEL3_REG             0xd4
  81#define MTK_NOR_DELSEL4_REG             0xd8
  82
  83/* commands for mtk nor controller */
  84#define MTK_NOR_READ_CMD                0x0
  85#define MTK_NOR_RDSR_CMD                0x2
  86#define MTK_NOR_PRG_CMD                 0x4
  87#define MTK_NOR_WR_CMD                  0x10
  88#define MTK_NOR_PIO_WR_CMD              0x90
  89#define MTK_NOR_WRSR_CMD                0x20
  90#define MTK_NOR_PIO_READ_CMD            0x81
  91#define MTK_NOR_WR_BUF_ENABLE           0x1
  92#define MTK_NOR_WR_BUF_DISABLE          0x0
  93#define MTK_NOR_ENABLE_SF_CMD           0x30
  94#define MTK_NOR_DUAD_ADDR_EN            0x8
  95#define MTK_NOR_QUAD_READ_EN            0x4
  96#define MTK_NOR_DUAL_ADDR_EN            0x2
  97#define MTK_NOR_DUAL_READ_EN            0x1
  98#define MTK_NOR_DUAL_DISABLE            0x0
  99#define MTK_NOR_FAST_READ               0x1
 100
 101#define SFLASH_WRBUF_SIZE               128
 102
 103/* Can shift up to 48 bits (6 bytes) of TX/RX */
 104#define MTK_NOR_MAX_RX_TX_SHIFT         6
 105/* can shift up to 56 bits (7 bytes) transfer by MTK_NOR_PRG_CMD */
 106#define MTK_NOR_MAX_SHIFT               7
 107
 108/* Helpers for accessing the program data / shift data registers */
 109#define MTK_NOR_PRG_REG(n)              (MTK_NOR_PRGDATA0_REG + 4 * (n))
 110#define MTK_NOR_SHREG(n)                (MTK_NOR_SHREG0_REG + 4 * (n))
 111
 112struct mt8173_nor {
 113        struct spi_nor nor;
 114        struct device *dev;
 115        void __iomem *base;     /* nor flash base address */
 116        struct clk *spi_clk;
 117        struct clk *nor_clk;
 118};
 119
 120static void mt8173_nor_set_read_mode(struct mt8173_nor *mt8173_nor)
 121{
 122        struct spi_nor *nor = &mt8173_nor->nor;
 123
 124        switch (nor->flash_read) {
 125        case SPI_NOR_FAST:
 126                writeb(nor->read_opcode, mt8173_nor->base +
 127                       MTK_NOR_PRGDATA3_REG);
 128                writeb(MTK_NOR_FAST_READ, mt8173_nor->base +
 129                       MTK_NOR_CFG1_REG);
 130                break;
 131        case SPI_NOR_DUAL:
 132                writeb(nor->read_opcode, mt8173_nor->base +
 133                       MTK_NOR_PRGDATA3_REG);
 134                writeb(MTK_NOR_DUAL_READ_EN, mt8173_nor->base +
 135                       MTK_NOR_DUAL_REG);
 136                break;
 137        case SPI_NOR_QUAD:
 138                writeb(nor->read_opcode, mt8173_nor->base +
 139                       MTK_NOR_PRGDATA4_REG);
 140                writeb(MTK_NOR_QUAD_READ_EN, mt8173_nor->base +
 141                       MTK_NOR_DUAL_REG);
 142                break;
 143        default:
 144                writeb(MTK_NOR_DUAL_DISABLE, mt8173_nor->base +
 145                       MTK_NOR_DUAL_REG);
 146                break;
 147        }
 148}
 149
 150static int mt8173_nor_execute_cmd(struct mt8173_nor *mt8173_nor, u8 cmdval)
 151{
 152        int reg;
 153        u8 val = cmdval & 0x1f;
 154
 155        writeb(cmdval, mt8173_nor->base + MTK_NOR_CMD_REG);
 156        return readl_poll_timeout(mt8173_nor->base + MTK_NOR_CMD_REG, reg,
 157                                  !(reg & val), 100, 10000);
 158}
 159
 160static int mt8173_nor_do_tx_rx(struct mt8173_nor *mt8173_nor, u8 op,
 161                               u8 *tx, int txlen, u8 *rx, int rxlen)
 162{
 163        int len = 1 + txlen + rxlen;
 164        int i, ret, idx;
 165
 166        if (len > MTK_NOR_MAX_SHIFT)
 167                return -EINVAL;
 168
 169        writeb(len * 8, mt8173_nor->base + MTK_NOR_CNT_REG);
 170
 171        /* start at PRGDATA5, go down to PRGDATA0 */
 172        idx = MTK_NOR_MAX_RX_TX_SHIFT - 1;
 173
 174        /* opcode */
 175        writeb(op, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
 176        idx--;
 177
 178        /* program TX data */
 179        for (i = 0; i < txlen; i++, idx--)
 180                writeb(tx[i], mt8173_nor->base + MTK_NOR_PRG_REG(idx));
 181
 182        /* clear out rest of TX registers */
 183        while (idx >= 0) {
 184                writeb(0, mt8173_nor->base + MTK_NOR_PRG_REG(idx));
 185                idx--;
 186        }
 187
 188        ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PRG_CMD);
 189        if (ret)
 190                return ret;
 191
 192        /* restart at first RX byte */
 193        idx = rxlen - 1;
 194
 195        /* read out RX data */
 196        for (i = 0; i < rxlen; i++, idx--)
 197                rx[i] = readb(mt8173_nor->base + MTK_NOR_SHREG(idx));
 198
 199        return 0;
 200}
 201
 202/* Do a WRSR (Write Status Register) command */
 203static int mt8173_nor_wr_sr(struct mt8173_nor *mt8173_nor, u8 sr)
 204{
 205        writeb(sr, mt8173_nor->base + MTK_NOR_PRGDATA5_REG);
 206        writeb(8, mt8173_nor->base + MTK_NOR_CNT_REG);
 207        return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WRSR_CMD);
 208}
 209
 210static int mt8173_nor_write_buffer_enable(struct mt8173_nor *mt8173_nor)
 211{
 212        u8 reg;
 213
 214        /* the bit0 of MTK_NOR_CFG2_REG is pre-fetch buffer
 215         * 0: pre-fetch buffer use for read
 216         * 1: pre-fetch buffer use for page program
 217         */
 218        writel(MTK_NOR_WR_BUF_ENABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
 219        return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
 220                                  0x01 == (reg & 0x01), 100, 10000);
 221}
 222
 223static int mt8173_nor_write_buffer_disable(struct mt8173_nor *mt8173_nor)
 224{
 225        u8 reg;
 226
 227        writel(MTK_NOR_WR_BUF_DISABLE, mt8173_nor->base + MTK_NOR_CFG2_REG);
 228        return readb_poll_timeout(mt8173_nor->base + MTK_NOR_CFG2_REG, reg,
 229                                  MTK_NOR_WR_BUF_DISABLE == (reg & 0x1), 100,
 230                                  10000);
 231}
 232
 233static void mt8173_nor_set_addr(struct mt8173_nor *mt8173_nor, u32 addr)
 234{
 235        int i;
 236
 237        for (i = 0; i < 3; i++) {
 238                writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR0_REG + i * 4);
 239                addr >>= 8;
 240        }
 241        /* Last register is non-contiguous */
 242        writeb(addr & 0xff, mt8173_nor->base + MTK_NOR_RADR3_REG);
 243}
 244
 245static ssize_t mt8173_nor_read(struct spi_nor *nor, loff_t from, size_t length,
 246                               u_char *buffer)
 247{
 248        int i, ret;
 249        int addr = (int)from;
 250        u8 *buf = (u8 *)buffer;
 251        struct mt8173_nor *mt8173_nor = nor->priv;
 252
 253        /* set mode for fast read mode ,dual mode or quad mode */
 254        mt8173_nor_set_read_mode(mt8173_nor);
 255        mt8173_nor_set_addr(mt8173_nor, addr);
 256
 257        for (i = 0; i < length; i++) {
 258                ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_READ_CMD);
 259                if (ret < 0)
 260                        return ret;
 261                buf[i] = readb(mt8173_nor->base + MTK_NOR_RDATA_REG);
 262        }
 263        return length;
 264}
 265
 266static int mt8173_nor_write_single_byte(struct mt8173_nor *mt8173_nor,
 267                                        int addr, int length, u8 *data)
 268{
 269        int i, ret;
 270
 271        mt8173_nor_set_addr(mt8173_nor, addr);
 272
 273        for (i = 0; i < length; i++) {
 274                writeb(*data++, mt8173_nor->base + MTK_NOR_WDATA_REG);
 275                ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_PIO_WR_CMD);
 276                if (ret < 0)
 277                        return ret;
 278        }
 279        return 0;
 280}
 281
 282static int mt8173_nor_write_buffer(struct mt8173_nor *mt8173_nor, int addr,
 283                                   const u8 *buf)
 284{
 285        int i, bufidx, data;
 286
 287        mt8173_nor_set_addr(mt8173_nor, addr);
 288
 289        bufidx = 0;
 290        for (i = 0; i < SFLASH_WRBUF_SIZE; i += 4) {
 291                data = buf[bufidx + 3]<<24 | buf[bufidx + 2]<<16 |
 292                       buf[bufidx + 1]<<8 | buf[bufidx];
 293                bufidx += 4;
 294                writel(data, mt8173_nor->base + MTK_NOR_PP_DATA_REG);
 295        }
 296        return mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_WR_CMD);
 297}
 298
 299static ssize_t mt8173_nor_write(struct spi_nor *nor, loff_t to, size_t len,
 300                                const u_char *buf)
 301{
 302        int ret;
 303        struct mt8173_nor *mt8173_nor = nor->priv;
 304        size_t i;
 305
 306        ret = mt8173_nor_write_buffer_enable(mt8173_nor);
 307        if (ret < 0) {
 308                dev_warn(mt8173_nor->dev, "write buffer enable failed!\n");
 309                return ret;
 310        }
 311
 312        for (i = 0; i + SFLASH_WRBUF_SIZE <= len; i += SFLASH_WRBUF_SIZE) {
 313                ret = mt8173_nor_write_buffer(mt8173_nor, to, buf);
 314                if (ret < 0) {
 315                        dev_err(mt8173_nor->dev, "write buffer failed!\n");
 316                        return ret;
 317                }
 318                to += SFLASH_WRBUF_SIZE;
 319                buf += SFLASH_WRBUF_SIZE;
 320        }
 321        ret = mt8173_nor_write_buffer_disable(mt8173_nor);
 322        if (ret < 0) {
 323                dev_warn(mt8173_nor->dev, "write buffer disable failed!\n");
 324                return ret;
 325        }
 326
 327        if (i < len) {
 328                ret = mt8173_nor_write_single_byte(mt8173_nor, to,
 329                                                   (int)(len - i), (u8 *)buf);
 330                if (ret < 0) {
 331                        dev_err(mt8173_nor->dev, "write single byte failed!\n");
 332                        return ret;
 333                }
 334        }
 335
 336        return len;
 337}
 338
 339static int mt8173_nor_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 340{
 341        int ret;
 342        struct mt8173_nor *mt8173_nor = nor->priv;
 343
 344        switch (opcode) {
 345        case SPINOR_OP_RDSR:
 346                ret = mt8173_nor_execute_cmd(mt8173_nor, MTK_NOR_RDSR_CMD);
 347                if (ret < 0)
 348                        return ret;
 349                if (len == 1)
 350                        *buf = readb(mt8173_nor->base + MTK_NOR_RDSR_REG);
 351                else
 352                        dev_err(mt8173_nor->dev, "len should be 1 for read status!\n");
 353                break;
 354        default:
 355                ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, NULL, 0, buf, len);
 356                break;
 357        }
 358        return ret;
 359}
 360
 361static int mt8173_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
 362                                int len)
 363{
 364        int ret;
 365        struct mt8173_nor *mt8173_nor = nor->priv;
 366
 367        switch (opcode) {
 368        case SPINOR_OP_WRSR:
 369                /* We only handle 1 byte */
 370                ret = mt8173_nor_wr_sr(mt8173_nor, *buf);
 371                break;
 372        default:
 373                ret = mt8173_nor_do_tx_rx(mt8173_nor, opcode, buf, len, NULL, 0);
 374                if (ret)
 375                        dev_warn(mt8173_nor->dev, "write reg failure!\n");
 376                break;
 377        }
 378        return ret;
 379}
 380
 381static int mtk_nor_init(struct mt8173_nor *mt8173_nor,
 382                        struct device_node *flash_node)
 383{
 384        int ret;
 385        struct spi_nor *nor;
 386
 387        /* initialize controller to accept commands */
 388        writel(MTK_NOR_ENABLE_SF_CMD, mt8173_nor->base + MTK_NOR_WRPROT_REG);
 389
 390        nor = &mt8173_nor->nor;
 391        nor->dev = mt8173_nor->dev;
 392        nor->priv = mt8173_nor;
 393        spi_nor_set_flash_node(nor, flash_node);
 394
 395        /* fill the hooks to spi nor */
 396        nor->read = mt8173_nor_read;
 397        nor->read_reg = mt8173_nor_read_reg;
 398        nor->write = mt8173_nor_write;
 399        nor->write_reg = mt8173_nor_write_reg;
 400        nor->mtd.name = "mtk_nor";
 401        /* initialized with NULL */
 402        ret = spi_nor_scan(nor, NULL, SPI_NOR_DUAL);
 403        if (ret)
 404                return ret;
 405
 406        return mtd_device_register(&nor->mtd, NULL, 0);
 407}
 408
 409static int mtk_nor_drv_probe(struct platform_device *pdev)
 410{
 411        struct device_node *flash_np;
 412        struct resource *res;
 413        int ret;
 414        struct mt8173_nor *mt8173_nor;
 415
 416        if (!pdev->dev.of_node) {
 417                dev_err(&pdev->dev, "No DT found\n");
 418                return -EINVAL;
 419        }
 420
 421        mt8173_nor = devm_kzalloc(&pdev->dev, sizeof(*mt8173_nor), GFP_KERNEL);
 422        if (!mt8173_nor)
 423                return -ENOMEM;
 424        platform_set_drvdata(pdev, mt8173_nor);
 425
 426        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 427        mt8173_nor->base = devm_ioremap_resource(&pdev->dev, res);
 428        if (IS_ERR(mt8173_nor->base))
 429                return PTR_ERR(mt8173_nor->base);
 430
 431        mt8173_nor->spi_clk = devm_clk_get(&pdev->dev, "spi");
 432        if (IS_ERR(mt8173_nor->spi_clk))
 433                return PTR_ERR(mt8173_nor->spi_clk);
 434
 435        mt8173_nor->nor_clk = devm_clk_get(&pdev->dev, "sf");
 436        if (IS_ERR(mt8173_nor->nor_clk))
 437                return PTR_ERR(mt8173_nor->nor_clk);
 438
 439        mt8173_nor->dev = &pdev->dev;
 440        ret = clk_prepare_enable(mt8173_nor->spi_clk);
 441        if (ret)
 442                return ret;
 443
 444        ret = clk_prepare_enable(mt8173_nor->nor_clk);
 445        if (ret) {
 446                clk_disable_unprepare(mt8173_nor->spi_clk);
 447                return ret;
 448        }
 449        /* only support one attached flash */
 450        flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
 451        if (!flash_np) {
 452                dev_err(&pdev->dev, "no SPI flash device to configure\n");
 453                ret = -ENODEV;
 454                goto nor_free;
 455        }
 456        ret = mtk_nor_init(mt8173_nor, flash_np);
 457
 458nor_free:
 459        if (ret) {
 460                clk_disable_unprepare(mt8173_nor->spi_clk);
 461                clk_disable_unprepare(mt8173_nor->nor_clk);
 462        }
 463        return ret;
 464}
 465
 466static int mtk_nor_drv_remove(struct platform_device *pdev)
 467{
 468        struct mt8173_nor *mt8173_nor = platform_get_drvdata(pdev);
 469
 470        clk_disable_unprepare(mt8173_nor->spi_clk);
 471        clk_disable_unprepare(mt8173_nor->nor_clk);
 472        return 0;
 473}
 474
 475static const struct of_device_id mtk_nor_of_ids[] = {
 476        { .compatible = "mediatek,mt8173-nor"},
 477        { /* sentinel */ }
 478};
 479MODULE_DEVICE_TABLE(of, mtk_nor_of_ids);
 480
 481static struct platform_driver mtk_nor_driver = {
 482        .probe = mtk_nor_drv_probe,
 483        .remove = mtk_nor_drv_remove,
 484        .driver = {
 485                .name = "mtk-nor",
 486                .of_match_table = mtk_nor_of_ids,
 487        },
 488};
 489
 490module_platform_driver(mtk_nor_driver);
 491MODULE_LICENSE("GPL v2");
 492MODULE_DESCRIPTION("MediaTek SPI NOR Flash Driver");
 493