linux/drivers/i2c/busses/i2c-mt65xx.c
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   1/*
   2 * Copyright (c) 2014 MediaTek Inc.
   3 * Author: Xudong Chen <xudong.chen@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/completion.h>
  17#include <linux/delay.h>
  18#include <linux/device.h>
  19#include <linux/dma-mapping.h>
  20#include <linux/err.h>
  21#include <linux/errno.h>
  22#include <linux/i2c.h>
  23#include <linux/init.h>
  24#include <linux/interrupt.h>
  25#include <linux/io.h>
  26#include <linux/kernel.h>
  27#include <linux/mm.h>
  28#include <linux/module.h>
  29#include <linux/of_address.h>
  30#include <linux/of_device.h>
  31#include <linux/of_irq.h>
  32#include <linux/platform_device.h>
  33#include <linux/scatterlist.h>
  34#include <linux/sched.h>
  35#include <linux/slab.h>
  36
  37#define I2C_RS_TRANSFER                 (1 << 4)
  38#define I2C_HS_NACKERR                  (1 << 2)
  39#define I2C_ACKERR                      (1 << 1)
  40#define I2C_TRANSAC_COMP                (1 << 0)
  41#define I2C_TRANSAC_START               (1 << 0)
  42#define I2C_RS_MUL_CNFG                 (1 << 15)
  43#define I2C_RS_MUL_TRIG                 (1 << 14)
  44#define I2C_DCM_DISABLE                 0x0000
  45#define I2C_IO_CONFIG_OPEN_DRAIN        0x0003
  46#define I2C_IO_CONFIG_PUSH_PULL         0x0000
  47#define I2C_SOFT_RST                    0x0001
  48#define I2C_FIFO_ADDR_CLR               0x0001
  49#define I2C_DELAY_LEN                   0x0002
  50#define I2C_ST_START_CON                0x8001
  51#define I2C_FS_START_CON                0x1800
  52#define I2C_TIME_CLR_VALUE              0x0000
  53#define I2C_TIME_DEFAULT_VALUE          0x0003
  54#define I2C_WRRD_TRANAC_VALUE           0x0002
  55#define I2C_RD_TRANAC_VALUE             0x0001
  56
  57#define I2C_DMA_CON_TX                  0x0000
  58#define I2C_DMA_CON_RX                  0x0001
  59#define I2C_DMA_START_EN                0x0001
  60#define I2C_DMA_INT_FLAG_NONE           0x0000
  61#define I2C_DMA_CLR_FLAG                0x0000
  62#define I2C_DMA_HARD_RST                0x0002
  63#define I2C_DMA_4G_MODE                 0x0001
  64
  65#define I2C_DEFAULT_CLK_DIV             5
  66#define I2C_DEFAULT_SPEED               100000  /* hz */
  67#define MAX_FS_MODE_SPEED               400000
  68#define MAX_HS_MODE_SPEED               3400000
  69#define MAX_SAMPLE_CNT_DIV              8
  70#define MAX_STEP_CNT_DIV                64
  71#define MAX_HS_STEP_CNT_DIV             8
  72
  73#define I2C_CONTROL_RS                  (0x1 << 1)
  74#define I2C_CONTROL_DMA_EN              (0x1 << 2)
  75#define I2C_CONTROL_CLK_EXT_EN          (0x1 << 3)
  76#define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
  77#define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
  78#define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
  79#define I2C_CONTROL_WRAPPER             (0x1 << 0)
  80
  81#define I2C_DRV_NAME            "i2c-mt65xx"
  82
  83enum DMA_REGS_OFFSET {
  84        OFFSET_INT_FLAG = 0x0,
  85        OFFSET_INT_EN = 0x04,
  86        OFFSET_EN = 0x08,
  87        OFFSET_RST = 0x0c,
  88        OFFSET_CON = 0x18,
  89        OFFSET_TX_MEM_ADDR = 0x1c,
  90        OFFSET_RX_MEM_ADDR = 0x20,
  91        OFFSET_TX_LEN = 0x24,
  92        OFFSET_RX_LEN = 0x28,
  93        OFFSET_TX_4G_MODE = 0x54,
  94        OFFSET_RX_4G_MODE = 0x58,
  95};
  96
  97enum i2c_trans_st_rs {
  98        I2C_TRANS_STOP = 0,
  99        I2C_TRANS_REPEATED_START,
 100};
 101
 102enum mtk_trans_op {
 103        I2C_MASTER_WR = 1,
 104        I2C_MASTER_RD,
 105        I2C_MASTER_WRRD,
 106};
 107
 108enum I2C_REGS_OFFSET {
 109        OFFSET_DATA_PORT = 0x0,
 110        OFFSET_SLAVE_ADDR = 0x04,
 111        OFFSET_INTR_MASK = 0x08,
 112        OFFSET_INTR_STAT = 0x0c,
 113        OFFSET_CONTROL = 0x10,
 114        OFFSET_TRANSFER_LEN = 0x14,
 115        OFFSET_TRANSAC_LEN = 0x18,
 116        OFFSET_DELAY_LEN = 0x1c,
 117        OFFSET_TIMING = 0x20,
 118        OFFSET_START = 0x24,
 119        OFFSET_EXT_CONF = 0x28,
 120        OFFSET_FIFO_STAT = 0x30,
 121        OFFSET_FIFO_THRESH = 0x34,
 122        OFFSET_FIFO_ADDR_CLR = 0x38,
 123        OFFSET_IO_CONFIG = 0x40,
 124        OFFSET_RSV_DEBUG = 0x44,
 125        OFFSET_HS = 0x48,
 126        OFFSET_SOFTRESET = 0x50,
 127        OFFSET_DCM_EN = 0x54,
 128        OFFSET_PATH_DIR = 0x60,
 129        OFFSET_DEBUGSTAT = 0x64,
 130        OFFSET_DEBUGCTRL = 0x68,
 131        OFFSET_TRANSFER_LEN_AUX = 0x6c,
 132        OFFSET_CLOCK_DIV = 0x70,
 133};
 134
 135struct mtk_i2c_compatible {
 136        const struct i2c_adapter_quirks *quirks;
 137        unsigned char pmic_i2c: 1;
 138        unsigned char dcm: 1;
 139        unsigned char auto_restart: 1;
 140        unsigned char aux_len_reg: 1;
 141        unsigned char support_33bits: 1;
 142        unsigned char timing_adjust: 1;
 143};
 144
 145struct mtk_i2c {
 146        struct i2c_adapter adap;        /* i2c host adapter */
 147        struct device *dev;
 148        struct completion msg_complete;
 149
 150        /* set in i2c probe */
 151        void __iomem *base;             /* i2c base addr */
 152        void __iomem *pdmabase;         /* dma base address*/
 153        struct clk *clk_main;           /* main clock for i2c bus */
 154        struct clk *clk_dma;            /* DMA clock for i2c via DMA */
 155        struct clk *clk_pmic;           /* PMIC clock for i2c from PMIC */
 156        bool have_pmic;                 /* can use i2c pins from PMIC */
 157        bool use_push_pull;             /* IO config push-pull mode */
 158
 159        u16 irq_stat;                   /* interrupt status */
 160        unsigned int clk_src_div;
 161        unsigned int speed_hz;          /* The speed in transfer */
 162        enum mtk_trans_op op;
 163        u16 timing_reg;
 164        u16 high_speed_reg;
 165        unsigned char auto_restart;
 166        bool ignore_restart_irq;
 167        const struct mtk_i2c_compatible *dev_comp;
 168};
 169
 170static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
 171        .flags = I2C_AQ_COMB_WRITE_THEN_READ,
 172        .max_num_msgs = 1,
 173        .max_write_len = 255,
 174        .max_read_len = 255,
 175        .max_comb_1st_msg_len = 255,
 176        .max_comb_2nd_msg_len = 31,
 177};
 178
 179static const struct i2c_adapter_quirks mt7622_i2c_quirks = {
 180        .max_num_msgs = 255,
 181};
 182
 183static const struct mtk_i2c_compatible mt2712_compat = {
 184        .pmic_i2c = 0,
 185        .dcm = 1,
 186        .auto_restart = 1,
 187        .aux_len_reg = 1,
 188        .support_33bits = 1,
 189        .timing_adjust = 1,
 190};
 191
 192static const struct mtk_i2c_compatible mt6577_compat = {
 193        .quirks = &mt6577_i2c_quirks,
 194        .pmic_i2c = 0,
 195        .dcm = 1,
 196        .auto_restart = 0,
 197        .aux_len_reg = 0,
 198        .support_33bits = 0,
 199        .timing_adjust = 0,
 200};
 201
 202static const struct mtk_i2c_compatible mt6589_compat = {
 203        .quirks = &mt6577_i2c_quirks,
 204        .pmic_i2c = 1,
 205        .dcm = 0,
 206        .auto_restart = 0,
 207        .aux_len_reg = 0,
 208        .support_33bits = 0,
 209        .timing_adjust = 0,
 210};
 211
 212static const struct mtk_i2c_compatible mt7622_compat = {
 213        .quirks = &mt7622_i2c_quirks,
 214        .pmic_i2c = 0,
 215        .dcm = 1,
 216        .auto_restart = 1,
 217        .aux_len_reg = 1,
 218        .support_33bits = 0,
 219        .timing_adjust = 0,
 220};
 221
 222static const struct mtk_i2c_compatible mt8173_compat = {
 223        .pmic_i2c = 0,
 224        .dcm = 1,
 225        .auto_restart = 1,
 226        .aux_len_reg = 1,
 227        .support_33bits = 1,
 228        .timing_adjust = 0,
 229};
 230
 231static const struct of_device_id mtk_i2c_of_match[] = {
 232        { .compatible = "mediatek,mt2712-i2c", .data = &mt2712_compat },
 233        { .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
 234        { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
 235        { .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
 236        { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
 237        {}
 238};
 239MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
 240
 241static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
 242{
 243        int ret;
 244
 245        ret = clk_prepare_enable(i2c->clk_dma);
 246        if (ret)
 247                return ret;
 248
 249        ret = clk_prepare_enable(i2c->clk_main);
 250        if (ret)
 251                goto err_main;
 252
 253        if (i2c->have_pmic) {
 254                ret = clk_prepare_enable(i2c->clk_pmic);
 255                if (ret)
 256                        goto err_pmic;
 257        }
 258        return 0;
 259
 260err_pmic:
 261        clk_disable_unprepare(i2c->clk_main);
 262err_main:
 263        clk_disable_unprepare(i2c->clk_dma);
 264
 265        return ret;
 266}
 267
 268static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
 269{
 270        if (i2c->have_pmic)
 271                clk_disable_unprepare(i2c->clk_pmic);
 272
 273        clk_disable_unprepare(i2c->clk_main);
 274        clk_disable_unprepare(i2c->clk_dma);
 275}
 276
 277static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 278{
 279        u16 control_reg;
 280
 281        writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET);
 282
 283        /* Set ioconfig */
 284        if (i2c->use_push_pull)
 285                writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG);
 286        else
 287                writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG);
 288
 289        if (i2c->dev_comp->dcm)
 290                writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN);
 291
 292        if (i2c->dev_comp->timing_adjust)
 293                writew(I2C_DEFAULT_CLK_DIV - 1, i2c->base + OFFSET_CLOCK_DIV);
 294
 295        writew(i2c->timing_reg, i2c->base + OFFSET_TIMING);
 296        writew(i2c->high_speed_reg, i2c->base + OFFSET_HS);
 297
 298        /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
 299        if (i2c->have_pmic)
 300                writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR);
 301
 302        control_reg = I2C_CONTROL_ACKERR_DET_EN |
 303                      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
 304        writew(control_reg, i2c->base + OFFSET_CONTROL);
 305        writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
 306
 307        writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
 308        udelay(50);
 309        writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
 310}
 311
 312/*
 313 * Calculate i2c port speed
 314 *
 315 * Hardware design:
 316 * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
 317 * clock_div: fixed in hardware, but may be various in different SoCs
 318 *
 319 * The calculation want to pick the highest bus frequency that is still
 320 * less than or equal to i2c->speed_hz. The calculation try to get
 321 * sample_cnt and step_cn
 322 */
 323static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
 324                                   unsigned int target_speed,
 325                                   unsigned int *timing_step_cnt,
 326                                   unsigned int *timing_sample_cnt)
 327{
 328        unsigned int step_cnt;
 329        unsigned int sample_cnt;
 330        unsigned int max_step_cnt;
 331        unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV;
 332        unsigned int base_step_cnt;
 333        unsigned int opt_div;
 334        unsigned int best_mul;
 335        unsigned int cnt_mul;
 336
 337        if (target_speed > MAX_HS_MODE_SPEED)
 338                target_speed = MAX_HS_MODE_SPEED;
 339
 340        if (target_speed > MAX_FS_MODE_SPEED)
 341                max_step_cnt = MAX_HS_STEP_CNT_DIV;
 342        else
 343                max_step_cnt = MAX_STEP_CNT_DIV;
 344
 345        base_step_cnt = max_step_cnt;
 346        /* Find the best combination */
 347        opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
 348        best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
 349
 350        /* Search for the best pair (sample_cnt, step_cnt) with
 351         * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
 352         * 0 < step_cnt < max_step_cnt
 353         * sample_cnt * step_cnt >= opt_div
 354         * optimizing for sample_cnt * step_cnt being minimal
 355         */
 356        for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
 357                step_cnt = DIV_ROUND_UP(opt_div, sample_cnt);
 358                cnt_mul = step_cnt * sample_cnt;
 359                if (step_cnt > max_step_cnt)
 360                        continue;
 361
 362                if (cnt_mul < best_mul) {
 363                        best_mul = cnt_mul;
 364                        base_sample_cnt = sample_cnt;
 365                        base_step_cnt = step_cnt;
 366                        if (best_mul == opt_div)
 367                                break;
 368                }
 369        }
 370
 371        sample_cnt = base_sample_cnt;
 372        step_cnt = base_step_cnt;
 373
 374        if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
 375                /* In this case, hardware can't support such
 376                 * low i2c_bus_freq
 377                 */
 378                dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n", target_speed);
 379                return -EINVAL;
 380        }
 381
 382        *timing_step_cnt = step_cnt - 1;
 383        *timing_sample_cnt = sample_cnt - 1;
 384
 385        return 0;
 386}
 387
 388static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 389{
 390        unsigned int clk_src;
 391        unsigned int step_cnt;
 392        unsigned int sample_cnt;
 393        unsigned int target_speed;
 394        int ret;
 395
 396        clk_src = parent_clk / i2c->clk_src_div;
 397        target_speed = i2c->speed_hz;
 398
 399        if (target_speed > MAX_FS_MODE_SPEED) {
 400                /* Set master code speed register */
 401                ret = mtk_i2c_calculate_speed(i2c, clk_src, MAX_FS_MODE_SPEED,
 402                                              &step_cnt, &sample_cnt);
 403                if (ret < 0)
 404                        return ret;
 405
 406                i2c->timing_reg = (sample_cnt << 8) | step_cnt;
 407
 408                /* Set the high speed mode register */
 409                ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
 410                                              &step_cnt, &sample_cnt);
 411                if (ret < 0)
 412                        return ret;
 413
 414                i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
 415                        (sample_cnt << 12) | (step_cnt << 8);
 416        } else {
 417                ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
 418                                              &step_cnt, &sample_cnt);
 419                if (ret < 0)
 420                        return ret;
 421
 422                i2c->timing_reg = (sample_cnt << 8) | step_cnt;
 423
 424                /* Disable the high speed transaction */
 425                i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
 426        }
 427
 428        return 0;
 429}
 430
 431static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
 432{
 433        return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
 434}
 435
 436static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 437                               int num, int left_num)
 438{
 439        u16 addr_reg;
 440        u16 start_reg;
 441        u16 control_reg;
 442        u16 restart_flag = 0;
 443        u32 reg_4g_mode;
 444        dma_addr_t rpaddr = 0;
 445        dma_addr_t wpaddr = 0;
 446        int ret;
 447
 448        i2c->irq_stat = 0;
 449
 450        if (i2c->auto_restart)
 451                restart_flag = I2C_RS_TRANSFER;
 452
 453        reinit_completion(&i2c->msg_complete);
 454
 455        control_reg = readw(i2c->base + OFFSET_CONTROL) &
 456                        ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
 457        if ((i2c->speed_hz > 400000) || (left_num >= 1))
 458                control_reg |= I2C_CONTROL_RS;
 459
 460        if (i2c->op == I2C_MASTER_WRRD)
 461                control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
 462
 463        writew(control_reg, i2c->base + OFFSET_CONTROL);
 464
 465        /* set start condition */
 466        if (i2c->speed_hz <= 100000)
 467                writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF);
 468        else
 469                writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF);
 470
 471        addr_reg = i2c_8bit_addr_from_msg(msgs);
 472        writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR);
 473
 474        /* Clear interrupt status */
 475        writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 476               I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
 477        writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR);
 478
 479        /* Enable interrupt */
 480        writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 481               I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK);
 482
 483        /* Set transfer and transaction len */
 484        if (i2c->op == I2C_MASTER_WRRD) {
 485                if (i2c->dev_comp->aux_len_reg) {
 486                        writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
 487                        writew((msgs + 1)->len, i2c->base +
 488                               OFFSET_TRANSFER_LEN_AUX);
 489                } else {
 490                        writew(msgs->len | ((msgs + 1)->len) << 8,
 491                               i2c->base + OFFSET_TRANSFER_LEN);
 492                }
 493                writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN);
 494        } else {
 495                writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
 496                writew(num, i2c->base + OFFSET_TRANSAC_LEN);
 497        }
 498
 499        /* Prepare buffer data to start transfer */
 500        if (i2c->op == I2C_MASTER_RD) {
 501                writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
 502                writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
 503                rpaddr = dma_map_single(i2c->dev, msgs->buf,
 504                                        msgs->len, DMA_FROM_DEVICE);
 505                if (dma_mapping_error(i2c->dev, rpaddr))
 506                        return -ENOMEM;
 507
 508                if (i2c->dev_comp->support_33bits) {
 509                        reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
 510                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
 511                }
 512
 513                writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 514                writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
 515        } else if (i2c->op == I2C_MASTER_WR) {
 516                writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
 517                writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
 518                wpaddr = dma_map_single(i2c->dev, msgs->buf,
 519                                        msgs->len, DMA_TO_DEVICE);
 520                if (dma_mapping_error(i2c->dev, wpaddr))
 521                        return -ENOMEM;
 522
 523                if (i2c->dev_comp->support_33bits) {
 524                        reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
 525                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
 526                }
 527
 528                writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 529                writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
 530        } else {
 531                writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
 532                writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
 533                wpaddr = dma_map_single(i2c->dev, msgs->buf,
 534                                        msgs->len, DMA_TO_DEVICE);
 535                if (dma_mapping_error(i2c->dev, wpaddr))
 536                        return -ENOMEM;
 537                rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf,
 538                                        (msgs + 1)->len,
 539                                        DMA_FROM_DEVICE);
 540                if (dma_mapping_error(i2c->dev, rpaddr)) {
 541                        dma_unmap_single(i2c->dev, wpaddr,
 542                                         msgs->len, DMA_TO_DEVICE);
 543                        return -ENOMEM;
 544                }
 545
 546                if (i2c->dev_comp->support_33bits) {
 547                        reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
 548                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
 549
 550                        reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
 551                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
 552                }
 553
 554                writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 555                writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 556                writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
 557                writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN);
 558        }
 559
 560        writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN);
 561
 562        if (!i2c->auto_restart) {
 563                start_reg = I2C_TRANSAC_START;
 564        } else {
 565                start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
 566                if (left_num >= 1)
 567                        start_reg |= I2C_RS_MUL_CNFG;
 568        }
 569        writew(start_reg, i2c->base + OFFSET_START);
 570
 571        ret = wait_for_completion_timeout(&i2c->msg_complete,
 572                                          i2c->adap.timeout);
 573
 574        /* Clear interrupt mask */
 575        writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 576               I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK);
 577
 578        if (i2c->op == I2C_MASTER_WR) {
 579                dma_unmap_single(i2c->dev, wpaddr,
 580                                 msgs->len, DMA_TO_DEVICE);
 581        } else if (i2c->op == I2C_MASTER_RD) {
 582                dma_unmap_single(i2c->dev, rpaddr,
 583                                 msgs->len, DMA_FROM_DEVICE);
 584        } else {
 585                dma_unmap_single(i2c->dev, wpaddr, msgs->len,
 586                                 DMA_TO_DEVICE);
 587                dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
 588                                 DMA_FROM_DEVICE);
 589        }
 590
 591        if (ret == 0) {
 592                dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
 593                mtk_i2c_init_hw(i2c);
 594                return -ETIMEDOUT;
 595        }
 596
 597        completion_done(&i2c->msg_complete);
 598
 599        if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) {
 600                dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr);
 601                mtk_i2c_init_hw(i2c);
 602                return -ENXIO;
 603        }
 604
 605        return 0;
 606}
 607
 608static int mtk_i2c_transfer(struct i2c_adapter *adap,
 609                            struct i2c_msg msgs[], int num)
 610{
 611        int ret;
 612        int left_num = num;
 613        struct mtk_i2c *i2c = i2c_get_adapdata(adap);
 614
 615        ret = mtk_i2c_clock_enable(i2c);
 616        if (ret)
 617                return ret;
 618
 619        i2c->auto_restart = i2c->dev_comp->auto_restart;
 620
 621        /* checking if we can skip restart and optimize using WRRD mode */
 622        if (i2c->auto_restart && num == 2) {
 623                if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) &&
 624                    msgs[0].addr == msgs[1].addr) {
 625                        i2c->auto_restart = 0;
 626                }
 627        }
 628
 629        if (i2c->auto_restart && num >= 2 && i2c->speed_hz > MAX_FS_MODE_SPEED)
 630                /* ignore the first restart irq after the master code,
 631                 * otherwise the first transfer will be discarded.
 632                 */
 633                i2c->ignore_restart_irq = true;
 634        else
 635                i2c->ignore_restart_irq = false;
 636
 637        while (left_num--) {
 638                if (!msgs->buf) {
 639                        dev_dbg(i2c->dev, "data buffer is NULL.\n");
 640                        ret = -EINVAL;
 641                        goto err_exit;
 642                }
 643
 644                if (msgs->flags & I2C_M_RD)
 645                        i2c->op = I2C_MASTER_RD;
 646                else
 647                        i2c->op = I2C_MASTER_WR;
 648
 649                if (!i2c->auto_restart) {
 650                        if (num > 1) {
 651                                /* combined two messages into one transaction */
 652                                i2c->op = I2C_MASTER_WRRD;
 653                                left_num--;
 654                        }
 655                }
 656
 657                /* always use DMA mode. */
 658                ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
 659                if (ret < 0)
 660                        goto err_exit;
 661
 662                msgs++;
 663        }
 664        /* the return value is number of executed messages */
 665        ret = num;
 666
 667err_exit:
 668        mtk_i2c_clock_disable(i2c);
 669        return ret;
 670}
 671
 672static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 673{
 674        struct mtk_i2c *i2c = dev_id;
 675        u16 restart_flag = 0;
 676        u16 intr_stat;
 677
 678        if (i2c->auto_restart)
 679                restart_flag = I2C_RS_TRANSFER;
 680
 681        intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
 682        writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
 683
 684        /*
 685         * when occurs ack error, i2c controller generate two interrupts
 686         * first is the ack error interrupt, then the complete interrupt
 687         * i2c->irq_stat need keep the two interrupt value.
 688         */
 689        i2c->irq_stat |= intr_stat;
 690
 691        if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) {
 692                i2c->ignore_restart_irq = false;
 693                i2c->irq_stat = 0;
 694                writew(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START,
 695                       i2c->base + OFFSET_START);
 696        } else {
 697                if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
 698                        complete(&i2c->msg_complete);
 699        }
 700
 701        return IRQ_HANDLED;
 702}
 703
 704static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
 705{
 706        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 707}
 708
 709static const struct i2c_algorithm mtk_i2c_algorithm = {
 710        .master_xfer = mtk_i2c_transfer,
 711        .functionality = mtk_i2c_functionality,
 712};
 713
 714static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 715{
 716        int ret;
 717
 718        ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz);
 719        if (ret < 0)
 720                i2c->speed_hz = I2C_DEFAULT_SPEED;
 721
 722        ret = of_property_read_u32(np, "clock-div", &i2c->clk_src_div);
 723        if (ret < 0)
 724                return ret;
 725
 726        if (i2c->clk_src_div == 0)
 727                return -EINVAL;
 728
 729        i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 730        i2c->use_push_pull =
 731                of_property_read_bool(np, "mediatek,use-push-pull");
 732
 733        return 0;
 734}
 735
 736static int mtk_i2c_probe(struct platform_device *pdev)
 737{
 738        int ret = 0;
 739        struct mtk_i2c *i2c;
 740        struct clk *clk;
 741        struct resource *res;
 742        int irq;
 743
 744        i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 745        if (!i2c)
 746                return -ENOMEM;
 747
 748        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 749        i2c->base = devm_ioremap_resource(&pdev->dev, res);
 750        if (IS_ERR(i2c->base))
 751                return PTR_ERR(i2c->base);
 752
 753        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 754        i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
 755        if (IS_ERR(i2c->pdmabase))
 756                return PTR_ERR(i2c->pdmabase);
 757
 758        irq = platform_get_irq(pdev, 0);
 759        if (irq <= 0)
 760                return irq;
 761
 762        init_completion(&i2c->msg_complete);
 763
 764        i2c->dev_comp = of_device_get_match_data(&pdev->dev);
 765        i2c->adap.dev.of_node = pdev->dev.of_node;
 766        i2c->dev = &pdev->dev;
 767        i2c->adap.dev.parent = &pdev->dev;
 768        i2c->adap.owner = THIS_MODULE;
 769        i2c->adap.algo = &mtk_i2c_algorithm;
 770        i2c->adap.quirks = i2c->dev_comp->quirks;
 771        i2c->adap.timeout = 2 * HZ;
 772        i2c->adap.retries = 1;
 773
 774        ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
 775        if (ret)
 776                return -EINVAL;
 777
 778        if (i2c->dev_comp->timing_adjust)
 779                i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV;
 780
 781        if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
 782                return -EINVAL;
 783
 784        i2c->clk_main = devm_clk_get(&pdev->dev, "main");
 785        if (IS_ERR(i2c->clk_main)) {
 786                dev_err(&pdev->dev, "cannot get main clock\n");
 787                return PTR_ERR(i2c->clk_main);
 788        }
 789
 790        i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
 791        if (IS_ERR(i2c->clk_dma)) {
 792                dev_err(&pdev->dev, "cannot get dma clock\n");
 793                return PTR_ERR(i2c->clk_dma);
 794        }
 795
 796        clk = i2c->clk_main;
 797        if (i2c->have_pmic) {
 798                i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
 799                if (IS_ERR(i2c->clk_pmic)) {
 800                        dev_err(&pdev->dev, "cannot get pmic clock\n");
 801                        return PTR_ERR(i2c->clk_pmic);
 802                }
 803                clk = i2c->clk_pmic;
 804        }
 805
 806        strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
 807
 808        ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
 809        if (ret) {
 810                dev_err(&pdev->dev, "Failed to set the speed.\n");
 811                return -EINVAL;
 812        }
 813
 814        if (i2c->dev_comp->support_33bits) {
 815                ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33));
 816                if (ret) {
 817                        dev_err(&pdev->dev, "dma_set_mask return error.\n");
 818                        return ret;
 819                }
 820        }
 821
 822        ret = mtk_i2c_clock_enable(i2c);
 823        if (ret) {
 824                dev_err(&pdev->dev, "clock enable failed!\n");
 825                return ret;
 826        }
 827        mtk_i2c_init_hw(i2c);
 828        mtk_i2c_clock_disable(i2c);
 829
 830        ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
 831                               IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c);
 832        if (ret < 0) {
 833                dev_err(&pdev->dev,
 834                        "Request I2C IRQ %d fail\n", irq);
 835                return ret;
 836        }
 837
 838        i2c_set_adapdata(&i2c->adap, i2c);
 839        ret = i2c_add_adapter(&i2c->adap);
 840        if (ret)
 841                return ret;
 842
 843        platform_set_drvdata(pdev, i2c);
 844
 845        return 0;
 846}
 847
 848static int mtk_i2c_remove(struct platform_device *pdev)
 849{
 850        struct mtk_i2c *i2c = platform_get_drvdata(pdev);
 851
 852        i2c_del_adapter(&i2c->adap);
 853
 854        return 0;
 855}
 856
 857#ifdef CONFIG_PM_SLEEP
 858static int mtk_i2c_resume(struct device *dev)
 859{
 860        int ret;
 861        struct mtk_i2c *i2c = dev_get_drvdata(dev);
 862
 863        ret = mtk_i2c_clock_enable(i2c);
 864        if (ret) {
 865                dev_err(dev, "clock enable failed!\n");
 866                return ret;
 867        }
 868
 869        mtk_i2c_init_hw(i2c);
 870
 871        mtk_i2c_clock_disable(i2c);
 872
 873        return 0;
 874}
 875#endif
 876
 877static const struct dev_pm_ops mtk_i2c_pm = {
 878        SET_SYSTEM_SLEEP_PM_OPS(NULL, mtk_i2c_resume)
 879};
 880
 881static struct platform_driver mtk_i2c_driver = {
 882        .probe = mtk_i2c_probe,
 883        .remove = mtk_i2c_remove,
 884        .driver = {
 885                .name = I2C_DRV_NAME,
 886                .pm = &mtk_i2c_pm,
 887                .of_match_table = of_match_ptr(mtk_i2c_of_match),
 888        },
 889};
 890
 891module_platform_driver(mtk_i2c_driver);
 892
 893MODULE_LICENSE("GPL v2");
 894MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
 895MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>");
 896