linux/drivers/i2c/busses/i2c-mt65xx.c
<<
>>
Prefs
   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_irq.h>
  31#include <linux/platform_device.h>
  32#include <linux/scatterlist.h>
  33#include <linux/sched.h>
  34#include <linux/slab.h>
  35
  36#define I2C_RS_TRANSFER                 (1 << 4)
  37#define I2C_HS_NACKERR                  (1 << 2)
  38#define I2C_ACKERR                      (1 << 1)
  39#define I2C_TRANSAC_COMP                (1 << 0)
  40#define I2C_TRANSAC_START               (1 << 0)
  41#define I2C_RS_MUL_CNFG                 (1 << 15)
  42#define I2C_RS_MUL_TRIG                 (1 << 14)
  43#define I2C_DCM_DISABLE                 0x0000
  44#define I2C_IO_CONFIG_OPEN_DRAIN        0x0003
  45#define I2C_IO_CONFIG_PUSH_PULL         0x0000
  46#define I2C_SOFT_RST                    0x0001
  47#define I2C_FIFO_ADDR_CLR               0x0001
  48#define I2C_DELAY_LEN                   0x0002
  49#define I2C_ST_START_CON                0x8001
  50#define I2C_FS_START_CON                0x1800
  51#define I2C_TIME_CLR_VALUE              0x0000
  52#define I2C_TIME_DEFAULT_VALUE          0x0003
  53#define I2C_FS_TIME_INIT_VALUE          0x1303
  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_SPEED               100000  /* hz */
  66#define MAX_FS_MODE_SPEED               400000
  67#define MAX_HS_MODE_SPEED               3400000
  68#define MAX_SAMPLE_CNT_DIV              8
  69#define MAX_STEP_CNT_DIV                64
  70#define MAX_HS_STEP_CNT_DIV             8
  71
  72#define I2C_CONTROL_RS                  (0x1 << 1)
  73#define I2C_CONTROL_DMA_EN              (0x1 << 2)
  74#define I2C_CONTROL_CLK_EXT_EN          (0x1 << 3)
  75#define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
  76#define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
  77#define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
  78#define I2C_CONTROL_WRAPPER             (0x1 << 0)
  79
  80#define I2C_DRV_NAME            "i2c-mt65xx"
  81
  82enum DMA_REGS_OFFSET {
  83        OFFSET_INT_FLAG = 0x0,
  84        OFFSET_INT_EN = 0x04,
  85        OFFSET_EN = 0x08,
  86        OFFSET_RST = 0x0c,
  87        OFFSET_CON = 0x18,
  88        OFFSET_TX_MEM_ADDR = 0x1c,
  89        OFFSET_RX_MEM_ADDR = 0x20,
  90        OFFSET_TX_LEN = 0x24,
  91        OFFSET_RX_LEN = 0x28,
  92        OFFSET_TX_4G_MODE = 0x54,
  93        OFFSET_RX_4G_MODE = 0x58,
  94};
  95
  96enum i2c_trans_st_rs {
  97        I2C_TRANS_STOP = 0,
  98        I2C_TRANS_REPEATED_START,
  99};
 100
 101enum mtk_trans_op {
 102        I2C_MASTER_WR = 1,
 103        I2C_MASTER_RD,
 104        I2C_MASTER_WRRD,
 105};
 106
 107enum I2C_REGS_OFFSET {
 108        OFFSET_DATA_PORT = 0x0,
 109        OFFSET_SLAVE_ADDR = 0x04,
 110        OFFSET_INTR_MASK = 0x08,
 111        OFFSET_INTR_STAT = 0x0c,
 112        OFFSET_CONTROL = 0x10,
 113        OFFSET_TRANSFER_LEN = 0x14,
 114        OFFSET_TRANSAC_LEN = 0x18,
 115        OFFSET_DELAY_LEN = 0x1c,
 116        OFFSET_TIMING = 0x20,
 117        OFFSET_START = 0x24,
 118        OFFSET_EXT_CONF = 0x28,
 119        OFFSET_FIFO_STAT = 0x30,
 120        OFFSET_FIFO_THRESH = 0x34,
 121        OFFSET_FIFO_ADDR_CLR = 0x38,
 122        OFFSET_IO_CONFIG = 0x40,
 123        OFFSET_RSV_DEBUG = 0x44,
 124        OFFSET_HS = 0x48,
 125        OFFSET_SOFTRESET = 0x50,
 126        OFFSET_DCM_EN = 0x54,
 127        OFFSET_PATH_DIR = 0x60,
 128        OFFSET_DEBUGSTAT = 0x64,
 129        OFFSET_DEBUGCTRL = 0x68,
 130        OFFSET_TRANSFER_LEN_AUX = 0x6c,
 131};
 132
 133struct mtk_i2c_compatible {
 134        const struct i2c_adapter_quirks *quirks;
 135        unsigned char pmic_i2c: 1;
 136        unsigned char dcm: 1;
 137        unsigned char auto_restart: 1;
 138        unsigned char aux_len_reg: 1;
 139        unsigned char support_33bits: 1;
 140};
 141
 142struct mtk_i2c {
 143        struct i2c_adapter adap;        /* i2c host adapter */
 144        struct device *dev;
 145        struct completion msg_complete;
 146
 147        /* set in i2c probe */
 148        void __iomem *base;             /* i2c base addr */
 149        void __iomem *pdmabase;         /* dma base address*/
 150        struct clk *clk_main;           /* main clock for i2c bus */
 151        struct clk *clk_dma;            /* DMA clock for i2c via DMA */
 152        struct clk *clk_pmic;           /* PMIC clock for i2c from PMIC */
 153        bool have_pmic;                 /* can use i2c pins from PMIC */
 154        bool use_push_pull;             /* IO config push-pull mode */
 155
 156        u16 irq_stat;                   /* interrupt status */
 157        unsigned int speed_hz;          /* The speed in transfer */
 158        enum mtk_trans_op op;
 159        u16 timing_reg;
 160        u16 high_speed_reg;
 161        unsigned char auto_restart;
 162        bool ignore_restart_irq;
 163        const struct mtk_i2c_compatible *dev_comp;
 164};
 165
 166static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
 167        .flags = I2C_AQ_COMB_WRITE_THEN_READ,
 168        .max_num_msgs = 1,
 169        .max_write_len = 255,
 170        .max_read_len = 255,
 171        .max_comb_1st_msg_len = 255,
 172        .max_comb_2nd_msg_len = 31,
 173};
 174
 175static const struct i2c_adapter_quirks mt8173_i2c_quirks = {
 176        .max_num_msgs = 65535,
 177        .max_write_len = 65535,
 178        .max_read_len = 65535,
 179        .max_comb_1st_msg_len = 65535,
 180        .max_comb_2nd_msg_len = 65535,
 181};
 182
 183static const struct mtk_i2c_compatible mt6577_compat = {
 184        .quirks = &mt6577_i2c_quirks,
 185        .pmic_i2c = 0,
 186        .dcm = 1,
 187        .auto_restart = 0,
 188        .aux_len_reg = 0,
 189        .support_33bits = 0,
 190};
 191
 192static const struct mtk_i2c_compatible mt6589_compat = {
 193        .quirks = &mt6577_i2c_quirks,
 194        .pmic_i2c = 1,
 195        .dcm = 0,
 196        .auto_restart = 0,
 197        .aux_len_reg = 0,
 198        .support_33bits = 0,
 199};
 200
 201static const struct mtk_i2c_compatible mt8173_compat = {
 202        .quirks = &mt8173_i2c_quirks,
 203        .pmic_i2c = 0,
 204        .dcm = 1,
 205        .auto_restart = 1,
 206        .aux_len_reg = 1,
 207        .support_33bits = 1,
 208};
 209
 210static const struct of_device_id mtk_i2c_of_match[] = {
 211        { .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
 212        { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
 213        { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
 214        {}
 215};
 216MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
 217
 218static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
 219{
 220        int ret;
 221
 222        ret = clk_prepare_enable(i2c->clk_dma);
 223        if (ret)
 224                return ret;
 225
 226        ret = clk_prepare_enable(i2c->clk_main);
 227        if (ret)
 228                goto err_main;
 229
 230        if (i2c->have_pmic) {
 231                ret = clk_prepare_enable(i2c->clk_pmic);
 232                if (ret)
 233                        goto err_pmic;
 234        }
 235        return 0;
 236
 237err_pmic:
 238        clk_disable_unprepare(i2c->clk_main);
 239err_main:
 240        clk_disable_unprepare(i2c->clk_dma);
 241
 242        return ret;
 243}
 244
 245static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
 246{
 247        if (i2c->have_pmic)
 248                clk_disable_unprepare(i2c->clk_pmic);
 249
 250        clk_disable_unprepare(i2c->clk_main);
 251        clk_disable_unprepare(i2c->clk_dma);
 252}
 253
 254static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 255{
 256        u16 control_reg;
 257
 258        writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET);
 259
 260        /* Set ioconfig */
 261        if (i2c->use_push_pull)
 262                writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG);
 263        else
 264                writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG);
 265
 266        if (i2c->dev_comp->dcm)
 267                writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN);
 268
 269        writew(i2c->timing_reg, i2c->base + OFFSET_TIMING);
 270        writew(i2c->high_speed_reg, i2c->base + OFFSET_HS);
 271
 272        /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
 273        if (i2c->have_pmic)
 274                writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR);
 275
 276        control_reg = I2C_CONTROL_ACKERR_DET_EN |
 277                      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
 278        writew(control_reg, i2c->base + OFFSET_CONTROL);
 279        writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
 280
 281        writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
 282        udelay(50);
 283        writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
 284}
 285
 286/*
 287 * Calculate i2c port speed
 288 *
 289 * Hardware design:
 290 * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
 291 * clock_div: fixed in hardware, but may be various in different SoCs
 292 *
 293 * The calculation want to pick the highest bus frequency that is still
 294 * less than or equal to i2c->speed_hz. The calculation try to get
 295 * sample_cnt and step_cn
 296 */
 297static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk,
 298                             unsigned int clock_div)
 299{
 300        unsigned int clk_src;
 301        unsigned int step_cnt;
 302        unsigned int sample_cnt;
 303        unsigned int max_step_cnt;
 304        unsigned int target_speed;
 305        unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV;
 306        unsigned int base_step_cnt;
 307        unsigned int opt_div;
 308        unsigned int best_mul;
 309        unsigned int cnt_mul;
 310
 311        clk_src = parent_clk / clock_div;
 312        target_speed = i2c->speed_hz;
 313
 314        if (target_speed > MAX_HS_MODE_SPEED)
 315                target_speed = MAX_HS_MODE_SPEED;
 316
 317        if (target_speed > MAX_FS_MODE_SPEED)
 318                max_step_cnt = MAX_HS_STEP_CNT_DIV;
 319        else
 320                max_step_cnt = MAX_STEP_CNT_DIV;
 321
 322        base_step_cnt = max_step_cnt;
 323        /* Find the best combination */
 324        opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
 325        best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
 326
 327        /* Search for the best pair (sample_cnt, step_cnt) with
 328         * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
 329         * 0 < step_cnt < max_step_cnt
 330         * sample_cnt * step_cnt >= opt_div
 331         * optimizing for sample_cnt * step_cnt being minimal
 332         */
 333        for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
 334                step_cnt = DIV_ROUND_UP(opt_div, sample_cnt);
 335                cnt_mul = step_cnt * sample_cnt;
 336                if (step_cnt > max_step_cnt)
 337                        continue;
 338
 339                if (cnt_mul < best_mul) {
 340                        best_mul = cnt_mul;
 341                        base_sample_cnt = sample_cnt;
 342                        base_step_cnt = step_cnt;
 343                        if (best_mul == opt_div)
 344                                break;
 345                }
 346        }
 347
 348        sample_cnt = base_sample_cnt;
 349        step_cnt = base_step_cnt;
 350
 351        if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
 352                /* In this case, hardware can't support such
 353                 * low i2c_bus_freq
 354                 */
 355                dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n", target_speed);
 356                return -EINVAL;
 357        }
 358
 359        step_cnt--;
 360        sample_cnt--;
 361
 362        if (target_speed > MAX_FS_MODE_SPEED) {
 363                /* Set the high speed mode register */
 364                i2c->timing_reg = I2C_FS_TIME_INIT_VALUE;
 365                i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
 366                        (sample_cnt << 12) | (step_cnt << 8);
 367        } else {
 368                i2c->timing_reg = (sample_cnt << 8) | (step_cnt << 0);
 369                /* Disable the high speed transaction */
 370                i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
 371        }
 372
 373        return 0;
 374}
 375
 376static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
 377{
 378        return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
 379}
 380
 381static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 382                               int num, int left_num)
 383{
 384        u16 addr_reg;
 385        u16 start_reg;
 386        u16 control_reg;
 387        u16 restart_flag = 0;
 388        u32 reg_4g_mode;
 389        dma_addr_t rpaddr = 0;
 390        dma_addr_t wpaddr = 0;
 391        int ret;
 392
 393        i2c->irq_stat = 0;
 394
 395        if (i2c->auto_restart)
 396                restart_flag = I2C_RS_TRANSFER;
 397
 398        reinit_completion(&i2c->msg_complete);
 399
 400        control_reg = readw(i2c->base + OFFSET_CONTROL) &
 401                        ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
 402        if ((i2c->speed_hz > 400000) || (left_num >= 1))
 403                control_reg |= I2C_CONTROL_RS;
 404
 405        if (i2c->op == I2C_MASTER_WRRD)
 406                control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
 407
 408        writew(control_reg, i2c->base + OFFSET_CONTROL);
 409
 410        /* set start condition */
 411        if (i2c->speed_hz <= 100000)
 412                writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF);
 413        else
 414                writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF);
 415
 416        addr_reg = i2c_8bit_addr_from_msg(msgs);
 417        writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR);
 418
 419        /* Clear interrupt status */
 420        writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 421               I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
 422        writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR);
 423
 424        /* Enable interrupt */
 425        writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 426               I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK);
 427
 428        /* Set transfer and transaction len */
 429        if (i2c->op == I2C_MASTER_WRRD) {
 430                if (i2c->dev_comp->aux_len_reg) {
 431                        writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
 432                        writew((msgs + 1)->len, i2c->base +
 433                               OFFSET_TRANSFER_LEN_AUX);
 434                } else {
 435                        writew(msgs->len | ((msgs + 1)->len) << 8,
 436                               i2c->base + OFFSET_TRANSFER_LEN);
 437                }
 438                writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN);
 439        } else {
 440                writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
 441                writew(num, i2c->base + OFFSET_TRANSAC_LEN);
 442        }
 443
 444        /* Prepare buffer data to start transfer */
 445        if (i2c->op == I2C_MASTER_RD) {
 446                writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
 447                writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
 448                rpaddr = dma_map_single(i2c->dev, msgs->buf,
 449                                        msgs->len, DMA_FROM_DEVICE);
 450                if (dma_mapping_error(i2c->dev, rpaddr))
 451                        return -ENOMEM;
 452
 453                if (i2c->dev_comp->support_33bits) {
 454                        reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
 455                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
 456                }
 457
 458                writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 459                writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
 460        } else if (i2c->op == I2C_MASTER_WR) {
 461                writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
 462                writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
 463                wpaddr = dma_map_single(i2c->dev, msgs->buf,
 464                                        msgs->len, DMA_TO_DEVICE);
 465                if (dma_mapping_error(i2c->dev, wpaddr))
 466                        return -ENOMEM;
 467
 468                if (i2c->dev_comp->support_33bits) {
 469                        reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
 470                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
 471                }
 472
 473                writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 474                writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
 475        } else {
 476                writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
 477                writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
 478                wpaddr = dma_map_single(i2c->dev, msgs->buf,
 479                                        msgs->len, DMA_TO_DEVICE);
 480                if (dma_mapping_error(i2c->dev, wpaddr))
 481                        return -ENOMEM;
 482                rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf,
 483                                        (msgs + 1)->len,
 484                                        DMA_FROM_DEVICE);
 485                if (dma_mapping_error(i2c->dev, rpaddr)) {
 486                        dma_unmap_single(i2c->dev, wpaddr,
 487                                         msgs->len, DMA_TO_DEVICE);
 488                        return -ENOMEM;
 489                }
 490
 491                if (i2c->dev_comp->support_33bits) {
 492                        reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
 493                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
 494
 495                        reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
 496                        writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
 497                }
 498
 499                writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 500                writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 501                writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
 502                writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN);
 503        }
 504
 505        writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN);
 506
 507        if (!i2c->auto_restart) {
 508                start_reg = I2C_TRANSAC_START;
 509        } else {
 510                start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
 511                if (left_num >= 1)
 512                        start_reg |= I2C_RS_MUL_CNFG;
 513        }
 514        writew(start_reg, i2c->base + OFFSET_START);
 515
 516        ret = wait_for_completion_timeout(&i2c->msg_complete,
 517                                          i2c->adap.timeout);
 518
 519        /* Clear interrupt mask */
 520        writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
 521               I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK);
 522
 523        if (i2c->op == I2C_MASTER_WR) {
 524                dma_unmap_single(i2c->dev, wpaddr,
 525                                 msgs->len, DMA_TO_DEVICE);
 526        } else if (i2c->op == I2C_MASTER_RD) {
 527                dma_unmap_single(i2c->dev, rpaddr,
 528                                 msgs->len, DMA_FROM_DEVICE);
 529        } else {
 530                dma_unmap_single(i2c->dev, wpaddr, msgs->len,
 531                                 DMA_TO_DEVICE);
 532                dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
 533                                 DMA_FROM_DEVICE);
 534        }
 535
 536        if (ret == 0) {
 537                dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
 538                mtk_i2c_init_hw(i2c);
 539                return -ETIMEDOUT;
 540        }
 541
 542        completion_done(&i2c->msg_complete);
 543
 544        if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) {
 545                dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr);
 546                mtk_i2c_init_hw(i2c);
 547                return -ENXIO;
 548        }
 549
 550        return 0;
 551}
 552
 553static int mtk_i2c_transfer(struct i2c_adapter *adap,
 554                            struct i2c_msg msgs[], int num)
 555{
 556        int ret;
 557        int left_num = num;
 558        struct mtk_i2c *i2c = i2c_get_adapdata(adap);
 559
 560        ret = mtk_i2c_clock_enable(i2c);
 561        if (ret)
 562                return ret;
 563
 564        i2c->auto_restart = i2c->dev_comp->auto_restart;
 565
 566        /* checking if we can skip restart and optimize using WRRD mode */
 567        if (i2c->auto_restart && num == 2) {
 568                if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) &&
 569                    msgs[0].addr == msgs[1].addr) {
 570                        i2c->auto_restart = 0;
 571                }
 572        }
 573
 574        if (i2c->auto_restart && num >= 2 && i2c->speed_hz > MAX_FS_MODE_SPEED)
 575                /* ignore the first restart irq after the master code,
 576                 * otherwise the first transfer will be discarded.
 577                 */
 578                i2c->ignore_restart_irq = true;
 579        else
 580                i2c->ignore_restart_irq = false;
 581
 582        while (left_num--) {
 583                if (!msgs->buf) {
 584                        dev_dbg(i2c->dev, "data buffer is NULL.\n");
 585                        ret = -EINVAL;
 586                        goto err_exit;
 587                }
 588
 589                if (msgs->flags & I2C_M_RD)
 590                        i2c->op = I2C_MASTER_RD;
 591                else
 592                        i2c->op = I2C_MASTER_WR;
 593
 594                if (!i2c->auto_restart) {
 595                        if (num > 1) {
 596                                /* combined two messages into one transaction */
 597                                i2c->op = I2C_MASTER_WRRD;
 598                                left_num--;
 599                        }
 600                }
 601
 602                /* always use DMA mode. */
 603                ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
 604                if (ret < 0)
 605                        goto err_exit;
 606
 607                msgs++;
 608        }
 609        /* the return value is number of executed messages */
 610        ret = num;
 611
 612err_exit:
 613        mtk_i2c_clock_disable(i2c);
 614        return ret;
 615}
 616
 617static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 618{
 619        struct mtk_i2c *i2c = dev_id;
 620        u16 restart_flag = 0;
 621        u16 intr_stat;
 622
 623        if (i2c->auto_restart)
 624                restart_flag = I2C_RS_TRANSFER;
 625
 626        intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
 627        writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
 628
 629        /*
 630         * when occurs ack error, i2c controller generate two interrupts
 631         * first is the ack error interrupt, then the complete interrupt
 632         * i2c->irq_stat need keep the two interrupt value.
 633         */
 634        i2c->irq_stat |= intr_stat;
 635
 636        if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) {
 637                i2c->ignore_restart_irq = false;
 638                i2c->irq_stat = 0;
 639                writew(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START,
 640                       i2c->base + OFFSET_START);
 641        } else {
 642                if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
 643                        complete(&i2c->msg_complete);
 644        }
 645
 646        return IRQ_HANDLED;
 647}
 648
 649static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
 650{
 651        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 652}
 653
 654static const struct i2c_algorithm mtk_i2c_algorithm = {
 655        .master_xfer = mtk_i2c_transfer,
 656        .functionality = mtk_i2c_functionality,
 657};
 658
 659static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c,
 660                            unsigned int *clk_src_div)
 661{
 662        int ret;
 663
 664        ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz);
 665        if (ret < 0)
 666                i2c->speed_hz = I2C_DEFAULT_SPEED;
 667
 668        ret = of_property_read_u32(np, "clock-div", clk_src_div);
 669        if (ret < 0)
 670                return ret;
 671
 672        if (*clk_src_div == 0)
 673                return -EINVAL;
 674
 675        i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 676        i2c->use_push_pull =
 677                of_property_read_bool(np, "mediatek,use-push-pull");
 678
 679        return 0;
 680}
 681
 682static int mtk_i2c_probe(struct platform_device *pdev)
 683{
 684        const struct of_device_id *of_id;
 685        int ret = 0;
 686        struct mtk_i2c *i2c;
 687        struct clk *clk;
 688        unsigned int clk_src_div;
 689        struct resource *res;
 690        int irq;
 691
 692        i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 693        if (!i2c)
 694                return -ENOMEM;
 695
 696        ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c, &clk_src_div);
 697        if (ret)
 698                return -EINVAL;
 699
 700        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 701        i2c->base = devm_ioremap_resource(&pdev->dev, res);
 702        if (IS_ERR(i2c->base))
 703                return PTR_ERR(i2c->base);
 704
 705        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 706        i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
 707        if (IS_ERR(i2c->pdmabase))
 708                return PTR_ERR(i2c->pdmabase);
 709
 710        irq = platform_get_irq(pdev, 0);
 711        if (irq <= 0)
 712                return irq;
 713
 714        init_completion(&i2c->msg_complete);
 715
 716        of_id = of_match_node(mtk_i2c_of_match, pdev->dev.of_node);
 717        if (!of_id)
 718                return -EINVAL;
 719
 720        i2c->dev_comp = of_id->data;
 721        i2c->adap.dev.of_node = pdev->dev.of_node;
 722        i2c->dev = &pdev->dev;
 723        i2c->adap.dev.parent = &pdev->dev;
 724        i2c->adap.owner = THIS_MODULE;
 725        i2c->adap.algo = &mtk_i2c_algorithm;
 726        i2c->adap.quirks = i2c->dev_comp->quirks;
 727        i2c->adap.timeout = 2 * HZ;
 728        i2c->adap.retries = 1;
 729
 730        if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
 731                return -EINVAL;
 732
 733        i2c->clk_main = devm_clk_get(&pdev->dev, "main");
 734        if (IS_ERR(i2c->clk_main)) {
 735                dev_err(&pdev->dev, "cannot get main clock\n");
 736                return PTR_ERR(i2c->clk_main);
 737        }
 738
 739        i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
 740        if (IS_ERR(i2c->clk_dma)) {
 741                dev_err(&pdev->dev, "cannot get dma clock\n");
 742                return PTR_ERR(i2c->clk_dma);
 743        }
 744
 745        clk = i2c->clk_main;
 746        if (i2c->have_pmic) {
 747                i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
 748                if (IS_ERR(i2c->clk_pmic)) {
 749                        dev_err(&pdev->dev, "cannot get pmic clock\n");
 750                        return PTR_ERR(i2c->clk_pmic);
 751                }
 752                clk = i2c->clk_pmic;
 753        }
 754
 755        strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
 756
 757        ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk), clk_src_div);
 758        if (ret) {
 759                dev_err(&pdev->dev, "Failed to set the speed.\n");
 760                return -EINVAL;
 761        }
 762
 763        if (i2c->dev_comp->support_33bits) {
 764                ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33));
 765                if (ret) {
 766                        dev_err(&pdev->dev, "dma_set_mask return error.\n");
 767                        return ret;
 768                }
 769        }
 770
 771        ret = mtk_i2c_clock_enable(i2c);
 772        if (ret) {
 773                dev_err(&pdev->dev, "clock enable failed!\n");
 774                return ret;
 775        }
 776        mtk_i2c_init_hw(i2c);
 777        mtk_i2c_clock_disable(i2c);
 778
 779        ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
 780                               IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c);
 781        if (ret < 0) {
 782                dev_err(&pdev->dev,
 783                        "Request I2C IRQ %d fail\n", irq);
 784                return ret;
 785        }
 786
 787        i2c_set_adapdata(&i2c->adap, i2c);
 788        ret = i2c_add_adapter(&i2c->adap);
 789        if (ret) {
 790                dev_err(&pdev->dev, "Failed to add i2c bus to i2c core\n");
 791                return ret;
 792        }
 793
 794        platform_set_drvdata(pdev, i2c);
 795
 796        return 0;
 797}
 798
 799static int mtk_i2c_remove(struct platform_device *pdev)
 800{
 801        struct mtk_i2c *i2c = platform_get_drvdata(pdev);
 802
 803        i2c_del_adapter(&i2c->adap);
 804
 805        return 0;
 806}
 807
 808#ifdef CONFIG_PM_SLEEP
 809static int mtk_i2c_resume(struct device *dev)
 810{
 811        struct mtk_i2c *i2c = dev_get_drvdata(dev);
 812
 813        mtk_i2c_init_hw(i2c);
 814
 815        return 0;
 816}
 817#endif
 818
 819static const struct dev_pm_ops mtk_i2c_pm = {
 820        SET_SYSTEM_SLEEP_PM_OPS(NULL, mtk_i2c_resume)
 821};
 822
 823static struct platform_driver mtk_i2c_driver = {
 824        .probe = mtk_i2c_probe,
 825        .remove = mtk_i2c_remove,
 826        .driver = {
 827                .name = I2C_DRV_NAME,
 828                .pm = &mtk_i2c_pm,
 829                .of_match_table = of_match_ptr(mtk_i2c_of_match),
 830        },
 831};
 832
 833module_platform_driver(mtk_i2c_driver);
 834
 835MODULE_LICENSE("GPL v2");
 836MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
 837MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>");
 838