linux/drivers/i2c/busses/i2c-rcar.c
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   1/*
   2 * Driver for the Renesas RCar I2C unit
   3 *
   4 * Copyright (C) 2014-15 Wolfram Sang <wsa@sang-engineering.com>
   5 * Copyright (C) 2011-2015 Renesas Electronics Corporation
   6 *
   7 * Copyright (C) 2012-14 Renesas Solutions Corp.
   8 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
   9 *
  10 * This file is based on the drivers/i2c/busses/i2c-sh7760.c
  11 * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
  12 *
  13 * This program is free software; you can redistribute it and/or modify
  14 * it under the terms of the GNU General Public License as published by
  15 * the Free Software Foundation; version 2 of the License.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 * GNU General Public License for more details.
  21 */
  22#include <linux/clk.h>
  23#include <linux/delay.h>
  24#include <linux/err.h>
  25#include <linux/interrupt.h>
  26#include <linux/io.h>
  27#include <linux/i2c.h>
  28#include <linux/kernel.h>
  29#include <linux/module.h>
  30#include <linux/of_device.h>
  31#include <linux/platform_device.h>
  32#include <linux/pm_runtime.h>
  33#include <linux/slab.h>
  34
  35/* register offsets */
  36#define ICSCR   0x00    /* slave ctrl */
  37#define ICMCR   0x04    /* master ctrl */
  38#define ICSSR   0x08    /* slave status */
  39#define ICMSR   0x0C    /* master status */
  40#define ICSIER  0x10    /* slave irq enable */
  41#define ICMIER  0x14    /* master irq enable */
  42#define ICCCR   0x18    /* clock dividers */
  43#define ICSAR   0x1C    /* slave address */
  44#define ICMAR   0x20    /* master address */
  45#define ICRXTX  0x24    /* data port */
  46
  47/* ICSCR */
  48#define SDBS    (1 << 3)        /* slave data buffer select */
  49#define SIE     (1 << 2)        /* slave interface enable */
  50#define GCAE    (1 << 1)        /* general call address enable */
  51#define FNA     (1 << 0)        /* forced non acknowledgment */
  52
  53/* ICMCR */
  54#define MDBS    (1 << 7)        /* non-fifo mode switch */
  55#define FSCL    (1 << 6)        /* override SCL pin */
  56#define FSDA    (1 << 5)        /* override SDA pin */
  57#define OBPC    (1 << 4)        /* override pins */
  58#define MIE     (1 << 3)        /* master if enable */
  59#define TSBE    (1 << 2)
  60#define FSB     (1 << 1)        /* force stop bit */
  61#define ESG     (1 << 0)        /* en startbit gen */
  62
  63/* ICSSR (also for ICSIER) */
  64#define GCAR    (1 << 6)        /* general call received */
  65#define STM     (1 << 5)        /* slave transmit mode */
  66#define SSR     (1 << 4)        /* stop received */
  67#define SDE     (1 << 3)        /* slave data empty */
  68#define SDT     (1 << 2)        /* slave data transmitted */
  69#define SDR     (1 << 1)        /* slave data received */
  70#define SAR     (1 << 0)        /* slave addr received */
  71
  72/* ICMSR (also for ICMIE) */
  73#define MNR     (1 << 6)        /* nack received */
  74#define MAL     (1 << 5)        /* arbitration lost */
  75#define MST     (1 << 4)        /* sent a stop */
  76#define MDE     (1 << 3)
  77#define MDT     (1 << 2)
  78#define MDR     (1 << 1)
  79#define MAT     (1 << 0)        /* slave addr xfer done */
  80
  81
  82#define RCAR_BUS_PHASE_START    (MDBS | MIE | ESG)
  83#define RCAR_BUS_PHASE_DATA     (MDBS | MIE)
  84#define RCAR_BUS_MASK_DATA      (~(ESG | FSB) & 0xFF)
  85#define RCAR_BUS_PHASE_STOP     (MDBS | MIE | FSB)
  86
  87#define RCAR_IRQ_SEND   (MNR | MAL | MST | MAT | MDE)
  88#define RCAR_IRQ_RECV   (MNR | MAL | MST | MAT | MDR)
  89#define RCAR_IRQ_STOP   (MST)
  90
  91#define RCAR_IRQ_ACK_SEND       (~(MAT | MDE) & 0xFF)
  92#define RCAR_IRQ_ACK_RECV       (~(MAT | MDR) & 0xFF)
  93
  94#define ID_LAST_MSG     (1 << 0)
  95#define ID_FIRST_MSG    (1 << 1)
  96#define ID_DONE         (1 << 2)
  97#define ID_ARBLOST      (1 << 3)
  98#define ID_NACK         (1 << 4)
  99/* persistent flags */
 100#define ID_P_PM_BLOCKED (1 << 31)
 101#define ID_P_MASK       ID_P_PM_BLOCKED
 102
 103enum rcar_i2c_type {
 104        I2C_RCAR_GEN1,
 105        I2C_RCAR_GEN2,
 106        I2C_RCAR_GEN3,
 107};
 108
 109struct rcar_i2c_priv {
 110        void __iomem *io;
 111        struct i2c_adapter adap;
 112        struct i2c_msg *msg;
 113        int msgs_left;
 114        struct clk *clk;
 115
 116        wait_queue_head_t wait;
 117
 118        int pos;
 119        u32 icccr;
 120        u32 flags;
 121        enum rcar_i2c_type devtype;
 122        struct i2c_client *slave;
 123};
 124
 125#define rcar_i2c_priv_to_dev(p)         ((p)->adap.dev.parent)
 126#define rcar_i2c_is_recv(p)             ((p)->msg->flags & I2C_M_RD)
 127
 128#define LOOP_TIMEOUT    1024
 129
 130
 131static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 132{
 133        writel(val, priv->io + reg);
 134}
 135
 136static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
 137{
 138        return readl(priv->io + reg);
 139}
 140
 141static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 142{
 143        /* reset master mode */
 144        rcar_i2c_write(priv, ICMIER, 0);
 145        rcar_i2c_write(priv, ICMCR, MDBS);
 146        rcar_i2c_write(priv, ICMSR, 0);
 147        /* start clock */
 148        rcar_i2c_write(priv, ICCCR, priv->icccr);
 149}
 150
 151static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 152{
 153        int i;
 154
 155        for (i = 0; i < LOOP_TIMEOUT; i++) {
 156                /* make sure that bus is not busy */
 157                if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
 158                        return 0;
 159                udelay(1);
 160        }
 161
 162        return -EBUSY;
 163}
 164
 165static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t)
 166{
 167        u32 scgd, cdf, round, ick, sum, scl, cdf_width;
 168        unsigned long rate;
 169        struct device *dev = rcar_i2c_priv_to_dev(priv);
 170
 171        /* Fall back to previously used values if not supplied */
 172        t->bus_freq_hz = t->bus_freq_hz ?: 100000;
 173        t->scl_fall_ns = t->scl_fall_ns ?: 35;
 174        t->scl_rise_ns = t->scl_rise_ns ?: 200;
 175        t->scl_int_delay_ns = t->scl_int_delay_ns ?: 50;
 176
 177        switch (priv->devtype) {
 178        case I2C_RCAR_GEN1:
 179                cdf_width = 2;
 180                break;
 181        case I2C_RCAR_GEN2:
 182        case I2C_RCAR_GEN3:
 183                cdf_width = 3;
 184                break;
 185        default:
 186                dev_err(dev, "device type error\n");
 187                return -EIO;
 188        }
 189
 190        /*
 191         * calculate SCL clock
 192         * see
 193         *      ICCCR
 194         *
 195         * ick  = clkp / (1 + CDF)
 196         * SCL  = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
 197         *
 198         * ick  : I2C internal clock < 20 MHz
 199         * ticf : I2C SCL falling time
 200         * tr   : I2C SCL rising  time
 201         * intd : LSI internal delay
 202         * clkp : peripheral_clk
 203         * F[]  : integer up-valuation
 204         */
 205        rate = clk_get_rate(priv->clk);
 206        cdf = rate / 20000000;
 207        if (cdf >= 1U << cdf_width) {
 208                dev_err(dev, "Input clock %lu too high\n", rate);
 209                return -EIO;
 210        }
 211        ick = rate / (cdf + 1);
 212
 213        /*
 214         * it is impossible to calculate large scale
 215         * number on u32. separate it
 216         *
 217         * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd)
 218         *  = F[sum * ick / 1000000000]
 219         *  = F[(ick / 1000000) * sum / 1000]
 220         */
 221        sum = t->scl_fall_ns + t->scl_rise_ns + t->scl_int_delay_ns;
 222        round = (ick + 500000) / 1000000 * sum;
 223        round = (round + 500) / 1000;
 224
 225        /*
 226         * SCL  = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
 227         *
 228         * Calculation result (= SCL) should be less than
 229         * bus_speed for hardware safety
 230         *
 231         * We could use something along the lines of
 232         *      div = ick / (bus_speed + 1) + 1;
 233         *      scgd = (div - 20 - round + 7) / 8;
 234         *      scl = ick / (20 + (scgd * 8) + round);
 235         * (not fully verified) but that would get pretty involved
 236         */
 237        for (scgd = 0; scgd < 0x40; scgd++) {
 238                scl = ick / (20 + (scgd * 8) + round);
 239                if (scl <= t->bus_freq_hz)
 240                        goto scgd_find;
 241        }
 242        dev_err(dev, "it is impossible to calculate best SCL\n");
 243        return -EIO;
 244
 245scgd_find:
 246        dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
 247                scl, t->bus_freq_hz, clk_get_rate(priv->clk), round, cdf, scgd);
 248
 249        /* keep icccr value */
 250        priv->icccr = scgd << cdf_width | cdf;
 251
 252        return 0;
 253}
 254
 255static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
 256{
 257        int read = !!rcar_i2c_is_recv(priv);
 258
 259        priv->pos = 0;
 260        if (priv->msgs_left == 1)
 261                priv->flags |= ID_LAST_MSG;
 262
 263        rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
 264        /*
 265         * We don't have a testcase but the HW engineers say that the write order
 266         * of ICMSR and ICMCR depends on whether we issue START or REP_START. Since
 267         * it didn't cause a drawback for me, let's rather be safe than sorry.
 268         */
 269        if (priv->flags & ID_FIRST_MSG) {
 270                rcar_i2c_write(priv, ICMSR, 0);
 271                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
 272        } else {
 273                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
 274                rcar_i2c_write(priv, ICMSR, 0);
 275        }
 276        rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
 277}
 278
 279static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
 280{
 281        priv->msg++;
 282        priv->msgs_left--;
 283        priv->flags &= ID_P_MASK;
 284        rcar_i2c_prepare_msg(priv);
 285}
 286
 287/*
 288 *              interrupt functions
 289 */
 290static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
 291{
 292        struct i2c_msg *msg = priv->msg;
 293
 294        /* FIXME: sometimes, unknown interrupt happened. Do nothing */
 295        if (!(msr & MDE))
 296                return;
 297
 298        if (priv->pos < msg->len) {
 299                /*
 300                 * Prepare next data to ICRXTX register.
 301                 * This data will go to _SHIFT_ register.
 302                 *
 303                 *    *
 304                 * [ICRXTX] -> [SHIFT] -> [I2C bus]
 305                 */
 306                rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
 307                priv->pos++;
 308
 309        } else {
 310                /*
 311                 * The last data was pushed to ICRXTX on _PREV_ empty irq.
 312                 * It is on _SHIFT_ register, and will sent to I2C bus.
 313                 *
 314                 *                *
 315                 * [ICRXTX] -> [SHIFT] -> [I2C bus]
 316                 */
 317
 318                if (priv->flags & ID_LAST_MSG) {
 319                        /*
 320                         * If current msg is the _LAST_ msg,
 321                         * prepare stop condition here.
 322                         * ID_DONE will be set on STOP irq.
 323                         */
 324                        rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
 325                } else {
 326                        rcar_i2c_next_msg(priv);
 327                        return;
 328                }
 329        }
 330
 331        rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
 332}
 333
 334static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
 335{
 336        struct i2c_msg *msg = priv->msg;
 337
 338        /* FIXME: sometimes, unknown interrupt happened. Do nothing */
 339        if (!(msr & MDR))
 340                return;
 341
 342        if (msr & MAT) {
 343                /* Address transfer phase finished, but no data at this point. */
 344        } else if (priv->pos < msg->len) {
 345                /* get received data */
 346                msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
 347                priv->pos++;
 348        }
 349
 350        /*
 351         * If next received data is the _LAST_, go to STOP phase. Might be
 352         * overwritten by REP START when setting up a new msg. Not elegant
 353         * but the only stable sequence for REP START I have found so far.
 354         */
 355        if (priv->pos + 1 >= msg->len)
 356                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
 357
 358        if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))
 359                rcar_i2c_next_msg(priv);
 360        else
 361                rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
 362}
 363
 364static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
 365{
 366        u32 ssr_raw, ssr_filtered;
 367        u8 value;
 368
 369        ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff;
 370        ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER);
 371
 372        if (!ssr_filtered)
 373                return false;
 374
 375        /* address detected */
 376        if (ssr_filtered & SAR) {
 377                /* read or write request */
 378                if (ssr_raw & STM) {
 379                        i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);
 380                        rcar_i2c_write(priv, ICRXTX, value);
 381                        rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR);
 382                } else {
 383                        i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
 384                        rcar_i2c_read(priv, ICRXTX);    /* dummy read */
 385                        rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR);
 386                }
 387
 388                rcar_i2c_write(priv, ICSSR, ~SAR & 0xff);
 389        }
 390
 391        /* master sent stop */
 392        if (ssr_filtered & SSR) {
 393                i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
 394                rcar_i2c_write(priv, ICSIER, SAR | SSR);
 395                rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
 396        }
 397
 398        /* master wants to write to us */
 399        if (ssr_filtered & SDR) {
 400                int ret;
 401
 402                value = rcar_i2c_read(priv, ICRXTX);
 403                ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
 404                /* Send NACK in case of error */
 405                rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0));
 406                rcar_i2c_write(priv, ICSSR, ~SDR & 0xff);
 407        }
 408
 409        /* master wants to read from us */
 410        if (ssr_filtered & SDE) {
 411                i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);
 412                rcar_i2c_write(priv, ICRXTX, value);
 413                rcar_i2c_write(priv, ICSSR, ~SDE & 0xff);
 414        }
 415
 416        return true;
 417}
 418
 419static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 420{
 421        struct rcar_i2c_priv *priv = ptr;
 422        u32 msr, val;
 423
 424        /* Clear START or STOP as soon as we can */
 425        val = rcar_i2c_read(priv, ICMCR);
 426        rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA);
 427
 428        msr = rcar_i2c_read(priv, ICMSR);
 429
 430        /* Only handle interrupts that are currently enabled */
 431        msr &= rcar_i2c_read(priv, ICMIER);
 432        if (!msr) {
 433                if (rcar_i2c_slave_irq(priv))
 434                        return IRQ_HANDLED;
 435
 436                return IRQ_NONE;
 437        }
 438
 439        /* Arbitration lost */
 440        if (msr & MAL) {
 441                priv->flags |= ID_DONE | ID_ARBLOST;
 442                goto out;
 443        }
 444
 445        /* Nack */
 446        if (msr & MNR) {
 447                /* HW automatically sends STOP after received NACK */
 448                rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
 449                priv->flags |= ID_NACK;
 450                goto out;
 451        }
 452
 453        /* Stop */
 454        if (msr & MST) {
 455                priv->msgs_left--; /* The last message also made it */
 456                priv->flags |= ID_DONE;
 457                goto out;
 458        }
 459
 460        if (rcar_i2c_is_recv(priv))
 461                rcar_i2c_irq_recv(priv, msr);
 462        else
 463                rcar_i2c_irq_send(priv, msr);
 464
 465out:
 466        if (priv->flags & ID_DONE) {
 467                rcar_i2c_write(priv, ICMIER, 0);
 468                rcar_i2c_write(priv, ICMSR, 0);
 469                wake_up(&priv->wait);
 470        }
 471
 472        return IRQ_HANDLED;
 473}
 474
 475static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 476                                struct i2c_msg *msgs,
 477                                int num)
 478{
 479        struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
 480        struct device *dev = rcar_i2c_priv_to_dev(priv);
 481        int i, ret;
 482        long time_left;
 483
 484        pm_runtime_get_sync(dev);
 485
 486        ret = rcar_i2c_bus_barrier(priv);
 487        if (ret < 0)
 488                goto out;
 489
 490        for (i = 0; i < num; i++) {
 491                /* This HW can't send STOP after address phase */
 492                if (msgs[i].len == 0) {
 493                        ret = -EOPNOTSUPP;
 494                        goto out;
 495                }
 496        }
 497
 498        /* init first message */
 499        priv->msg = msgs;
 500        priv->msgs_left = num;
 501        priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
 502        rcar_i2c_prepare_msg(priv);
 503
 504        time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE,
 505                                     num * adap->timeout);
 506        if (!time_left) {
 507                rcar_i2c_init(priv);
 508                ret = -ETIMEDOUT;
 509        } else if (priv->flags & ID_NACK) {
 510                ret = -ENXIO;
 511        } else if (priv->flags & ID_ARBLOST) {
 512                ret = -EAGAIN;
 513        } else {
 514                ret = num - priv->msgs_left; /* The number of transfer */
 515        }
 516out:
 517        pm_runtime_put(dev);
 518
 519        if (ret < 0 && ret != -ENXIO)
 520                dev_err(dev, "error %d : %x\n", ret, priv->flags);
 521
 522        return ret;
 523}
 524
 525static int rcar_reg_slave(struct i2c_client *slave)
 526{
 527        struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
 528
 529        if (priv->slave)
 530                return -EBUSY;
 531
 532        if (slave->flags & I2C_CLIENT_TEN)
 533                return -EAFNOSUPPORT;
 534
 535        pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv));
 536
 537        priv->slave = slave;
 538        rcar_i2c_write(priv, ICSAR, slave->addr);
 539        rcar_i2c_write(priv, ICSSR, 0);
 540        rcar_i2c_write(priv, ICSIER, SAR | SSR);
 541        rcar_i2c_write(priv, ICSCR, SIE | SDBS);
 542
 543        return 0;
 544}
 545
 546static int rcar_unreg_slave(struct i2c_client *slave)
 547{
 548        struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
 549
 550        WARN_ON(!priv->slave);
 551
 552        rcar_i2c_write(priv, ICSIER, 0);
 553        rcar_i2c_write(priv, ICSCR, 0);
 554
 555        priv->slave = NULL;
 556
 557        pm_runtime_put(rcar_i2c_priv_to_dev(priv));
 558
 559        return 0;
 560}
 561
 562static u32 rcar_i2c_func(struct i2c_adapter *adap)
 563{
 564        /* This HW can't do SMBUS_QUICK and NOSTART */
 565        return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
 566                (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 567}
 568
 569static const struct i2c_algorithm rcar_i2c_algo = {
 570        .master_xfer    = rcar_i2c_master_xfer,
 571        .functionality  = rcar_i2c_func,
 572        .reg_slave      = rcar_reg_slave,
 573        .unreg_slave    = rcar_unreg_slave,
 574};
 575
 576static const struct of_device_id rcar_i2c_dt_ids[] = {
 577        { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
 578        { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
 579        { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
 580        { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
 581        { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
 582        { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
 583        { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
 584        { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
 585        { .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
 586        {},
 587};
 588MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
 589
 590static int rcar_i2c_probe(struct platform_device *pdev)
 591{
 592        struct rcar_i2c_priv *priv;
 593        struct i2c_adapter *adap;
 594        struct resource *res;
 595        struct device *dev = &pdev->dev;
 596        struct i2c_timings i2c_t;
 597        int irq, ret;
 598
 599        priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
 600        if (!priv)
 601                return -ENOMEM;
 602
 603        priv->clk = devm_clk_get(dev, NULL);
 604        if (IS_ERR(priv->clk)) {
 605                dev_err(dev, "cannot get clock\n");
 606                return PTR_ERR(priv->clk);
 607        }
 608
 609        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 610        priv->io = devm_ioremap_resource(dev, res);
 611        if (IS_ERR(priv->io))
 612                return PTR_ERR(priv->io);
 613
 614        priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev);
 615        init_waitqueue_head(&priv->wait);
 616
 617        adap = &priv->adap;
 618        adap->nr = pdev->id;
 619        adap->algo = &rcar_i2c_algo;
 620        adap->class = I2C_CLASS_DEPRECATED;
 621        adap->retries = 3;
 622        adap->dev.parent = dev;
 623        adap->dev.of_node = dev->of_node;
 624        i2c_set_adapdata(adap, priv);
 625        strlcpy(adap->name, pdev->name, sizeof(adap->name));
 626
 627        i2c_parse_fw_timings(dev, &i2c_t, false);
 628
 629        pm_runtime_enable(dev);
 630        pm_runtime_get_sync(dev);
 631        ret = rcar_i2c_clock_calculate(priv, &i2c_t);
 632        if (ret < 0)
 633                goto out_pm_put;
 634
 635        rcar_i2c_init(priv);
 636
 637        /* Don't suspend when multi-master to keep arbitration working */
 638        if (of_property_read_bool(dev->of_node, "multi-master"))
 639                priv->flags |= ID_P_PM_BLOCKED;
 640        else
 641                pm_runtime_put(dev);
 642
 643
 644        irq = platform_get_irq(pdev, 0);
 645        ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv);
 646        if (ret < 0) {
 647                dev_err(dev, "cannot get irq %d\n", irq);
 648                goto out_pm_disable;
 649        }
 650
 651        platform_set_drvdata(pdev, priv);
 652
 653        ret = i2c_add_numbered_adapter(adap);
 654        if (ret < 0) {
 655                dev_err(dev, "reg adap failed: %d\n", ret);
 656                goto out_pm_disable;
 657        }
 658
 659        dev_info(dev, "probed\n");
 660
 661        return 0;
 662
 663 out_pm_put:
 664        pm_runtime_put(dev);
 665 out_pm_disable:
 666        pm_runtime_disable(dev);
 667        return ret;
 668}
 669
 670static int rcar_i2c_remove(struct platform_device *pdev)
 671{
 672        struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
 673        struct device *dev = &pdev->dev;
 674
 675        i2c_del_adapter(&priv->adap);
 676        if (priv->flags & ID_P_PM_BLOCKED)
 677                pm_runtime_put(dev);
 678        pm_runtime_disable(dev);
 679
 680        return 0;
 681}
 682
 683static struct platform_driver rcar_i2c_driver = {
 684        .driver = {
 685                .name   = "i2c-rcar",
 686                .of_match_table = rcar_i2c_dt_ids,
 687        },
 688        .probe          = rcar_i2c_probe,
 689        .remove         = rcar_i2c_remove,
 690};
 691
 692module_platform_driver(rcar_i2c_driver);
 693
 694MODULE_LICENSE("GPL v2");
 695MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
 696MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
 697