drivers/i2c/busses/i2c-sh_mobile.c

   1 /*
   2  * SuperH Mobile I2C Controller
   3  *
   4  * Copyright (C) 2008 Magnus Damm
   5  *
   6  * Portions of the code based on out-of-tree driver i2c-sh7343.c
   7  * Copyright (c) 2006 Carlos Munoz <carlos@kenati.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/i2c.h>
  30 #include <linux/of_i2c.h>
  31 #include <linux/err.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/clk.h>
  34 #include <linux/io.h>
  35 #include <linux/slab.h>
  36 #include <linux/i2c/i2c-sh_mobile.h>
  37
  38 /* Transmit operation:                                                      */
  39 /*                                                                          */
  40 /* 0 byte transmit                                                          */
  41 /* BUS:     S     A8     ACK   P(*)                                         */
  42 /* IRQ:       DTE   WAIT                                                    */
  43 /* ICIC:                                                                    */
  44 /* ICCR: 0x94 0x90                                                          */
  45 /* ICDR:      A8                                                            */
  46 /*                                                                          */
  47 /* 1 byte transmit                                                          */
  48 /* BUS:     S     A8     ACK   D8(1)   ACK   P(*)                           */
  49 /* IRQ:       DTE   WAIT         WAIT                                       */
  50 /* ICIC:      -DTE                                                          */
  51 /* ICCR: 0x94       0x90                                                    */
  52 /* ICDR:      A8    D8(1)                                                   */
  53 /*                                                                          */
  54 /* 2 byte transmit                                                          */
  55 /* BUS:     S     A8     ACK   D8(1)   ACK   D8(2)   ACK   P(*)             */
  56 /* IRQ:       DTE   WAIT         WAIT          WAIT                         */
  57 /* ICIC:      -DTE                                                          */
  58 /* ICCR: 0x94                    0x90                                       */
  59 /* ICDR:      A8    D8(1)        D8(2)                                      */
  60 /*                                                                          */
  61 /* 3 bytes or more, +---------+ gets repeated                               */
  62 /*                                                                          */
  63 /*                                                                          */
  64 /* Receive operation:                                                       */
  65 /*                                                                          */
  66 /* 0 byte receive - not supported since slave may hold SDA low              */
  67 /*                                                                          */
  68 /* 1 byte receive       [TX] | [RX]                                         */
  69 /* BUS:     S     A8     ACK | D8(1)   ACK   P(*)                           */
  70 /* IRQ:       DTE   WAIT     |   WAIT     DTE                               */
  71 /* ICIC:      -DTE           |   +DTE                                       */
  72 /* ICCR: 0x94       0x81     |   0xc0                                       */
  73 /* ICDR:      A8             |            D8(1)                             */
  74 /*                                                                          */
  75 /* 2 byte receive        [TX]| [RX]                                         */
  76 /* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   P(*)             */
  77 /* IRQ:       DTE   WAIT     |   WAIT          WAIT     DTE                 */
  78 /* ICIC:      -DTE           |                 +DTE                         */
  79 /* ICCR: 0x94       0x81     |                 0xc0                         */
  80 /* ICDR:      A8             |                 D8(1)    D8(2)               */
  81 /*                                                                          */
  82 /* 3 byte receive       [TX] | [RX]                                     (*) */
  83 /* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   D8(3)   ACK    P */
  84 /* IRQ:       DTE   WAIT     |   WAIT          WAIT         WAIT      DTE   */
  85 /* ICIC:      -DTE           |                              +DTE            */
  86 /* ICCR: 0x94       0x81     |                              0xc0            */
  87 /* ICDR:      A8             |                 D8(1)        D8(2)     D8(3) */
  88 /*                                                                          */
  89 /* 4 bytes or more, this part is repeated    +---------+                    */
  90 /*                                                                          */
  91 /*                                                                          */
  92 /* Interrupt order and BUSY flag                                            */
  93 /*     ___                                                 _                */
  94 /* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/                 */
  95 /* SCL      \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/                   */
  96 /*                                                                          */
  97 /*        S   D7  D6  D5  D4  D3  D2  D1  D0              P(*)              */
  98 /*                                           ___                            */
  99 /* WAIT IRQ ________________________________/   \___________                */
 100 /* TACK IRQ ____________________________________/   \_______                */
 101 /* DTE  IRQ __________________________________________/   \_                */
 102 /* AL   IRQ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX                */
 103 /*         _______________________________________________                  */
 104 /* BUSY __/                                               \_                */
 105 /*                                                                          */
 106 /* (*) The STOP condition is only sent by the master at the end of the last */
 107 /* I2C message or if the I2C_M_STOP flag is set. Similarly, the BUSY bit is */
 108 /* only cleared after the STOP condition, so, between messages we have to   */
 109 /* poll for the DTE bit.                                                    */
 110 /*                                                                          */
 111
 112 enum sh_mobile_i2c_op {
 113         OP_START = 0,
 114         OP_TX_FIRST,
 115         OP_TX,
 116         OP_TX_STOP,
 117         OP_TX_TO_RX,
 118         OP_RX,
 119         OP_RX_STOP,
 120         OP_RX_STOP_DATA,
 121 };
 122
 123 struct sh_mobile_i2c_data {
 124         struct device *dev;
 125         void __iomem *reg;
 126         struct i2c_adapter adap;
 127         unsigned long bus_speed;
 128         unsigned int clks_per_count;
 129         struct clk *clk;
 130         u_int8_t icic;
 131         u_int8_t flags;
 132         u_int16_t iccl;
 133         u_int16_t icch;
 134
 135         spinlock_t lock;
 136         wait_queue_head_t wait;
 137         struct i2c_msg *msg;
 138         int pos;
 139         int sr;
 140         bool send_stop;
 141 };
 142
 143 #define IIC_FLAG_HAS_ICIC67     (1 << 0)
 144
 145 #define STANDARD_MODE           100000
 146 #define FAST_MODE               400000
 147
 148 /* Register offsets */
 149 #define ICDR                    0x00
 150 #define ICCR                    0x04
 151 #define ICSR                    0x08
 152 #define ICIC                    0x0c
 153 #define ICCL                    0x10
 154 #define ICCH                    0x14
 155
 156 /* Register bits */
 157 #define ICCR_ICE                0x80
 158 #define ICCR_RACK               0x40
 159 #define ICCR_TRS                0x10
 160 #define ICCR_BBSY               0x04
 161 #define ICCR_SCP                0x01
 162
 163 #define ICSR_SCLM               0x80
 164 #define ICSR_SDAM               0x40
 165 #define SW_DONE                 0x20
 166 #define ICSR_BUSY               0x10
 167 #define ICSR_AL                 0x08
 168 #define ICSR_TACK               0x04
 169 #define ICSR_WAIT               0x02
 170 #define ICSR_DTE                0x01
 171
 172 #define ICIC_ICCLB8             0x80
 173 #define ICIC_ICCHB8             0x40
 174 #define ICIC_ALE                0x08
 175 #define ICIC_TACKE              0x04
 176 #define ICIC_WAITE              0x02
 177 #define ICIC_DTEE               0x01
 178
 179 static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
 180 {
 181         if (offs == ICIC)
 182                 data |= pd->icic;
 183
 184         iowrite8(data, pd->reg + offs);
 185 }
 186
 187 static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs)
 188 {
 189         return ioread8(pd->reg + offs);
 190 }
 191
 192 static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs,
 193                         unsigned char set, unsigned char clr)
 194 {
 195         iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr);
 196 }
 197
 198 static u32 sh_mobile_i2c_iccl(unsigned long count_khz, u32 tLOW, u32 tf, int offset)
 199 {
 200         /*
 201          * Conditional expression:
 202          *   ICCL >= COUNT_CLK * (tLOW + tf)
 203          *
 204          * SH-Mobile IIC hardware starts counting the LOW period of
 205          * the SCL signal (tLOW) as soon as it pulls the SCL line.
 206          * In order to meet the tLOW timing spec, we need to take into
 207          * account the fall time of SCL signal (tf).  Default tf value
 208          * should be 0.3 us, for safety.
 209          */
 210         return (((count_khz * (tLOW + tf)) + 5000) / 10000) + offset;
 211 }
 212
 213 static u32 sh_mobile_i2c_icch(unsigned long count_khz, u32 tHIGH, u32 tf, int offset)
 214 {
 215         /*
 216          * Conditional expression:
 217          *   ICCH >= COUNT_CLK * (tHIGH + tf)
 218          *
 219          * SH-Mobile IIC hardware is aware of SCL transition period 'tr',
 220          * and can ignore it.  SH-Mobile IIC controller starts counting
 221          * the HIGH period of the SCL signal (tHIGH) after the SCL input
 222          * voltage increases at VIH.
 223          *
 224          * Afterward it turned out calculating ICCH using only tHIGH spec
 225          * will result in violation of the tHD;STA timing spec.  We need
 226          * to take into account the fall time of SDA signal (tf) at START
 227          * condition, in order to meet both tHIGH and tHD;STA specs.
 228          */
 229         return (((count_khz * (tHIGH + tf)) + 5000) / 10000) + offset;
 230 }
 231
 232 static void sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
 233 {
 234         unsigned long i2c_clk_khz;
 235         u32 tHIGH, tLOW, tf;
 236         int offset;
 237
 238         /* Get clock rate after clock is enabled */
 239         clk_enable(pd->clk);
 240         i2c_clk_khz = clk_get_rate(pd->clk) / 1000;
 241         i2c_clk_khz /= pd->clks_per_count;
 242
 243         if (pd->bus_speed == STANDARD_MODE) {
 244                 tLOW    = 47;   /* tLOW = 4.7 us */
 245                 tHIGH   = 40;   /* tHD;STA = tHIGH = 4.0 us */
 246                 tf      = 3;    /* tf = 0.3 us */
 247                 offset  = 0;    /* No offset */
 248         } else if (pd->bus_speed == FAST_MODE) {
 249                 tLOW    = 13;   /* tLOW = 1.3 us */
 250                 tHIGH   = 6;    /* tHD;STA = tHIGH = 0.6 us */
 251                 tf      = 3;    /* tf = 0.3 us */
 252                 offset  = 0;    /* No offset */
 253         } else {
 254                 dev_err(pd->dev, "unrecognized bus speed %lu Hz\n",
 255                         pd->bus_speed);
 256                 goto out;
 257         }
 258
 259         pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf, offset);
 260         /* one more bit of ICCL in ICIC */
 261         if ((pd->iccl > 0xff) && (pd->flags & IIC_FLAG_HAS_ICIC67))
 262                 pd->icic |= ICIC_ICCLB8;
 263         else
 264                 pd->icic &= ~ICIC_ICCLB8;
 265
 266         pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf, offset);
 267         /* one more bit of ICCH in ICIC */
 268         if ((pd->icch > 0xff) && (pd->flags & IIC_FLAG_HAS_ICIC67))
 269                 pd->icic |= ICIC_ICCHB8;
 270         else
 271                 pd->icic &= ~ICIC_ICCHB8;
 272
 273 out:
 274         clk_disable(pd->clk);
 275 }
 276
 277 static void activate_ch(struct sh_mobile_i2c_data *pd)
 278 {
 279         /* Wake up device and enable clock */
 280         pm_runtime_get_sync(pd->dev);
 281         clk_enable(pd->clk);
 282
 283         /* Enable channel and configure rx ack */
 284         iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 285
 286         /* Mask all interrupts */
 287         iic_wr(pd, ICIC, 0);
 288
 289         /* Set the clock */
 290         iic_wr(pd, ICCL, pd->iccl & 0xff);
 291         iic_wr(pd, ICCH, pd->icch & 0xff);
 292 }
 293
 294 static void deactivate_ch(struct sh_mobile_i2c_data *pd)
 295 {
 296         /* Clear/disable interrupts */
 297         iic_wr(pd, ICSR, 0);
 298         iic_wr(pd, ICIC, 0);
 299
 300         /* Disable channel */
 301         iic_set_clr(pd, ICCR, 0, ICCR_ICE);
 302
 303         /* Disable clock and mark device as idle */
 304         clk_disable(pd->clk);
 305         pm_runtime_put_sync(pd->dev);
 306 }
 307
 308 static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
 309                             enum sh_mobile_i2c_op op, unsigned char data)
 310 {
 311         unsigned char ret = 0;
 312         unsigned long flags;
 313
 314         dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
 315
 316         spin_lock_irqsave(&pd->lock, flags);
 317
 318         switch (op) {
 319         case OP_START: /* issue start and trigger DTE interrupt */
 320                 iic_wr(pd, ICCR, 0x94);
 321                 break;
 322         case OP_TX_FIRST: /* disable DTE interrupt and write data */
 323                 iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
 324                 iic_wr(pd, ICDR, data);
 325                 break;
 326         case OP_TX: /* write data */
 327                 iic_wr(pd, ICDR, data);
 328                 break;
 329         case OP_TX_STOP: /* write data and issue a stop afterwards */
 330                 iic_wr(pd, ICDR, data);
 331                 iic_wr(pd, ICCR, pd->send_stop ? 0x90 : 0x94);
 332                 break;
 333         case OP_TX_TO_RX: /* select read mode */
 334                 iic_wr(pd, ICCR, 0x81);
 335                 break;
 336         case OP_RX: /* just read data */
 337                 ret = iic_rd(pd, ICDR);
 338                 break;
 339         case OP_RX_STOP: /* enable DTE interrupt, issue stop */
 340                 iic_wr(pd, ICIC,
 341                        ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
 342                 iic_wr(pd, ICCR, 0xc0);
 343                 break;
 344         case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
 345                 iic_wr(pd, ICIC,
 346                        ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
 347                 ret = iic_rd(pd, ICDR);
 348                 iic_wr(pd, ICCR, 0xc0);
 349                 break;
 350         }
 351
 352         spin_unlock_irqrestore(&pd->lock, flags);
 353
 354         dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
 355         return ret;
 356 }
 357
 358 static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
 359 {
 360         return pd->pos == -1;
 361 }
 362
 363 static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
 364 {
 365         return pd->pos == pd->msg->len - 1;
 366 }
 367
 368 static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
 369                                    unsigned char *buf)
 370 {
 371         switch (pd->pos) {
 372         case -1:
 373                 *buf = (pd->msg->addr & 0x7f) << 1;
 374                 *buf |= (pd->msg->flags & I2C_M_RD) ? 1 : 0;
 375                 break;
 376         default:
 377                 *buf = pd->msg->buf[pd->pos];
 378         }
 379 }
 380
 381 static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
 382 {
 383         unsigned char data;
 384
 385         if (pd->pos == pd->msg->len)
 386                 return 1;
 387
 388         sh_mobile_i2c_get_data(pd, &data);
 389
 390         if (sh_mobile_i2c_is_last_byte(pd))
 391                 i2c_op(pd, OP_TX_STOP, data);
 392         else if (sh_mobile_i2c_is_first_byte(pd))
 393                 i2c_op(pd, OP_TX_FIRST, data);
 394         else
 395                 i2c_op(pd, OP_TX, data);
 396
 397         pd->pos++;
 398         return 0;
 399 }
 400
 401 static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 402 {
 403         unsigned char data;
 404         int real_pos;
 405
 406         do {
 407                 if (pd->pos <= -1) {
 408                         sh_mobile_i2c_get_data(pd, &data);
 409
 410                         if (sh_mobile_i2c_is_first_byte(pd))
 411                                 i2c_op(pd, OP_TX_FIRST, data);
 412                         else
 413                                 i2c_op(pd, OP_TX, data);
 414                         break;
 415                 }
 416
 417                 if (pd->pos == 0) {
 418                         i2c_op(pd, OP_TX_TO_RX, 0);
 419                         break;
 420                 }
 421
 422                 real_pos = pd->pos - 2;
 423
 424                 if (pd->pos == pd->msg->len) {
 425                         if (real_pos < 0) {
 426                                 i2c_op(pd, OP_RX_STOP, 0);
 427                                 break;
 428                         }
 429                         data = i2c_op(pd, OP_RX_STOP_DATA, 0);
 430                 } else
 431                         data = i2c_op(pd, OP_RX, 0);
 432
 433                 if (real_pos >= 0)
 434                         pd->msg->buf[real_pos] = data;
 435         } while (0);
 436
 437         pd->pos++;
 438         return pd->pos == (pd->msg->len + 2);
 439 }
 440
 441 static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
 442 {
 443         struct platform_device *dev = dev_id;
 444         struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
 445         unsigned char sr;
 446         int wakeup;
 447
 448         sr = iic_rd(pd, ICSR);
 449         pd->sr |= sr; /* remember state */
 450
 451         dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
 452                (pd->msg->flags & I2C_M_RD) ? "read" : "write",
 453                pd->pos, pd->msg->len);
 454
 455         if (sr & (ICSR_AL | ICSR_TACK)) {
 456                 /* don't interrupt transaction - continue to issue stop */
 457                 iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
 458                 wakeup = 0;
 459         } else if (pd->msg->flags & I2C_M_RD)
 460                 wakeup = sh_mobile_i2c_isr_rx(pd);
 461         else
 462                 wakeup = sh_mobile_i2c_isr_tx(pd);
 463
 464         if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
 465                 iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
 466
 467         if (wakeup) {
 468                 pd->sr |= SW_DONE;
 469                 wake_up(&pd->wait);
 470         }
 471
 472         /* defeat write posting to avoid spurious WAIT interrupts */
 473         iic_rd(pd, ICSR);
 474
 475         return IRQ_HANDLED;
 476 }
 477
 478 static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 479                     bool do_init)
 480 {
 481         if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
 482                 dev_err(pd->dev, "Unsupported zero length i2c read\n");
 483                 return -EIO;
 484         }
 485
 486         if (do_init) {
 487                 /* Initialize channel registers */
 488                 iic_set_clr(pd, ICCR, 0, ICCR_ICE);
 489
 490                 /* Enable channel and configure rx ack */
 491                 iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 492
 493                 /* Set the clock */
 494                 iic_wr(pd, ICCL, pd->iccl & 0xff);
 495                 iic_wr(pd, ICCH, pd->icch & 0xff);
 496         }
 497
 498         pd->msg = usr_msg;
 499         pd->pos = -1;
 500         pd->sr = 0;
 501
 502         /* Enable all interrupts to begin with */
 503         iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
 504         return 0;
 505 }
 506
 507 static int poll_dte(struct sh_mobile_i2c_data *pd)
 508 {
 509         int i;
 510
 511         for (i = 1000; i; i--) {
 512                 u_int8_t val = iic_rd(pd, ICSR);
 513
 514                 if (val & ICSR_DTE)
 515                         break;
 516
 517                 if (val & ICSR_TACK)
 518                         return -EIO;
 519
 520                 udelay(10);
 521         }
 522
 523         if (!i) {
 524                 dev_warn(pd->dev, "Timeout polling for DTE!\n");
 525                 return -ETIMEDOUT;
 526         }
 527
 528         return 0;
 529 }
 530
 531 static int poll_busy(struct sh_mobile_i2c_data *pd)
 532 {
 533         int i;
 534
 535         for (i = 1000; i; i--) {
 536                 u_int8_t val = iic_rd(pd, ICSR);
 537
 538                 dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
 539
 540                 /* the interrupt handler may wake us up before the
 541                  * transfer is finished, so poll the hardware
 542                  * until we're done.
 543                  */
 544                 if (!(val & ICSR_BUSY)) {
 545                         /* handle missing acknowledge and arbitration lost */
 546                         if ((val | pd->sr) & (ICSR_TACK | ICSR_AL))
 547                                 return -EIO;
 548                         break;
 549                 }
 550
 551                 udelay(10);
 552         }
 553
 554         if (!i) {
 555                 dev_err(pd->dev, "Polling timed out\n");
 556                 return -ETIMEDOUT;
 557         }
 558
 559         return 0;
 560 }
 561
 562 static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 563                               struct i2c_msg *msgs,
 564                               int num)
 565 {
 566         struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
 567         struct i2c_msg  *msg;
 568         int err = 0;
 569         int i, k;
 570
 571         activate_ch(pd);
 572
 573         /* Process all messages */
 574         for (i = 0; i < num; i++) {
 575                 bool do_start = pd->send_stop || !i;
 576                 msg = &msgs[i];
 577                 pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
 578
 579                 err = start_ch(pd, msg, do_start);
 580                 if (err)
 581                         break;
 582
 583                 if (do_start)
 584                         i2c_op(pd, OP_START, 0);
 585
 586                 /* The interrupt handler takes care of the rest... */
 587                 k = wait_event_timeout(pd->wait,
 588                                        pd->sr & (ICSR_TACK | SW_DONE),
 589                                        5 * HZ);
 590                 if (!k) {
 591                         dev_err(pd->dev, "Transfer request timed out\n");
 592                         err = -ETIMEDOUT;
 593                         break;
 594                 }
 595
 596                 if (pd->send_stop)
 597                         err = poll_busy(pd);
 598                 else
 599                         err = poll_dte(pd);
 600                 if (err < 0)
 601                         break;
 602         }
 603
 604         deactivate_ch(pd);
 605
 606         if (!err)
 607                 err = num;
 608         return err;
 609 }
 610
 611 static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
 612 {
 613         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
 614 }
 615
 616 static struct i2c_algorithm sh_mobile_i2c_algorithm = {
 617         .functionality  = sh_mobile_i2c_func,
 618         .master_xfer    = sh_mobile_i2c_xfer,
 619 };
 620
 621 static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, int hook)
 622 {
 623         struct resource *res;
 624         int ret = -ENXIO;
 625         int n, k = 0;
 626
 627         while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
 628                 for (n = res->start; hook && n <= res->end; n++) {
 629                         if (request_irq(n, sh_mobile_i2c_isr, 0,
 630                                         dev_name(&dev->dev), dev)) {
 631                                 for (n--; n >= res->start; n--)
 632                                         free_irq(n, dev);
 633
 634                                 goto rollback;
 635                         }
 636                 }
 637                 k++;
 638         }
 639
 640         if (hook)
 641                 return k > 0 ? 0 : -ENOENT;
 642
 643         ret = 0;
 644
 645  rollback:
 646         k--;
 647
 648         while (k >= 0) {
 649                 res = platform_get_resource(dev, IORESOURCE_IRQ, k);
 650                 for (n = res->start; n <= res->end; n++)
 651                         free_irq(n, dev);
 652
 653                 k--;
 654         }
 655
 656         return ret;
 657 }
 658
 659 static int sh_mobile_i2c_probe(struct platform_device *dev)
 660 {
 661         struct i2c_sh_mobile_platform_data *pdata = dev->dev.platform_data;
 662         struct sh_mobile_i2c_data *pd;
 663         struct i2c_adapter *adap;
 664         struct resource *res;
 665         int size;
 666         int ret;
 667
 668         pd = kzalloc(sizeof(struct sh_mobile_i2c_data), GFP_KERNEL);
 669         if (pd == NULL) {
 670                 dev_err(&dev->dev, "cannot allocate private data\n");
 671                 return -ENOMEM;
 672         }
 673
 674         pd->clk = clk_get(&dev->dev, NULL);
 675         if (IS_ERR(pd->clk)) {
 676                 dev_err(&dev->dev, "cannot get clock\n");
 677                 ret = PTR_ERR(pd->clk);
 678                 goto err;
 679         }
 680
 681         ret = sh_mobile_i2c_hook_irqs(dev, 1);
 682         if (ret) {
 683                 dev_err(&dev->dev, "cannot request IRQ\n");
 684                 goto err_clk;
 685         }
 686
 687         pd->dev = &dev->dev;
 688         platform_set_drvdata(dev, pd);
 689
 690         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 691         if (res == NULL) {
 692                 dev_err(&dev->dev, "cannot find IO resource\n");
 693                 ret = -ENOENT;
 694                 goto err_irq;
 695         }
 696
 697         size = resource_size(res);
 698
 699         pd->reg = ioremap(res->start, size);
 700         if (pd->reg == NULL) {
 701                 dev_err(&dev->dev, "cannot map IO\n");
 702                 ret = -ENXIO;
 703                 goto err_irq;
 704         }
 705
 706         /* Use platform data bus speed or STANDARD_MODE */
 707         pd->bus_speed = STANDARD_MODE;
 708         if (pdata && pdata->bus_speed)
 709                 pd->bus_speed = pdata->bus_speed;
 710         pd->clks_per_count = 1;
 711         if (pdata && pdata->clks_per_count)
 712                 pd->clks_per_count = pdata->clks_per_count;
 713
 714         /* The IIC blocks on SH-Mobile ARM processors
 715          * come with two new bits in ICIC.
 716          */
 717         if (size > 0x17)
 718                 pd->flags |= IIC_FLAG_HAS_ICIC67;
 719
 720         sh_mobile_i2c_init(pd);
 721
 722         /* Enable Runtime PM for this device.
 723          *
 724          * Also tell the Runtime PM core to ignore children
 725          * for this device since it is valid for us to suspend
 726          * this I2C master driver even though the slave devices
 727          * on the I2C bus may not be suspended.
 728          *
 729          * The state of the I2C hardware bus is unaffected by
 730          * the Runtime PM state.
 731          */
 732         pm_suspend_ignore_children(&dev->dev, true);
 733         pm_runtime_enable(&dev->dev);
 734
 735         /* setup the private data */
 736         adap = &pd->adap;
 737         i2c_set_adapdata(adap, pd);
 738
 739         adap->owner = THIS_MODULE;
 740         adap->algo = &sh_mobile_i2c_algorithm;
 741         adap->dev.parent = &dev->dev;
 742         adap->retries = 5;
 743         adap->nr = dev->id;
 744         adap->dev.of_node = dev->dev.of_node;
 745
 746         strlcpy(adap->name, dev->name, sizeof(adap->name));
 747
 748         spin_lock_init(&pd->lock);
 749         init_waitqueue_head(&pd->wait);
 750
 751         ret = i2c_add_numbered_adapter(adap);
 752         if (ret < 0) {
 753                 dev_err(&dev->dev, "cannot add numbered adapter\n");
 754                 goto err_all;
 755         }
 756
 757         dev_info(&dev->dev,
 758                  "I2C adapter %d with bus speed %lu Hz (L/H=%x/%x)\n",
 759                  adap->nr, pd->bus_speed, pd->iccl, pd->icch);
 760
 761         of_i2c_register_devices(adap);
 762         return 0;
 763
 764  err_all:
 765         iounmap(pd->reg);
 766  err_irq:
 767         sh_mobile_i2c_hook_irqs(dev, 0);
 768  err_clk:
 769         clk_put(pd->clk);
 770  err:
 771         kfree(pd);
 772         return ret;
 773 }
 774
 775 static int sh_mobile_i2c_remove(struct platform_device *dev)
 776 {
 777         struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
 778
 779         i2c_del_adapter(&pd->adap);
 780         iounmap(pd->reg);
 781         sh_mobile_i2c_hook_irqs(dev, 0);
 782         clk_put(pd->clk);
 783         pm_runtime_disable(&dev->dev);
 784         kfree(pd);
 785         return 0;
 786 }
 787
 788 static int sh_mobile_i2c_runtime_nop(struct device *dev)
 789 {
 790         /* Runtime PM callback shared between ->runtime_suspend()
 791          * and ->runtime_resume(). Simply returns success.
 792          *
 793          * This driver re-initializes all registers after
 794          * pm_runtime_get_sync() anyway so there is no need
 795          * to save and restore registers here.
 796          */
 797         return 0;
 798 }
 799
 800 static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
 801         .runtime_suspend = sh_mobile_i2c_runtime_nop,
 802         .runtime_resume = sh_mobile_i2c_runtime_nop,
 803 };
 804
 805 static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
 806         { .compatible = "renesas,rmobile-iic", },
 807         {},
 808 };
 809 MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
 810
 811 static struct platform_driver sh_mobile_i2c_driver = {
 812         .driver         = {
 813                 .name           = "i2c-sh_mobile",
 814                 .owner          = THIS_MODULE,
 815                 .pm             = &sh_mobile_i2c_dev_pm_ops,
 816                 .of_match_table = sh_mobile_i2c_dt_ids,
 817         },
 818         .probe          = sh_mobile_i2c_probe,
 819         .remove         = sh_mobile_i2c_remove,
 820 };
 821
 822 static int __init sh_mobile_i2c_adap_init(void)
 823 {
 824         return platform_driver_register(&sh_mobile_i2c_driver);
 825 }
 826
 827 static void __exit sh_mobile_i2c_adap_exit(void)
 828 {
 829         platform_driver_unregister(&sh_mobile_i2c_driver);
 830 }
 831
 832 subsys_initcall(sh_mobile_i2c_adap_init);
 833 module_exit(sh_mobile_i2c_adap_exit);
 834
 835 MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
 836 MODULE_AUTHOR("Magnus Damm");
 837 MODULE_LICENSE("GPL v2");
 838 MODULE_ALIAS("platform:i2c-sh_mobile");