drivers/i2c/busses/i2c-jz4780.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Ingenic JZ4780 I2C bus driver
   4  *
   5  * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
   6  * Copyright (C) 2015 Imagination Technologies
   7  * Copyright (C) 2019 周琰杰 (Zhou Yanjie) <[email protected]>
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/clk.h>
  12 #include <linux/completion.h>
  13 #include <linux/delay.h>
  14 #include <linux/errno.h>
  15 #include <linux/i2c.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_device.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25 #include <linux/time.h>
  26
  27 #define JZ4780_I2C_CTRL         0x00
  28 #define JZ4780_I2C_TAR          0x04
  29 #define JZ4780_I2C_SAR          0x08
  30 #define JZ4780_I2C_DC           0x10
  31 #define JZ4780_I2C_SHCNT        0x14
  32 #define JZ4780_I2C_SLCNT        0x18
  33 #define JZ4780_I2C_FHCNT        0x1C
  34 #define JZ4780_I2C_FLCNT        0x20
  35 #define JZ4780_I2C_INTST        0x2C
  36 #define JZ4780_I2C_INTM         0x30
  37 #define JZ4780_I2C_RXTL         0x38
  38 #define JZ4780_I2C_TXTL         0x3C
  39 #define JZ4780_I2C_CINTR        0x40
  40 #define JZ4780_I2C_CRXUF        0x44
  41 #define JZ4780_I2C_CRXOF        0x48
  42 #define JZ4780_I2C_CTXOF        0x4C
  43 #define JZ4780_I2C_CRXREQ       0x50
  44 #define JZ4780_I2C_CTXABRT      0x54
  45 #define JZ4780_I2C_CRXDONE      0x58
  46 #define JZ4780_I2C_CACT         0x5C
  47 #define JZ4780_I2C_CSTP         0x60
  48 #define JZ4780_I2C_CSTT         0x64
  49 #define JZ4780_I2C_CGC          0x68
  50 #define JZ4780_I2C_ENB          0x6C
  51 #define JZ4780_I2C_STA          0x70
  52 #define JZ4780_I2C_TXABRT       0x80
  53 #define JZ4780_I2C_DMACR        0x88
  54 #define JZ4780_I2C_DMATDLR      0x8C
  55 #define JZ4780_I2C_DMARDLR      0x90
  56 #define JZ4780_I2C_SDASU        0x94
  57 #define JZ4780_I2C_ACKGC        0x98
  58 #define JZ4780_I2C_ENSTA        0x9C
  59 #define JZ4780_I2C_SDAHD        0xD0
  60 #define X1000_I2C_SDAHD         0x7C
  61
  62 #define JZ4780_I2C_CTRL_STPHLD          BIT(7)
  63 #define JZ4780_I2C_CTRL_SLVDIS          BIT(6)
  64 #define JZ4780_I2C_CTRL_REST            BIT(5)
  65 #define JZ4780_I2C_CTRL_MATP            BIT(4)
  66 #define JZ4780_I2C_CTRL_SATP            BIT(3)
  67 #define JZ4780_I2C_CTRL_SPDF            BIT(2)
  68 #define JZ4780_I2C_CTRL_SPDS            BIT(1)
  69 #define JZ4780_I2C_CTRL_MD              BIT(0)
  70
  71 #define JZ4780_I2C_STA_SLVACT           BIT(6)
  72 #define JZ4780_I2C_STA_MSTACT           BIT(5)
  73 #define JZ4780_I2C_STA_RFF              BIT(4)
  74 #define JZ4780_I2C_STA_RFNE             BIT(3)
  75 #define JZ4780_I2C_STA_TFE              BIT(2)
  76 #define JZ4780_I2C_STA_TFNF             BIT(1)
  77 #define JZ4780_I2C_STA_ACT              BIT(0)
  78
  79 #define X1000_I2C_DC_STOP               BIT(9)
  80
  81 #define JZ4780_I2C_INTST_IGC            BIT(11)
  82 #define JZ4780_I2C_INTST_ISTT           BIT(10)
  83 #define JZ4780_I2C_INTST_ISTP           BIT(9)
  84 #define JZ4780_I2C_INTST_IACT           BIT(8)
  85 #define JZ4780_I2C_INTST_RXDN           BIT(7)
  86 #define JZ4780_I2C_INTST_TXABT          BIT(6)
  87 #define JZ4780_I2C_INTST_RDREQ          BIT(5)
  88 #define JZ4780_I2C_INTST_TXEMP          BIT(4)
  89 #define JZ4780_I2C_INTST_TXOF           BIT(3)
  90 #define JZ4780_I2C_INTST_RXFL           BIT(2)
  91 #define JZ4780_I2C_INTST_RXOF           BIT(1)
  92 #define JZ4780_I2C_INTST_RXUF           BIT(0)
  93
  94 #define JZ4780_I2C_INTM_MIGC            BIT(11)
  95 #define JZ4780_I2C_INTM_MISTT           BIT(10)
  96 #define JZ4780_I2C_INTM_MISTP           BIT(9)
  97 #define JZ4780_I2C_INTM_MIACT           BIT(8)
  98 #define JZ4780_I2C_INTM_MRXDN           BIT(7)
  99 #define JZ4780_I2C_INTM_MTXABT          BIT(6)
 100 #define JZ4780_I2C_INTM_MRDREQ          BIT(5)
 101 #define JZ4780_I2C_INTM_MTXEMP          BIT(4)
 102 #define JZ4780_I2C_INTM_MTXOF           BIT(3)
 103 #define JZ4780_I2C_INTM_MRXFL           BIT(2)
 104 #define JZ4780_I2C_INTM_MRXOF           BIT(1)
 105 #define JZ4780_I2C_INTM_MRXUF           BIT(0)
 106
 107 #define JZ4780_I2C_DC_READ              BIT(8)
 108
 109 #define JZ4780_I2C_SDAHD_HDENB          BIT(8)
 110
 111 #define JZ4780_I2C_ENB_I2C              BIT(0)
 112
 113 #define JZ4780_I2CSHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 114 #define JZ4780_I2CSLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 115 #define JZ4780_I2CFHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 116 #define JZ4780_I2CFLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 117
 118 #define JZ4780_I2C_FIFO_LEN     16
 119
 120 #define X1000_I2C_FIFO_LEN      64
 121
 122 #define JZ4780_I2C_TIMEOUT      300
 123
 124 #define BUFSIZE 200
 125
 126 enum ingenic_i2c_version {
 127         ID_JZ4780,
 128         ID_X1000,
 129 };
 130
 131 /* ingenic_i2c_config: SoC specific config data. */
 132 struct ingenic_i2c_config {
 133         enum ingenic_i2c_version version;
 134
 135         int fifosize;
 136         int tx_level;
 137         int rx_level;
 138 };
 139
 140 struct jz4780_i2c {
 141         void __iomem            *iomem;
 142         int                      irq;
 143         struct clk              *clk;
 144         struct i2c_adapter       adap;
 145         const struct ingenic_i2c_config *cdata;
 146
 147         /* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
 148         spinlock_t              lock;
 149
 150         /* beginning of lock scope */
 151         unsigned char           *rbuf;
 152         int                     rd_total_len;
 153         int                     rd_data_xfered;
 154         int                     rd_cmd_xfered;
 155
 156         unsigned char           *wbuf;
 157         int                     wt_len;
 158
 159         int                     is_write;
 160         int                     stop_hold;
 161         int                     speed;
 162
 163         int                     data_buf[BUFSIZE];
 164         int                     cmd_buf[BUFSIZE];
 165         int                     cmd;
 166
 167         /* end of lock scope */
 168         struct completion       trans_waitq;
 169 };
 170
 171 static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
 172                                               unsigned long offset)
 173 {
 174         return readw(i2c->iomem + offset);
 175 }
 176
 177 static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
 178                                      unsigned long offset, unsigned short val)
 179 {
 180         writew(val, i2c->iomem + offset);
 181 }
 182
 183 static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
 184 {
 185         unsigned short regval;
 186         unsigned long loops = 5;
 187
 188         jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
 189
 190         do {
 191                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 192                 if (!(regval & JZ4780_I2C_ENB_I2C))
 193                         return 0;
 194
 195                 usleep_range(5000, 15000);
 196         } while (--loops);
 197
 198         dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
 199         return -ETIMEDOUT;
 200 }
 201
 202 static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
 203 {
 204         unsigned short regval;
 205         unsigned long loops = 5;
 206
 207         jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
 208
 209         do {
 210                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 211                 if (regval & JZ4780_I2C_ENB_I2C)
 212                         return 0;
 213
 214                 usleep_range(5000, 15000);
 215         } while (--loops);
 216
 217         dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
 218         return -ETIMEDOUT;
 219 }
 220
 221 static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
 222 {
 223         unsigned short regval;
 224         unsigned long loops = 5;
 225
 226         do {
 227                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 228                 if ((regval & JZ4780_I2C_STA_TFE) &&
 229                     !(regval & JZ4780_I2C_STA_MSTACT))
 230                         break;
 231
 232                 usleep_range(5000, 15000);
 233         } while (--loops);
 234
 235         if (loops) {
 236                 jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
 237                 return 0;
 238         }
 239
 240         dev_err(&i2c->adap.dev,
 241                 "set device to address 0x%02x failed, STA=0x%04x\n",
 242                 address, regval);
 243
 244         return -ENXIO;
 245 }
 246
 247 static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
 248 {
 249         int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
 250         int cnt_high = 0;       /* HIGH period count of the SCL clock */
 251         int cnt_low = 0;        /* LOW period count of the SCL clock */
 252         int cnt_period = 0;     /* period count of the SCL clock */
 253         int setup_time = 0;
 254         int hold_time = 0;
 255         unsigned short tmp = 0;
 256         int i2c_clk = i2c->speed;
 257
 258         if (jz4780_i2c_disable(i2c))
 259                 dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
 260
 261         /*
 262          * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
 263          * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
 264          * fast mode, min LOW and HIGH period are 1300 ns and 600 ns
 265          */
 266         cnt_period = dev_clk_khz / i2c_clk;
 267
 268         if (i2c_clk <= 100)
 269                 cnt_high = (cnt_period * 4000) / (4700 + 4000);
 270         else
 271                 cnt_high = (cnt_period * 600) / (1300 + 600);
 272
 273         cnt_low = cnt_period - cnt_high;
 274
 275         /*
 276          * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
 277          * normal read are 2 messages, we cannot disable i2c controller
 278          * between these two messages, this means that we must always set
 279          * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
 280          *
 281          */
 282         if (i2c_clk <= 100) {
 283                 tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
 284                       | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
 285                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 286
 287                 jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
 288                                   JZ4780_I2CSHCNT_ADJUST(cnt_high));
 289                 jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
 290                                   JZ4780_I2CSLCNT_ADJUST(cnt_low));
 291         } else {
 292                 tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST
 293                       | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
 294                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 295
 296                 jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,
 297                                   JZ4780_I2CFHCNT_ADJUST(cnt_high));
 298                 jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
 299                                   JZ4780_I2CFLCNT_ADJUST(cnt_low));
 300         }
 301
 302         /*
 303          * a i2c device must internally provide a hold time at least 300ns
 304          * tHD:DAT
 305          *      Standard Mode: min=300ns, max=3450ns
 306          *      Fast Mode: min=0ns, max=900ns
 307          * tSU:DAT
 308          *      Standard Mode: min=250ns, max=infinite
 309          *      Fast Mode: min=100(250ns is recommended), max=infinite
 310          *
 311          * 1i2c_clk = 10^6 / dev_clk_khz
 312          * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
 313          * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
 314          *
 315          * The actual hold time is (SDAHD + 1) * (i2c_clk period).
 316          *
 317          * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
 318          *
 319          */
 320         if (i2c_clk <= 100) { /* standard mode */
 321                 setup_time = 300;
 322                 hold_time = 400;
 323         } else {
 324                 setup_time = 450;
 325                 hold_time = 450;
 326         }
 327
 328         hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
 329         setup_time = ((setup_time * dev_clk_khz) / 1000000)  + 1;
 330
 331         if (setup_time > 255)
 332                 setup_time = 255;
 333
 334         if (setup_time <= 0)
 335                 setup_time = 1;
 336
 337         jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
 338
 339         if (hold_time > 255)
 340                 hold_time = 255;
 341
 342         if (hold_time >= 0) {
 343                 /*i2c hold time enable */
 344                 if (i2c->cdata->version >= ID_X1000) {
 345                         jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, hold_time);
 346                 } else {
 347                         hold_time |= JZ4780_I2C_SDAHD_HDENB;
 348                         jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
 349                 }
 350         } else {
 351                 /* disable hold time */
 352                 if (i2c->cdata->version >= ID_X1000)
 353                         jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, 0);
 354                 else
 355                         jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
 362 {
 363         int ret;
 364         unsigned long flags;
 365         unsigned short tmp;
 366
 367         spin_lock_irqsave(&i2c->lock, flags);
 368
 369         /* can send stop now if need */
 370         if (i2c->cdata->version < ID_X1000) {
 371                 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 372                 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 373                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 374         }
 375
 376         /* disable all interrupts first */
 377         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 378
 379         /* then clear all interrupts */
 380         jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
 381         jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
 382
 383         /* then disable the controller */
 384         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 385         tmp &= ~JZ4780_I2C_ENB_I2C;
 386         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 387         udelay(10);
 388         tmp |= JZ4780_I2C_ENB_I2C;
 389         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 390
 391         spin_unlock_irqrestore(&i2c->lock, flags);
 392
 393         ret = jz4780_i2c_disable(i2c);
 394         if (ret)
 395                 dev_err(&i2c->adap.dev,
 396                         "unable to disable device during cleanup!\n");
 397
 398         if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
 399                      & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
 400                 dev_err(&i2c->adap.dev,
 401                         "device has interrupts after a complete cleanup!\n");
 402
 403         return ret;
 404 }
 405
 406 static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
 407 {
 408         jz4780_i2c_set_speed(i2c);
 409         return jz4780_i2c_enable(i2c);
 410 }
 411
 412 static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c,
 413                                                                  int cmd_count,
 414                                                                  int cmd_left)
 415 {
 416         int i;
 417
 418         for (i = 0; i < cmd_count - 1; i++)
 419                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
 420
 421         if ((cmd_left == 0) && (i2c->cdata->version >= ID_X1000))
 422                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
 423                                 JZ4780_I2C_DC_READ | X1000_I2C_DC_STOP);
 424         else
 425                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
 426 }
 427
 428 static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
 429 {
 430         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 431         complete(&i2c->trans_waitq);
 432 }
 433
 434 static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
 435 {
 436         unsigned short tmp;
 437         unsigned short intst;
 438         unsigned short intmsk;
 439         struct jz4780_i2c *i2c = dev_id;
 440
 441         spin_lock(&i2c->lock);
 442         intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 443         intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
 444
 445         intst &= intmsk;
 446
 447         if (intst & JZ4780_I2C_INTST_TXABT) {
 448                 jz4780_i2c_trans_done(i2c);
 449                 goto done;
 450         }
 451
 452         if (intst & JZ4780_I2C_INTST_RXOF) {
 453                 dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
 454                 jz4780_i2c_trans_done(i2c);
 455                 goto done;
 456         }
 457
 458         /*
 459          * When reading, always drain RX FIFO before we send more Read
 460          * Commands to avoid fifo overrun
 461          */
 462         if (i2c->is_write == 0) {
 463                 int rd_left;
 464
 465                 while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
 466                                   & JZ4780_I2C_STA_RFNE)) {
 467                         *(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
 468                                          & 0xff;
 469                         i2c->rd_data_xfered++;
 470                         if (i2c->rd_data_xfered == i2c->rd_total_len) {
 471                                 jz4780_i2c_trans_done(i2c);
 472                                 goto done;
 473                         }
 474                 }
 475
 476                 rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
 477
 478                 if (rd_left <= i2c->cdata->fifosize)
 479                         jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
 480         }
 481
 482         if (intst & JZ4780_I2C_INTST_TXEMP) {
 483                 if (i2c->is_write == 0) {
 484                         int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
 485                         int max_send = (i2c->cdata->fifosize - 1)
 486                                          - (i2c->rd_cmd_xfered
 487                                          - i2c->rd_data_xfered);
 488                         int cmd_to_send = min(cmd_left, max_send);
 489
 490                         if (i2c->rd_cmd_xfered != 0)
 491                                 cmd_to_send = min(cmd_to_send,
 492                                                   i2c->cdata->fifosize
 493                                                   - i2c->cdata->tx_level - 1);
 494
 495                         if (cmd_to_send) {
 496                                 i2c->rd_cmd_xfered += cmd_to_send;
 497                                 cmd_left = i2c->rd_total_len -
 498                                                 i2c->rd_cmd_xfered;
 499                                 jz4780_i2c_send_rcmd(i2c,
 500                                                 cmd_to_send, cmd_left);
 501
 502                         }
 503
 504                         if (cmd_left == 0) {
 505                                 intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 506                                 intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
 507                                 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
 508
 509                                 if (i2c->cdata->version < ID_X1000) {
 510                                         tmp = jz4780_i2c_readw(i2c,
 511                                                         JZ4780_I2C_CTRL);
 512                                         tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 513                                         jz4780_i2c_writew(i2c,
 514                                                         JZ4780_I2C_CTRL, tmp);
 515                                 }
 516                         }
 517                 } else {
 518                         unsigned short data;
 519                         unsigned short i2c_sta;
 520
 521                         i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 522
 523                         while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
 524                                         (i2c->wt_len > 0)) {
 525                                 i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 526                                 data = *i2c->wbuf;
 527                                 data &= ~JZ4780_I2C_DC_READ;
 528                                 if ((i2c->wt_len == 1) && (!i2c->stop_hold) &&
 529                                                 (i2c->cdata->version >= ID_X1000))
 530                                         data |= X1000_I2C_DC_STOP;
 531                                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC, data);
 532                                 i2c->wbuf++;
 533                                 i2c->wt_len--;
 534                         }
 535
 536                         if (i2c->wt_len == 0) {
 537                                 if ((!i2c->stop_hold) && (i2c->cdata->version <
 538                                                 ID_X1000)) {
 539                                         tmp = jz4780_i2c_readw(i2c,
 540                                                         JZ4780_I2C_CTRL);
 541                                         tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 542                                         jz4780_i2c_writew(i2c,
 543                                                         JZ4780_I2C_CTRL, tmp);
 544                                 }
 545
 546                                 jz4780_i2c_trans_done(i2c);
 547                                 goto done;
 548                         }
 549                 }
 550         }
 551
 552 done:
 553         spin_unlock(&i2c->lock);
 554         return IRQ_HANDLED;
 555 }
 556
 557 static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
 558 {
 559         dev_dbg(&i2c->adap.dev, "txabrt: 0x%08x, cmd: %d, send: %d, recv: %d\n",
 560                 src, i2c->cmd, i2c->cmd_buf[i2c->cmd], i2c->data_buf[i2c->cmd]);
 561 }
 562
 563 static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
 564                                        unsigned char *buf, int len, int cnt,
 565                                        int idx)
 566 {
 567         int ret = 0;
 568         long timeout;
 569         int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 570         unsigned short tmp;
 571         unsigned long flags;
 572
 573         memset(buf, 0, len);
 574
 575         spin_lock_irqsave(&i2c->lock, flags);
 576
 577         i2c->stop_hold = 0;
 578         i2c->is_write = 0;
 579         i2c->rbuf = buf;
 580         i2c->rd_total_len = len;
 581         i2c->rd_data_xfered = 0;
 582         i2c->rd_cmd_xfered = 0;
 583
 584         if (len <= i2c->cdata->fifosize)
 585                 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
 586         else
 587                 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, i2c->cdata->rx_level);
 588
 589         jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);
 590
 591         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
 592                           JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
 593                           | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
 594
 595         if (i2c->cdata->version < ID_X1000) {
 596                 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 597                 tmp |= JZ4780_I2C_CTRL_STPHLD;
 598                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 599         }
 600
 601         spin_unlock_irqrestore(&i2c->lock, flags);
 602
 603         timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 604                                               msecs_to_jiffies(wait_time));
 605
 606         if (!timeout) {
 607                 dev_err(&i2c->adap.dev, "irq read timeout\n");
 608                 dev_dbg(&i2c->adap.dev, "send cmd count:%d  %d\n",
 609                         i2c->cmd, i2c->cmd_buf[i2c->cmd]);
 610                 dev_dbg(&i2c->adap.dev, "receive data count:%d  %d\n",
 611                         i2c->cmd, i2c->data_buf[i2c->cmd]);
 612                 ret = -EIO;
 613         }
 614
 615         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 616         if (tmp) {
 617                 jz4780_i2c_txabrt(i2c, tmp);
 618                 ret = -EIO;
 619         }
 620
 621         return ret;
 622 }
 623
 624 static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
 625                                         unsigned char *buf, int len,
 626                                         int cnt, int idx)
 627 {
 628         int ret = 0;
 629         int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 630         long timeout;
 631         unsigned short tmp;
 632         unsigned long flags;
 633
 634         spin_lock_irqsave(&i2c->lock, flags);
 635
 636         if (idx < (cnt - 1))
 637                 i2c->stop_hold = 1;
 638         else
 639                 i2c->stop_hold = 0;
 640
 641         i2c->is_write = 1;
 642         i2c->wbuf = buf;
 643         i2c->wt_len = len;
 644
 645         jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);
 646
 647         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
 648                                         | JZ4780_I2C_INTM_MTXABT);
 649
 650         if (i2c->cdata->version < ID_X1000) {
 651                 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 652                 tmp |= JZ4780_I2C_CTRL_STPHLD;
 653                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 654         }
 655
 656         spin_unlock_irqrestore(&i2c->lock, flags);
 657
 658         timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 659                                               msecs_to_jiffies(wait_time));
 660         if (timeout && !i2c->stop_hold) {
 661                 unsigned short i2c_sta;
 662                 int write_in_process;
 663
 664                 timeout = JZ4780_I2C_TIMEOUT * 100;
 665                 for (; timeout > 0; timeout--) {
 666                         i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 667
 668                         write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
 669                                 !(i2c_sta & JZ4780_I2C_STA_TFE);
 670                         if (!write_in_process)
 671                                 break;
 672                         udelay(10);
 673                 }
 674         }
 675
 676         if (!timeout) {
 677                 dev_err(&i2c->adap.dev, "write wait timeout\n");
 678                 ret = -EIO;
 679         }
 680
 681         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 682         if (tmp) {
 683                 jz4780_i2c_txabrt(i2c, tmp);
 684                 ret = -EIO;
 685         }
 686
 687         return ret;
 688 }
 689
 690 static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
 691                            int count)
 692 {
 693         int i = -EIO;
 694         int ret = 0;
 695         struct jz4780_i2c *i2c = adap->algo_data;
 696
 697         ret = jz4780_i2c_prepare(i2c);
 698         if (ret) {
 699                 dev_err(&i2c->adap.dev, "I2C prepare failed\n");
 700                 goto out;
 701         }
 702
 703         if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
 704                 ret = jz4780_i2c_set_target(i2c, msg->addr);
 705                 if (ret)
 706                         goto out;
 707         }
 708         for (i = 0; i < count; i++, msg++) {
 709                 if (msg->flags & I2C_M_RD)
 710                         ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
 711                                                    count, i);
 712                 else
 713                         ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
 714                                                     count, i);
 715
 716                 if (ret)
 717                         goto out;
 718         }
 719
 720         ret = i;
 721
 722 out:
 723         jz4780_i2c_cleanup(i2c);
 724         return ret;
 725 }
 726
 727 static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
 728 {
 729         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 730 }
 731
 732 static const struct i2c_algorithm jz4780_i2c_algorithm = {
 733         .master_xfer    = jz4780_i2c_xfer,
 734         .functionality  = jz4780_i2c_functionality,
 735 };
 736
 737 static const struct ingenic_i2c_config jz4780_i2c_config = {
 738         .version = ID_JZ4780,
 739
 740         .fifosize = JZ4780_I2C_FIFO_LEN,
 741         .tx_level = JZ4780_I2C_FIFO_LEN / 2,
 742         .rx_level = JZ4780_I2C_FIFO_LEN / 2 - 1,
 743 };
 744
 745 static const struct ingenic_i2c_config x1000_i2c_config = {
 746         .version = ID_X1000,
 747
 748         .fifosize = X1000_I2C_FIFO_LEN,
 749         .tx_level = X1000_I2C_FIFO_LEN / 2,
 750         .rx_level = X1000_I2C_FIFO_LEN / 2 - 1,
 751 };
 752
 753 static const struct of_device_id jz4780_i2c_of_matches[] = {
 754         { .compatible = "ingenic,jz4770-i2c", .data = &jz4780_i2c_config },
 755         { .compatible = "ingenic,jz4780-i2c", .data = &jz4780_i2c_config },
 756         { .compatible = "ingenic,x1000-i2c", .data = &x1000_i2c_config },
 757         { /* sentinel */ }
 758 };
 759 MODULE_DEVICE_TABLE(of, jz4780_i2c_of_matches);
 760
 761 static int jz4780_i2c_probe(struct platform_device *pdev)
 762 {
 763         int ret = 0;
 764         unsigned int clk_freq = 0;
 765         unsigned short tmp;
 766         struct jz4780_i2c *i2c;
 767
 768         i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
 769         if (!i2c)
 770                 return -ENOMEM;
 771
 772         i2c->cdata = device_get_match_data(&pdev->dev);
 773         if (!i2c->cdata) {
 774                 dev_err(&pdev->dev, "Error: No device match found\n");
 775                 return -ENODEV;
 776         }
 777
 778         i2c->adap.owner         = THIS_MODULE;
 779         i2c->adap.algo          = &jz4780_i2c_algorithm;
 780         i2c->adap.algo_data     = i2c;
 781         i2c->adap.retries       = 5;
 782         i2c->adap.dev.parent    = &pdev->dev;
 783         i2c->adap.dev.of_node   = pdev->dev.of_node;
 784         sprintf(i2c->adap.name, "%s", pdev->name);
 785
 786         init_completion(&i2c->trans_waitq);
 787         spin_lock_init(&i2c->lock);
 788
 789         i2c->iomem = devm_platform_ioremap_resource(pdev, 0);
 790         if (IS_ERR(i2c->iomem))
 791                 return PTR_ERR(i2c->iomem);
 792
 793         platform_set_drvdata(pdev, i2c);
 794
 795         i2c->clk = devm_clk_get(&pdev->dev, NULL);
 796         if (IS_ERR(i2c->clk))
 797                 return PTR_ERR(i2c->clk);
 798
 799         ret = clk_prepare_enable(i2c->clk);
 800         if (ret)
 801                 return ret;
 802
 803         ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 804                                    &clk_freq);
 805         if (ret) {
 806                 dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
 807                 goto err;
 808         }
 809
 810         i2c->speed = clk_freq / 1000;
 811         if (i2c->speed == 0) {
 812                 ret = -EINVAL;
 813                 dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
 814                 goto err;
 815         }
 816         jz4780_i2c_set_speed(i2c);
 817
 818         dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
 819
 820         if (i2c->cdata->version < ID_X1000) {
 821                 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 822                 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 823                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 824         }
 825
 826         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
 827
 828         ret = platform_get_irq(pdev, 0);
 829         if (ret < 0)
 830                 goto err;
 831         i2c->irq = ret;
 832         ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
 833                                dev_name(&pdev->dev), i2c);
 834         if (ret)
 835                 goto err;
 836
 837         ret = i2c_add_adapter(&i2c->adap);
 838         if (ret < 0)
 839                 goto err;
 840
 841         return 0;
 842
 843 err:
 844         clk_disable_unprepare(i2c->clk);
 845         return ret;
 846 }
 847
 848 static int jz4780_i2c_remove(struct platform_device *pdev)
 849 {
 850         struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
 851
 852         clk_disable_unprepare(i2c->clk);
 853         i2c_del_adapter(&i2c->adap);
 854         return 0;
 855 }
 856
 857 static struct platform_driver jz4780_i2c_driver = {
 858         .probe          = jz4780_i2c_probe,
 859         .remove         = jz4780_i2c_remove,
 860         .driver         = {
 861                 .name   = "jz4780-i2c",
 862                 .of_match_table = jz4780_i2c_of_matches,
 863         },
 864 };
 865
 866 module_platform_driver(jz4780_i2c_driver);
 867
 868 MODULE_LICENSE("GPL");
 869 MODULE_AUTHOR("ztyan<[email protected]>");
 870 MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");