drivers/i2c/busses/i2c-jz4780.c

   1 /*
   2  * Ingenic JZ4780 I2C bus driver
   3  *
   4  * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
   5  * Copyright (C) 2015 Imagination Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/bitops.h>
  19 #include <linux/clk.h>
  20 #include <linux/completion.h>
  21 #include <linux/delay.h>
  22 #include <linux/errno.h>
  23 #include <linux/i2c.h>
  24 #include <linux/init.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/io.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/sched.h>
  31 #include <linux/slab.h>
  32 #include <linux/time.h>
  33
  34 #define JZ4780_I2C_CTRL         0x00
  35 #define JZ4780_I2C_TAR          0x04
  36 #define JZ4780_I2C_SAR          0x08
  37 #define JZ4780_I2C_DC           0x10
  38 #define JZ4780_I2C_SHCNT        0x14
  39 #define JZ4780_I2C_SLCNT        0x18
  40 #define JZ4780_I2C_FHCNT        0x1C
  41 #define JZ4780_I2C_FLCNT        0x20
  42 #define JZ4780_I2C_INTST        0x2C
  43 #define JZ4780_I2C_INTM         0x30
  44 #define JZ4780_I2C_RXTL         0x38
  45 #define JZ4780_I2C_TXTL         0x3C
  46 #define JZ4780_I2C_CINTR        0x40
  47 #define JZ4780_I2C_CRXUF        0x44
  48 #define JZ4780_I2C_CRXOF        0x48
  49 #define JZ4780_I2C_CTXOF        0x4C
  50 #define JZ4780_I2C_CRXREQ       0x50
  51 #define JZ4780_I2C_CTXABRT      0x54
  52 #define JZ4780_I2C_CRXDONE      0x58
  53 #define JZ4780_I2C_CACT         0x5C
  54 #define JZ4780_I2C_CSTP         0x60
  55 #define JZ4780_I2C_CSTT         0x64
  56 #define JZ4780_I2C_CGC          0x68
  57 #define JZ4780_I2C_ENB          0x6C
  58 #define JZ4780_I2C_STA          0x70
  59 #define JZ4780_I2C_TXABRT       0x80
  60 #define JZ4780_I2C_DMACR        0x88
  61 #define JZ4780_I2C_DMATDLR      0x8C
  62 #define JZ4780_I2C_DMARDLR      0x90
  63 #define JZ4780_I2C_SDASU        0x94
  64 #define JZ4780_I2C_ACKGC        0x98
  65 #define JZ4780_I2C_ENSTA        0x9C
  66 #define JZ4780_I2C_SDAHD        0xD0
  67
  68 #define JZ4780_I2C_CTRL_STPHLD          BIT(7)
  69 #define JZ4780_I2C_CTRL_SLVDIS          BIT(6)
  70 #define JZ4780_I2C_CTRL_REST            BIT(5)
  71 #define JZ4780_I2C_CTRL_MATP            BIT(4)
  72 #define JZ4780_I2C_CTRL_SATP            BIT(3)
  73 #define JZ4780_I2C_CTRL_SPDF            BIT(2)
  74 #define JZ4780_I2C_CTRL_SPDS            BIT(1)
  75 #define JZ4780_I2C_CTRL_MD              BIT(0)
  76
  77 #define JZ4780_I2C_STA_SLVACT           BIT(6)
  78 #define JZ4780_I2C_STA_MSTACT           BIT(5)
  79 #define JZ4780_I2C_STA_RFF              BIT(4)
  80 #define JZ4780_I2C_STA_RFNE             BIT(3)
  81 #define JZ4780_I2C_STA_TFE              BIT(2)
  82 #define JZ4780_I2C_STA_TFNF             BIT(1)
  83 #define JZ4780_I2C_STA_ACT              BIT(0)
  84
  85 static const char * const jz4780_i2c_abrt_src[] = {
  86         "ABRT_7B_ADDR_NOACK",
  87         "ABRT_10ADDR1_NOACK",
  88         "ABRT_10ADDR2_NOACK",
  89         "ABRT_XDATA_NOACK",
  90         "ABRT_GCALL_NOACK",
  91         "ABRT_GCALL_READ",
  92         "ABRT_HS_ACKD",
  93         "SBYTE_ACKDET",
  94         "ABRT_HS_NORSTRT",
  95         "SBYTE_NORSTRT",
  96         "ABRT_10B_RD_NORSTRT",
  97         "ABRT_MASTER_DIS",
  98         "ARB_LOST",
  99         "SLVFLUSH_TXFIFO",
 100         "SLV_ARBLOST",
 101         "SLVRD_INTX",
 102 };
 103
 104 #define JZ4780_I2C_INTST_IGC            BIT(11)
 105 #define JZ4780_I2C_INTST_ISTT           BIT(10)
 106 #define JZ4780_I2C_INTST_ISTP           BIT(9)
 107 #define JZ4780_I2C_INTST_IACT           BIT(8)
 108 #define JZ4780_I2C_INTST_RXDN           BIT(7)
 109 #define JZ4780_I2C_INTST_TXABT          BIT(6)
 110 #define JZ4780_I2C_INTST_RDREQ          BIT(5)
 111 #define JZ4780_I2C_INTST_TXEMP          BIT(4)
 112 #define JZ4780_I2C_INTST_TXOF           BIT(3)
 113 #define JZ4780_I2C_INTST_RXFL           BIT(2)
 114 #define JZ4780_I2C_INTST_RXOF           BIT(1)
 115 #define JZ4780_I2C_INTST_RXUF           BIT(0)
 116
 117 #define JZ4780_I2C_INTM_MIGC            BIT(11)
 118 #define JZ4780_I2C_INTM_MISTT           BIT(10)
 119 #define JZ4780_I2C_INTM_MISTP           BIT(9)
 120 #define JZ4780_I2C_INTM_MIACT           BIT(8)
 121 #define JZ4780_I2C_INTM_MRXDN           BIT(7)
 122 #define JZ4780_I2C_INTM_MTXABT          BIT(6)
 123 #define JZ4780_I2C_INTM_MRDREQ          BIT(5)
 124 #define JZ4780_I2C_INTM_MTXEMP          BIT(4)
 125 #define JZ4780_I2C_INTM_MTXOF           BIT(3)
 126 #define JZ4780_I2C_INTM_MRXFL           BIT(2)
 127 #define JZ4780_I2C_INTM_MRXOF           BIT(1)
 128 #define JZ4780_I2C_INTM_MRXUF           BIT(0)
 129
 130 #define JZ4780_I2C_DC_READ              BIT(8)
 131
 132 #define JZ4780_I2C_SDAHD_HDENB          BIT(8)
 133
 134 #define JZ4780_I2C_ENB_I2C              BIT(0)
 135
 136 #define JZ4780_I2CSHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 137 #define JZ4780_I2CSLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 138 #define JZ4780_I2CFHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 139 #define JZ4780_I2CFLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 140
 141 #define JZ4780_I2C_FIFO_LEN     16
 142 #define TX_LEVEL                3
 143 #define RX_LEVEL                (JZ4780_I2C_FIFO_LEN - TX_LEVEL - 1)
 144
 145 #define JZ4780_I2C_TIMEOUT      300
 146
 147 #define BUFSIZE 200
 148
 149 struct jz4780_i2c {
 150         void __iomem            *iomem;
 151         int                      irq;
 152         struct clk              *clk;
 153         struct i2c_adapter       adap;
 154
 155         /* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
 156         spinlock_t              lock;
 157
 158         /* beginning of lock scope */
 159         unsigned char           *rbuf;
 160         int                     rd_total_len;
 161         int                     rd_data_xfered;
 162         int                     rd_cmd_xfered;
 163
 164         unsigned char           *wbuf;
 165         int                     wt_len;
 166
 167         int                     is_write;
 168         int                     stop_hold;
 169         int                     speed;
 170
 171         int                     data_buf[BUFSIZE];
 172         int                     cmd_buf[BUFSIZE];
 173         int                     cmd;
 174
 175         /* end of lock scope */
 176         struct completion       trans_waitq;
 177 };
 178
 179 static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
 180                                               unsigned long offset)
 181 {
 182         return readw(i2c->iomem + offset);
 183 }
 184
 185 static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
 186                                      unsigned long offset, unsigned short val)
 187 {
 188         writew(val, i2c->iomem + offset);
 189 }
 190
 191 static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
 192 {
 193         unsigned short regval;
 194         unsigned long loops = 5;
 195
 196         jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
 197
 198         do {
 199                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 200                 if (!(regval & JZ4780_I2C_ENB_I2C))
 201                         return 0;
 202
 203                 usleep_range(5000, 15000);
 204         } while (--loops);
 205
 206         dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
 207         return -ETIMEDOUT;
 208 }
 209
 210 static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
 211 {
 212         unsigned short regval;
 213         unsigned long loops = 5;
 214
 215         jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
 216
 217         do {
 218                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 219                 if (regval & JZ4780_I2C_ENB_I2C)
 220                         return 0;
 221
 222                 usleep_range(5000, 15000);
 223         } while (--loops);
 224
 225         dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
 226         return -ETIMEDOUT;
 227 }
 228
 229 static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
 230 {
 231         unsigned short regval;
 232         unsigned long loops = 5;
 233
 234         do {
 235                 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 236                 if ((regval & JZ4780_I2C_STA_TFE) &&
 237                     !(regval & JZ4780_I2C_STA_MSTACT))
 238                         break;
 239
 240                 usleep_range(5000, 15000);
 241         } while (--loops);
 242
 243         if (loops) {
 244                 jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
 245                 return 0;
 246         }
 247
 248         dev_err(&i2c->adap.dev,
 249                 "set device to address 0x%02x failed, STA=0x%04x\n",
 250                 address, regval);
 251
 252         return -ENXIO;
 253 }
 254
 255 static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
 256 {
 257         int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
 258         int cnt_high = 0;       /* HIGH period count of the SCL clock */
 259         int cnt_low = 0;        /* LOW period count of the SCL clock */
 260         int cnt_period = 0;     /* period count of the SCL clock */
 261         int setup_time = 0;
 262         int hold_time = 0;
 263         unsigned short tmp = 0;
 264         int i2c_clk = i2c->speed;
 265
 266         if (jz4780_i2c_disable(i2c))
 267                 dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
 268
 269         /*
 270          * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
 271          * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
 272          * fast mode, min LOW and HIGH period are 1300 ns and 600 ns
 273          */
 274         cnt_period = dev_clk_khz / i2c_clk;
 275
 276         if (i2c_clk <= 100)
 277                 cnt_high = (cnt_period * 4000) / (4700 + 4000);
 278         else
 279                 cnt_high = (cnt_period * 600) / (1300 + 600);
 280
 281         cnt_low = cnt_period - cnt_high;
 282
 283         /*
 284          * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
 285          * normal read are 2 messages, we cannot disable i2c controller
 286          * between these two messages, this means that we must always set
 287          * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
 288          *
 289          */
 290         if (i2c_clk <= 100) {
 291                 tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
 292                       | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
 293                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 294
 295                 jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
 296                                   JZ4780_I2CSHCNT_ADJUST(cnt_high));
 297                 jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
 298                                   JZ4780_I2CSLCNT_ADJUST(cnt_low));
 299         } else {
 300                 tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST
 301                       | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
 302                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 303
 304                 jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,
 305                                   JZ4780_I2CFHCNT_ADJUST(cnt_high));
 306                 jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
 307                                   JZ4780_I2CFLCNT_ADJUST(cnt_low));
 308         }
 309
 310         /*
 311          * a i2c device must internally provide a hold time at least 300ns
 312          * tHD:DAT
 313          *      Standard Mode: min=300ns, max=3450ns
 314          *      Fast Mode: min=0ns, max=900ns
 315          * tSU:DAT
 316          *      Standard Mode: min=250ns, max=infinite
 317          *      Fast Mode: min=100(250ns is recommended), max=infinite
 318          *
 319          * 1i2c_clk = 10^6 / dev_clk_khz
 320          * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
 321          * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
 322          *
 323          * The actual hold time is (SDAHD + 1) * (i2c_clk period).
 324          *
 325          * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
 326          *
 327          */
 328         if (i2c_clk <= 100) { /* standard mode */
 329                 setup_time = 300;
 330                 hold_time = 400;
 331         } else {
 332                 setup_time = 450;
 333                 hold_time = 450;
 334         }
 335
 336         hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
 337         setup_time = ((setup_time * dev_clk_khz) / 1000000)  + 1;
 338
 339         if (setup_time > 255)
 340                 setup_time = 255;
 341
 342         if (setup_time <= 0)
 343                 setup_time = 1;
 344
 345         jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
 346
 347         if (hold_time > 255)
 348                 hold_time = 255;
 349
 350         if (hold_time >= 0) {
 351                 /*i2c hold time enable */
 352                 hold_time |= JZ4780_I2C_SDAHD_HDENB;
 353                 jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
 354         } else {
 355                 /* disable hold time */
 356                 jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
 363 {
 364         int ret;
 365         unsigned long flags;
 366         unsigned short tmp;
 367
 368         spin_lock_irqsave(&i2c->lock, flags);
 369
 370         /* can send stop now if need */
 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         /* disable all interrupts first */
 376         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 377
 378         /* then clear all interrupts */
 379         jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
 380         jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
 381
 382         /* then disable the controller */
 383         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 384         tmp &= ~JZ4780_I2C_ENB_I2C;
 385         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 386         udelay(10);
 387         tmp |= JZ4780_I2C_ENB_I2C;
 388         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 389
 390         spin_unlock_irqrestore(&i2c->lock, flags);
 391
 392         ret = jz4780_i2c_disable(i2c);
 393         if (ret)
 394                 dev_err(&i2c->adap.dev,
 395                         "unable to disable device during cleanup!\n");
 396
 397         if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
 398                      & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
 399                 dev_err(&i2c->adap.dev,
 400                         "device has interrupts after a complete cleanup!\n");
 401
 402         return ret;
 403 }
 404
 405 static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
 406 {
 407         jz4780_i2c_set_speed(i2c);
 408         return jz4780_i2c_enable(i2c);
 409 }
 410
 411 static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c, int cmd_count)
 412 {
 413         int i;
 414
 415         for (i = 0; i < cmd_count; i++)
 416                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
 417 }
 418
 419 static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
 420 {
 421         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 422         complete(&i2c->trans_waitq);
 423 }
 424
 425 static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
 426 {
 427         unsigned short tmp;
 428         unsigned short intst;
 429         unsigned short intmsk;
 430         struct jz4780_i2c *i2c = dev_id;
 431         unsigned long flags;
 432
 433         spin_lock_irqsave(&i2c->lock, flags);
 434         intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 435         intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
 436
 437         intst &= intmsk;
 438
 439         if (intst & JZ4780_I2C_INTST_TXABT) {
 440                 jz4780_i2c_trans_done(i2c);
 441                 goto done;
 442         }
 443
 444         if (intst & JZ4780_I2C_INTST_RXOF) {
 445                 dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
 446                 jz4780_i2c_trans_done(i2c);
 447                 goto done;
 448         }
 449
 450         /*
 451          * When reading, always drain RX FIFO before we send more Read
 452          * Commands to avoid fifo overrun
 453          */
 454         if (i2c->is_write == 0) {
 455                 int rd_left;
 456
 457                 while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
 458                                   & JZ4780_I2C_STA_RFNE)) {
 459                         *(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
 460                                          & 0xff;
 461                         i2c->rd_data_xfered++;
 462                         if (i2c->rd_data_xfered == i2c->rd_total_len) {
 463                                 jz4780_i2c_trans_done(i2c);
 464                                 goto done;
 465                         }
 466                 }
 467
 468                 rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
 469
 470                 if (rd_left <= JZ4780_I2C_FIFO_LEN)
 471                         jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
 472         }
 473
 474         if (intst & JZ4780_I2C_INTST_TXEMP) {
 475                 if (i2c->is_write == 0) {
 476                         int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
 477                         int max_send = (JZ4780_I2C_FIFO_LEN - 1)
 478                                          - (i2c->rd_cmd_xfered
 479                                          - i2c->rd_data_xfered);
 480                         int cmd_to_send = min(cmd_left, max_send);
 481
 482                         if (i2c->rd_cmd_xfered != 0)
 483                                 cmd_to_send = min(cmd_to_send,
 484                                                   JZ4780_I2C_FIFO_LEN
 485                                                   - TX_LEVEL - 1);
 486
 487                         if (cmd_to_send) {
 488                                 jz4780_i2c_send_rcmd(i2c, cmd_to_send);
 489                                 i2c->rd_cmd_xfered += cmd_to_send;
 490                         }
 491
 492                         cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
 493                         if (cmd_left == 0) {
 494                                 intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 495                                 intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
 496                                 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
 497
 498                                 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 499                                 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 500                                 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 501                         }
 502                 } else {
 503                         unsigned short data;
 504                         unsigned short i2c_sta;
 505
 506                         i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 507
 508                         while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
 509                                (i2c->wt_len > 0)) {
 510                                 i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 511                                 data = *i2c->wbuf;
 512                                 data &= ~JZ4780_I2C_DC_READ;
 513                                 jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
 514                                                   data);
 515                                 i2c->wbuf++;
 516                                 i2c->wt_len--;
 517                         }
 518
 519                         if (i2c->wt_len == 0) {
 520                                 if (!i2c->stop_hold) {
 521                                         tmp = jz4780_i2c_readw(i2c,
 522                                                                JZ4780_I2C_CTRL);
 523                                         tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 524                                         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL,
 525                                                           tmp);
 526                                 }
 527
 528                                 jz4780_i2c_trans_done(i2c);
 529                                 goto done;
 530                         }
 531                 }
 532         }
 533
 534 done:
 535         spin_unlock_irqrestore(&i2c->lock, flags);
 536         return IRQ_HANDLED;
 537 }
 538
 539 static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
 540 {
 541         int i;
 542
 543         dev_err(&i2c->adap.dev, "txabrt: 0x%08x\n", src);
 544         dev_err(&i2c->adap.dev, "device addr=%x\n",
 545                 jz4780_i2c_readw(i2c, JZ4780_I2C_TAR));
 546         dev_err(&i2c->adap.dev, "send cmd count:%d  %d\n",
 547                 i2c->cmd, i2c->cmd_buf[i2c->cmd]);
 548         dev_err(&i2c->adap.dev, "receive data count:%d  %d\n",
 549                 i2c->cmd, i2c->data_buf[i2c->cmd]);
 550
 551         for (i = 0; i < 16; i++) {
 552                 if (src & BIT(i))
 553                         dev_dbg(&i2c->adap.dev, "I2C TXABRT[%d]=%s\n",
 554                                 i, jz4780_i2c_abrt_src[i]);
 555         }
 556 }
 557
 558 static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
 559                                        unsigned char *buf, int len, int cnt,
 560                                        int idx)
 561 {
 562         int ret = 0;
 563         long timeout;
 564         int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 565         unsigned short tmp;
 566         unsigned long flags;
 567
 568         memset(buf, 0, len);
 569
 570         spin_lock_irqsave(&i2c->lock, flags);
 571
 572         i2c->stop_hold = 0;
 573         i2c->is_write = 0;
 574         i2c->rbuf = buf;
 575         i2c->rd_total_len = len;
 576         i2c->rd_data_xfered = 0;
 577         i2c->rd_cmd_xfered = 0;
 578
 579         if (len <= JZ4780_I2C_FIFO_LEN)
 580                 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
 581         else
 582                 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, RX_LEVEL);
 583
 584         jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
 585
 586         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
 587                           JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
 588                           | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
 589
 590         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 591         tmp |= JZ4780_I2C_CTRL_STPHLD;
 592         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 593
 594         spin_unlock_irqrestore(&i2c->lock, flags);
 595
 596         timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 597                                               msecs_to_jiffies(wait_time));
 598
 599         if (!timeout) {
 600                 dev_err(&i2c->adap.dev, "irq read timeout\n");
 601                 dev_dbg(&i2c->adap.dev, "send cmd count:%d  %d\n",
 602                         i2c->cmd, i2c->cmd_buf[i2c->cmd]);
 603                 dev_dbg(&i2c->adap.dev, "receive data count:%d  %d\n",
 604                         i2c->cmd, i2c->data_buf[i2c->cmd]);
 605                 ret = -EIO;
 606         }
 607
 608         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 609         if (tmp) {
 610                 jz4780_i2c_txabrt(i2c, tmp);
 611                 ret = -EIO;
 612         }
 613
 614         return ret;
 615 }
 616
 617 static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
 618                                         unsigned char *buf, int len,
 619                                         int cnt, int idx)
 620 {
 621         int ret = 0;
 622         int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 623         long timeout;
 624         unsigned short tmp;
 625         unsigned long flags;
 626
 627         spin_lock_irqsave(&i2c->lock, flags);
 628
 629         if (idx < (cnt - 1))
 630                 i2c->stop_hold = 1;
 631         else
 632                 i2c->stop_hold = 0;
 633
 634         i2c->is_write = 1;
 635         i2c->wbuf = buf;
 636         i2c->wt_len = len;
 637
 638         jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
 639
 640         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
 641                                         | JZ4780_I2C_INTM_MTXABT);
 642
 643         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 644         tmp |= JZ4780_I2C_CTRL_STPHLD;
 645         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 646
 647         spin_unlock_irqrestore(&i2c->lock, flags);
 648
 649         timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 650                                               msecs_to_jiffies(wait_time));
 651         if (timeout && !i2c->stop_hold) {
 652                 unsigned short i2c_sta;
 653                 int write_in_process;
 654
 655                 timeout = JZ4780_I2C_TIMEOUT * 100;
 656                 for (; timeout > 0; timeout--) {
 657                         i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 658
 659                         write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
 660                                 !(i2c_sta & JZ4780_I2C_STA_TFE);
 661                         if (!write_in_process)
 662                                 break;
 663                         udelay(10);
 664                 }
 665         }
 666
 667         if (!timeout) {
 668                 dev_err(&i2c->adap.dev, "write wait timeout\n");
 669                 ret = -EIO;
 670         }
 671
 672         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 673         if (tmp) {
 674                 jz4780_i2c_txabrt(i2c, tmp);
 675                 ret = -EIO;
 676         }
 677
 678         return ret;
 679 }
 680
 681 static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
 682                            int count)
 683 {
 684         int i = -EIO;
 685         int ret = 0;
 686         struct jz4780_i2c *i2c = adap->algo_data;
 687
 688         ret = jz4780_i2c_prepare(i2c);
 689         if (ret) {
 690                 dev_err(&i2c->adap.dev, "I2C prepare failed\n");
 691                 goto out;
 692         }
 693
 694         if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
 695                 ret = jz4780_i2c_set_target(i2c, msg->addr);
 696                 if (ret)
 697                         goto out;
 698         }
 699         for (i = 0; i < count; i++, msg++) {
 700                 if (msg->flags & I2C_M_RD)
 701                         ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
 702                                                    count, i);
 703                 else
 704                         ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
 705                                                     count, i);
 706
 707                 if (ret)
 708                         goto out;
 709         }
 710
 711         ret = i;
 712
 713 out:
 714         jz4780_i2c_cleanup(i2c);
 715         return ret;
 716 }
 717
 718 static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
 719 {
 720         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 721 }
 722
 723 static const struct i2c_algorithm jz4780_i2c_algorithm = {
 724         .master_xfer    = jz4780_i2c_xfer,
 725         .functionality  = jz4780_i2c_functionality,
 726 };
 727
 728 static const struct of_device_id jz4780_i2c_of_matches[] = {
 729         { .compatible = "ingenic,jz4780-i2c", },
 730         { /* sentinel */ }
 731 };
 732
 733 static int jz4780_i2c_probe(struct platform_device *pdev)
 734 {
 735         int ret = 0;
 736         unsigned int clk_freq = 0;
 737         unsigned short tmp;
 738         struct resource *r;
 739         struct jz4780_i2c *i2c;
 740
 741         i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
 742         if (!i2c)
 743                 return -ENOMEM;
 744
 745         i2c->adap.owner         = THIS_MODULE;
 746         i2c->adap.algo          = &jz4780_i2c_algorithm;
 747         i2c->adap.algo_data     = i2c;
 748         i2c->adap.retries       = 5;
 749         i2c->adap.dev.parent    = &pdev->dev;
 750         i2c->adap.dev.of_node   = pdev->dev.of_node;
 751         sprintf(i2c->adap.name, "%s", pdev->name);
 752
 753         init_completion(&i2c->trans_waitq);
 754         spin_lock_init(&i2c->lock);
 755
 756         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 757         i2c->iomem = devm_ioremap_resource(&pdev->dev, r);
 758         if (IS_ERR(i2c->iomem))
 759                 return PTR_ERR(i2c->iomem);
 760
 761         platform_set_drvdata(pdev, i2c);
 762
 763         i2c->clk = devm_clk_get(&pdev->dev, NULL);
 764         if (IS_ERR(i2c->clk))
 765                 return PTR_ERR(i2c->clk);
 766
 767         clk_prepare_enable(i2c->clk);
 768
 769         if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 770                                  &clk_freq)) {
 771                 dev_err(&pdev->dev, "clock-frequency not specified in DT");
 772                 return clk_freq;
 773         }
 774
 775         i2c->speed = clk_freq / 1000;
 776         jz4780_i2c_set_speed(i2c);
 777
 778         dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
 779
 780         tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 781         tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 782         jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 783
 784         jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
 785
 786         i2c->cmd = 0;
 787         memset(i2c->cmd_buf, 0, BUFSIZE);
 788         memset(i2c->data_buf, 0, BUFSIZE);
 789
 790         i2c->irq = platform_get_irq(pdev, 0);
 791         ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
 792                                dev_name(&pdev->dev), i2c);
 793         if (ret) {
 794                 ret = -ENODEV;
 795                 goto err;
 796         }
 797
 798         ret = i2c_add_adapter(&i2c->adap);
 799         if (ret < 0) {
 800                 dev_err(&pdev->dev, "Failed to add bus\n");
 801                 goto err;
 802         }
 803
 804         return 0;
 805
 806 err:
 807         clk_disable_unprepare(i2c->clk);
 808         return ret;
 809 }
 810
 811 static int jz4780_i2c_remove(struct platform_device *pdev)
 812 {
 813         struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
 814
 815         clk_disable_unprepare(i2c->clk);
 816         i2c_del_adapter(&i2c->adap);
 817         return 0;
 818 }
 819
 820 static struct platform_driver jz4780_i2c_driver = {
 821         .probe          = jz4780_i2c_probe,
 822         .remove         = jz4780_i2c_remove,
 823         .driver         = {
 824                 .name   = "jz4780-i2c",
 825                 .of_match_table = of_match_ptr(jz4780_i2c_of_matches),
 826         },
 827 };
 828
 829 module_platform_driver(jz4780_i2c_driver);
 830
 831 MODULE_LICENSE("GPL");
 832 MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>");
 833 MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");