linux/drivers/i2c/busses/i2c-jz4780.c
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   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 */
   8
   9#include <linux/bitops.h>
  10#include <linux/clk.h>
  11#include <linux/completion.h>
  12#include <linux/delay.h>
  13#include <linux/errno.h>
  14#include <linux/i2c.h>
  15#include <linux/init.h>
  16#include <linux/interrupt.h>
  17#include <linux/io.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/platform_device.h>
  21#include <linux/sched.h>
  22#include <linux/slab.h>
  23#include <linux/time.h>
  24
  25#define JZ4780_I2C_CTRL         0x00
  26#define JZ4780_I2C_TAR          0x04
  27#define JZ4780_I2C_SAR          0x08
  28#define JZ4780_I2C_DC           0x10
  29#define JZ4780_I2C_SHCNT        0x14
  30#define JZ4780_I2C_SLCNT        0x18
  31#define JZ4780_I2C_FHCNT        0x1C
  32#define JZ4780_I2C_FLCNT        0x20
  33#define JZ4780_I2C_INTST        0x2C
  34#define JZ4780_I2C_INTM         0x30
  35#define JZ4780_I2C_RXTL         0x38
  36#define JZ4780_I2C_TXTL         0x3C
  37#define JZ4780_I2C_CINTR        0x40
  38#define JZ4780_I2C_CRXUF        0x44
  39#define JZ4780_I2C_CRXOF        0x48
  40#define JZ4780_I2C_CTXOF        0x4C
  41#define JZ4780_I2C_CRXREQ       0x50
  42#define JZ4780_I2C_CTXABRT      0x54
  43#define JZ4780_I2C_CRXDONE      0x58
  44#define JZ4780_I2C_CACT         0x5C
  45#define JZ4780_I2C_CSTP         0x60
  46#define JZ4780_I2C_CSTT         0x64
  47#define JZ4780_I2C_CGC          0x68
  48#define JZ4780_I2C_ENB          0x6C
  49#define JZ4780_I2C_STA          0x70
  50#define JZ4780_I2C_TXABRT       0x80
  51#define JZ4780_I2C_DMACR        0x88
  52#define JZ4780_I2C_DMATDLR      0x8C
  53#define JZ4780_I2C_DMARDLR      0x90
  54#define JZ4780_I2C_SDASU        0x94
  55#define JZ4780_I2C_ACKGC        0x98
  56#define JZ4780_I2C_ENSTA        0x9C
  57#define JZ4780_I2C_SDAHD        0xD0
  58
  59#define JZ4780_I2C_CTRL_STPHLD          BIT(7)
  60#define JZ4780_I2C_CTRL_SLVDIS          BIT(6)
  61#define JZ4780_I2C_CTRL_REST            BIT(5)
  62#define JZ4780_I2C_CTRL_MATP            BIT(4)
  63#define JZ4780_I2C_CTRL_SATP            BIT(3)
  64#define JZ4780_I2C_CTRL_SPDF            BIT(2)
  65#define JZ4780_I2C_CTRL_SPDS            BIT(1)
  66#define JZ4780_I2C_CTRL_MD              BIT(0)
  67
  68#define JZ4780_I2C_STA_SLVACT           BIT(6)
  69#define JZ4780_I2C_STA_MSTACT           BIT(5)
  70#define JZ4780_I2C_STA_RFF              BIT(4)
  71#define JZ4780_I2C_STA_RFNE             BIT(3)
  72#define JZ4780_I2C_STA_TFE              BIT(2)
  73#define JZ4780_I2C_STA_TFNF             BIT(1)
  74#define JZ4780_I2C_STA_ACT              BIT(0)
  75
  76static const char * const jz4780_i2c_abrt_src[] = {
  77        "ABRT_7B_ADDR_NOACK",
  78        "ABRT_10ADDR1_NOACK",
  79        "ABRT_10ADDR2_NOACK",
  80        "ABRT_XDATA_NOACK",
  81        "ABRT_GCALL_NOACK",
  82        "ABRT_GCALL_READ",
  83        "ABRT_HS_ACKD",
  84        "SBYTE_ACKDET",
  85        "ABRT_HS_NORSTRT",
  86        "SBYTE_NORSTRT",
  87        "ABRT_10B_RD_NORSTRT",
  88        "ABRT_MASTER_DIS",
  89        "ARB_LOST",
  90        "SLVFLUSH_TXFIFO",
  91        "SLV_ARBLOST",
  92        "SLVRD_INTX",
  93};
  94
  95#define JZ4780_I2C_INTST_IGC            BIT(11)
  96#define JZ4780_I2C_INTST_ISTT           BIT(10)
  97#define JZ4780_I2C_INTST_ISTP           BIT(9)
  98#define JZ4780_I2C_INTST_IACT           BIT(8)
  99#define JZ4780_I2C_INTST_RXDN           BIT(7)
 100#define JZ4780_I2C_INTST_TXABT          BIT(6)
 101#define JZ4780_I2C_INTST_RDREQ          BIT(5)
 102#define JZ4780_I2C_INTST_TXEMP          BIT(4)
 103#define JZ4780_I2C_INTST_TXOF           BIT(3)
 104#define JZ4780_I2C_INTST_RXFL           BIT(2)
 105#define JZ4780_I2C_INTST_RXOF           BIT(1)
 106#define JZ4780_I2C_INTST_RXUF           BIT(0)
 107
 108#define JZ4780_I2C_INTM_MIGC            BIT(11)
 109#define JZ4780_I2C_INTM_MISTT           BIT(10)
 110#define JZ4780_I2C_INTM_MISTP           BIT(9)
 111#define JZ4780_I2C_INTM_MIACT           BIT(8)
 112#define JZ4780_I2C_INTM_MRXDN           BIT(7)
 113#define JZ4780_I2C_INTM_MTXABT          BIT(6)
 114#define JZ4780_I2C_INTM_MRDREQ          BIT(5)
 115#define JZ4780_I2C_INTM_MTXEMP          BIT(4)
 116#define JZ4780_I2C_INTM_MTXOF           BIT(3)
 117#define JZ4780_I2C_INTM_MRXFL           BIT(2)
 118#define JZ4780_I2C_INTM_MRXOF           BIT(1)
 119#define JZ4780_I2C_INTM_MRXUF           BIT(0)
 120
 121#define JZ4780_I2C_DC_READ              BIT(8)
 122
 123#define JZ4780_I2C_SDAHD_HDENB          BIT(8)
 124
 125#define JZ4780_I2C_ENB_I2C              BIT(0)
 126
 127#define JZ4780_I2CSHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 128#define JZ4780_I2CSLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 129#define JZ4780_I2CFHCNT_ADJUST(n)       (((n) - 8) < 6 ? 6 : ((n) - 8))
 130#define JZ4780_I2CFLCNT_ADJUST(n)       (((n) - 1) < 8 ? 8 : ((n) - 1))
 131
 132#define JZ4780_I2C_FIFO_LEN     16
 133#define TX_LEVEL                3
 134#define RX_LEVEL                (JZ4780_I2C_FIFO_LEN - TX_LEVEL - 1)
 135
 136#define JZ4780_I2C_TIMEOUT      300
 137
 138#define BUFSIZE 200
 139
 140struct jz4780_i2c {
 141        void __iomem            *iomem;
 142        int                      irq;
 143        struct clk              *clk;
 144        struct i2c_adapter       adap;
 145
 146        /* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
 147        spinlock_t              lock;
 148
 149        /* beginning of lock scope */
 150        unsigned char           *rbuf;
 151        int                     rd_total_len;
 152        int                     rd_data_xfered;
 153        int                     rd_cmd_xfered;
 154
 155        unsigned char           *wbuf;
 156        int                     wt_len;
 157
 158        int                     is_write;
 159        int                     stop_hold;
 160        int                     speed;
 161
 162        int                     data_buf[BUFSIZE];
 163        int                     cmd_buf[BUFSIZE];
 164        int                     cmd;
 165
 166        /* end of lock scope */
 167        struct completion       trans_waitq;
 168};
 169
 170static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
 171                                              unsigned long offset)
 172{
 173        return readw(i2c->iomem + offset);
 174}
 175
 176static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
 177                                     unsigned long offset, unsigned short val)
 178{
 179        writew(val, i2c->iomem + offset);
 180}
 181
 182static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
 183{
 184        unsigned short regval;
 185        unsigned long loops = 5;
 186
 187        jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
 188
 189        do {
 190                regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 191                if (!(regval & JZ4780_I2C_ENB_I2C))
 192                        return 0;
 193
 194                usleep_range(5000, 15000);
 195        } while (--loops);
 196
 197        dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
 198        return -ETIMEDOUT;
 199}
 200
 201static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
 202{
 203        unsigned short regval;
 204        unsigned long loops = 5;
 205
 206        jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
 207
 208        do {
 209                regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
 210                if (regval & JZ4780_I2C_ENB_I2C)
 211                        return 0;
 212
 213                usleep_range(5000, 15000);
 214        } while (--loops);
 215
 216        dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
 217        return -ETIMEDOUT;
 218}
 219
 220static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
 221{
 222        unsigned short regval;
 223        unsigned long loops = 5;
 224
 225        do {
 226                regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 227                if ((regval & JZ4780_I2C_STA_TFE) &&
 228                    !(regval & JZ4780_I2C_STA_MSTACT))
 229                        break;
 230
 231                usleep_range(5000, 15000);
 232        } while (--loops);
 233
 234        if (loops) {
 235                jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
 236                return 0;
 237        }
 238
 239        dev_err(&i2c->adap.dev,
 240                "set device to address 0x%02x failed, STA=0x%04x\n",
 241                address, regval);
 242
 243        return -ENXIO;
 244}
 245
 246static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
 247{
 248        int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
 249        int cnt_high = 0;       /* HIGH period count of the SCL clock */
 250        int cnt_low = 0;        /* LOW period count of the SCL clock */
 251        int cnt_period = 0;     /* period count of the SCL clock */
 252        int setup_time = 0;
 253        int hold_time = 0;
 254        unsigned short tmp = 0;
 255        int i2c_clk = i2c->speed;
 256
 257        if (jz4780_i2c_disable(i2c))
 258                dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
 259
 260        /*
 261         * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
 262         * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
 263         * fast mode, min LOW and HIGH period are 1300 ns and 600 ns
 264         */
 265        cnt_period = dev_clk_khz / i2c_clk;
 266
 267        if (i2c_clk <= 100)
 268                cnt_high = (cnt_period * 4000) / (4700 + 4000);
 269        else
 270                cnt_high = (cnt_period * 600) / (1300 + 600);
 271
 272        cnt_low = cnt_period - cnt_high;
 273
 274        /*
 275         * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
 276         * normal read are 2 messages, we cannot disable i2c controller
 277         * between these two messages, this means that we must always set
 278         * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
 279         *
 280         */
 281        if (i2c_clk <= 100) {
 282                tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
 283                      | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
 284                jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 285
 286                jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
 287                                  JZ4780_I2CSHCNT_ADJUST(cnt_high));
 288                jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
 289                                  JZ4780_I2CSLCNT_ADJUST(cnt_low));
 290        } else {
 291                tmp = JZ4780_I2C_CTRL_SPDF | 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_FHCNT,
 296                                  JZ4780_I2CFHCNT_ADJUST(cnt_high));
 297                jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
 298                                  JZ4780_I2CFLCNT_ADJUST(cnt_low));
 299        }
 300
 301        /*
 302         * a i2c device must internally provide a hold time at least 300ns
 303         * tHD:DAT
 304         *      Standard Mode: min=300ns, max=3450ns
 305         *      Fast Mode: min=0ns, max=900ns
 306         * tSU:DAT
 307         *      Standard Mode: min=250ns, max=infinite
 308         *      Fast Mode: min=100(250ns is recommended), max=infinite
 309         *
 310         * 1i2c_clk = 10^6 / dev_clk_khz
 311         * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
 312         * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
 313         *
 314         * The actual hold time is (SDAHD + 1) * (i2c_clk period).
 315         *
 316         * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
 317         *
 318         */
 319        if (i2c_clk <= 100) { /* standard mode */
 320                setup_time = 300;
 321                hold_time = 400;
 322        } else {
 323                setup_time = 450;
 324                hold_time = 450;
 325        }
 326
 327        hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
 328        setup_time = ((setup_time * dev_clk_khz) / 1000000)  + 1;
 329
 330        if (setup_time > 255)
 331                setup_time = 255;
 332
 333        if (setup_time <= 0)
 334                setup_time = 1;
 335
 336        jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
 337
 338        if (hold_time > 255)
 339                hold_time = 255;
 340
 341        if (hold_time >= 0) {
 342                /*i2c hold time enable */
 343                hold_time |= JZ4780_I2C_SDAHD_HDENB;
 344                jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
 345        } else {
 346                /* disable hold time */
 347                jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
 348        }
 349
 350        return 0;
 351}
 352
 353static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
 354{
 355        int ret;
 356        unsigned long flags;
 357        unsigned short tmp;
 358
 359        spin_lock_irqsave(&i2c->lock, flags);
 360
 361        /* can send stop now if need */
 362        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 363        tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 364        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 365
 366        /* disable all interrupts first */
 367        jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 368
 369        /* then clear all interrupts */
 370        jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
 371        jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
 372
 373        /* then disable the controller */
 374        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 375        tmp &= ~JZ4780_I2C_ENB_I2C;
 376        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 377        udelay(10);
 378        tmp |= JZ4780_I2C_ENB_I2C;
 379        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 380
 381        spin_unlock_irqrestore(&i2c->lock, flags);
 382
 383        ret = jz4780_i2c_disable(i2c);
 384        if (ret)
 385                dev_err(&i2c->adap.dev,
 386                        "unable to disable device during cleanup!\n");
 387
 388        if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
 389                     & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
 390                dev_err(&i2c->adap.dev,
 391                        "device has interrupts after a complete cleanup!\n");
 392
 393        return ret;
 394}
 395
 396static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
 397{
 398        jz4780_i2c_set_speed(i2c);
 399        return jz4780_i2c_enable(i2c);
 400}
 401
 402static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c, int cmd_count)
 403{
 404        int i;
 405
 406        for (i = 0; i < cmd_count; i++)
 407                jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
 408}
 409
 410static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
 411{
 412        jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
 413        complete(&i2c->trans_waitq);
 414}
 415
 416static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
 417{
 418        unsigned short tmp;
 419        unsigned short intst;
 420        unsigned short intmsk;
 421        struct jz4780_i2c *i2c = dev_id;
 422        unsigned long flags;
 423
 424        spin_lock_irqsave(&i2c->lock, flags);
 425        intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 426        intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
 427
 428        intst &= intmsk;
 429
 430        if (intst & JZ4780_I2C_INTST_TXABT) {
 431                jz4780_i2c_trans_done(i2c);
 432                goto done;
 433        }
 434
 435        if (intst & JZ4780_I2C_INTST_RXOF) {
 436                dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
 437                jz4780_i2c_trans_done(i2c);
 438                goto done;
 439        }
 440
 441        /*
 442         * When reading, always drain RX FIFO before we send more Read
 443         * Commands to avoid fifo overrun
 444         */
 445        if (i2c->is_write == 0) {
 446                int rd_left;
 447
 448                while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
 449                                  & JZ4780_I2C_STA_RFNE)) {
 450                        *(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
 451                                         & 0xff;
 452                        i2c->rd_data_xfered++;
 453                        if (i2c->rd_data_xfered == i2c->rd_total_len) {
 454                                jz4780_i2c_trans_done(i2c);
 455                                goto done;
 456                        }
 457                }
 458
 459                rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
 460
 461                if (rd_left <= JZ4780_I2C_FIFO_LEN)
 462                        jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
 463        }
 464
 465        if (intst & JZ4780_I2C_INTST_TXEMP) {
 466                if (i2c->is_write == 0) {
 467                        int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
 468                        int max_send = (JZ4780_I2C_FIFO_LEN - 1)
 469                                         - (i2c->rd_cmd_xfered
 470                                         - i2c->rd_data_xfered);
 471                        int cmd_to_send = min(cmd_left, max_send);
 472
 473                        if (i2c->rd_cmd_xfered != 0)
 474                                cmd_to_send = min(cmd_to_send,
 475                                                  JZ4780_I2C_FIFO_LEN
 476                                                  - TX_LEVEL - 1);
 477
 478                        if (cmd_to_send) {
 479                                jz4780_i2c_send_rcmd(i2c, cmd_to_send);
 480                                i2c->rd_cmd_xfered += cmd_to_send;
 481                        }
 482
 483                        cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
 484                        if (cmd_left == 0) {
 485                                intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
 486                                intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
 487                                jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
 488
 489                                tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 490                                tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 491                                jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 492                        }
 493                } else {
 494                        unsigned short data;
 495                        unsigned short i2c_sta;
 496
 497                        i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 498
 499                        while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
 500                               (i2c->wt_len > 0)) {
 501                                i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 502                                data = *i2c->wbuf;
 503                                data &= ~JZ4780_I2C_DC_READ;
 504                                jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
 505                                                  data);
 506                                i2c->wbuf++;
 507                                i2c->wt_len--;
 508                        }
 509
 510                        if (i2c->wt_len == 0) {
 511                                if (!i2c->stop_hold) {
 512                                        tmp = jz4780_i2c_readw(i2c,
 513                                                               JZ4780_I2C_CTRL);
 514                                        tmp &= ~JZ4780_I2C_CTRL_STPHLD;
 515                                        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL,
 516                                                          tmp);
 517                                }
 518
 519                                jz4780_i2c_trans_done(i2c);
 520                                goto done;
 521                        }
 522                }
 523        }
 524
 525done:
 526        spin_unlock_irqrestore(&i2c->lock, flags);
 527        return IRQ_HANDLED;
 528}
 529
 530static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
 531{
 532        int i;
 533
 534        dev_err(&i2c->adap.dev, "txabrt: 0x%08x\n", src);
 535        dev_err(&i2c->adap.dev, "device addr=%x\n",
 536                jz4780_i2c_readw(i2c, JZ4780_I2C_TAR));
 537        dev_err(&i2c->adap.dev, "send cmd count:%d  %d\n",
 538                i2c->cmd, i2c->cmd_buf[i2c->cmd]);
 539        dev_err(&i2c->adap.dev, "receive data count:%d  %d\n",
 540                i2c->cmd, i2c->data_buf[i2c->cmd]);
 541
 542        for (i = 0; i < 16; i++) {
 543                if (src & BIT(i))
 544                        dev_dbg(&i2c->adap.dev, "I2C TXABRT[%d]=%s\n",
 545                                i, jz4780_i2c_abrt_src[i]);
 546        }
 547}
 548
 549static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
 550                                       unsigned char *buf, int len, int cnt,
 551                                       int idx)
 552{
 553        int ret = 0;
 554        long timeout;
 555        int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 556        unsigned short tmp;
 557        unsigned long flags;
 558
 559        memset(buf, 0, len);
 560
 561        spin_lock_irqsave(&i2c->lock, flags);
 562
 563        i2c->stop_hold = 0;
 564        i2c->is_write = 0;
 565        i2c->rbuf = buf;
 566        i2c->rd_total_len = len;
 567        i2c->rd_data_xfered = 0;
 568        i2c->rd_cmd_xfered = 0;
 569
 570        if (len <= JZ4780_I2C_FIFO_LEN)
 571                jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
 572        else
 573                jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, RX_LEVEL);
 574
 575        jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
 576
 577        jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
 578                          JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
 579                          | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
 580
 581        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 582        tmp |= JZ4780_I2C_CTRL_STPHLD;
 583        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 584
 585        spin_unlock_irqrestore(&i2c->lock, flags);
 586
 587        timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 588                                              msecs_to_jiffies(wait_time));
 589
 590        if (!timeout) {
 591                dev_err(&i2c->adap.dev, "irq read timeout\n");
 592                dev_dbg(&i2c->adap.dev, "send cmd count:%d  %d\n",
 593                        i2c->cmd, i2c->cmd_buf[i2c->cmd]);
 594                dev_dbg(&i2c->adap.dev, "receive data count:%d  %d\n",
 595                        i2c->cmd, i2c->data_buf[i2c->cmd]);
 596                ret = -EIO;
 597        }
 598
 599        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 600        if (tmp) {
 601                jz4780_i2c_txabrt(i2c, tmp);
 602                ret = -EIO;
 603        }
 604
 605        return ret;
 606}
 607
 608static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
 609                                        unsigned char *buf, int len,
 610                                        int cnt, int idx)
 611{
 612        int ret = 0;
 613        int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
 614        long timeout;
 615        unsigned short tmp;
 616        unsigned long flags;
 617
 618        spin_lock_irqsave(&i2c->lock, flags);
 619
 620        if (idx < (cnt - 1))
 621                i2c->stop_hold = 1;
 622        else
 623                i2c->stop_hold = 0;
 624
 625        i2c->is_write = 1;
 626        i2c->wbuf = buf;
 627        i2c->wt_len = len;
 628
 629        jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
 630
 631        jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
 632                                        | JZ4780_I2C_INTM_MTXABT);
 633
 634        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
 635        tmp |= JZ4780_I2C_CTRL_STPHLD;
 636        jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
 637
 638        spin_unlock_irqrestore(&i2c->lock, flags);
 639
 640        timeout = wait_for_completion_timeout(&i2c->trans_waitq,
 641                                              msecs_to_jiffies(wait_time));
 642        if (timeout && !i2c->stop_hold) {
 643                unsigned short i2c_sta;
 644                int write_in_process;
 645
 646                timeout = JZ4780_I2C_TIMEOUT * 100;
 647                for (; timeout > 0; timeout--) {
 648                        i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 649
 650                        write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
 651                                !(i2c_sta & JZ4780_I2C_STA_TFE);
 652                        if (!write_in_process)
 653                                break;
 654                        udelay(10);
 655                }
 656        }
 657
 658        if (!timeout) {
 659                dev_err(&i2c->adap.dev, "write wait timeout\n");
 660                ret = -EIO;
 661        }
 662
 663        tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
 664        if (tmp) {
 665                jz4780_i2c_txabrt(i2c, tmp);
 666                ret = -EIO;
 667        }
 668
 669        return ret;
 670}
 671
 672static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
 673                           int count)
 674{
 675        int i = -EIO;
 676        int ret = 0;
 677        struct jz4780_i2c *i2c = adap->algo_data;
 678
 679        ret = jz4780_i2c_prepare(i2c);
 680        if (ret) {
 681                dev_err(&i2c->adap.dev, "I2C prepare failed\n");
 682                goto out;
 683        }
 684
 685        if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
 686                ret = jz4780_i2c_set_target(i2c, msg->addr);
 687                if (ret)
 688                        goto out;
 689        }
 690        for (i = 0; i < count; i++, msg++) {
 691                if (msg->flags & I2C_M_RD)
 692                        ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
 693                                                   count, i);
 694                else
 695                        ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
 696                                                    count, i);
 697
 698                if (ret)
 699                        goto out;
 700        }
 701
 702        ret = i;
 703
 704out:
 705        jz4780_i2c_cleanup(i2c);
 706        return ret;
 707}
 708
 709static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
 710{
 711        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 712}
 713
 714static const struct i2c_algorithm jz4780_i2c_algorithm = {
 715        .master_xfer    = jz4780_i2c_xfer,
 716        .functionality  = jz4780_i2c_functionality,
 717};
 718
 719static const struct of_device_id jz4780_i2c_of_matches[] = {
 720        { .compatible = "ingenic,jz4780-i2c", },
 721        { /* sentinel */ }
 722};
 723MODULE_DEVICE_TABLE(of, jz4780_i2c_of_matches);
 724
 725static int jz4780_i2c_probe(struct platform_device *pdev)
 726{
 727        int ret = 0;
 728        unsigned int clk_freq = 0;
 729        unsigned short tmp;
 730        struct resource *r;
 731        struct jz4780_i2c *i2c;
 732
 733        i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
 734        if (!i2c)
 735                return -ENOMEM;
 736
 737        i2c->adap.owner         = THIS_MODULE;
 738        i2c->adap.algo          = &jz4780_i2c_algorithm;
 739        i2c->adap.algo_data     = i2c;
 740        i2c->adap.retries       = 5;
 741        i2c->adap.dev.parent    = &pdev->dev;
 742        i2c->adap.dev.of_node   = pdev->dev.of_node;
 743        sprintf(i2c->adap.name, "%s", pdev->name);
 744
 745        init_completion(&i2c->trans_waitq);
 746        spin_lock_init(&i2c->lock);
 747
 748        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 749        i2c->iomem = devm_ioremap_resource(&pdev->dev, r);
 750        if (IS_ERR(i2c->iomem))
 751                return PTR_ERR(i2c->iomem);
 752
 753        platform_set_drvdata(pdev, i2c);
 754
 755        i2c->clk = devm_clk_get(&pdev->dev, NULL);
 756        if (IS_ERR(i2c->clk))
 757                return PTR_ERR(i2c->clk);
 758
 759        ret = clk_prepare_enable(i2c->clk);
 760        if (ret)
 761                return ret;
 762
 763        ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 764                                   &clk_freq);
 765        if (ret) {
 766                dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
 767                goto err;
 768        }
 769
 770        i2c->speed = clk_freq / 1000;
 771        if (i2c->speed == 0) {
 772                ret = -EINVAL;
 773                dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
 774                goto err;
 775        }
 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->irq = platform_get_irq(pdev, 0);
 787        ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
 788                               dev_name(&pdev->dev), i2c);
 789        if (ret)
 790                goto err;
 791
 792        ret = i2c_add_adapter(&i2c->adap);
 793        if (ret < 0)
 794                goto err;
 795
 796        return 0;
 797
 798err:
 799        clk_disable_unprepare(i2c->clk);
 800        return ret;
 801}
 802
 803static int jz4780_i2c_remove(struct platform_device *pdev)
 804{
 805        struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
 806
 807        clk_disable_unprepare(i2c->clk);
 808        i2c_del_adapter(&i2c->adap);
 809        return 0;
 810}
 811
 812static struct platform_driver jz4780_i2c_driver = {
 813        .probe          = jz4780_i2c_probe,
 814        .remove         = jz4780_i2c_remove,
 815        .driver         = {
 816                .name   = "jz4780-i2c",
 817                .of_match_table = of_match_ptr(jz4780_i2c_of_matches),
 818        },
 819};
 820
 821module_platform_driver(jz4780_i2c_driver);
 822
 823MODULE_LICENSE("GPL");
 824MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>");
 825MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");
 826