uboot/drivers/i2c/kona_i2c.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright 2013 Broadcom Corporation.
   4 *
   5 * NOTE: This driver should be converted to driver model before June 2017.
   6 * Please see doc/driver-model/i2c-howto.txt for instructions.
   7 */
   8
   9#include <common.h>
  10#include <asm/io.h>
  11#include <linux/errno.h>
  12#include <asm/arch/sysmap.h>
  13#include <asm/kona-common/clk.h>
  14#include <i2c.h>
  15
  16/* Hardware register offsets and field defintions */
  17#define CS_OFFSET                               0x00000020
  18#define CS_ACK_SHIFT                            3
  19#define CS_ACK_MASK                             0x00000008
  20#define CS_ACK_CMD_GEN_START                    0x00000000
  21#define CS_ACK_CMD_GEN_RESTART                  0x00000001
  22#define CS_CMD_SHIFT                            1
  23#define CS_CMD_CMD_NO_ACTION                    0x00000000
  24#define CS_CMD_CMD_START_RESTART                0x00000001
  25#define CS_CMD_CMD_STOP                         0x00000002
  26#define CS_EN_SHIFT                             0
  27#define CS_EN_CMD_ENABLE_BSC                    0x00000001
  28
  29#define TIM_OFFSET                              0x00000024
  30#define TIM_PRESCALE_SHIFT                      6
  31#define TIM_P_SHIFT                             3
  32#define TIM_NO_DIV_SHIFT                        2
  33#define TIM_DIV_SHIFT                           0
  34
  35#define DAT_OFFSET                              0x00000028
  36
  37#define TOUT_OFFSET                             0x0000002c
  38
  39#define TXFCR_OFFSET                            0x0000003c
  40#define TXFCR_FIFO_FLUSH_MASK                   0x00000080
  41#define TXFCR_FIFO_EN_MASK                      0x00000040
  42
  43#define IER_OFFSET                              0x00000044
  44#define IER_READ_COMPLETE_INT_MASK              0x00000010
  45#define IER_I2C_INT_EN_MASK                     0x00000008
  46#define IER_FIFO_INT_EN_MASK                    0x00000002
  47#define IER_NOACK_EN_MASK                       0x00000001
  48
  49#define ISR_OFFSET                              0x00000048
  50#define ISR_RESERVED_MASK                       0xffffff60
  51#define ISR_CMDBUSY_MASK                        0x00000080
  52#define ISR_READ_COMPLETE_MASK                  0x00000010
  53#define ISR_SES_DONE_MASK                       0x00000008
  54#define ISR_ERR_MASK                            0x00000004
  55#define ISR_TXFIFOEMPTY_MASK                    0x00000002
  56#define ISR_NOACK_MASK                          0x00000001
  57
  58#define CLKEN_OFFSET                            0x0000004c
  59#define CLKEN_AUTOSENSE_OFF_MASK                0x00000080
  60#define CLKEN_M_SHIFT                           4
  61#define CLKEN_N_SHIFT                           1
  62#define CLKEN_CLKEN_MASK                        0x00000001
  63
  64#define FIFO_STATUS_OFFSET                      0x00000054
  65#define FIFO_STATUS_RXFIFO_EMPTY_MASK           0x00000004
  66#define FIFO_STATUS_TXFIFO_EMPTY_MASK           0x00000010
  67
  68#define HSTIM_OFFSET                            0x00000058
  69#define HSTIM_HS_MODE_MASK                      0x00008000
  70#define HSTIM_HS_HOLD_SHIFT                     10
  71#define HSTIM_HS_HIGH_PHASE_SHIFT               5
  72#define HSTIM_HS_SETUP_SHIFT                    0
  73
  74#define PADCTL_OFFSET                           0x0000005c
  75#define PADCTL_PAD_OUT_EN_MASK                  0x00000004
  76
  77#define RXFCR_OFFSET                            0x00000068
  78#define RXFCR_NACK_EN_SHIFT                     7
  79#define RXFCR_READ_COUNT_SHIFT                  0
  80#define RXFIFORDOUT_OFFSET                      0x0000006c
  81
  82/* Locally used constants */
  83#define MAX_RX_FIFO_SIZE                64U     /* bytes */
  84#define MAX_TX_FIFO_SIZE                64U     /* bytes */
  85
  86#define I2C_TIMEOUT                     100000  /* usecs */
  87
  88#define WAIT_INT_CHK                    100     /* usecs */
  89#if I2C_TIMEOUT % WAIT_INT_CHK
  90#error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
  91#endif
  92
  93/* Operations that can be commanded to the controller */
  94enum bcm_kona_cmd_t {
  95        BCM_CMD_NOACTION = 0,
  96        BCM_CMD_START,
  97        BCM_CMD_RESTART,
  98        BCM_CMD_STOP,
  99};
 100
 101/* Internal divider settings for standard mode, fast mode and fast mode plus */
 102struct bus_speed_cfg {
 103        uint8_t time_m;         /* Number of cycles for setup time */
 104        uint8_t time_n;         /* Number of cycles for hold time */
 105        uint8_t prescale;       /* Prescale divider */
 106        uint8_t time_p;         /* Timing coefficient */
 107        uint8_t no_div;         /* Disable clock divider */
 108        uint8_t time_div;       /* Post-prescale divider */
 109};
 110
 111static const struct bus_speed_cfg std_cfg_table[] = {
 112        [IC_SPEED_MODE_STANDARD] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
 113        [IC_SPEED_MODE_FAST] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
 114        [IC_SPEED_MODE_FAST_PLUS] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
 115};
 116
 117struct bcm_kona_i2c_dev {
 118        void *base;
 119        uint speed;
 120        const struct bus_speed_cfg *std_cfg;
 121};
 122
 123/* Keep these two defines in sync */
 124#define DEF_SPD I2C_SPEED_STANDARD_RATE
 125#define DEF_SPD_ENUM IC_SPEED_MODE_STANDARD
 126
 127#define DEF_DEVICE(num) \
 128{(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
 129
 130static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
 131#ifdef CONFIG_SYS_I2C_BASE0
 132        DEF_DEVICE(0),
 133#endif
 134#ifdef CONFIG_SYS_I2C_BASE1
 135        DEF_DEVICE(1),
 136#endif
 137#ifdef CONFIG_SYS_I2C_BASE2
 138        DEF_DEVICE(2),
 139#endif
 140#ifdef CONFIG_SYS_I2C_BASE3
 141        DEF_DEVICE(3),
 142#endif
 143#ifdef CONFIG_SYS_I2C_BASE4
 144        DEF_DEVICE(4),
 145#endif
 146#ifdef CONFIG_SYS_I2C_BASE5
 147        DEF_DEVICE(5),
 148#endif
 149};
 150
 151#define I2C_M_TEN       0x0010  /* ten bit address */
 152#define I2C_M_RD        0x0001  /* read data */
 153#define I2C_M_NOSTART   0x4000  /* no restart between msgs */
 154
 155struct kona_i2c_msg {
 156        uint16_t addr;
 157        uint16_t flags;
 158        uint16_t len;
 159        uint8_t *buf;
 160};
 161
 162static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
 163                                          enum bcm_kona_cmd_t cmd)
 164{
 165        debug("%s, %d\n", __func__, cmd);
 166
 167        switch (cmd) {
 168        case BCM_CMD_NOACTION:
 169                writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
 170                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 171                       dev->base + CS_OFFSET);
 172                break;
 173
 174        case BCM_CMD_START:
 175                writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
 176                       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
 177                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 178                       dev->base + CS_OFFSET);
 179                break;
 180
 181        case BCM_CMD_RESTART:
 182                writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
 183                       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
 184                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 185                       dev->base + CS_OFFSET);
 186                break;
 187
 188        case BCM_CMD_STOP:
 189                writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
 190                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 191                       dev->base + CS_OFFSET);
 192                break;
 193
 194        default:
 195                printf("Unknown command %d\n", cmd);
 196        }
 197}
 198
 199static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
 200{
 201        writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
 202               dev->base + CLKEN_OFFSET);
 203}
 204
 205static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
 206{
 207        writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
 208               dev->base + CLKEN_OFFSET);
 209}
 210
 211/* Wait until at least one of the mask bit(s) are set */
 212static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
 213                                          unsigned long time_left,
 214                                          uint32_t mask)
 215{
 216        uint32_t status;
 217
 218        while (time_left) {
 219                status = readl(dev->base + ISR_OFFSET);
 220
 221                if ((status & ~ISR_RESERVED_MASK) == 0) {
 222                        debug("Bogus I2C interrupt 0x%x\n", status);
 223                        continue;
 224                }
 225
 226                /* Must flush the TX FIFO when NAK detected */
 227                if (status & ISR_NOACK_MASK)
 228                        writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
 229                               dev->base + TXFCR_OFFSET);
 230
 231                writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
 232
 233                if (status & mask) {
 234                        /* We are done since one of the mask bits are set */
 235                        return time_left;
 236                }
 237                udelay(WAIT_INT_CHK);
 238                time_left -= WAIT_INT_CHK;
 239        }
 240        return 0;
 241}
 242
 243/* Send command to I2C bus */
 244static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
 245                                 enum bcm_kona_cmd_t cmd)
 246{
 247        int rc = 0;
 248        unsigned long time_left = I2C_TIMEOUT;
 249
 250        /* Send the command */
 251        bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
 252
 253        /* Wait for transaction to finish or timeout */
 254        time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
 255
 256        if (!time_left) {
 257                printf("controller timed out\n");
 258                rc = -ETIMEDOUT;
 259        }
 260
 261        /* Clear command */
 262        bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
 263
 264        return rc;
 265}
 266
 267/* Read a single RX FIFO worth of data from the i2c bus */
 268static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
 269                                         uint8_t *buf, unsigned int len,
 270                                         unsigned int last_byte_nak)
 271{
 272        unsigned long time_left = I2C_TIMEOUT;
 273
 274        /* Start the RX FIFO */
 275        writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
 276               (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
 277
 278        /* Wait for FIFO read to complete */
 279        time_left =
 280            wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
 281
 282        if (!time_left) {
 283                printf("RX FIFO time out\n");
 284                return -EREMOTEIO;
 285        }
 286
 287        /* Read data from FIFO */
 288        for (; len > 0; len--, buf++)
 289                *buf = readl(dev->base + RXFIFORDOUT_OFFSET);
 290
 291        return 0;
 292}
 293
 294/* Read any amount of data using the RX FIFO from the i2c bus */
 295static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
 296                                  struct kona_i2c_msg *msg)
 297{
 298        unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
 299        unsigned int last_byte_nak = 0;
 300        unsigned int bytes_read = 0;
 301        int rc;
 302
 303        uint8_t *tmp_buf = msg->buf;
 304
 305        while (bytes_read < msg->len) {
 306                if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
 307                        last_byte_nak = 1;      /* NAK last byte of transfer */
 308                        bytes_to_read = msg->len - bytes_read;
 309                }
 310
 311                rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
 312                                                   last_byte_nak);
 313                if (rc < 0)
 314                        return -EREMOTEIO;
 315
 316                bytes_read += bytes_to_read;
 317                tmp_buf += bytes_to_read;
 318        }
 319
 320        return 0;
 321}
 322
 323/* Write a single byte of data to the i2c bus */
 324static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
 325                                   unsigned int nak_expected)
 326{
 327        unsigned long time_left = I2C_TIMEOUT;
 328        unsigned int nak_received;
 329
 330        /* Clear pending session done interrupt */
 331        writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
 332
 333        /* Send one byte of data */
 334        writel(data, dev->base + DAT_OFFSET);
 335
 336        time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
 337
 338        if (!time_left) {
 339                debug("controller timed out\n");
 340                return -ETIMEDOUT;
 341        }
 342
 343        nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
 344
 345        if (nak_received ^ nak_expected) {
 346                debug("unexpected NAK/ACK\n");
 347                return -EREMOTEIO;
 348        }
 349
 350        return 0;
 351}
 352
 353/* Write a single TX FIFO worth of data to the i2c bus */
 354static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
 355                                          uint8_t *buf, unsigned int len)
 356{
 357        int k;
 358        unsigned long time_left = I2C_TIMEOUT;
 359        unsigned int fifo_status;
 360
 361        /* Write data into FIFO */
 362        for (k = 0; k < len; k++)
 363                writel(buf[k], (dev->base + DAT_OFFSET));
 364
 365        /* Wait for FIFO to empty */
 366        do {
 367                time_left =
 368                    wait_for_int_timeout(dev, time_left,
 369                                         (IER_FIFO_INT_EN_MASK |
 370                                          IER_NOACK_EN_MASK));
 371                fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
 372        } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
 373
 374        /* Check if there was a NAK */
 375        if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
 376                printf("unexpected NAK\n");
 377                return -EREMOTEIO;
 378        }
 379
 380        /* Check if a timeout occurred */
 381        if (!time_left) {
 382                printf("completion timed out\n");
 383                return -EREMOTEIO;
 384        }
 385
 386        return 0;
 387}
 388
 389/* Write any amount of data using TX FIFO to the i2c bus */
 390static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
 391                                   struct kona_i2c_msg *msg)
 392{
 393        unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
 394        unsigned int bytes_written = 0;
 395        int rc;
 396
 397        uint8_t *tmp_buf = msg->buf;
 398
 399        while (bytes_written < msg->len) {
 400                if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
 401                        bytes_to_write = msg->len - bytes_written;
 402
 403                rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
 404                                                    bytes_to_write);
 405                if (rc < 0)
 406                        return -EREMOTEIO;
 407
 408                bytes_written += bytes_to_write;
 409                tmp_buf += bytes_to_write;
 410        }
 411
 412        return 0;
 413}
 414
 415/* Send i2c address */
 416static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
 417                                struct kona_i2c_msg *msg)
 418{
 419        unsigned char addr;
 420
 421        if (msg->flags & I2C_M_TEN) {
 422                /* First byte is 11110XX0 where XX is upper 2 bits */
 423                addr = 0xf0 | ((msg->addr & 0x300) >> 7);
 424                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 425                        return -EREMOTEIO;
 426
 427                /* Second byte is the remaining 8 bits */
 428                addr = msg->addr & 0xff;
 429                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 430                        return -EREMOTEIO;
 431
 432                if (msg->flags & I2C_M_RD) {
 433                        /* For read, send restart command */
 434                        if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
 435                                return -EREMOTEIO;
 436
 437                        /* Then re-send the first byte with the read bit set */
 438                        addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
 439                        if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 440                                return -EREMOTEIO;
 441                }
 442        } else {
 443                addr = msg->addr << 1;
 444
 445                if (msg->flags & I2C_M_RD)
 446                        addr |= 1;
 447
 448                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 449                        return -EREMOTEIO;
 450        }
 451
 452        return 0;
 453}
 454
 455static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
 456{
 457        writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
 458               dev->base + CLKEN_OFFSET);
 459}
 460
 461static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
 462{
 463        writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
 464               dev->base + HSTIM_OFFSET);
 465
 466        writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
 467               (dev->std_cfg->time_p << TIM_P_SHIFT) |
 468               (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
 469               (dev->std_cfg->time_div << TIM_DIV_SHIFT),
 470               dev->base + TIM_OFFSET);
 471
 472        writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
 473               (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
 474               CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
 475}
 476
 477/* Master transfer function */
 478static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
 479                             struct kona_i2c_msg msgs[], int num)
 480{
 481        struct kona_i2c_msg *pmsg;
 482        int rc = 0;
 483        int i;
 484
 485        /* Enable pad output */
 486        writel(0, dev->base + PADCTL_OFFSET);
 487
 488        /* Enable internal clocks */
 489        bcm_kona_i2c_enable_clock(dev);
 490
 491        /* Send start command */
 492        rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
 493        if (rc < 0) {
 494                printf("Start command failed rc = %d\n", rc);
 495                goto xfer_disable_pad;
 496        }
 497
 498        /* Loop through all messages */
 499        for (i = 0; i < num; i++) {
 500                pmsg = &msgs[i];
 501
 502                /* Send restart for subsequent messages */
 503                if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
 504                        rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
 505                        if (rc < 0) {
 506                                printf("restart cmd failed rc = %d\n", rc);
 507                                goto xfer_send_stop;
 508                        }
 509                }
 510
 511                /* Send slave address */
 512                if (!(pmsg->flags & I2C_M_NOSTART)) {
 513                        rc = bcm_kona_i2c_do_addr(dev, pmsg);
 514                        if (rc < 0) {
 515                                debug("NAK from addr %2.2x msg#%d rc = %d\n",
 516                                      pmsg->addr, i, rc);
 517                                goto xfer_send_stop;
 518                        }
 519                }
 520
 521                /* Perform data transfer */
 522                if (pmsg->flags & I2C_M_RD) {
 523                        rc = bcm_kona_i2c_read_fifo(dev, pmsg);
 524                        if (rc < 0) {
 525                                printf("read failure\n");
 526                                goto xfer_send_stop;
 527                        }
 528                } else {
 529                        rc = bcm_kona_i2c_write_fifo(dev, pmsg);
 530                        if (rc < 0) {
 531                                printf("write failure");
 532                                goto xfer_send_stop;
 533                        }
 534                }
 535        }
 536
 537        rc = num;
 538
 539xfer_send_stop:
 540        /* Send a STOP command */
 541        bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
 542
 543xfer_disable_pad:
 544        /* Disable pad output */
 545        writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
 546
 547        /* Stop internal clock */
 548        bcm_kona_i2c_disable_clock(dev);
 549
 550        return rc;
 551}
 552
 553static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
 554                                          uint speed)
 555{
 556        switch (speed) {
 557        case I2C_SPEED_STANDARD_RATE:
 558                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_STANDARD];
 559                break;
 560        case I2C_SPEED_FAST_RATE:
 561                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST];
 562                break;
 563        case I2C_SPEED_FAST_PLUS_RATE:
 564                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST_PLUS];
 565                break;
 566        default:
 567                printf("%d hz bus speed not supported\n", speed);
 568                return -EINVAL;
 569        }
 570        dev->speed = speed;
 571        return 0;
 572}
 573
 574static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
 575{
 576        /* Parse bus speed */
 577        bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
 578
 579        /* Enable internal clocks */
 580        bcm_kona_i2c_enable_clock(dev);
 581
 582        /* Configure internal dividers */
 583        bcm_kona_i2c_config_timing(dev);
 584
 585        /* Disable timeout */
 586        writel(0, dev->base + TOUT_OFFSET);
 587
 588        /* Enable autosense */
 589        bcm_kona_i2c_enable_autosense(dev);
 590
 591        /* Enable TX FIFO */
 592        writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
 593               dev->base + TXFCR_OFFSET);
 594
 595        /* Mask all interrupts */
 596        writel(0, dev->base + IER_OFFSET);
 597
 598        /* Clear all pending interrupts */
 599        writel(ISR_CMDBUSY_MASK |
 600               ISR_READ_COMPLETE_MASK |
 601               ISR_SES_DONE_MASK |
 602               ISR_ERR_MASK |
 603               ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
 604
 605        /* Enable the controller but leave it idle */
 606        bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
 607
 608        /* Disable pad output */
 609        writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
 610}
 611
 612/*
 613 * uboot layer
 614 */
 615struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
 616{
 617        return &g_i2c_devs[adap->hwadapnr];
 618}
 619
 620static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 621{
 622        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 623
 624        if (clk_bsc_enable(dev->base))
 625                return;
 626
 627        bcm_kona_i2c_init(dev);
 628}
 629
 630static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
 631                         int alen, uchar *buffer, int len)
 632{
 633        /* msg[0] writes the addr, msg[1] reads the data */
 634        struct kona_i2c_msg msg[2];
 635        unsigned char msgbuf0[64];
 636        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 637
 638        msg[0].addr = chip;
 639        msg[0].flags = 0;
 640        msg[0].len = 1;
 641        msg[0].buf = msgbuf0;   /* msgbuf0 contains incrementing reg addr */
 642
 643        msg[1].addr = chip;
 644        msg[1].flags = I2C_M_RD;
 645        /* msg[1].buf dest ptr increments each read */
 646
 647        msgbuf0[0] = (unsigned char)addr;
 648        msg[1].buf = buffer;
 649        msg[1].len = len;
 650        if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
 651                /* Sending 2 i2c messages */
 652                kona_i2c_init(adap, adap->speed, adap->slaveaddr);
 653                debug("I2C read: I/O error\n");
 654                return -EIO;
 655        }
 656        return 0;
 657}
 658
 659static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
 660                          int alen, uchar *buffer, int len)
 661{
 662        struct kona_i2c_msg msg[1];
 663        unsigned char msgbuf0[64];
 664        unsigned int i;
 665        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 666
 667        msg[0].addr = chip;
 668        msg[0].flags = 0;
 669        msg[0].len = 2;         /* addr byte plus data */
 670        msg[0].buf = msgbuf0;
 671
 672        for (i = 0; i < len; i++) {
 673                msgbuf0[0] = addr++;
 674                msgbuf0[1] = buffer[i];
 675                if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
 676                        kona_i2c_init(adap, adap->speed, adap->slaveaddr);
 677                        debug("I2C write: I/O error\n");
 678                        return -EIO;
 679                }
 680        }
 681        return 0;
 682}
 683
 684static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
 685{
 686        uchar tmp;
 687
 688        /*
 689         * read addr 0x0 of the given chip.
 690         */
 691        return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
 692}
 693
 694static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
 695{
 696        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 697        return bcm_kona_i2c_assign_bus_speed(dev, speed);
 698}
 699
 700/*
 701 * Register kona i2c adapters. Keep the order below so
 702 * that the bus number matches the adapter number.
 703 */
 704#define DEF_ADAPTER(num) \
 705U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
 706                         kona_i2c_read, kona_i2c_write, \
 707                         kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
 708
 709#ifdef CONFIG_SYS_I2C_BASE0
 710        DEF_ADAPTER(0)
 711#endif
 712#ifdef CONFIG_SYS_I2C_BASE1
 713        DEF_ADAPTER(1)
 714#endif
 715#ifdef CONFIG_SYS_I2C_BASE2
 716        DEF_ADAPTER(2)
 717#endif
 718#ifdef CONFIG_SYS_I2C_BASE3
 719        DEF_ADAPTER(3)
 720#endif
 721#ifdef CONFIG_SYS_I2C_BASE4
 722        DEF_ADAPTER(4)
 723#endif
 724#ifdef CONFIG_SYS_I2C_BASE5
 725        DEF_ADAPTER(5)
 726#endif
 727