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.rst for instructions.
   7 */
   8
   9#include <common.h>
  10#include <log.h>
  11#include <asm/io.h>
  12#include <linux/delay.h>
  13#include <linux/errno.h>
  14#include <asm/arch/sysmap.h>
  15#include <asm/kona-common/clk.h>
  16#include <i2c.h>
  17
  18/* Hardware register offsets and field defintions */
  19#define CS_OFFSET                               0x00000020
  20#define CS_ACK_SHIFT                            3
  21#define CS_ACK_MASK                             0x00000008
  22#define CS_ACK_CMD_GEN_START                    0x00000000
  23#define CS_ACK_CMD_GEN_RESTART                  0x00000001
  24#define CS_CMD_SHIFT                            1
  25#define CS_CMD_CMD_NO_ACTION                    0x00000000
  26#define CS_CMD_CMD_START_RESTART                0x00000001
  27#define CS_CMD_CMD_STOP                         0x00000002
  28#define CS_EN_SHIFT                             0
  29#define CS_EN_CMD_ENABLE_BSC                    0x00000001
  30
  31#define TIM_OFFSET                              0x00000024
  32#define TIM_PRESCALE_SHIFT                      6
  33#define TIM_P_SHIFT                             3
  34#define TIM_NO_DIV_SHIFT                        2
  35#define TIM_DIV_SHIFT                           0
  36
  37#define DAT_OFFSET                              0x00000028
  38
  39#define TOUT_OFFSET                             0x0000002c
  40
  41#define TXFCR_OFFSET                            0x0000003c
  42#define TXFCR_FIFO_FLUSH_MASK                   0x00000080
  43#define TXFCR_FIFO_EN_MASK                      0x00000040
  44
  45#define IER_OFFSET                              0x00000044
  46#define IER_READ_COMPLETE_INT_MASK              0x00000010
  47#define IER_I2C_INT_EN_MASK                     0x00000008
  48#define IER_FIFO_INT_EN_MASK                    0x00000002
  49#define IER_NOACK_EN_MASK                       0x00000001
  50
  51#define ISR_OFFSET                              0x00000048
  52#define ISR_RESERVED_MASK                       0xffffff60
  53#define ISR_CMDBUSY_MASK                        0x00000080
  54#define ISR_READ_COMPLETE_MASK                  0x00000010
  55#define ISR_SES_DONE_MASK                       0x00000008
  56#define ISR_ERR_MASK                            0x00000004
  57#define ISR_TXFIFOEMPTY_MASK                    0x00000002
  58#define ISR_NOACK_MASK                          0x00000001
  59
  60#define CLKEN_OFFSET                            0x0000004c
  61#define CLKEN_AUTOSENSE_OFF_MASK                0x00000080
  62#define CLKEN_M_SHIFT                           4
  63#define CLKEN_N_SHIFT                           1
  64#define CLKEN_CLKEN_MASK                        0x00000001
  65
  66#define FIFO_STATUS_OFFSET                      0x00000054
  67#define FIFO_STATUS_RXFIFO_EMPTY_MASK           0x00000004
  68#define FIFO_STATUS_TXFIFO_EMPTY_MASK           0x00000010
  69
  70#define HSTIM_OFFSET                            0x00000058
  71#define HSTIM_HS_MODE_MASK                      0x00008000
  72#define HSTIM_HS_HOLD_SHIFT                     10
  73#define HSTIM_HS_HIGH_PHASE_SHIFT               5
  74#define HSTIM_HS_SETUP_SHIFT                    0
  75
  76#define PADCTL_OFFSET                           0x0000005c
  77#define PADCTL_PAD_OUT_EN_MASK                  0x00000004
  78
  79#define RXFCR_OFFSET                            0x00000068
  80#define RXFCR_NACK_EN_SHIFT                     7
  81#define RXFCR_READ_COUNT_SHIFT                  0
  82#define RXFIFORDOUT_OFFSET                      0x0000006c
  83
  84/* Locally used constants */
  85#define MAX_RX_FIFO_SIZE                64U     /* bytes */
  86#define MAX_TX_FIFO_SIZE                64U     /* bytes */
  87
  88#define I2C_TIMEOUT                     100000  /* usecs */
  89
  90#define WAIT_INT_CHK                    100     /* usecs */
  91#if I2C_TIMEOUT % WAIT_INT_CHK
  92#error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
  93#endif
  94
  95/* Operations that can be commanded to the controller */
  96enum bcm_kona_cmd_t {
  97        BCM_CMD_NOACTION = 0,
  98        BCM_CMD_START,
  99        BCM_CMD_RESTART,
 100        BCM_CMD_STOP,
 101};
 102
 103/* Internal divider settings for standard mode, fast mode and fast mode plus */
 104struct bus_speed_cfg {
 105        uint8_t time_m;         /* Number of cycles for setup time */
 106        uint8_t time_n;         /* Number of cycles for hold time */
 107        uint8_t prescale;       /* Prescale divider */
 108        uint8_t time_p;         /* Timing coefficient */
 109        uint8_t no_div;         /* Disable clock divider */
 110        uint8_t time_div;       /* Post-prescale divider */
 111};
 112
 113static const struct bus_speed_cfg std_cfg_table[] = {
 114        [IC_SPEED_MODE_STANDARD] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
 115        [IC_SPEED_MODE_FAST] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
 116        [IC_SPEED_MODE_FAST_PLUS] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
 117};
 118
 119struct bcm_kona_i2c_dev {
 120        void *base;
 121        uint speed;
 122        const struct bus_speed_cfg *std_cfg;
 123};
 124
 125/* Keep these two defines in sync */
 126#define DEF_SPD I2C_SPEED_STANDARD_RATE
 127#define DEF_SPD_ENUM IC_SPEED_MODE_STANDARD
 128
 129#define DEF_DEVICE(num) \
 130{(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
 131
 132static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
 133#ifdef CONFIG_SYS_I2C_BASE0
 134        DEF_DEVICE(0),
 135#endif
 136#ifdef CONFIG_SYS_I2C_BASE1
 137        DEF_DEVICE(1),
 138#endif
 139#ifdef CONFIG_SYS_I2C_BASE2
 140        DEF_DEVICE(2),
 141#endif
 142#ifdef CONFIG_SYS_I2C_BASE3
 143        DEF_DEVICE(3),
 144#endif
 145#ifdef CONFIG_SYS_I2C_BASE4
 146        DEF_DEVICE(4),
 147#endif
 148#ifdef CONFIG_SYS_I2C_BASE5
 149        DEF_DEVICE(5),
 150#endif
 151};
 152
 153#define I2C_M_TEN       0x0010  /* ten bit address */
 154#define I2C_M_RD        0x0001  /* read data */
 155#define I2C_M_NOSTART   0x4000  /* no restart between msgs */
 156
 157struct kona_i2c_msg {
 158        uint16_t addr;
 159        uint16_t flags;
 160        uint16_t len;
 161        uint8_t *buf;
 162};
 163
 164static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
 165                                          enum bcm_kona_cmd_t cmd)
 166{
 167        debug("%s, %d\n", __func__, cmd);
 168
 169        switch (cmd) {
 170        case BCM_CMD_NOACTION:
 171                writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
 172                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 173                       dev->base + CS_OFFSET);
 174                break;
 175
 176        case BCM_CMD_START:
 177                writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
 178                       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
 179                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 180                       dev->base + CS_OFFSET);
 181                break;
 182
 183        case BCM_CMD_RESTART:
 184                writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
 185                       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
 186                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 187                       dev->base + CS_OFFSET);
 188                break;
 189
 190        case BCM_CMD_STOP:
 191                writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
 192                       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
 193                       dev->base + CS_OFFSET);
 194                break;
 195
 196        default:
 197                printf("Unknown command %d\n", cmd);
 198        }
 199}
 200
 201static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
 202{
 203        writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
 204               dev->base + CLKEN_OFFSET);
 205}
 206
 207static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
 208{
 209        writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
 210               dev->base + CLKEN_OFFSET);
 211}
 212
 213/* Wait until at least one of the mask bit(s) are set */
 214static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
 215                                          unsigned long time_left,
 216                                          uint32_t mask)
 217{
 218        uint32_t status;
 219
 220        while (time_left) {
 221                status = readl(dev->base + ISR_OFFSET);
 222
 223                if ((status & ~ISR_RESERVED_MASK) == 0) {
 224                        debug("Bogus I2C interrupt 0x%x\n", status);
 225                        continue;
 226                }
 227
 228                /* Must flush the TX FIFO when NAK detected */
 229                if (status & ISR_NOACK_MASK)
 230                        writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
 231                               dev->base + TXFCR_OFFSET);
 232
 233                writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
 234
 235                if (status & mask) {
 236                        /* We are done since one of the mask bits are set */
 237                        return time_left;
 238                }
 239                udelay(WAIT_INT_CHK);
 240                time_left -= WAIT_INT_CHK;
 241        }
 242        return 0;
 243}
 244
 245/* Send command to I2C bus */
 246static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
 247                                 enum bcm_kona_cmd_t cmd)
 248{
 249        int rc = 0;
 250        unsigned long time_left = I2C_TIMEOUT;
 251
 252        /* Send the command */
 253        bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
 254
 255        /* Wait for transaction to finish or timeout */
 256        time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
 257
 258        if (!time_left) {
 259                printf("controller timed out\n");
 260                rc = -ETIMEDOUT;
 261        }
 262
 263        /* Clear command */
 264        bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
 265
 266        return rc;
 267}
 268
 269/* Read a single RX FIFO worth of data from the i2c bus */
 270static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
 271                                         uint8_t *buf, unsigned int len,
 272                                         unsigned int last_byte_nak)
 273{
 274        unsigned long time_left = I2C_TIMEOUT;
 275
 276        /* Start the RX FIFO */
 277        writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
 278               (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
 279
 280        /* Wait for FIFO read to complete */
 281        time_left =
 282            wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
 283
 284        if (!time_left) {
 285                printf("RX FIFO time out\n");
 286                return -EREMOTEIO;
 287        }
 288
 289        /* Read data from FIFO */
 290        for (; len > 0; len--, buf++)
 291                *buf = readl(dev->base + RXFIFORDOUT_OFFSET);
 292
 293        return 0;
 294}
 295
 296/* Read any amount of data using the RX FIFO from the i2c bus */
 297static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
 298                                  struct kona_i2c_msg *msg)
 299{
 300        unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
 301        unsigned int last_byte_nak = 0;
 302        unsigned int bytes_read = 0;
 303        int rc;
 304
 305        uint8_t *tmp_buf = msg->buf;
 306
 307        while (bytes_read < msg->len) {
 308                if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
 309                        last_byte_nak = 1;      /* NAK last byte of transfer */
 310                        bytes_to_read = msg->len - bytes_read;
 311                }
 312
 313                rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
 314                                                   last_byte_nak);
 315                if (rc < 0)
 316                        return -EREMOTEIO;
 317
 318                bytes_read += bytes_to_read;
 319                tmp_buf += bytes_to_read;
 320        }
 321
 322        return 0;
 323}
 324
 325/* Write a single byte of data to the i2c bus */
 326static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
 327                                   unsigned int nak_expected)
 328{
 329        unsigned long time_left = I2C_TIMEOUT;
 330        unsigned int nak_received;
 331
 332        /* Clear pending session done interrupt */
 333        writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
 334
 335        /* Send one byte of data */
 336        writel(data, dev->base + DAT_OFFSET);
 337
 338        time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
 339
 340        if (!time_left) {
 341                debug("controller timed out\n");
 342                return -ETIMEDOUT;
 343        }
 344
 345        nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
 346
 347        if (nak_received ^ nak_expected) {
 348                debug("unexpected NAK/ACK\n");
 349                return -EREMOTEIO;
 350        }
 351
 352        return 0;
 353}
 354
 355/* Write a single TX FIFO worth of data to the i2c bus */
 356static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
 357                                          uint8_t *buf, unsigned int len)
 358{
 359        int k;
 360        unsigned long time_left = I2C_TIMEOUT;
 361        unsigned int fifo_status;
 362
 363        /* Write data into FIFO */
 364        for (k = 0; k < len; k++)
 365                writel(buf[k], (dev->base + DAT_OFFSET));
 366
 367        /* Wait for FIFO to empty */
 368        do {
 369                time_left =
 370                    wait_for_int_timeout(dev, time_left,
 371                                         (IER_FIFO_INT_EN_MASK |
 372                                          IER_NOACK_EN_MASK));
 373                fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
 374        } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
 375
 376        /* Check if there was a NAK */
 377        if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
 378                printf("unexpected NAK\n");
 379                return -EREMOTEIO;
 380        }
 381
 382        /* Check if a timeout occurred */
 383        if (!time_left) {
 384                printf("completion timed out\n");
 385                return -EREMOTEIO;
 386        }
 387
 388        return 0;
 389}
 390
 391/* Write any amount of data using TX FIFO to the i2c bus */
 392static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
 393                                   struct kona_i2c_msg *msg)
 394{
 395        unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
 396        unsigned int bytes_written = 0;
 397        int rc;
 398
 399        uint8_t *tmp_buf = msg->buf;
 400
 401        while (bytes_written < msg->len) {
 402                if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
 403                        bytes_to_write = msg->len - bytes_written;
 404
 405                rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
 406                                                    bytes_to_write);
 407                if (rc < 0)
 408                        return -EREMOTEIO;
 409
 410                bytes_written += bytes_to_write;
 411                tmp_buf += bytes_to_write;
 412        }
 413
 414        return 0;
 415}
 416
 417/* Send i2c address */
 418static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
 419                                struct kona_i2c_msg *msg)
 420{
 421        unsigned char addr;
 422
 423        if (msg->flags & I2C_M_TEN) {
 424                /* First byte is 11110XX0 where XX is upper 2 bits */
 425                addr = 0xf0 | ((msg->addr & 0x300) >> 7);
 426                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 427                        return -EREMOTEIO;
 428
 429                /* Second byte is the remaining 8 bits */
 430                addr = msg->addr & 0xff;
 431                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 432                        return -EREMOTEIO;
 433
 434                if (msg->flags & I2C_M_RD) {
 435                        /* For read, send restart command */
 436                        if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
 437                                return -EREMOTEIO;
 438
 439                        /* Then re-send the first byte with the read bit set */
 440                        addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
 441                        if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 442                                return -EREMOTEIO;
 443                }
 444        } else {
 445                addr = msg->addr << 1;
 446
 447                if (msg->flags & I2C_M_RD)
 448                        addr |= 1;
 449
 450                if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
 451                        return -EREMOTEIO;
 452        }
 453
 454        return 0;
 455}
 456
 457static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
 458{
 459        writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
 460               dev->base + CLKEN_OFFSET);
 461}
 462
 463static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
 464{
 465        writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
 466               dev->base + HSTIM_OFFSET);
 467
 468        writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
 469               (dev->std_cfg->time_p << TIM_P_SHIFT) |
 470               (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
 471               (dev->std_cfg->time_div << TIM_DIV_SHIFT),
 472               dev->base + TIM_OFFSET);
 473
 474        writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
 475               (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
 476               CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
 477}
 478
 479/* Master transfer function */
 480static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
 481                             struct kona_i2c_msg msgs[], int num)
 482{
 483        struct kona_i2c_msg *pmsg;
 484        int rc = 0;
 485        int i;
 486
 487        /* Enable pad output */
 488        writel(0, dev->base + PADCTL_OFFSET);
 489
 490        /* Enable internal clocks */
 491        bcm_kona_i2c_enable_clock(dev);
 492
 493        /* Send start command */
 494        rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
 495        if (rc < 0) {
 496                printf("Start command failed rc = %d\n", rc);
 497                goto xfer_disable_pad;
 498        }
 499
 500        /* Loop through all messages */
 501        for (i = 0; i < num; i++) {
 502                pmsg = &msgs[i];
 503
 504                /* Send restart for subsequent messages */
 505                if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
 506                        rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
 507                        if (rc < 0) {
 508                                printf("restart cmd failed rc = %d\n", rc);
 509                                goto xfer_send_stop;
 510                        }
 511                }
 512
 513                /* Send slave address */
 514                if (!(pmsg->flags & I2C_M_NOSTART)) {
 515                        rc = bcm_kona_i2c_do_addr(dev, pmsg);
 516                        if (rc < 0) {
 517                                debug("NAK from addr %2.2x msg#%d rc = %d\n",
 518                                      pmsg->addr, i, rc);
 519                                goto xfer_send_stop;
 520                        }
 521                }
 522
 523                /* Perform data transfer */
 524                if (pmsg->flags & I2C_M_RD) {
 525                        rc = bcm_kona_i2c_read_fifo(dev, pmsg);
 526                        if (rc < 0) {
 527                                printf("read failure\n");
 528                                goto xfer_send_stop;
 529                        }
 530                } else {
 531                        rc = bcm_kona_i2c_write_fifo(dev, pmsg);
 532                        if (rc < 0) {
 533                                printf("write failure");
 534                                goto xfer_send_stop;
 535                        }
 536                }
 537        }
 538
 539        rc = num;
 540
 541xfer_send_stop:
 542        /* Send a STOP command */
 543        bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
 544
 545xfer_disable_pad:
 546        /* Disable pad output */
 547        writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
 548
 549        /* Stop internal clock */
 550        bcm_kona_i2c_disable_clock(dev);
 551
 552        return rc;
 553}
 554
 555static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
 556                                          uint speed)
 557{
 558        switch (speed) {
 559        case I2C_SPEED_STANDARD_RATE:
 560                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_STANDARD];
 561                break;
 562        case I2C_SPEED_FAST_RATE:
 563                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST];
 564                break;
 565        case I2C_SPEED_FAST_PLUS_RATE:
 566                dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST_PLUS];
 567                break;
 568        default:
 569                printf("%d hz bus speed not supported\n", speed);
 570                return -EINVAL;
 571        }
 572        dev->speed = speed;
 573        return 0;
 574}
 575
 576static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
 577{
 578        /* Parse bus speed */
 579        bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
 580
 581        /* Enable internal clocks */
 582        bcm_kona_i2c_enable_clock(dev);
 583
 584        /* Configure internal dividers */
 585        bcm_kona_i2c_config_timing(dev);
 586
 587        /* Disable timeout */
 588        writel(0, dev->base + TOUT_OFFSET);
 589
 590        /* Enable autosense */
 591        bcm_kona_i2c_enable_autosense(dev);
 592
 593        /* Enable TX FIFO */
 594        writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
 595               dev->base + TXFCR_OFFSET);
 596
 597        /* Mask all interrupts */
 598        writel(0, dev->base + IER_OFFSET);
 599
 600        /* Clear all pending interrupts */
 601        writel(ISR_CMDBUSY_MASK |
 602               ISR_READ_COMPLETE_MASK |
 603               ISR_SES_DONE_MASK |
 604               ISR_ERR_MASK |
 605               ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
 606
 607        /* Enable the controller but leave it idle */
 608        bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
 609
 610        /* Disable pad output */
 611        writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
 612}
 613
 614/*
 615 * uboot layer
 616 */
 617struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
 618{
 619        return &g_i2c_devs[adap->hwadapnr];
 620}
 621
 622static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 623{
 624        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 625
 626        if (clk_bsc_enable(dev->base))
 627                return;
 628
 629        bcm_kona_i2c_init(dev);
 630}
 631
 632static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
 633                         int alen, uchar *buffer, int len)
 634{
 635        /* msg[0] writes the addr, msg[1] reads the data */
 636        struct kona_i2c_msg msg[2];
 637        unsigned char msgbuf0[64];
 638        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 639
 640        msg[0].addr = chip;
 641        msg[0].flags = 0;
 642        msg[0].len = 1;
 643        msg[0].buf = msgbuf0;   /* msgbuf0 contains incrementing reg addr */
 644
 645        msg[1].addr = chip;
 646        msg[1].flags = I2C_M_RD;
 647        /* msg[1].buf dest ptr increments each read */
 648
 649        msgbuf0[0] = (unsigned char)addr;
 650        msg[1].buf = buffer;
 651        msg[1].len = len;
 652        if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
 653                /* Sending 2 i2c messages */
 654                kona_i2c_init(adap, adap->speed, adap->slaveaddr);
 655                debug("I2C read: I/O error\n");
 656                return -EIO;
 657        }
 658        return 0;
 659}
 660
 661static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
 662                          int alen, uchar *buffer, int len)
 663{
 664        struct kona_i2c_msg msg[1];
 665        unsigned char msgbuf0[64];
 666        unsigned int i;
 667        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 668
 669        msg[0].addr = chip;
 670        msg[0].flags = 0;
 671        msg[0].len = 2;         /* addr byte plus data */
 672        msg[0].buf = msgbuf0;
 673
 674        for (i = 0; i < len; i++) {
 675                msgbuf0[0] = addr++;
 676                msgbuf0[1] = buffer[i];
 677                if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
 678                        kona_i2c_init(adap, adap->speed, adap->slaveaddr);
 679                        debug("I2C write: I/O error\n");
 680                        return -EIO;
 681                }
 682        }
 683        return 0;
 684}
 685
 686static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
 687{
 688        uchar tmp;
 689
 690        /*
 691         * read addr 0x0 of the given chip.
 692         */
 693        return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
 694}
 695
 696static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
 697{
 698        struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
 699        return bcm_kona_i2c_assign_bus_speed(dev, speed);
 700}
 701
 702/*
 703 * Register kona i2c adapters. Keep the order below so
 704 * that the bus number matches the adapter number.
 705 */
 706#define DEF_ADAPTER(num) \
 707U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
 708                         kona_i2c_read, kona_i2c_write, \
 709                         kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
 710
 711#ifdef CONFIG_SYS_I2C_BASE0
 712        DEF_ADAPTER(0)
 713#endif
 714#ifdef CONFIG_SYS_I2C_BASE1
 715        DEF_ADAPTER(1)
 716#endif
 717#ifdef CONFIG_SYS_I2C_BASE2
 718        DEF_ADAPTER(2)
 719#endif
 720#ifdef CONFIG_SYS_I2C_BASE3
 721        DEF_ADAPTER(3)
 722#endif
 723#ifdef CONFIG_SYS_I2C_BASE4
 724        DEF_ADAPTER(4)
 725#endif
 726#ifdef CONFIG_SYS_I2C_BASE5
 727        DEF_ADAPTER(5)
 728#endif
 729