drivers/i2c/busses/i2c-brcmstb.c

   1 /*
   2  * Copyright (C) 2014 Broadcom Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation version 2.
   7  *
   8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
   9  * kind, whether express or implied; without even the implied warranty
  10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16 #include <linux/device.h>
  17 #include <linux/i2c.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/io.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25
  26 #define N_DATA_REGS                                     8
  27
  28 /*
  29  * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register
  30  * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per
  31  * data register whereas STB SoCs use 4 byte per data register transfer,
  32  * account for this difference in total count per transaction and mask to
  33  * use.
  34  */
  35 #define BSC_CNT_REG1_MASK(nb)   (nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))
  36 #define BSC_CNT_REG1_SHIFT      0
  37
  38 /* BSC CTL register field definitions */
  39 #define BSC_CTL_REG_DTF_MASK                            0x00000003
  40 #define BSC_CTL_REG_SCL_SEL_MASK                        0x00000030
  41 #define BSC_CTL_REG_SCL_SEL_SHIFT                       4
  42 #define BSC_CTL_REG_INT_EN_MASK                         0x00000040
  43 #define BSC_CTL_REG_INT_EN_SHIFT                        6
  44 #define BSC_CTL_REG_DIV_CLK_MASK                        0x00000080
  45
  46 /* BSC_IIC_ENABLE r/w enable and interrupt field definitions */
  47 #define BSC_IIC_EN_RESTART_MASK                         0x00000040
  48 #define BSC_IIC_EN_NOSTART_MASK                         0x00000020
  49 #define BSC_IIC_EN_NOSTOP_MASK                          0x00000010
  50 #define BSC_IIC_EN_NOACK_MASK                           0x00000004
  51 #define BSC_IIC_EN_INTRP_MASK                           0x00000002
  52 #define BSC_IIC_EN_ENABLE_MASK                          0x00000001
  53
  54 /* BSC_CTLHI control register field definitions */
  55 #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK        0x00000080
  56 #define BSC_CTLHI_REG_DATAREG_SIZE_MASK                 0x00000040
  57 #define BSC_CTLHI_REG_IGNORE_ACK_MASK                   0x00000002
  58 #define BSC_CTLHI_REG_WAIT_DIS_MASK                     0x00000001
  59
  60 #define I2C_TIMEOUT                                     100 /* msecs */
  61
  62 /* Condition mask used for non combined transfer */
  63 #define COND_RESTART            BSC_IIC_EN_RESTART_MASK
  64 #define COND_NOSTART            BSC_IIC_EN_NOSTART_MASK
  65 #define COND_NOSTOP             BSC_IIC_EN_NOSTOP_MASK
  66 #define COND_START_STOP         (COND_RESTART | COND_NOSTART | COND_NOSTOP)
  67
  68 /* BSC data transfer direction */
  69 #define DTF_WR_MASK             0x00000000
  70 #define DTF_RD_MASK             0x00000001
  71 /* BSC data transfer direction combined format */
  72 #define DTF_RD_WR_MASK          0x00000002
  73 #define DTF_WR_RD_MASK          0x00000003
  74
  75 #define INT_ENABLE              true
  76 #define INT_DISABLE             false
  77
  78 /* BSC block register map structure to cache fields to be written */
  79 struct bsc_regs {
  80         u32     chip_address;           /* slave address */
  81         u32     data_in[N_DATA_REGS];   /* tx data buffer*/
  82         u32     cnt_reg;                /* rx/tx data length */
  83         u32     ctl_reg;                /* control register */
  84         u32     iic_enable;             /* xfer enable and status */
  85         u32     data_out[N_DATA_REGS];  /* rx data buffer */
  86         u32     ctlhi_reg;              /* more control fields */
  87         u32     scl_param;              /* reserved */
  88 };
  89
  90 struct bsc_clk_param {
  91         u32 hz;
  92         u32 scl_mask;
  93         u32 div_mask;
  94 };
  95
  96 enum bsc_xfer_cmd {
  97         CMD_WR,
  98         CMD_RD,
  99         CMD_WR_NOACK,
 100         CMD_RD_NOACK,
 101 };
 102
 103 static char const *cmd_string[] = {
 104         [CMD_WR] = "WR",
 105         [CMD_RD] = "RD",
 106         [CMD_WR_NOACK] = "WR NOACK",
 107         [CMD_RD_NOACK] = "RD NOACK",
 108 };
 109
 110 enum bus_speeds {
 111         SPD_375K,
 112         SPD_390K,
 113         SPD_187K,
 114         SPD_200K,
 115         SPD_93K,
 116         SPD_97K,
 117         SPD_46K,
 118         SPD_50K
 119 };
 120
 121 static const struct bsc_clk_param bsc_clk[] = {
 122         [SPD_375K] = {
 123                 .hz = 375000,
 124                 .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
 125                 .div_mask = 0
 126         },
 127         [SPD_390K] = {
 128                 .hz = 390000,
 129                 .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
 130                 .div_mask = 0
 131         },
 132         [SPD_187K] = {
 133                 .hz = 187500,
 134                 .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
 135                 .div_mask = 0
 136         },
 137         [SPD_200K] = {
 138                 .hz = 200000,
 139                 .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
 140                 .div_mask = 0
 141         },
 142         [SPD_93K]  = {
 143                 .hz = 93750,
 144                 .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
 145                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 146         },
 147         [SPD_97K]  = {
 148                 .hz = 97500,
 149                 .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
 150                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 151         },
 152         [SPD_46K]  = {
 153                 .hz = 46875,
 154                 .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
 155                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 156         },
 157         [SPD_50K]  = {
 158                 .hz = 50000,
 159                 .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
 160                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 161         }
 162 };
 163
 164 struct brcmstb_i2c_dev {
 165         struct device *device;
 166         void __iomem *base;
 167         int irq;
 168         struct bsc_regs *bsc_regmap;
 169         struct i2c_adapter adapter;
 170         struct completion done;
 171         u32 clk_freq_hz;
 172         int data_regsz;
 173 };
 174
 175 /* register accessors for both be and le cpu arch */
 176 #ifdef CONFIG_CPU_BIG_ENDIAN
 177 #define __bsc_readl(_reg) ioread32be(_reg)
 178 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
 179 #else
 180 #define __bsc_readl(_reg) ioread32(_reg)
 181 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
 182 #endif
 183
 184 #define bsc_readl(_dev, _reg)                                           \
 185         __bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
 186
 187 #define bsc_writel(_dev, _val, _reg)                                    \
 188         __bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
 189
 190 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
 191 {
 192         return (N_DATA_REGS * dev->data_regsz);
 193 }
 194
 195 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
 196 {
 197         return dev->data_regsz;
 198 }
 199
 200 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
 201                                            bool int_en)
 202 {
 203
 204         if (int_en)
 205                 /* Enable BSC  CTL interrupt line */
 206                 dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
 207         else
 208                 /* Disable BSC CTL interrupt line */
 209                 dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
 210
 211         barrier();
 212         bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
 213 }
 214
 215 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
 216 {
 217         struct brcmstb_i2c_dev *dev = devid;
 218         u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
 219         u32 status_iic_intrp = bsc_readl(dev, iic_enable);
 220
 221         dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
 222                 status_bsc_ctl, status_iic_intrp);
 223
 224         if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
 225                 return IRQ_NONE;
 226
 227         brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 228         complete(&dev->done);
 229
 230         dev_dbg(dev->device, "isr handled");
 231         return IRQ_HANDLED;
 232 }
 233
 234 /* Wait for device to be ready */
 235 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
 236 {
 237         unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
 238
 239         while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
 240                 if (time_after(jiffies, timeout))
 241                         return -ETIMEDOUT;
 242                 cpu_relax();
 243         }
 244         return 0;
 245 }
 246
 247 /* i2c xfer completion function, handles both irq and polling mode */
 248 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
 249 {
 250         int ret = 0;
 251         unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
 252
 253         if (dev->irq >= 0) {
 254                 if (!wait_for_completion_timeout(&dev->done, timeout))
 255                         ret = -ETIMEDOUT;
 256         } else {
 257                 /* we are in polling mode */
 258                 u32 bsc_intrp;
 259                 unsigned long time_left = jiffies + timeout;
 260
 261                 do {
 262                         bsc_intrp = bsc_readl(dev, iic_enable) &
 263                                 BSC_IIC_EN_INTRP_MASK;
 264                         if (time_after(jiffies, time_left)) {
 265                                 ret = -ETIMEDOUT;
 266                                 break;
 267                         }
 268                         cpu_relax();
 269                 } while (!bsc_intrp);
 270         }
 271
 272         if (dev->irq < 0 || ret == -ETIMEDOUT)
 273                 brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 274
 275         return ret;
 276 }
 277
 278 /* Set xfer START/STOP conditions for subsequent transfer */
 279 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
 280                                        u32 cond_flag)
 281 {
 282         u32 regval = dev->bsc_regmap->iic_enable;
 283
 284         dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
 285 }
 286
 287 /* Send I2C request check completion */
 288 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
 289                                 enum bsc_xfer_cmd cmd)
 290 {
 291         int rc = 0;
 292         struct bsc_regs *pi2creg = dev->bsc_regmap;
 293
 294         /* Make sure the hardware is ready */
 295         rc = brcmstb_i2c_wait_if_busy(dev);
 296         if (rc < 0)
 297                 return rc;
 298
 299         /* only if we are in interrupt mode */
 300         if (dev->irq >= 0)
 301                 reinit_completion(&dev->done);
 302
 303         /* enable BSC CTL interrupt line */
 304         brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
 305
 306         /* initiate transfer by setting iic_enable */
 307         pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
 308         bsc_writel(dev, pi2creg->iic_enable, iic_enable);
 309
 310         /* Wait for transaction to finish or timeout */
 311         rc = brcmstb_i2c_wait_for_completion(dev);
 312         if (rc) {
 313                 dev_dbg(dev->device, "intr timeout for cmd %s\n",
 314                         cmd_string[cmd]);
 315                 goto cmd_out;
 316         }
 317
 318         if ((cmd == CMD_RD || cmd == CMD_WR) &&
 319             bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
 320                 rc = -EREMOTEIO;
 321                 dev_dbg(dev->device, "controller received NOACK intr for %s\n",
 322                         cmd_string[cmd]);
 323         }
 324
 325 cmd_out:
 326         bsc_writel(dev, 0, cnt_reg);
 327         bsc_writel(dev, 0, iic_enable);
 328
 329         return rc;
 330 }
 331
 332 /* Actual data transfer through the BSC master */
 333 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
 334                                      u8 *buf, unsigned int len,
 335                                      struct i2c_msg *pmsg)
 336 {
 337         int cnt, byte, i, rc;
 338         enum bsc_xfer_cmd cmd;
 339         u32 ctl_reg;
 340         struct bsc_regs *pi2creg = dev->bsc_regmap;
 341         int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
 342         int data_regsz = brcmstb_i2c_get_data_regsz(dev);
 343
 344         /* see if the transaction needs to check NACK conditions */
 345         if (no_ack) {
 346                 cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
 347                         : CMD_WR_NOACK;
 348                 pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
 349         } else {
 350                 cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
 351                 pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
 352         }
 353         bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
 354
 355         /* set data transfer direction */
 356         ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
 357         if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
 358                 pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
 359         else
 360                 pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
 361
 362         /* set the read/write length */
 363         bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
 364                    (len << BSC_CNT_REG1_SHIFT), cnt_reg);
 365
 366         /* Write data into data_in register */
 367
 368         if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
 369                 for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
 370                         u32 word = 0;
 371
 372                         for (byte = 0; byte < data_regsz; byte++) {
 373                                 word >>= BITS_PER_BYTE;
 374                                 if ((cnt + byte) < len)
 375                                         word |= buf[cnt + byte] <<
 376                                         (BITS_PER_BYTE * (data_regsz - 1));
 377                         }
 378                         bsc_writel(dev, word, data_in[i]);
 379                 }
 380         }
 381
 382         /* Initiate xfer, the function will return on completion */
 383         rc = brcmstb_send_i2c_cmd(dev, cmd);
 384
 385         if (rc != 0) {
 386                 dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
 387                 return rc;
 388         }
 389
 390         /* Read data from data_out register */
 391         if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
 392                 for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
 393                         u32 data = bsc_readl(dev, data_out[i]);
 394
 395                         for (byte = 0; byte < data_regsz &&
 396                                      (byte + cnt) < len; byte++) {
 397                                 buf[cnt + byte] = data & 0xff;
 398                                 data >>= BITS_PER_BYTE;
 399                         }
 400                 }
 401         }
 402
 403         return 0;
 404 }
 405
 406 /* Write a single byte of data to the i2c bus */
 407 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
 408                                        u8 *buf, unsigned int nak_expected)
 409 {
 410         enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
 411
 412         bsc_writel(dev, 1, cnt_reg);
 413         bsc_writel(dev, *buf, data_in);
 414
 415         return brcmstb_send_i2c_cmd(dev, cmd);
 416 }
 417
 418 /* Send i2c address */
 419 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
 420                                struct i2c_msg *msg)
 421 {
 422         unsigned char addr;
 423
 424         if (msg->flags & I2C_M_TEN) {
 425                 /* First byte is 11110XX0 where XX is upper 2 bits */
 426                 addr = 0xF0 | ((msg->addr & 0x300) >> 7);
 427                 bsc_writel(dev, addr, chip_address);
 428
 429                 /* Second byte is the remaining 8 bits */
 430                 addr = msg->addr & 0xFF;
 431                 if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
 432                         return -EREMOTEIO;
 433
 434                 if (msg->flags & I2C_M_RD) {
 435                         /* For read, send restart without stop condition */
 436                         brcmstb_set_i2c_start_stop(dev, COND_RESTART
 437                                                    | COND_NOSTOP);
 438                         /* Then re-send the first byte with the read bit set */
 439                         addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
 440                         if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
 441                                 return -EREMOTEIO;
 442
 443                 }
 444         } else {
 445                 addr = i2c_8bit_addr_from_msg(msg);
 446
 447                 bsc_writel(dev, addr, chip_address);
 448         }
 449
 450         return 0;
 451 }
 452
 453 /* Master transfer function */
 454 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
 455                             struct i2c_msg msgs[], int num)
 456 {
 457         struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
 458         struct i2c_msg *pmsg;
 459         int rc = 0;
 460         int i;
 461         int bytes_to_xfer;
 462         u8 *tmp_buf;
 463         int len = 0;
 464         int xfersz = brcmstb_i2c_get_xfersz(dev);
 465         u32 cond, cond_per_msg;
 466
 467         /* Loop through all messages */
 468         for (i = 0; i < num; i++) {
 469                 pmsg = &msgs[i];
 470                 len = pmsg->len;
 471                 tmp_buf = pmsg->buf;
 472
 473                 dev_dbg(dev->device,
 474                         "msg# %d/%d flg %x buf %x len %d\n", i,
 475                         num - 1, pmsg->flags,
 476                         pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
 477
 478                 if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
 479                         cond = ~COND_START_STOP;
 480                 else
 481                         cond = COND_RESTART | COND_NOSTOP;
 482
 483                 brcmstb_set_i2c_start_stop(dev, cond);
 484
 485                 /* Send slave address */
 486                 if (!(pmsg->flags & I2C_M_NOSTART)) {
 487                         rc = brcmstb_i2c_do_addr(dev, pmsg);
 488                         if (rc < 0) {
 489                                 dev_dbg(dev->device,
 490                                         "NACK for addr %2.2x msg#%d rc = %d\n",
 491                                         pmsg->addr, i, rc);
 492                                 goto out;
 493                         }
 494                 }
 495
 496                 cond_per_msg = cond;
 497
 498                 /* Perform data transfer */
 499                 while (len) {
 500                         bytes_to_xfer = min(len, xfersz);
 501
 502                         if (len <= xfersz) {
 503                                 if (i == (num - 1))
 504                                         cond_per_msg = cond_per_msg &
 505                                                 ~(COND_RESTART | COND_NOSTOP);
 506                                 else
 507                                         cond_per_msg = cond;
 508                         } else {
 509                                 cond_per_msg = (cond_per_msg & ~COND_RESTART) |
 510                                         COND_NOSTOP;
 511                         }
 512
 513                         brcmstb_set_i2c_start_stop(dev, cond_per_msg);
 514
 515                         rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
 516                                                        bytes_to_xfer, pmsg);
 517                         if (rc < 0)
 518                                 goto out;
 519
 520                         len -=  bytes_to_xfer;
 521                         tmp_buf += bytes_to_xfer;
 522
 523                         cond_per_msg = COND_NOSTART | COND_NOSTOP;
 524                 }
 525         }
 526
 527         rc = num;
 528 out:
 529         return rc;
 530
 531 }
 532
 533 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
 534 {
 535         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
 536                 | I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
 537 }
 538
 539 static const struct i2c_algorithm brcmstb_i2c_algo = {
 540         .master_xfer = brcmstb_i2c_xfer,
 541         .functionality = brcmstb_i2c_functionality,
 542 };
 543
 544 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
 545 {
 546         int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
 547         u32 clk_freq_hz = dev->clk_freq_hz;
 548
 549         for (i = 0; i < num_speeds; i++) {
 550                 if (bsc_clk[i].hz == clk_freq_hz) {
 551                         dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
 552                                                 | BSC_CTL_REG_DIV_CLK_MASK);
 553                         dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
 554                                                      bsc_clk[i].div_mask);
 555                         bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
 556                         break;
 557                 }
 558         }
 559
 560         /* in case we did not get find a valid speed */
 561         if (i == num_speeds) {
 562                 i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
 563                         BSC_CTL_REG_SCL_SEL_SHIFT;
 564                 dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
 565                         bsc_clk[i].hz);
 566         }
 567 }
 568
 569 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
 570 {
 571         if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
 572                 /* set 4 byte data in/out xfers  */
 573                 dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
 574         else
 575                 dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
 576
 577         bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
 578         /* set bus speed */
 579         brcmstb_i2c_set_bus_speed(dev);
 580 }
 581
 582 #define AUTOI2C_CTRL0           0x26c
 583 #define AUTOI2C_CTRL0_RELEASE_BSC       BIT(1)
 584
 585 static int bcm2711_release_bsc(struct brcmstb_i2c_dev *dev)
 586 {
 587         struct platform_device *pdev = to_platform_device(dev->device);
 588         struct resource *iomem;
 589         void __iomem *autoi2c;
 590
 591         /* Map hardware registers */
 592         iomem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "auto-i2c");
 593         autoi2c = devm_ioremap_resource(&pdev->dev, iomem);
 594         if (IS_ERR(autoi2c))
 595                 return PTR_ERR(autoi2c);
 596
 597         writel(AUTOI2C_CTRL0_RELEASE_BSC, autoi2c + AUTOI2C_CTRL0);
 598         devm_iounmap(&pdev->dev, autoi2c);
 599
 600         /* We need to reset the controller after the release */
 601         dev->bsc_regmap->iic_enable = 0;
 602         bsc_writel(dev, dev->bsc_regmap->iic_enable, iic_enable);
 603
 604         return 0;
 605 }
 606
 607 static int brcmstb_i2c_probe(struct platform_device *pdev)
 608 {
 609         int rc = 0;
 610         struct brcmstb_i2c_dev *dev;
 611         struct i2c_adapter *adap;
 612         struct resource *iomem;
 613         const char *int_name;
 614
 615         /* Allocate memory for private data structure */
 616         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 617         if (!dev)
 618                 return -ENOMEM;
 619
 620         dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
 621         if (!dev->bsc_regmap)
 622                 return -ENOMEM;
 623
 624         platform_set_drvdata(pdev, dev);
 625         dev->device = &pdev->dev;
 626         init_completion(&dev->done);
 627
 628         /* Map hardware registers */
 629         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 630         dev->base = devm_ioremap_resource(dev->device, iomem);
 631         if (IS_ERR(dev->base)) {
 632                 rc = -ENOMEM;
 633                 goto probe_errorout;
 634         }
 635
 636         if (of_device_is_compatible(dev->device->of_node,
 637                                     "brcm,bcm2711-hdmi-i2c")) {
 638                 rc = bcm2711_release_bsc(dev);
 639                 if (rc)
 640                         goto probe_errorout;
 641         }
 642
 643         rc = of_property_read_string(dev->device->of_node, "interrupt-names",
 644                                      &int_name);
 645         if (rc < 0)
 646                 int_name = NULL;
 647
 648         /* Get the interrupt number */
 649         dev->irq = platform_get_irq_optional(pdev, 0);
 650
 651         /* disable the bsc interrupt line */
 652         brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 653
 654         /* register the ISR handler */
 655         if (dev->irq >= 0) {
 656                 rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
 657                                       IRQF_SHARED,
 658                                       int_name ? int_name : pdev->name,
 659                                       dev);
 660
 661                 if (rc) {
 662                         dev_dbg(dev->device, "falling back to polling mode");
 663                         dev->irq = -1;
 664                 }
 665         }
 666
 667         if (of_property_read_u32(dev->device->of_node,
 668                                  "clock-frequency", &dev->clk_freq_hz)) {
 669                 dev_warn(dev->device, "setting clock-frequency@%dHz\n",
 670                          bsc_clk[0].hz);
 671                 dev->clk_freq_hz = bsc_clk[0].hz;
 672         }
 673
 674         /* set the data in/out register size for compatible SoCs */
 675         if (of_device_is_compatible(dev->device->of_node,
 676                                     "brcm,brcmper-i2c"))
 677                 dev->data_regsz = sizeof(u8);
 678         else
 679                 dev->data_regsz = sizeof(u32);
 680
 681         brcmstb_i2c_set_bsc_reg_defaults(dev);
 682
 683         /* Add the i2c adapter */
 684         adap = &dev->adapter;
 685         i2c_set_adapdata(adap, dev);
 686         adap->owner = THIS_MODULE;
 687         strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
 688         if (int_name)
 689                 strlcat(adap->name, int_name, sizeof(adap->name));
 690         adap->algo = &brcmstb_i2c_algo;
 691         adap->dev.parent = &pdev->dev;
 692         adap->dev.of_node = pdev->dev.of_node;
 693         rc = i2c_add_adapter(adap);
 694         if (rc)
 695                 goto probe_errorout;
 696
 697         dev_info(dev->device, "%s@%dhz registered in %s mode\n",
 698                  int_name ? int_name : " ", dev->clk_freq_hz,
 699                  (dev->irq >= 0) ? "interrupt" : "polling");
 700
 701         return 0;
 702
 703 probe_errorout:
 704         return rc;
 705 }
 706
 707 static int brcmstb_i2c_remove(struct platform_device *pdev)
 708 {
 709         struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
 710
 711         i2c_del_adapter(&dev->adapter);
 712         return 0;
 713 }
 714
 715 #ifdef CONFIG_PM_SLEEP
 716 static int brcmstb_i2c_suspend(struct device *dev)
 717 {
 718         struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 719
 720         i2c_mark_adapter_suspended(&i2c_dev->adapter);
 721         return 0;
 722 }
 723
 724 static int brcmstb_i2c_resume(struct device *dev)
 725 {
 726         struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 727
 728         brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
 729         i2c_mark_adapter_resumed(&i2c_dev->adapter);
 730
 731         return 0;
 732 }
 733 #endif
 734
 735 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
 736                          brcmstb_i2c_resume);
 737
 738 static const struct of_device_id brcmstb_i2c_of_match[] = {
 739         {.compatible = "brcm,brcmstb-i2c"},
 740         {.compatible = "brcm,brcmper-i2c"},
 741         {.compatible = "brcm,bcm2711-hdmi-i2c"},
 742         {},
 743 };
 744 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
 745
 746 static struct platform_driver brcmstb_i2c_driver = {
 747         .driver = {
 748                    .name = "brcmstb-i2c",
 749                    .of_match_table = brcmstb_i2c_of_match,
 750                    .pm = &brcmstb_i2c_pm,
 751                    },
 752         .probe = brcmstb_i2c_probe,
 753         .remove = brcmstb_i2c_remove,
 754 };
 755 module_platform_driver(brcmstb_i2c_driver);
 756
 757 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
 758 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
 759 MODULE_LICENSE("GPL v2");