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 #include <linux/version.h>
  26
  27 #define N_DATA_REGS                                     8
  28
  29 /*
  30  * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register
  31  * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per
  32  * data register whereas STB SoCs use 4 byte per data register transfer,
  33  * account for this difference in total count per transaction and mask to
  34  * use.
  35  */
  36 #define BSC_CNT_REG1_MASK(nb)   (nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))
  37 #define BSC_CNT_REG1_SHIFT      0
  38
  39 /* BSC CTL register field definitions */
  40 #define BSC_CTL_REG_DTF_MASK                            0x00000003
  41 #define BSC_CTL_REG_SCL_SEL_MASK                        0x00000030
  42 #define BSC_CTL_REG_SCL_SEL_SHIFT                       4
  43 #define BSC_CTL_REG_INT_EN_MASK                         0x00000040
  44 #define BSC_CTL_REG_INT_EN_SHIFT                        6
  45 #define BSC_CTL_REG_DIV_CLK_MASK                        0x00000080
  46
  47 /* BSC_IIC_ENABLE r/w enable and interrupt field definitions */
  48 #define BSC_IIC_EN_RESTART_MASK                         0x00000040
  49 #define BSC_IIC_EN_NOSTART_MASK                         0x00000020
  50 #define BSC_IIC_EN_NOSTOP_MASK                          0x00000010
  51 #define BSC_IIC_EN_NOACK_MASK                           0x00000004
  52 #define BSC_IIC_EN_INTRP_MASK                           0x00000002
  53 #define BSC_IIC_EN_ENABLE_MASK                          0x00000001
  54
  55 /* BSC_CTLHI control register field definitions */
  56 #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK        0x00000080
  57 #define BSC_CTLHI_REG_DATAREG_SIZE_MASK                 0x00000040
  58 #define BSC_CTLHI_REG_IGNORE_ACK_MASK                   0x00000002
  59 #define BSC_CTLHI_REG_WAIT_DIS_MASK                     0x00000001
  60
  61 #define I2C_TIMEOUT                                     100 /* msecs */
  62
  63 /* Condition mask used for non combined transfer */
  64 #define COND_RESTART            BSC_IIC_EN_RESTART_MASK
  65 #define COND_NOSTART            BSC_IIC_EN_NOSTART_MASK
  66 #define COND_NOSTOP             BSC_IIC_EN_NOSTOP_MASK
  67 #define COND_START_STOP         (COND_RESTART | COND_NOSTART | COND_NOSTOP)
  68
  69 /* BSC data transfer direction */
  70 #define DTF_WR_MASK             0x00000000
  71 #define DTF_RD_MASK             0x00000001
  72 /* BSC data transfer direction combined format */
  73 #define DTF_RD_WR_MASK          0x00000002
  74 #define DTF_WR_RD_MASK          0x00000003
  75
  76 #define INT_ENABLE              true
  77 #define INT_DISABLE             false
  78
  79 /* BSC block register map structure to cache fields to be written */
  80 struct bsc_regs {
  81         u32     chip_address;           /* slave address */
  82         u32     data_in[N_DATA_REGS];   /* tx data buffer*/
  83         u32     cnt_reg;                /* rx/tx data length */
  84         u32     ctl_reg;                /* control register */
  85         u32     iic_enable;             /* xfer enable and status */
  86         u32     data_out[N_DATA_REGS];  /* rx data buffer */
  87         u32     ctlhi_reg;              /* more control fields */
  88         u32     scl_param;              /* reserved */
  89 };
  90
  91 struct bsc_clk_param {
  92         u32 hz;
  93         u32 scl_mask;
  94         u32 div_mask;
  95 };
  96
  97 enum bsc_xfer_cmd {
  98         CMD_WR,
  99         CMD_RD,
 100         CMD_WR_NOACK,
 101         CMD_RD_NOACK,
 102 };
 103
 104 static char const *cmd_string[] = {
 105         [CMD_WR] = "WR",
 106         [CMD_RD] = "RD",
 107         [CMD_WR_NOACK] = "WR NOACK",
 108         [CMD_RD_NOACK] = "RD NOACK",
 109 };
 110
 111 enum bus_speeds {
 112         SPD_375K,
 113         SPD_390K,
 114         SPD_187K,
 115         SPD_200K,
 116         SPD_93K,
 117         SPD_97K,
 118         SPD_46K,
 119         SPD_50K
 120 };
 121
 122 static const struct bsc_clk_param bsc_clk[] = {
 123         [SPD_375K] = {
 124                 .hz = 375000,
 125                 .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
 126                 .div_mask = 0
 127         },
 128         [SPD_390K] = {
 129                 .hz = 390000,
 130                 .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
 131                 .div_mask = 0
 132         },
 133         [SPD_187K] = {
 134                 .hz = 187500,
 135                 .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
 136                 .div_mask = 0
 137         },
 138         [SPD_200K] = {
 139                 .hz = 200000,
 140                 .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
 141                 .div_mask = 0
 142         },
 143         [SPD_93K]  = {
 144                 .hz = 93750,
 145                 .scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
 146                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 147         },
 148         [SPD_97K]  = {
 149                 .hz = 97500,
 150                 .scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
 151                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 152         },
 153         [SPD_46K]  = {
 154                 .hz = 46875,
 155                 .scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
 156                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 157         },
 158         [SPD_50K]  = {
 159                 .hz = 50000,
 160                 .scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
 161                 .div_mask = BSC_CTL_REG_DIV_CLK_MASK
 162         }
 163 };
 164
 165 struct brcmstb_i2c_dev {
 166         struct device *device;
 167         void __iomem *base;
 168         void __iomem *irq_base;
 169         int irq;
 170         struct bsc_regs *bsc_regmap;
 171         struct i2c_adapter adapter;
 172         struct completion done;
 173         bool is_suspended;
 174         u32 clk_freq_hz;
 175         int data_regsz;
 176 };
 177
 178 /* register accessors for both be and le cpu arch */
 179 #ifdef CONFIG_CPU_BIG_ENDIAN
 180 #define __bsc_readl(_reg) ioread32be(_reg)
 181 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
 182 #else
 183 #define __bsc_readl(_reg) ioread32(_reg)
 184 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
 185 #endif
 186
 187 #define bsc_readl(_dev, _reg)                                           \
 188         __bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
 189
 190 #define bsc_writel(_dev, _val, _reg)                                    \
 191         __bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
 192
 193 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
 194 {
 195         return (N_DATA_REGS * dev->data_regsz);
 196 }
 197
 198 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
 199 {
 200         return dev->data_regsz;
 201 }
 202
 203 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
 204                                            bool int_en)
 205 {
 206
 207         if (int_en)
 208                 /* Enable BSC  CTL interrupt line */
 209                 dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
 210         else
 211                 /* Disable BSC CTL interrupt line */
 212                 dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
 213
 214         barrier();
 215         bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
 216 }
 217
 218 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
 219 {
 220         struct brcmstb_i2c_dev *dev = devid;
 221         u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
 222         u32 status_iic_intrp = bsc_readl(dev, iic_enable);
 223
 224         dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
 225                 status_bsc_ctl, status_iic_intrp);
 226
 227         if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
 228                 return IRQ_NONE;
 229
 230         brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 231         complete_all(&dev->done);
 232
 233         dev_dbg(dev->device, "isr handled");
 234         return IRQ_HANDLED;
 235 }
 236
 237 /* Wait for device to be ready */
 238 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
 239 {
 240         unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
 241
 242         while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
 243                 if (time_after(jiffies, timeout))
 244                         return -ETIMEDOUT;
 245                 cpu_relax();
 246         }
 247         return 0;
 248 }
 249
 250 /* i2c xfer completion function, handles both irq and polling mode */
 251 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
 252 {
 253         int ret = 0;
 254         unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
 255
 256         if (dev->irq >= 0) {
 257                 if (!wait_for_completion_timeout(&dev->done, timeout))
 258                         ret = -ETIMEDOUT;
 259         } else {
 260                 /* we are in polling mode */
 261                 u32 bsc_intrp;
 262                 unsigned long time_left = jiffies + timeout;
 263
 264                 do {
 265                         bsc_intrp = bsc_readl(dev, iic_enable) &
 266                                 BSC_IIC_EN_INTRP_MASK;
 267                         if (time_after(jiffies, time_left)) {
 268                                 ret = -ETIMEDOUT;
 269                                 break;
 270                         }
 271                         cpu_relax();
 272                 } while (!bsc_intrp);
 273         }
 274
 275         if (dev->irq < 0 || ret == -ETIMEDOUT)
 276                 brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 277
 278         return ret;
 279 }
 280
 281 /* Set xfer START/STOP conditions for subsequent transfer */
 282 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
 283                                        u32 cond_flag)
 284 {
 285         u32 regval = dev->bsc_regmap->iic_enable;
 286
 287         dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
 288 }
 289
 290 /* Send I2C request check completion */
 291 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
 292                                 enum bsc_xfer_cmd cmd)
 293 {
 294         int rc = 0;
 295         struct bsc_regs *pi2creg = dev->bsc_regmap;
 296
 297         /* Make sure the hardware is ready */
 298         rc = brcmstb_i2c_wait_if_busy(dev);
 299         if (rc < 0)
 300                 return rc;
 301
 302         /* only if we are in interrupt mode */
 303         if (dev->irq >= 0)
 304                 reinit_completion(&dev->done);
 305
 306         /* enable BSC CTL interrupt line */
 307         brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
 308
 309         /* initiate transfer by setting iic_enable */
 310         pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
 311         bsc_writel(dev, pi2creg->iic_enable, iic_enable);
 312
 313         /* Wait for transaction to finish or timeout */
 314         rc = brcmstb_i2c_wait_for_completion(dev);
 315         if (rc) {
 316                 dev_dbg(dev->device, "intr timeout for cmd %s\n",
 317                         cmd_string[cmd]);
 318                 goto cmd_out;
 319         }
 320
 321         if ((CMD_RD || CMD_WR) &&
 322             bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
 323                 rc = -EREMOTEIO;
 324                 dev_dbg(dev->device, "controller received NOACK intr for %s\n",
 325                         cmd_string[cmd]);
 326         }
 327
 328 cmd_out:
 329         bsc_writel(dev, 0, cnt_reg);
 330         bsc_writel(dev, 0, iic_enable);
 331
 332         return rc;
 333 }
 334
 335 /* Actual data transfer through the BSC master */
 336 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
 337                                      u8 *buf, unsigned int len,
 338                                      struct i2c_msg *pmsg)
 339 {
 340         int cnt, byte, i, rc;
 341         enum bsc_xfer_cmd cmd;
 342         u32 ctl_reg;
 343         struct bsc_regs *pi2creg = dev->bsc_regmap;
 344         int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
 345         int data_regsz = brcmstb_i2c_get_data_regsz(dev);
 346         int xfersz = brcmstb_i2c_get_xfersz(dev);
 347
 348         /* see if the transaction needs to check NACK conditions */
 349         if (no_ack || len <= xfersz) {
 350                 cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
 351                         : CMD_WR_NOACK;
 352                 pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
 353         } else {
 354                 cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
 355                 pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
 356         }
 357         bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
 358
 359         /* set data transfer direction */
 360         ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
 361         if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
 362                 pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
 363         else
 364                 pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
 365
 366         /* set the read/write length */
 367         bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
 368                    (len << BSC_CNT_REG1_SHIFT), cnt_reg);
 369
 370         /* Write data into data_in register */
 371
 372         if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
 373                 for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
 374                         u32 word = 0;
 375
 376                         for (byte = 0; byte < data_regsz; byte++) {
 377                                 word >>= BITS_PER_BYTE;
 378                                 if ((cnt + byte) < len)
 379                                         word |= buf[cnt + byte] <<
 380                                         (BITS_PER_BYTE * (data_regsz - 1));
 381                         }
 382                         bsc_writel(dev, word, data_in[i]);
 383                 }
 384         }
 385
 386         /* Initiate xfer, the function will return on completion */
 387         rc = brcmstb_send_i2c_cmd(dev, cmd);
 388
 389         if (rc != 0) {
 390                 dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
 391                 return rc;
 392         }
 393
 394         /* Read data from data_out register */
 395         if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
 396                 for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
 397                         u32 data = bsc_readl(dev, data_out[i]);
 398
 399                         for (byte = 0; byte < data_regsz &&
 400                                      (byte + cnt) < len; byte++) {
 401                                 buf[cnt + byte] = data & 0xff;
 402                                 data >>= BITS_PER_BYTE;
 403                         }
 404                 }
 405         }
 406
 407         return 0;
 408 }
 409
 410 /* Write a single byte of data to the i2c bus */
 411 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
 412                                        u8 *buf, unsigned int nak_expected)
 413 {
 414         enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
 415
 416         bsc_writel(dev, 1, cnt_reg);
 417         bsc_writel(dev, *buf, data_in);
 418
 419         return brcmstb_send_i2c_cmd(dev, cmd);
 420 }
 421
 422 /* Send i2c address */
 423 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
 424                                struct i2c_msg *msg)
 425 {
 426         unsigned char addr;
 427
 428         if (msg->flags & I2C_M_TEN) {
 429                 /* First byte is 11110XX0 where XX is upper 2 bits */
 430                 addr = 0xF0 | ((msg->addr & 0x300) >> 7);
 431                 bsc_writel(dev, addr, chip_address);
 432
 433                 /* Second byte is the remaining 8 bits */
 434                 addr = msg->addr & 0xFF;
 435                 if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
 436                         return -EREMOTEIO;
 437
 438                 if (msg->flags & I2C_M_RD) {
 439                         /* For read, send restart without stop condition */
 440                         brcmstb_set_i2c_start_stop(dev, COND_RESTART
 441                                                    | COND_NOSTOP);
 442                         /* Then re-send the first byte with the read bit set */
 443                         addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
 444                         if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
 445                                 return -EREMOTEIO;
 446
 447                 }
 448         } else {
 449                 addr = i2c_8bit_addr_from_msg(msg);
 450
 451                 bsc_writel(dev, addr, chip_address);
 452         }
 453
 454         return 0;
 455 }
 456
 457 /* Master transfer function */
 458 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
 459                             struct i2c_msg msgs[], int num)
 460 {
 461         struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
 462         struct i2c_msg *pmsg;
 463         int rc = 0;
 464         int i;
 465         int bytes_to_xfer;
 466         u8 *tmp_buf;
 467         int len = 0;
 468         int xfersz = brcmstb_i2c_get_xfersz(dev);
 469
 470         if (dev->is_suspended)
 471                 return -EBUSY;
 472
 473         /* Loop through all messages */
 474         for (i = 0; i < num; i++) {
 475                 pmsg = &msgs[i];
 476                 len = pmsg->len;
 477                 tmp_buf = pmsg->buf;
 478
 479                 dev_dbg(dev->device,
 480                         "msg# %d/%d flg %x buf %x len %d\n", i,
 481                         num - 1, pmsg->flags,
 482                         pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
 483
 484                 if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
 485                         brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
 486                 else
 487                         brcmstb_set_i2c_start_stop(dev,
 488                                                    COND_RESTART | COND_NOSTOP);
 489
 490                 /* Send slave address */
 491                 if (!(pmsg->flags & I2C_M_NOSTART)) {
 492                         rc = brcmstb_i2c_do_addr(dev, pmsg);
 493                         if (rc < 0) {
 494                                 dev_dbg(dev->device,
 495                                         "NACK for addr %2.2x msg#%d rc = %d\n",
 496                                         pmsg->addr, i, rc);
 497                                 goto out;
 498                         }
 499                 }
 500
 501                 /* Perform data transfer */
 502                 while (len) {
 503                         bytes_to_xfer = min(len, xfersz);
 504
 505                         if (len <= xfersz && i == (num - 1))
 506                                 brcmstb_set_i2c_start_stop(dev,
 507                                                            ~(COND_START_STOP));
 508
 509                         rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
 510                                                        bytes_to_xfer, pmsg);
 511                         if (rc < 0)
 512                                 goto out;
 513
 514                         len -=  bytes_to_xfer;
 515                         tmp_buf += bytes_to_xfer;
 516                 }
 517         }
 518
 519         rc = num;
 520 out:
 521         return rc;
 522
 523 }
 524
 525 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
 526 {
 527         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
 528                 | I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
 529 }
 530
 531 static const struct i2c_algorithm brcmstb_i2c_algo = {
 532         .master_xfer = brcmstb_i2c_xfer,
 533         .functionality = brcmstb_i2c_functionality,
 534 };
 535
 536 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
 537 {
 538         int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
 539         u32 clk_freq_hz = dev->clk_freq_hz;
 540
 541         for (i = 0; i < num_speeds; i++) {
 542                 if (bsc_clk[i].hz == clk_freq_hz) {
 543                         dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
 544                                                 | BSC_CTL_REG_DIV_CLK_MASK);
 545                         dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
 546                                                      bsc_clk[i].div_mask);
 547                         bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
 548                         break;
 549                 }
 550         }
 551
 552         /* in case we did not get find a valid speed */
 553         if (i == num_speeds) {
 554                 i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
 555                         BSC_CTL_REG_SCL_SEL_SHIFT;
 556                 dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
 557                         bsc_clk[i].hz);
 558         }
 559 }
 560
 561 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
 562 {
 563         if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
 564                 /* set 4 byte data in/out xfers  */
 565                 dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
 566         else
 567                 dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
 568
 569         bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
 570         /* set bus speed */
 571         brcmstb_i2c_set_bus_speed(dev);
 572 }
 573
 574 static int brcmstb_i2c_probe(struct platform_device *pdev)
 575 {
 576         int rc = 0;
 577         struct brcmstb_i2c_dev *dev;
 578         struct i2c_adapter *adap;
 579         struct resource *iomem;
 580         const char *int_name;
 581
 582         /* Allocate memory for private data structure */
 583         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 584         if (!dev)
 585                 return -ENOMEM;
 586
 587         dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
 588         if (!dev->bsc_regmap)
 589                 return -ENOMEM;
 590
 591         platform_set_drvdata(pdev, dev);
 592         dev->device = &pdev->dev;
 593         init_completion(&dev->done);
 594
 595         /* Map hardware registers */
 596         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 597         dev->base = devm_ioremap_resource(dev->device, iomem);
 598         if (IS_ERR(dev->base)) {
 599                 rc = -ENOMEM;
 600                 goto probe_errorout;
 601         }
 602
 603         rc = of_property_read_string(dev->device->of_node, "interrupt-names",
 604                                      &int_name);
 605         if (rc < 0)
 606                 int_name = NULL;
 607
 608         /* Get the interrupt number */
 609         dev->irq = platform_get_irq(pdev, 0);
 610
 611         /* disable the bsc interrupt line */
 612         brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
 613
 614         /* register the ISR handler */
 615         rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
 616                               IRQF_SHARED,
 617                               int_name ? int_name : pdev->name,
 618                               dev);
 619
 620         if (rc) {
 621                 dev_dbg(dev->device, "falling back to polling mode");
 622                 dev->irq = -1;
 623         }
 624
 625         if (of_property_read_u32(dev->device->of_node,
 626                                  "clock-frequency", &dev->clk_freq_hz)) {
 627                 dev_warn(dev->device, "setting clock-frequency@%dHz\n",
 628                          bsc_clk[0].hz);
 629                 dev->clk_freq_hz = bsc_clk[0].hz;
 630         }
 631
 632         /* set the data in/out register size for compatible SoCs */
 633         if (of_device_is_compatible(dev->device->of_node,
 634                                     "brcmstb,brcmper-i2c"))
 635                 dev->data_regsz = sizeof(u8);
 636         else
 637                 dev->data_regsz = sizeof(u32);
 638
 639         brcmstb_i2c_set_bsc_reg_defaults(dev);
 640
 641         /* Add the i2c adapter */
 642         adap = &dev->adapter;
 643         i2c_set_adapdata(adap, dev);
 644         adap->owner = THIS_MODULE;
 645         strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
 646         if (int_name)
 647                 strlcat(adap->name, int_name, sizeof(adap->name));
 648         adap->algo = &brcmstb_i2c_algo;
 649         adap->dev.parent = &pdev->dev;
 650         adap->dev.of_node = pdev->dev.of_node;
 651         rc = i2c_add_adapter(adap);
 652         if (rc) {
 653                 dev_err(dev->device, "failed to add adapter\n");
 654                 goto probe_errorout;
 655         }
 656
 657         dev_info(dev->device, "%s@%dhz registered in %s mode\n",
 658                  int_name ? int_name : " ", dev->clk_freq_hz,
 659                  (dev->irq >= 0) ? "interrupt" : "polling");
 660
 661         return 0;
 662
 663 probe_errorout:
 664         return rc;
 665 }
 666
 667 static int brcmstb_i2c_remove(struct platform_device *pdev)
 668 {
 669         struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
 670
 671         i2c_del_adapter(&dev->adapter);
 672         return 0;
 673 }
 674
 675 #ifdef CONFIG_PM_SLEEP
 676 static int brcmstb_i2c_suspend(struct device *dev)
 677 {
 678         struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 679
 680         i2c_lock_adapter(&i2c_dev->adapter);
 681         i2c_dev->is_suspended = true;
 682         i2c_unlock_adapter(&i2c_dev->adapter);
 683
 684         return 0;
 685 }
 686
 687 static int brcmstb_i2c_resume(struct device *dev)
 688 {
 689         struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 690
 691         i2c_lock_adapter(&i2c_dev->adapter);
 692         brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
 693         i2c_dev->is_suspended = false;
 694         i2c_unlock_adapter(&i2c_dev->adapter);
 695
 696         return 0;
 697 }
 698 #endif
 699
 700 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
 701                          brcmstb_i2c_resume);
 702
 703 static const struct of_device_id brcmstb_i2c_of_match[] = {
 704         {.compatible = "brcm,brcmstb-i2c"},
 705         {.compatible = "brcm,brcmper-i2c"},
 706         {},
 707 };
 708 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
 709
 710 static struct platform_driver brcmstb_i2c_driver = {
 711         .driver = {
 712                    .name = "brcmstb-i2c",
 713                    .of_match_table = brcmstb_i2c_of_match,
 714                    .pm = &brcmstb_i2c_pm,
 715                    },
 716         .probe = brcmstb_i2c_probe,
 717         .remove = brcmstb_i2c_remove,
 718 };
 719 module_platform_driver(brcmstb_i2c_driver);
 720
 721 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
 722 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
 723 MODULE_LICENSE("GPL v2");