drivers/i2c/designware_i2c.c

   1 /*
   2  * (C) Copyright 2009
   3  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <i2c.h>
  11 #include <pci.h>
  12 #include <asm/io.h>
  13 #include "designware_i2c.h"
  14
  15 struct dw_scl_sda_cfg {
  16         u32 ss_hcnt;
  17         u32 fs_hcnt;
  18         u32 ss_lcnt;
  19         u32 fs_lcnt;
  20         u32 sda_hold;
  21 };
  22
  23 #ifdef CONFIG_X86
  24 /* BayTrail HCNT/LCNT/SDA hold time */
  25 static struct dw_scl_sda_cfg byt_config = {
  26         .ss_hcnt = 0x200,
  27         .fs_hcnt = 0x55,
  28         .ss_lcnt = 0x200,
  29         .fs_lcnt = 0x99,
  30         .sda_hold = 0x6,
  31 };
  32 #endif
  33
  34 struct dw_i2c {
  35         struct i2c_regs *regs;
  36         struct dw_scl_sda_cfg *scl_sda_cfg;
  37 };
  38
  39 static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
  40 {
  41         u32 ena = enable ? IC_ENABLE_0B : 0;
  42         int timeout = 100;
  43
  44         do {
  45                 writel(ena, &i2c_base->ic_enable);
  46                 if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
  47                         return;
  48
  49                 /*
  50                  * Wait 10 times the signaling period of the highest I2C
  51                  * transfer supported by the driver (for 400KHz this is
  52                  * 25us) as described in the DesignWare I2C databook.
  53                  */
  54                 udelay(25);
  55         } while (timeout--);
  56
  57         printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
  58 }
  59
  60 /*
  61  * i2c_set_bus_speed - Set the i2c speed
  62  * @speed:      required i2c speed
  63  *
  64  * Set the i2c speed.
  65  */
  66 static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
  67                                            struct dw_scl_sda_cfg *scl_sda_cfg,
  68                                            unsigned int speed)
  69 {
  70         unsigned int cntl;
  71         unsigned int hcnt, lcnt;
  72         int i2c_spd;
  73
  74         if (speed >= I2C_MAX_SPEED)
  75                 i2c_spd = IC_SPEED_MODE_MAX;
  76         else if (speed >= I2C_FAST_SPEED)
  77                 i2c_spd = IC_SPEED_MODE_FAST;
  78         else
  79                 i2c_spd = IC_SPEED_MODE_STANDARD;
  80
  81         /* to set speed cltr must be disabled */
  82         dw_i2c_enable(i2c_base, false);
  83
  84         cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
  85
  86         switch (i2c_spd) {
  87 #ifndef CONFIG_X86 /* No High-speed for BayTrail yet */
  88         case IC_SPEED_MODE_MAX:
  89                 cntl |= IC_CON_SPD_SS;
  90                 if (scl_sda_cfg) {
  91                         hcnt = scl_sda_cfg->fs_hcnt;
  92                         lcnt = scl_sda_cfg->fs_lcnt;
  93                 } else {
  94                         hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
  95                         lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
  96                 }
  97                 writel(hcnt, &i2c_base->ic_hs_scl_hcnt);
  98                 writel(lcnt, &i2c_base->ic_hs_scl_lcnt);
  99                 break;
 100 #endif
 101
 102         case IC_SPEED_MODE_STANDARD:
 103                 cntl |= IC_CON_SPD_SS;
 104                 if (scl_sda_cfg) {
 105                         hcnt = scl_sda_cfg->ss_hcnt;
 106                         lcnt = scl_sda_cfg->ss_lcnt;
 107                 } else {
 108                         hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
 109                         lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
 110                 }
 111                 writel(hcnt, &i2c_base->ic_ss_scl_hcnt);
 112                 writel(lcnt, &i2c_base->ic_ss_scl_lcnt);
 113                 break;
 114
 115         case IC_SPEED_MODE_FAST:
 116         default:
 117                 cntl |= IC_CON_SPD_FS;
 118                 if (scl_sda_cfg) {
 119                         hcnt = scl_sda_cfg->fs_hcnt;
 120                         lcnt = scl_sda_cfg->fs_lcnt;
 121                 } else {
 122                         hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
 123                         lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
 124                 }
 125                 writel(hcnt, &i2c_base->ic_fs_scl_hcnt);
 126                 writel(lcnt, &i2c_base->ic_fs_scl_lcnt);
 127                 break;
 128         }
 129
 130         writel(cntl, &i2c_base->ic_con);
 131
 132         /* Configure SDA Hold Time if required */
 133         if (scl_sda_cfg)
 134                 writel(scl_sda_cfg->sda_hold, &i2c_base->ic_sda_hold);
 135
 136         /* Enable back i2c now speed set */
 137         dw_i2c_enable(i2c_base, true);
 138
 139         return 0;
 140 }
 141
 142 /*
 143  * i2c_setaddress - Sets the target slave address
 144  * @i2c_addr:   target i2c address
 145  *
 146  * Sets the target slave address.
 147  */
 148 static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr)
 149 {
 150         /* Disable i2c */
 151         dw_i2c_enable(i2c_base, false);
 152
 153         writel(i2c_addr, &i2c_base->ic_tar);
 154
 155         /* Enable i2c */
 156         dw_i2c_enable(i2c_base, true);
 157 }
 158
 159 /*
 160  * i2c_flush_rxfifo - Flushes the i2c RX FIFO
 161  *
 162  * Flushes the i2c RX FIFO
 163  */
 164 static void i2c_flush_rxfifo(struct i2c_regs *i2c_base)
 165 {
 166         while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE)
 167                 readl(&i2c_base->ic_cmd_data);
 168 }
 169
 170 /*
 171  * i2c_wait_for_bb - Waits for bus busy
 172  *
 173  * Waits for bus busy
 174  */
 175 static int i2c_wait_for_bb(struct i2c_regs *i2c_base)
 176 {
 177         unsigned long start_time_bb = get_timer(0);
 178
 179         while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) ||
 180                !(readl(&i2c_base->ic_status) & IC_STATUS_TFE)) {
 181
 182                 /* Evaluate timeout */
 183                 if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
 184                         return 1;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr,
 191                          int alen)
 192 {
 193         if (i2c_wait_for_bb(i2c_base))
 194                 return 1;
 195
 196         i2c_setaddress(i2c_base, chip);
 197         while (alen) {
 198                 alen--;
 199                 /* high byte address going out first */
 200                 writel((addr >> (alen * 8)) & 0xff,
 201                        &i2c_base->ic_cmd_data);
 202         }
 203         return 0;
 204 }
 205
 206 static int i2c_xfer_finish(struct i2c_regs *i2c_base)
 207 {
 208         ulong start_stop_det = get_timer(0);
 209
 210         while (1) {
 211                 if ((readl(&i2c_base->ic_raw_intr_stat) & IC_STOP_DET)) {
 212                         readl(&i2c_base->ic_clr_stop_det);
 213                         break;
 214                 } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
 215                         break;
 216                 }
 217         }
 218
 219         if (i2c_wait_for_bb(i2c_base)) {
 220                 printf("Timed out waiting for bus\n");
 221                 return 1;
 222         }
 223
 224         i2c_flush_rxfifo(i2c_base);
 225
 226         return 0;
 227 }
 228
 229 /*
 230  * i2c_read - Read from i2c memory
 231  * @chip:       target i2c address
 232  * @addr:       address to read from
 233  * @alen:
 234  * @buffer:     buffer for read data
 235  * @len:        no of bytes to be read
 236  *
 237  * Read from i2c memory.
 238  */
 239 static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr,
 240                          int alen, u8 *buffer, int len)
 241 {
 242         unsigned long start_time_rx;
 243
 244 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
 245         /*
 246          * EEPROM chips that implement "address overflow" are ones
 247          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
 248          * address and the extra bits end up in the "chip address"
 249          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
 250          * four 256 byte chips.
 251          *
 252          * Note that we consider the length of the address field to
 253          * still be one byte because the extra address bits are
 254          * hidden in the chip address.
 255          */
 256         dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
 257         addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
 258
 259         debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
 260               addr);
 261 #endif
 262
 263         if (i2c_xfer_init(i2c_base, dev, addr, alen))
 264                 return 1;
 265
 266         start_time_rx = get_timer(0);
 267         while (len) {
 268                 if (len == 1)
 269                         writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
 270                 else
 271                         writel(IC_CMD, &i2c_base->ic_cmd_data);
 272
 273                 if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) {
 274                         *buffer++ = (uchar)readl(&i2c_base->ic_cmd_data);
 275                         len--;
 276                         start_time_rx = get_timer(0);
 277
 278                 } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
 279                                 return 1;
 280                 }
 281         }
 282
 283         return i2c_xfer_finish(i2c_base);
 284 }
 285
 286 /*
 287  * i2c_write - Write to i2c memory
 288  * @chip:       target i2c address
 289  * @addr:       address to read from
 290  * @alen:
 291  * @buffer:     buffer for read data
 292  * @len:        no of bytes to be read
 293  *
 294  * Write to i2c memory.
 295  */
 296 static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
 297                           int alen, u8 *buffer, int len)
 298 {
 299         int nb = len;
 300         unsigned long start_time_tx;
 301
 302 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
 303         /*
 304          * EEPROM chips that implement "address overflow" are ones
 305          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
 306          * address and the extra bits end up in the "chip address"
 307          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
 308          * four 256 byte chips.
 309          *
 310          * Note that we consider the length of the address field to
 311          * still be one byte because the extra address bits are
 312          * hidden in the chip address.
 313          */
 314         dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
 315         addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
 316
 317         debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
 318               addr);
 319 #endif
 320
 321         if (i2c_xfer_init(i2c_base, dev, addr, alen))
 322                 return 1;
 323
 324         start_time_tx = get_timer(0);
 325         while (len) {
 326                 if (readl(&i2c_base->ic_status) & IC_STATUS_TFNF) {
 327                         if (--len == 0) {
 328                                 writel(*buffer | IC_STOP,
 329                                        &i2c_base->ic_cmd_data);
 330                         } else {
 331                                 writel(*buffer, &i2c_base->ic_cmd_data);
 332                         }
 333                         buffer++;
 334                         start_time_tx = get_timer(0);
 335
 336                 } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
 337                                 printf("Timed out. i2c write Failed\n");
 338                                 return 1;
 339                 }
 340         }
 341
 342         return i2c_xfer_finish(i2c_base);
 343 }
 344
 345 /*
 346  * __dw_i2c_init - Init function
 347  * @speed:      required i2c speed
 348  * @slaveaddr:  slave address for the device
 349  *
 350  * Initialization function.
 351  */
 352 static void __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr)
 353 {
 354         /* Disable i2c */
 355         dw_i2c_enable(i2c_base, false);
 356
 357         writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_base->ic_con);
 358         writel(IC_RX_TL, &i2c_base->ic_rx_tl);
 359         writel(IC_TX_TL, &i2c_base->ic_tx_tl);
 360         writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
 361 #ifndef CONFIG_DM_I2C
 362         __dw_i2c_set_bus_speed(i2c_base, NULL, speed);
 363         writel(slaveaddr, &i2c_base->ic_sar);
 364 #endif
 365
 366         /* Enable i2c */
 367         dw_i2c_enable(i2c_base, true);
 368 }
 369
 370 #ifndef CONFIG_DM_I2C
 371 /*
 372  * The legacy I2C functions. These need to get removed once
 373  * all users of this driver are converted to DM.
 374  */
 375 static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
 376 {
 377         switch (adap->hwadapnr) {
 378 #if CONFIG_SYS_I2C_BUS_MAX >= 4
 379         case 3:
 380                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
 381 #endif
 382 #if CONFIG_SYS_I2C_BUS_MAX >= 3
 383         case 2:
 384                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
 385 #endif
 386 #if CONFIG_SYS_I2C_BUS_MAX >= 2
 387         case 1:
 388                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
 389 #endif
 390         case 0:
 391                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
 392         default:
 393                 printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
 394         }
 395
 396         return NULL;
 397 }
 398
 399 static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
 400                                          unsigned int speed)
 401 {
 402         adap->speed = speed;
 403         return __dw_i2c_set_bus_speed(i2c_get_base(adap), NULL, speed);
 404 }
 405
 406 static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 407 {
 408         __dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
 409 }
 410
 411 static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
 412                        int alen, u8 *buffer, int len)
 413 {
 414         return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len);
 415 }
 416
 417 static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
 418                         int alen, u8 *buffer, int len)
 419 {
 420         return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len);
 421 }
 422
 423 /* dw_i2c_probe - Probe the i2c chip */
 424 static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev)
 425 {
 426         struct i2c_regs *i2c_base = i2c_get_base(adap);
 427         u32 tmp;
 428         int ret;
 429
 430         /*
 431          * Try to read the first location of the chip.
 432          */
 433         ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1);
 434         if (ret)
 435                 dw_i2c_init(adap, adap->speed, adap->slaveaddr);
 436
 437         return ret;
 438 }
 439
 440 U_BOOT_I2C_ADAP_COMPLETE(dw_0, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
 441                          dw_i2c_write, dw_i2c_set_bus_speed,
 442                          CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0)
 443
 444 #if CONFIG_SYS_I2C_BUS_MAX >= 2
 445 U_BOOT_I2C_ADAP_COMPLETE(dw_1, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
 446                          dw_i2c_write, dw_i2c_set_bus_speed,
 447                          CONFIG_SYS_I2C_SPEED1, CONFIG_SYS_I2C_SLAVE1, 1)
 448 #endif
 449
 450 #if CONFIG_SYS_I2C_BUS_MAX >= 3
 451 U_BOOT_I2C_ADAP_COMPLETE(dw_2, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
 452                          dw_i2c_write, dw_i2c_set_bus_speed,
 453                          CONFIG_SYS_I2C_SPEED2, CONFIG_SYS_I2C_SLAVE2, 2)
 454 #endif
 455
 456 #if CONFIG_SYS_I2C_BUS_MAX >= 4
 457 U_BOOT_I2C_ADAP_COMPLETE(dw_3, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
 458                          dw_i2c_write, dw_i2c_set_bus_speed,
 459                          CONFIG_SYS_I2C_SPEED3, CONFIG_SYS_I2C_SLAVE3, 3)
 460 #endif
 461
 462 #else /* CONFIG_DM_I2C */
 463 /* The DM I2C functions */
 464
 465 static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 466                                int nmsgs)
 467 {
 468         struct dw_i2c *i2c = dev_get_priv(bus);
 469         int ret;
 470
 471         debug("i2c_xfer: %d messages\n", nmsgs);
 472         for (; nmsgs > 0; nmsgs--, msg++) {
 473                 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 474                 if (msg->flags & I2C_M_RD) {
 475                         ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0,
 476                                             msg->buf, msg->len);
 477                 } else {
 478                         ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0,
 479                                              msg->buf, msg->len);
 480                 }
 481                 if (ret) {
 482                         debug("i2c_write: error sending\n");
 483                         return -EREMOTEIO;
 484                 }
 485         }
 486
 487         return 0;
 488 }
 489
 490 static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 491 {
 492         struct dw_i2c *i2c = dev_get_priv(bus);
 493
 494         return __dw_i2c_set_bus_speed(i2c->regs, i2c->scl_sda_cfg, speed);
 495 }
 496
 497 static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr,
 498                                      uint chip_flags)
 499 {
 500         struct dw_i2c *i2c = dev_get_priv(bus);
 501         struct i2c_regs *i2c_base = i2c->regs;
 502         u32 tmp;
 503         int ret;
 504
 505         /* Try to read the first location of the chip */
 506         ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1);
 507         if (ret)
 508                 __dw_i2c_init(i2c_base, 0, 0);
 509
 510         return ret;
 511 }
 512
 513 static int designware_i2c_probe(struct udevice *bus)
 514 {
 515         struct dw_i2c *priv = dev_get_priv(bus);
 516
 517         if (device_is_on_pci_bus(bus)) {
 518 #ifdef CONFIG_DM_PCI
 519                 /* Save base address from PCI BAR */
 520                 priv->regs = (struct i2c_regs *)
 521                         dm_pci_map_bar(bus, PCI_BASE_ADDRESS_0, PCI_REGION_MEM);
 522 #ifdef CONFIG_X86
 523                 /* Use BayTrail specific timing values */
 524                 priv->scl_sda_cfg = &byt_config;
 525 #endif
 526 #endif
 527         } else {
 528                 priv->regs = (struct i2c_regs *)dev_get_addr_ptr(bus);
 529         }
 530
 531         __dw_i2c_init(priv->regs, 0, 0);
 532
 533         return 0;
 534 }
 535
 536 static int designware_i2c_bind(struct udevice *dev)
 537 {
 538         static int num_cards;
 539         char name[20];
 540
 541         /* Create a unique device name for PCI type devices */
 542         if (device_is_on_pci_bus(dev)) {
 543                 /*
 544                  * ToDo:
 545                  * Setting req_seq in the driver is probably not recommended.
 546                  * But without a DT alias the number is not configured. And
 547                  * using this driver is impossible for PCIe I2C devices.
 548                  * This can be removed, once a better (correct) way for this
 549                  * is found and implemented.
 550                  */
 551                 dev->req_seq = num_cards;
 552                 sprintf(name, "i2c_designware#%u", num_cards++);
 553                 device_set_name(dev, name);
 554         }
 555
 556         return 0;
 557 }
 558
 559 static const struct dm_i2c_ops designware_i2c_ops = {
 560         .xfer           = designware_i2c_xfer,
 561         .probe_chip     = designware_i2c_probe_chip,
 562         .set_bus_speed  = designware_i2c_set_bus_speed,
 563 };
 564
 565 static const struct udevice_id designware_i2c_ids[] = {
 566         { .compatible = "snps,designware-i2c" },
 567         { }
 568 };
 569
 570 U_BOOT_DRIVER(i2c_designware) = {
 571         .name   = "i2c_designware",
 572         .id     = UCLASS_I2C,
 573         .of_match = designware_i2c_ids,
 574         .bind   = designware_i2c_bind,
 575         .probe  = designware_i2c_probe,
 576         .priv_auto_alloc_size = sizeof(struct dw_i2c),
 577         .ops    = &designware_i2c_ops,
 578 };
 579
 580 #ifdef CONFIG_X86
 581 static struct pci_device_id designware_pci_supported[] = {
 582         /* Intel BayTrail has 7 I2C controller located on the PCI bus */
 583         { PCI_VDEVICE(INTEL, 0x0f41) },
 584         { PCI_VDEVICE(INTEL, 0x0f42) },
 585         { PCI_VDEVICE(INTEL, 0x0f43) },
 586         { PCI_VDEVICE(INTEL, 0x0f44) },
 587         { PCI_VDEVICE(INTEL, 0x0f45) },
 588         { PCI_VDEVICE(INTEL, 0x0f46) },
 589         { PCI_VDEVICE(INTEL, 0x0f47) },
 590         {},
 591 };
 592
 593 U_BOOT_PCI_DEVICE(i2c_designware, designware_pci_supported);
 594 #endif
 595
 596 #endif /* CONFIG_DM_I2C */