drivers/i2c/designware_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2009
   4  * Vipin Kumar, STMicroelectronics, vipin.kumar@st.com.
   5  */
   6
   7 #include <common.h>
   8 #include <clk.h>
   9 #include <dm.h>
  10 #include <i2c.h>
  11 #include <log.h>
  12 #include <malloc.h>
  13 #include <pci.h>
  14 #include <reset.h>
  15 #include <asm/io.h>
  16 #include <linux/delay.h>
  17 #include "designware_i2c.h"
  18 #include <dm/device_compat.h>
  19 #include <linux/err.h>
  20
  21 /*
  22  * This assigned unique hex value is constant and is derived from the two ASCII
  23  * letters 'DW' followed by a 16-bit unsigned number
  24  */
  25 #define DW_I2C_COMP_TYPE        0x44570140
  26
  27 static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
  28 {
  29         u32 ena = enable ? IC_ENABLE_0B : 0;
  30         int timeout = 100;
  31
  32         do {
  33                 writel(ena, &i2c_base->ic_enable);
  34                 if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
  35                         return 0;
  36
  37                 /*
  38                  * Wait 10 times the signaling period of the highest I2C
  39                  * transfer supported by the driver (for 400KHz this is
  40                  * 25us) as described in the DesignWare I2C databook.
  41                  */
  42                 udelay(25);
  43         } while (timeout--);
  44         printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
  45
  46         return -ETIMEDOUT;
  47 }
  48
  49 /* High and low times in different speed modes (in ns) */
  50 enum {
  51         /* SDA Hold Time */
  52         DEFAULT_SDA_HOLD_TIME           = 300,
  53 };
  54
  55 /**
  56  * calc_counts() - Convert a period to a number of IC clk cycles
  57  *
  58  * @ic_clk: Input clock in Hz
  59  * @period_ns: Period to represent, in ns
  60  * Return: calculated count
  61  */
  62 static uint calc_counts(uint ic_clk, uint period_ns)
  63 {
  64         return DIV_ROUND_UP(ic_clk / 1000 * period_ns, NANO_TO_KILO);
  65 }
  66
  67 /**
  68  * struct i2c_mode_info - Information about an I2C speed mode
  69  *
  70  * Each speed mode has its own characteristics. This struct holds these to aid
  71  * calculations in dw_i2c_calc_timing().
  72  *
  73  * @speed: Speed in Hz
  74  * @min_scl_lowtime_ns: Minimum value for SCL low period in ns
  75  * @min_scl_hightime_ns: Minimum value for SCL high period in ns
  76  * @def_rise_time_ns: Default rise time in ns
  77  * @def_fall_time_ns: Default fall time in ns
  78  */
  79 struct i2c_mode_info {
  80         int speed;
  81         int min_scl_hightime_ns;
  82         int min_scl_lowtime_ns;
  83         int def_rise_time_ns;
  84         int def_fall_time_ns;
  85 };
  86
  87 static const struct i2c_mode_info info_for_mode[] = {
  88         [IC_SPEED_MODE_STANDARD] = {
  89                 I2C_SPEED_STANDARD_RATE,
  90                 MIN_SS_SCL_HIGHTIME,
  91                 MIN_SS_SCL_LOWTIME,
  92                 1000,
  93                 300,
  94         },
  95         [IC_SPEED_MODE_FAST] = {
  96                 I2C_SPEED_FAST_RATE,
  97                 MIN_FS_SCL_HIGHTIME,
  98                 MIN_FS_SCL_LOWTIME,
  99                 300,
 100                 300,
 101         },
 102         [IC_SPEED_MODE_FAST_PLUS] = {
 103                 I2C_SPEED_FAST_PLUS_RATE,
 104                 MIN_FP_SCL_HIGHTIME,
 105                 MIN_FP_SCL_LOWTIME,
 106                 260,
 107                 500,
 108         },
 109         [IC_SPEED_MODE_HIGH] = {
 110                 I2C_SPEED_HIGH_RATE,
 111                 MIN_HS_SCL_HIGHTIME,
 112                 MIN_HS_SCL_LOWTIME,
 113                 120,
 114                 120,
 115         },
 116 };
 117
 118 /**
 119  * dw_i2c_calc_timing() - Calculate the timings to use for a bus
 120  *
 121  * @priv: Bus private information (NULL if not using driver model)
 122  * @mode: Speed mode to use
 123  * @ic_clk: IC clock speed in Hz
 124  * @spk_cnt: Spike-suppression count
 125  * @config: Returns value to use
 126  * Return: 0 if OK, -EINVAL if the calculation failed due to invalid data
 127  */
 128 static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode,
 129                               int ic_clk, int spk_cnt,
 130                               struct dw_i2c_speed_config *config)
 131 {
 132         int fall_cnt, rise_cnt, min_tlow_cnt, min_thigh_cnt;
 133         int hcnt, lcnt, period_cnt, diff, tot;
 134         int sda_hold_time_ns, scl_rise_time_ns, scl_fall_time_ns;
 135         const struct i2c_mode_info *info;
 136
 137         /*
 138          * Find the period, rise, fall, min tlow, and min thigh in terms of
 139          * counts of the IC clock
 140          */
 141         info = &info_for_mode[mode];
 142         period_cnt = ic_clk / info->speed;
 143         scl_rise_time_ns = priv && priv->scl_rise_time_ns ?
 144                  priv->scl_rise_time_ns : info->def_rise_time_ns;
 145         scl_fall_time_ns = priv && priv->scl_fall_time_ns ?
 146                  priv->scl_fall_time_ns : info->def_fall_time_ns;
 147         rise_cnt = calc_counts(ic_clk, scl_rise_time_ns);
 148         fall_cnt = calc_counts(ic_clk, scl_fall_time_ns);
 149         min_tlow_cnt = calc_counts(ic_clk, info->min_scl_lowtime_ns);
 150         min_thigh_cnt = calc_counts(ic_clk, info->min_scl_hightime_ns);
 151
 152         debug("dw_i2c: mode %d, ic_clk %d, speed %d, period %d rise %d fall %d tlow %d thigh %d spk %d\n",
 153               mode, ic_clk, info->speed, period_cnt, rise_cnt, fall_cnt,
 154               min_tlow_cnt, min_thigh_cnt, spk_cnt);
 155
 156         /*
 157          * Back-solve for hcnt and lcnt according to the following equations:
 158          * SCL_High_time = [(HCNT + IC_*_SPKLEN + 7) * ic_clk] + SCL_Fall_time
 159          * SCL_Low_time = [(LCNT + 1) * ic_clk] - SCL_Fall_time + SCL_Rise_time
 160          */
 161         hcnt = min_thigh_cnt - fall_cnt - 7 - spk_cnt;
 162         lcnt = min_tlow_cnt - rise_cnt + fall_cnt - 1;
 163
 164         if (hcnt < 0 || lcnt < 0) {
 165                 debug("dw_i2c: bad counts. hcnt = %d lcnt = %d\n", hcnt, lcnt);
 166                 return log_msg_ret("counts", -EINVAL);
 167         }
 168
 169         /*
 170          * Now add things back up to ensure the period is hit. If it is off,
 171          * split the difference and bias to lcnt for remainder
 172          */
 173         tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1;
 174
 175         if (tot < period_cnt) {
 176                 diff = (period_cnt - tot) / 2;
 177                 hcnt += diff;
 178                 lcnt += diff;
 179                 tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1;
 180                 lcnt += period_cnt - tot;
 181         }
 182
 183         config->scl_lcnt = lcnt;
 184         config->scl_hcnt = hcnt;
 185
 186         /* Use internal default unless other value is specified */
 187         sda_hold_time_ns = priv && priv->sda_hold_time_ns ?
 188                  priv->sda_hold_time_ns : DEFAULT_SDA_HOLD_TIME;
 189         config->sda_hold = calc_counts(ic_clk, sda_hold_time_ns);
 190
 191         debug("dw_i2c: hcnt = %d lcnt = %d sda hold = %d\n", hcnt, lcnt,
 192               config->sda_hold);
 193
 194         return 0;
 195 }
 196
 197 /**
 198  * calc_bus_speed() - Calculate the config to use for a particular i2c speed
 199  *
 200  * @priv: Private information for the driver (NULL if not using driver model)
 201  * @i2c_base: Registers for the I2C controller
 202  * @speed: Required i2c speed in Hz
 203  * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
 204  * @config: Returns the config to use for this speed
 205  * Return: 0 if OK, -ve on error
 206  */
 207 static int calc_bus_speed(struct dw_i2c *priv, struct i2c_regs *regs, int speed,
 208                           ulong bus_clk, struct dw_i2c_speed_config *config)
 209 {
 210         const struct dw_scl_sda_cfg *scl_sda_cfg = NULL;
 211         enum i2c_speed_mode i2c_spd;
 212         int spk_cnt;
 213         int ret;
 214
 215         if (priv)
 216                 scl_sda_cfg = priv->scl_sda_cfg;
 217         /* Allow high speed if there is no config, or the config allows it */
 218         if (speed >= I2C_SPEED_HIGH_RATE)
 219                 i2c_spd = IC_SPEED_MODE_HIGH;
 220         else if (speed >= I2C_SPEED_FAST_PLUS_RATE)
 221                 i2c_spd = IC_SPEED_MODE_FAST_PLUS;
 222         else if (speed >= I2C_SPEED_FAST_RATE)
 223                 i2c_spd = IC_SPEED_MODE_FAST;
 224         else
 225                 i2c_spd = IC_SPEED_MODE_STANDARD;
 226
 227         /* Check is high speed possible and fall back to fast mode if not */
 228         if (i2c_spd == IC_SPEED_MODE_HIGH) {
 229                 u32 comp_param1;
 230
 231                 comp_param1 = readl(&regs->comp_param1);
 232                 if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
 233                                 != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH)
 234                         i2c_spd = IC_SPEED_MODE_FAST;
 235         }
 236
 237         /* Get the proper spike-suppression count based on target speed */
 238         if (!priv || !priv->has_spk_cnt)
 239                 spk_cnt = 0;
 240         else if (i2c_spd >= IC_SPEED_MODE_HIGH)
 241                 spk_cnt = readl(&regs->hs_spklen);
 242         else
 243                 spk_cnt = readl(&regs->fs_spklen);
 244         if (scl_sda_cfg) {
 245                 config->sda_hold = scl_sda_cfg->sda_hold;
 246                 if (i2c_spd == IC_SPEED_MODE_STANDARD) {
 247                         config->scl_hcnt = scl_sda_cfg->ss_hcnt;
 248                         config->scl_lcnt = scl_sda_cfg->ss_lcnt;
 249                 } else if (i2c_spd == IC_SPEED_MODE_HIGH) {
 250                         config->scl_hcnt = scl_sda_cfg->hs_hcnt;
 251                         config->scl_lcnt = scl_sda_cfg->hs_lcnt;
 252                 } else {
 253                         config->scl_hcnt = scl_sda_cfg->fs_hcnt;
 254                         config->scl_lcnt = scl_sda_cfg->fs_lcnt;
 255                 }
 256         } else {
 257                 ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, spk_cnt,
 258                                          config);
 259                 if (ret)
 260                         return log_msg_ret("gen_confg", ret);
 261         }
 262         config->speed_mode = i2c_spd;
 263
 264         return 0;
 265 }
 266
 267 /**
 268  * _dw_i2c_set_bus_speed() - Set the i2c speed
 269  *
 270  * @priv: Private information for the driver (NULL if not using driver model)
 271  * @i2c_base: Registers for the I2C controller
 272  * @speed: Required i2c speed in Hz
 273  * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK)
 274  * Return: 0 if OK, -ve on error
 275  */
 276 static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base,
 277                                  unsigned int speed, unsigned int bus_clk)
 278 {
 279         struct dw_i2c_speed_config config;
 280         unsigned int cntl;
 281         unsigned int ena;
 282         int ret;
 283
 284         ret = calc_bus_speed(priv, i2c_base, speed, bus_clk, &config);
 285         if (ret)
 286                 return ret;
 287
 288         /* Get enable setting for restore later */
 289         ena = readl(&i2c_base->ic_enable) & IC_ENABLE_0B;
 290
 291         /* to set speed cltr must be disabled */
 292         dw_i2c_enable(i2c_base, false);
 293
 294         cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
 295
 296         switch (config.speed_mode) {
 297         case IC_SPEED_MODE_HIGH:
 298                 cntl |= IC_CON_SPD_HS;
 299                 writel(config.scl_hcnt, &i2c_base->ic_hs_scl_hcnt);
 300                 writel(config.scl_lcnt, &i2c_base->ic_hs_scl_lcnt);
 301                 break;
 302         case IC_SPEED_MODE_STANDARD:
 303                 cntl |= IC_CON_SPD_SS;
 304                 writel(config.scl_hcnt, &i2c_base->ic_ss_scl_hcnt);
 305                 writel(config.scl_lcnt, &i2c_base->ic_ss_scl_lcnt);
 306                 break;
 307         case IC_SPEED_MODE_FAST_PLUS:
 308         case IC_SPEED_MODE_FAST:
 309         default:
 310                 cntl |= IC_CON_SPD_FS;
 311                 writel(config.scl_hcnt, &i2c_base->ic_fs_scl_hcnt);
 312                 writel(config.scl_lcnt, &i2c_base->ic_fs_scl_lcnt);
 313                 break;
 314         }
 315
 316         writel(cntl, &i2c_base->ic_con);
 317
 318         /* Configure SDA Hold Time if required */
 319         if (config.sda_hold)
 320                 writel(config.sda_hold, &i2c_base->ic_sda_hold);
 321
 322         /* Restore back i2c now speed set */
 323         if (ena == IC_ENABLE_0B)
 324                 dw_i2c_enable(i2c_base, true);
 325         if (priv)
 326                 priv->config = config;
 327
 328         return 0;
 329 }
 330
 331 int dw_i2c_gen_speed_config(const struct udevice *dev, int speed_hz,
 332                             struct dw_i2c_speed_config *config)
 333 {
 334         struct dw_i2c *priv = dev_get_priv(dev);
 335         ulong rate;
 336         int ret;
 337
 338 #if CONFIG_IS_ENABLED(CLK)
 339         rate = clk_get_rate(&priv->clk);
 340         if (IS_ERR_VALUE(rate))
 341                 return log_msg_ret("clk", -EINVAL);
 342 #else
 343         rate = IC_CLK;
 344 #endif
 345
 346         ret = calc_bus_speed(priv, priv->regs, speed_hz, rate, config);
 347         if (ret)
 348                 printf("%s: ret=%d\n", __func__, ret);
 349         if (ret)
 350                 return log_msg_ret("calc_bus_speed", ret);
 351
 352         return 0;
 353 }
 354
 355 /*
 356  * i2c_setaddress - Sets the target slave address
 357  * @i2c_addr:   target i2c address
 358  *
 359  * Sets the target slave address.
 360  */
 361 static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr)
 362 {
 363         /* Disable i2c */
 364         dw_i2c_enable(i2c_base, false);
 365
 366         writel(i2c_addr, &i2c_base->ic_tar);
 367
 368         /* Enable i2c */
 369         dw_i2c_enable(i2c_base, true);
 370 }
 371
 372 /*
 373  * i2c_flush_rxfifo - Flushes the i2c RX FIFO
 374  *
 375  * Flushes the i2c RX FIFO
 376  */
 377 static void i2c_flush_rxfifo(struct i2c_regs *i2c_base)
 378 {
 379         while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE)
 380                 readl(&i2c_base->ic_cmd_data);
 381 }
 382
 383 /*
 384  * i2c_wait_for_bb - Waits for bus busy
 385  *
 386  * Waits for bus busy
 387  */
 388 static int i2c_wait_for_bb(struct i2c_regs *i2c_base)
 389 {
 390         unsigned long start_time_bb = get_timer(0);
 391
 392         while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) ||
 393                !(readl(&i2c_base->ic_status) & IC_STATUS_TFE)) {
 394
 395                 /* Evaluate timeout */
 396                 if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
 397                         return 1;
 398         }
 399
 400         return 0;
 401 }
 402
 403 static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr,
 404                          int alen)
 405 {
 406         if (i2c_wait_for_bb(i2c_base))
 407                 return 1;
 408
 409         i2c_setaddress(i2c_base, chip);
 410         while (alen) {
 411                 alen--;
 412                 /* high byte address going out first */
 413                 writel((addr >> (alen * 8)) & 0xff,
 414                        &i2c_base->ic_cmd_data);
 415         }
 416         return 0;
 417 }
 418
 419 static int i2c_xfer_finish(struct i2c_regs *i2c_base)
 420 {
 421         ulong start_stop_det = get_timer(0);
 422
 423         while (1) {
 424                 if ((readl(&i2c_base->ic_raw_intr_stat) & IC_STOP_DET)) {
 425                         readl(&i2c_base->ic_clr_stop_det);
 426                         break;
 427                 } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
 428                         break;
 429                 }
 430         }
 431
 432         if (i2c_wait_for_bb(i2c_base)) {
 433                 printf("Timed out waiting for bus\n");
 434                 return 1;
 435         }
 436
 437         i2c_flush_rxfifo(i2c_base);
 438
 439         return 0;
 440 }
 441
 442 /*
 443  * i2c_read - Read from i2c memory
 444  * @chip:       target i2c address
 445  * @addr:       address to read from
 446  * @alen:
 447  * @buffer:     buffer for read data
 448  * @len:        no of bytes to be read
 449  *
 450  * Read from i2c memory.
 451  */
 452 static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr,
 453                          int alen, u8 *buffer, int len)
 454 {
 455         unsigned long start_time_rx;
 456         unsigned int active = 0;
 457
 458 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
 459         /*
 460          * EEPROM chips that implement "address overflow" are ones
 461          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
 462          * address and the extra bits end up in the "chip address"
 463          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
 464          * four 256 byte chips.
 465          *
 466          * Note that we consider the length of the address field to
 467          * still be one byte because the extra address bits are
 468          * hidden in the chip address.
 469          */
 470         dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
 471         addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
 472
 473         debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
 474               addr);
 475 #endif
 476
 477         if (i2c_xfer_init(i2c_base, dev, addr, alen))
 478                 return 1;
 479
 480         start_time_rx = get_timer(0);
 481         while (len) {
 482                 if (!active) {
 483                         /*
 484                          * Avoid writing to ic_cmd_data multiple times
 485                          * in case this loop spins too quickly and the
 486                          * ic_status RFNE bit isn't set after the first
 487                          * write. Subsequent writes to ic_cmd_data can
 488                          * trigger spurious i2c transfer.
 489                          */
 490                         if (len == 1)
 491                                 writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
 492                         else
 493                                 writel(IC_CMD, &i2c_base->ic_cmd_data);
 494                         active = 1;
 495                 }
 496
 497                 if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) {
 498                         *buffer++ = (uchar)readl(&i2c_base->ic_cmd_data);
 499                         len--;
 500                         start_time_rx = get_timer(0);
 501                         active = 0;
 502                 } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
 503                         return 1;
 504                 }
 505         }
 506
 507         return i2c_xfer_finish(i2c_base);
 508 }
 509
 510 /*
 511  * i2c_write - Write to i2c memory
 512  * @chip:       target i2c address
 513  * @addr:       address to read from
 514  * @alen:
 515  * @buffer:     buffer for read data
 516  * @len:        no of bytes to be read
 517  *
 518  * Write to i2c memory.
 519  */
 520 static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
 521                           int alen, u8 *buffer, int len)
 522 {
 523         int nb = len;
 524         unsigned long start_time_tx;
 525
 526 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
 527         /*
 528          * EEPROM chips that implement "address overflow" are ones
 529          * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
 530          * address and the extra bits end up in the "chip address"
 531          * bit slots. This makes a 24WC08 (1Kbyte) chip look like
 532          * four 256 byte chips.
 533          *
 534          * Note that we consider the length of the address field to
 535          * still be one byte because the extra address bits are
 536          * hidden in the chip address.
 537          */
 538         dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
 539         addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
 540
 541         debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev,
 542               addr);
 543 #endif
 544
 545         if (i2c_xfer_init(i2c_base, dev, addr, alen))
 546                 return 1;
 547
 548         start_time_tx = get_timer(0);
 549         while (len) {
 550                 if (readl(&i2c_base->ic_status) & IC_STATUS_TFNF) {
 551                         if (--len == 0) {
 552                                 writel(*buffer | IC_STOP,
 553                                        &i2c_base->ic_cmd_data);
 554                         } else {
 555                                 writel(*buffer, &i2c_base->ic_cmd_data);
 556                         }
 557                         buffer++;
 558                         start_time_tx = get_timer(0);
 559
 560                 } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
 561                                 printf("Timed out. i2c write Failed\n");
 562                                 return 1;
 563                 }
 564         }
 565
 566         return i2c_xfer_finish(i2c_base);
 567 }
 568
 569 /*
 570  * __dw_i2c_init - Init function
 571  * @speed:      required i2c speed
 572  * @slaveaddr:  slave address for the device
 573  *
 574  * Initialization function.
 575  */
 576 static int __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr)
 577 {
 578         int ret;
 579
 580         /* Disable i2c */
 581         ret = dw_i2c_enable(i2c_base, false);
 582         if (ret)
 583                 return ret;
 584
 585         writel(IC_CON_SD | IC_CON_RE | IC_CON_SPD_FS | IC_CON_MM,
 586                &i2c_base->ic_con);
 587         writel(IC_RX_TL, &i2c_base->ic_rx_tl);
 588         writel(IC_TX_TL, &i2c_base->ic_tx_tl);
 589         writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
 590 #if !CONFIG_IS_ENABLED(DM_I2C)
 591         _dw_i2c_set_bus_speed(NULL, i2c_base, speed, IC_CLK);
 592         writel(slaveaddr, &i2c_base->ic_sar);
 593 #endif
 594
 595         /* Enable i2c */
 596         ret = dw_i2c_enable(i2c_base, true);
 597         if (ret)
 598                 return ret;
 599
 600         return 0;
 601 }
 602
 603 #if !CONFIG_IS_ENABLED(DM_I2C)
 604 /*
 605  * The legacy I2C functions. These need to get removed once
 606  * all users of this driver are converted to DM.
 607  */
 608 static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
 609 {
 610         switch (adap->hwadapnr) {
 611 #if CONFIG_SYS_I2C_BUS_MAX >= 4
 612         case 3:
 613                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
 614 #endif
 615 #if CONFIG_SYS_I2C_BUS_MAX >= 3
 616         case 2:
 617                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
 618 #endif
 619 #if CONFIG_SYS_I2C_BUS_MAX >= 2
 620         case 1:
 621                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
 622 #endif
 623         case 0:
 624                 return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
 625         default:
 626                 printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
 627         }
 628
 629         return NULL;
 630 }
 631
 632 static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
 633                                          unsigned int speed)
 634 {
 635         adap->speed = speed;
 636         return _dw_i2c_set_bus_speed(NULL, i2c_get_base(adap), speed, IC_CLK);
 637 }
 638
 639 static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 640 {
 641         __dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
 642 }
 643
 644 static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
 645                        int alen, u8 *buffer, int len)
 646 {
 647         return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len);
 648 }
 649
 650 static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
 651                         int alen, u8 *buffer, int len)
 652 {
 653         return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len);
 654 }
 655
 656 /* dw_i2c_probe - Probe the i2c chip */
 657 static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev)
 658 {
 659         struct i2c_regs *i2c_base = i2c_get_base(adap);
 660         u32 tmp;
 661         int ret;
 662
 663         /*
 664          * Try to read the first location of the chip.
 665          */
 666         ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1);
 667         if (ret)
 668                 dw_i2c_init(adap, adap->speed, adap->slaveaddr);
 669
 670         return ret;
 671 }
 672
 673 U_BOOT_I2C_ADAP_COMPLETE(dw_0, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
 674                          dw_i2c_write, dw_i2c_set_bus_speed,
 675                          CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0)
 676
 677 #else /* CONFIG_DM_I2C */
 678 /* The DM I2C functions */
 679
 680 static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 681                                int nmsgs)
 682 {
 683         struct dw_i2c *i2c = dev_get_priv(bus);
 684         int ret;
 685
 686         debug("i2c_xfer: %d messages\n", nmsgs);
 687         for (; nmsgs > 0; nmsgs--, msg++) {
 688                 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 689                 if (msg->flags & I2C_M_RD) {
 690                         ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0,
 691                                             msg->buf, msg->len);
 692                 } else {
 693                         ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0,
 694                                              msg->buf, msg->len);
 695                 }
 696                 if (ret) {
 697                         debug("i2c_write: error sending\n");
 698                         return -EREMOTEIO;
 699                 }
 700         }
 701
 702         return 0;
 703 }
 704
 705 static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 706 {
 707         struct dw_i2c *i2c = dev_get_priv(bus);
 708         ulong rate;
 709
 710 #if CONFIG_IS_ENABLED(CLK)
 711         rate = clk_get_rate(&i2c->clk);
 712         if (IS_ERR_VALUE(rate))
 713                 return log_ret(-EINVAL);
 714 #else
 715         rate = IC_CLK;
 716 #endif
 717         return _dw_i2c_set_bus_speed(i2c, i2c->regs, speed, rate);
 718 }
 719
 720 static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr,
 721                                      uint chip_flags)
 722 {
 723         struct dw_i2c *i2c = dev_get_priv(bus);
 724         struct i2c_regs *i2c_base = i2c->regs;
 725         u32 tmp;
 726         int ret;
 727
 728         /* Try to read the first location of the chip */
 729         ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1);
 730         if (ret)
 731                 __dw_i2c_init(i2c_base, 0, 0);
 732
 733         return ret;
 734 }
 735
 736 int designware_i2c_of_to_plat(struct udevice *bus)
 737 {
 738         struct dw_i2c *priv = dev_get_priv(bus);
 739         int ret;
 740
 741         if (!priv->regs)
 742                 priv->regs = dev_read_addr_ptr(bus);
 743         dev_read_u32(bus, "i2c-scl-rising-time-ns", &priv->scl_rise_time_ns);
 744         dev_read_u32(bus, "i2c-scl-falling-time-ns", &priv->scl_fall_time_ns);
 745         dev_read_u32(bus, "i2c-sda-hold-time-ns", &priv->sda_hold_time_ns);
 746
 747         ret = reset_get_bulk(bus, &priv->resets);
 748         if (ret) {
 749                 if (ret != -ENOTSUPP)
 750                         dev_warn(bus, "Can't get reset: %d\n", ret);
 751         } else {
 752                 reset_deassert_bulk(&priv->resets);
 753         }
 754
 755 #if CONFIG_IS_ENABLED(CLK)
 756         ret = clk_get_by_index(bus, 0, &priv->clk);
 757         if (ret)
 758                 return ret;
 759
 760         ret = clk_enable(&priv->clk);
 761         if (ret && ret != -ENOSYS && ret != -ENOTSUPP) {
 762                 clk_free(&priv->clk);
 763                 dev_err(bus, "failed to enable clock\n");
 764                 return ret;
 765         }
 766 #endif
 767
 768         return 0;
 769 }
 770
 771 int designware_i2c_probe(struct udevice *bus)
 772 {
 773         struct dw_i2c *priv = dev_get_priv(bus);
 774         uint comp_type;
 775
 776         comp_type = readl(&priv->regs->comp_type);
 777         if (comp_type != DW_I2C_COMP_TYPE) {
 778                 log_err("I2C bus %s has unknown type %#x\n", bus->name,
 779                         comp_type);
 780                 return -ENXIO;
 781         }
 782
 783         log_debug("I2C bus %s version %#x\n", bus->name,
 784                   readl(&priv->regs->comp_version));
 785
 786         return __dw_i2c_init(priv->regs, 0, 0);
 787 }
 788
 789 int designware_i2c_remove(struct udevice *dev)
 790 {
 791         struct dw_i2c *priv = dev_get_priv(dev);
 792
 793 #if CONFIG_IS_ENABLED(CLK)
 794         clk_disable(&priv->clk);
 795         clk_free(&priv->clk);
 796 #endif
 797
 798         return reset_release_bulk(&priv->resets);
 799 }
 800
 801 const struct dm_i2c_ops designware_i2c_ops = {
 802         .xfer           = designware_i2c_xfer,
 803         .probe_chip     = designware_i2c_probe_chip,
 804         .set_bus_speed  = designware_i2c_set_bus_speed,
 805 };
 806
 807 static const struct udevice_id designware_i2c_ids[] = {
 808         { .compatible = "snps,designware-i2c" },
 809         { }
 810 };
 811
 812 U_BOOT_DRIVER(i2c_designware) = {
 813         .name   = "i2c_designware",
 814         .id     = UCLASS_I2C,
 815         .of_match = designware_i2c_ids,
 816         .of_to_plat = designware_i2c_of_to_plat,
 817         .probe  = designware_i2c_probe,
 818         .priv_auto      = sizeof(struct dw_i2c),
 819         .remove = designware_i2c_remove,
 820         .flags  = DM_FLAG_OS_PREPARE,
 821         .ops    = &designware_i2c_ops,
 822 };
 823
 824 #endif /* CONFIG_DM_I2C */