drivers/i2c/ihs_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2013
   4  * Dirk Eibach,  Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
   5  */
   6
   7 #include <common.h>
   8 #include <i2c.h>
   9 #ifdef CONFIG_DM_I2C
  10 #include <dm.h>
  11 #include <regmap.h>
  12 #else
  13 #include <gdsys_fpga.h>
  14 #endif
  15 #include <log.h>
  16 #include <asm/unaligned.h>
  17 #include <linux/bitops.h>
  18 #include <linux/delay.h>
  19
  20 #ifdef CONFIG_DM_I2C
  21 struct ihs_i2c_priv {
  22         uint speed;
  23         struct regmap *map;
  24 };
  25
  26 struct ihs_i2c_regs {
  27         u16 interrupt_status;
  28         u16 interrupt_enable_control;
  29         u16 write_mailbox_ext;
  30         u16 write_mailbox;
  31         u16 read_mailbox_ext;
  32         u16 read_mailbox;
  33 };
  34
  35 #define ihs_i2c_set(map, member, val) \
  36         regmap_set(map, struct ihs_i2c_regs, member, val)
  37
  38 #define ihs_i2c_get(map, member, valp) \
  39         regmap_get(map, struct ihs_i2c_regs, member, valp)
  40
  41 #else /* !CONFIG_DM_I2C */
  42 DECLARE_GLOBAL_DATA_PTR;
  43
  44 #ifdef CONFIG_SYS_I2C_IHS_DUAL
  45
  46 #define I2C_SET_REG(fld, val) \
  47         do { \
  48                 if (I2C_ADAP_HWNR & 0x10) \
  49                         FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
  50                 else \
  51                         FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
  52         } while (0)
  53 #else
  54 #define I2C_SET_REG(fld, val) \
  55                 FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
  56 #endif
  57
  58 #ifdef CONFIG_SYS_I2C_IHS_DUAL
  59 #define I2C_GET_REG(fld, val) \
  60         do {                                    \
  61                 if (I2C_ADAP_HWNR & 0x10) \
  62                         FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
  63                 else \
  64                         FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
  65         } while (0)
  66 #else
  67 #define I2C_GET_REG(fld, val) \
  68                 FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
  69 #endif
  70 #endif /* CONFIG_DM_I2C */
  71
  72 enum {
  73         I2CINT_ERROR_EV = BIT(13),
  74         I2CINT_TRANSMIT_EV = BIT(14),
  75         I2CINT_RECEIVE_EV = BIT(15),
  76 };
  77
  78 enum {
  79         I2CMB_READ = 0 << 10,
  80         I2CMB_WRITE = 1 << 10,
  81         I2CMB_1BYTE = 0 << 11,
  82         I2CMB_2BYTE = 1 << 11,
  83         I2CMB_DONT_HOLD_BUS = 0 << 13,
  84         I2CMB_HOLD_BUS = 1 << 13,
  85         I2CMB_NATIVE = 2 << 14,
  86 };
  87
  88 enum {
  89         I2COP_WRITE = 0,
  90         I2COP_READ = 1,
  91 };
  92
  93 #ifdef CONFIG_DM_I2C
  94 static int wait_for_int(struct udevice *dev, int read)
  95 #else
  96 static int wait_for_int(bool read)
  97 #endif
  98 {
  99         u16 val;
 100         uint ctr = 0;
 101 #ifdef CONFIG_DM_I2C
 102         struct ihs_i2c_priv *priv = dev_get_priv(dev);
 103 #endif
 104
 105 #ifdef CONFIG_DM_I2C
 106         ihs_i2c_get(priv->map, interrupt_status, &val);
 107 #else
 108         I2C_GET_REG(interrupt_status, &val);
 109 #endif
 110         /* Wait until error or receive/transmit interrupt was raised */
 111         while (!(val & (I2CINT_ERROR_EV
 112                | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
 113                 udelay(10);
 114                 if (ctr++ > 5000) {
 115                         debug("%s: timed out\n", __func__);
 116                         return -ETIMEDOUT;
 117                 }
 118 #ifdef CONFIG_DM_I2C
 119                 ihs_i2c_get(priv->map, interrupt_status, &val);
 120 #else
 121                 I2C_GET_REG(interrupt_status, &val);
 122 #endif
 123         }
 124
 125         return (val & I2CINT_ERROR_EV) ? -EIO : 0;
 126 }
 127
 128 #ifdef CONFIG_DM_I2C
 129 static int ihs_i2c_transfer(struct udevice *dev, uchar chip,
 130                             uchar *buffer, int len, int read, bool is_last)
 131 #else
 132 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
 133                             bool is_last)
 134 #endif
 135 {
 136         u16 val;
 137         u16 data;
 138         int res;
 139 #ifdef CONFIG_DM_I2C
 140         struct ihs_i2c_priv *priv = dev_get_priv(dev);
 141 #endif
 142
 143         /* Clear interrupt status */
 144         data = I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV;
 145 #ifdef CONFIG_DM_I2C
 146         ihs_i2c_set(priv->map, interrupt_status, data);
 147         ihs_i2c_get(priv->map, interrupt_status, &val);
 148 #else
 149         I2C_SET_REG(interrupt_status, data);
 150         I2C_GET_REG(interrupt_status, &val);
 151 #endif
 152
 153         /* If we want to write and have data, write the bytes to the mailbox */
 154         if (!read && len) {
 155                 val = buffer[0];
 156
 157                 if (len > 1)
 158                         val |= buffer[1] << 8;
 159 #ifdef CONFIG_DM_I2C
 160                 ihs_i2c_set(priv->map, write_mailbox_ext, val);
 161 #else
 162                 I2C_SET_REG(write_mailbox_ext, val);
 163 #endif
 164         }
 165
 166         data = I2CMB_NATIVE
 167                | (read ? 0 : I2CMB_WRITE)
 168                | (chip << 1)
 169                | ((len > 1) ? I2CMB_2BYTE : 0)
 170                | (is_last ? 0 : I2CMB_HOLD_BUS);
 171
 172 #ifdef CONFIG_DM_I2C
 173         ihs_i2c_set(priv->map, write_mailbox, data);
 174 #else
 175         I2C_SET_REG(write_mailbox, data);
 176 #endif
 177
 178 #ifdef CONFIG_DM_I2C
 179         res = wait_for_int(dev, read);
 180 #else
 181         res = wait_for_int(read);
 182 #endif
 183         if (res) {
 184                 if (res == -ETIMEDOUT)
 185                         debug("%s: time out while waiting for event\n", __func__);
 186
 187                 return res;
 188         }
 189
 190         /* If we want to read, get the bytes from the mailbox */
 191         if (read) {
 192 #ifdef CONFIG_DM_I2C
 193                 ihs_i2c_get(priv->map, read_mailbox_ext, &val);
 194 #else
 195                 I2C_GET_REG(read_mailbox_ext, &val);
 196 #endif
 197                 buffer[0] = val & 0xff;
 198                 if (len > 1)
 199                         buffer[1] = val >> 8;
 200         }
 201
 202         return 0;
 203 }
 204
 205 #ifdef CONFIG_DM_I2C
 206 static int ihs_i2c_send_buffer(struct udevice *dev, uchar chip, u8 *data, int len, bool hold_bus, int read)
 207 #else
 208 static int ihs_i2c_send_buffer(uchar chip, u8 *data, int len, bool hold_bus,
 209                                int read)
 210 #endif
 211 {
 212         int res;
 213
 214         while (len) {
 215                 int transfer = min(len, 2);
 216                 bool is_last = len <= transfer;
 217
 218 #ifdef CONFIG_DM_I2C
 219                 res = ihs_i2c_transfer(dev, chip, data, transfer, read,
 220                                        hold_bus ? false : is_last);
 221 #else
 222                 res = ihs_i2c_transfer(chip, data, transfer, read,
 223                                        hold_bus ? false : is_last);
 224 #endif
 225                 if (res)
 226                         return res;
 227
 228                 data += transfer;
 229                 len -= transfer;
 230         }
 231
 232         return 0;
 233 }
 234
 235 #ifdef CONFIG_DM_I2C
 236 static int ihs_i2c_address(struct udevice *dev, uchar chip, u8 *addr, int alen,
 237                            bool hold_bus)
 238 #else
 239 static int ihs_i2c_address(uchar chip, u8 *addr, int alen, bool hold_bus)
 240 #endif
 241 {
 242 #ifdef CONFIG_DM_I2C
 243         return ihs_i2c_send_buffer(dev, chip, addr, alen, hold_bus, I2COP_WRITE);
 244 #else
 245         return ihs_i2c_send_buffer(chip, addr, alen, hold_bus, I2COP_WRITE);
 246 #endif
 247 }
 248
 249 #ifdef CONFIG_DM_I2C
 250 static int ihs_i2c_access(struct udevice *dev, uchar chip, u8 *addr,
 251                           int alen, uchar *buffer, int len, int read)
 252 #else
 253 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr,
 254                           int alen, uchar *buffer, int len, int read)
 255 #endif
 256 {
 257         int res;
 258
 259         /* Don't hold the bus if length of data to send/receive is zero */
 260         if (len <= 0)
 261                 return -EINVAL;
 262
 263 #ifdef CONFIG_DM_I2C
 264         res = ihs_i2c_address(dev, chip, addr, alen, len);
 265 #else
 266         res = ihs_i2c_address(chip, addr, alen, len);
 267 #endif
 268         if (res)
 269                 return res;
 270
 271 #ifdef CONFIG_DM_I2C
 272         return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
 273 #else
 274         return ihs_i2c_send_buffer(chip, buffer, len, false, read);
 275 #endif
 276 }
 277
 278 #ifdef CONFIG_DM_I2C
 279
 280 int ihs_i2c_probe(struct udevice *bus)
 281 {
 282         struct ihs_i2c_priv *priv = dev_get_priv(bus);
 283
 284         regmap_init_mem(dev_ofnode(bus), &priv->map);
 285
 286         return 0;
 287 }
 288
 289 static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
 290 {
 291         struct ihs_i2c_priv *priv = dev_get_priv(bus);
 292
 293         if (speed != priv->speed && priv->speed != 0)
 294                 return -EINVAL;
 295
 296         priv->speed = speed;
 297
 298         return 0;
 299 }
 300
 301 static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
 302 {
 303         struct i2c_msg *dmsg, *omsg, dummy;
 304
 305         memset(&dummy, 0, sizeof(struct i2c_msg));
 306
 307         /* We expect either two messages (one with an offset and one with the
 308          * actucal data) or one message (just data)
 309          */
 310         if (nmsgs > 2 || nmsgs == 0) {
 311                 debug("%s: Only one or two messages are supported\n", __func__);
 312                 return -ENOTSUPP;
 313         }
 314
 315         omsg = nmsgs == 1 ? &dummy : msg;
 316         dmsg = nmsgs == 1 ? msg : msg + 1;
 317
 318         if (dmsg->flags & I2C_M_RD)
 319                 return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
 320                                       omsg->len, dmsg->buf, dmsg->len,
 321                                       I2COP_READ);
 322         else
 323                 return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
 324                                       omsg->len, dmsg->buf, dmsg->len,
 325                                       I2COP_WRITE);
 326 }
 327
 328 static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
 329                               u32 chip_flags)
 330 {
 331         uchar buffer[2];
 332         int res;
 333
 334         res = ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true);
 335         if (res)
 336                 return res;
 337
 338         return 0;
 339 }
 340
 341 static const struct dm_i2c_ops ihs_i2c_ops = {
 342         .xfer           = ihs_i2c_xfer,
 343         .probe_chip     = ihs_i2c_probe_chip,
 344         .set_bus_speed  = ihs_i2c_set_bus_speed,
 345 };
 346
 347 static const struct udevice_id ihs_i2c_ids[] = {
 348         { .compatible = "gdsys,ihs_i2cmaster", },
 349         { /* sentinel */ }
 350 };
 351
 352 U_BOOT_DRIVER(i2c_ihs) = {
 353         .name = "i2c_ihs",
 354         .id = UCLASS_I2C,
 355         .of_match = ihs_i2c_ids,
 356         .probe = ihs_i2c_probe,
 357         .priv_auto_alloc_size = sizeof(struct ihs_i2c_priv),
 358         .ops = &ihs_i2c_ops,
 359 };
 360
 361 #else /* CONFIG_DM_I2C */
 362
 363 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 364 {
 365 #ifdef CONFIG_SYS_I2C_INIT_BOARD
 366         /*
 367          * Call board specific i2c bus reset routine before accessing the
 368          * environment, which might be in a chip on that bus. For details
 369          * about this problem see doc/I2C_Edge_Conditions.
 370          */
 371         i2c_init_board();
 372 #endif
 373 }
 374
 375 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
 376 {
 377         uchar buffer[2];
 378         int res;
 379
 380         res = ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true);
 381         if (res)
 382                 return res;
 383
 384         return 0;
 385 }
 386
 387 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
 388                         int alen, uchar *buffer, int len)
 389 {
 390         u8 addr_bytes[4];
 391
 392         put_unaligned_le32(addr, addr_bytes);
 393
 394         return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
 395                               I2COP_READ);
 396 }
 397
 398 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
 399                          int alen, uchar *buffer, int len)
 400 {
 401         u8 addr_bytes[4];
 402
 403         put_unaligned_le32(addr, addr_bytes);
 404
 405         return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len,
 406                               I2COP_WRITE);
 407 }
 408
 409 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
 410                                           unsigned int speed)
 411 {
 412         if (speed != adap->speed)
 413                 return -EINVAL;
 414         return speed;
 415 }
 416
 417 /*
 418  * Register IHS i2c adapters
 419  */
 420 #ifdef CONFIG_SYS_I2C_IHS_CH0
 421 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
 422                          ihs_i2c_read, ihs_i2c_write,
 423                          ihs_i2c_set_bus_speed,
 424                          CONFIG_SYS_I2C_IHS_SPEED_0,
 425                          CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
 426 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 427 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
 428                          ihs_i2c_read, ihs_i2c_write,
 429                          ihs_i2c_set_bus_speed,
 430                          CONFIG_SYS_I2C_IHS_SPEED_0_1,
 431                          CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
 432 #endif
 433 #endif
 434 #ifdef CONFIG_SYS_I2C_IHS_CH1
 435 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
 436                          ihs_i2c_read, ihs_i2c_write,
 437                          ihs_i2c_set_bus_speed,
 438                          CONFIG_SYS_I2C_IHS_SPEED_1,
 439                          CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
 440 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 441 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
 442                          ihs_i2c_read, ihs_i2c_write,
 443                          ihs_i2c_set_bus_speed,
 444                          CONFIG_SYS_I2C_IHS_SPEED_1_1,
 445                          CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
 446 #endif
 447 #endif
 448 #ifdef CONFIG_SYS_I2C_IHS_CH2
 449 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
 450                          ihs_i2c_read, ihs_i2c_write,
 451                          ihs_i2c_set_bus_speed,
 452                          CONFIG_SYS_I2C_IHS_SPEED_2,
 453                          CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
 454 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 455 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
 456                          ihs_i2c_read, ihs_i2c_write,
 457                          ihs_i2c_set_bus_speed,
 458                          CONFIG_SYS_I2C_IHS_SPEED_2_1,
 459                          CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
 460 #endif
 461 #endif
 462 #ifdef CONFIG_SYS_I2C_IHS_CH3
 463 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
 464                          ihs_i2c_read, ihs_i2c_write,
 465                          ihs_i2c_set_bus_speed,
 466                          CONFIG_SYS_I2C_IHS_SPEED_3,
 467                          CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
 468 #ifdef CONFIG_SYS_I2C_IHS_DUAL
 469 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
 470                          ihs_i2c_read, ihs_i2c_write,
 471                          ihs_i2c_set_bus_speed,
 472                          CONFIG_SYS_I2C_IHS_SPEED_3_1,
 473                          CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
 474 #endif
 475 #endif
 476 #endif /* CONFIG_DM_I2C */