drivers/gpu/drm/nouveau/nouveau_i2c.c

   1 /*
   2  * Copyright 2009 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Ben Skeggs
  23  */
  24
  25 #include <linux/module.h>
  26
  27 #include "drmP.h"
  28 #include "nouveau_drv.h"
  29 #include "nouveau_i2c.h"
  30 #include "nouveau_hw.h"
  31
  32 #define T_TIMEOUT  2200000
  33 #define T_RISEFALL 1000
  34 #define T_HOLD     5000
  35
  36 static void
  37 i2c_drive_scl(void *data, int state)
  38 {
  39         struct nouveau_i2c_chan *port = data;
  40         if (port->type == 0) {
  41                 u8 val = NVReadVgaCrtc(port->dev, 0, port->drive);
  42                 if (state) val |= 0x20;
  43                 else       val &= 0xdf;
  44                 NVWriteVgaCrtc(port->dev, 0, port->drive, val | 0x01);
  45         } else
  46         if (port->type == 4) {
  47                 nv_mask(port->dev, port->drive, 0x2f, state ? 0x21 : 0x01);
  48         } else
  49         if (port->type == 5) {
  50                 if (state) port->state |= 0x01;
  51                 else       port->state &= 0xfe;
  52                 nv_wr32(port->dev, port->drive, 4 | port->state);
  53         }
  54 }
  55
  56 static void
  57 i2c_drive_sda(void *data, int state)
  58 {
  59         struct nouveau_i2c_chan *port = data;
  60         if (port->type == 0) {
  61                 u8 val = NVReadVgaCrtc(port->dev, 0, port->drive);
  62                 if (state) val |= 0x10;
  63                 else       val &= 0xef;
  64                 NVWriteVgaCrtc(port->dev, 0, port->drive, val | 0x01);
  65         } else
  66         if (port->type == 4) {
  67                 nv_mask(port->dev, port->drive, 0x1f, state ? 0x11 : 0x01);
  68         } else
  69         if (port->type == 5) {
  70                 if (state) port->state |= 0x02;
  71                 else       port->state &= 0xfd;
  72                 nv_wr32(port->dev, port->drive, 4 | port->state);
  73         }
  74 }
  75
  76 static int
  77 i2c_sense_scl(void *data)
  78 {
  79         struct nouveau_i2c_chan *port = data;
  80         struct drm_nouveau_private *dev_priv = port->dev->dev_private;
  81         if (port->type == 0) {
  82                 return !!(NVReadVgaCrtc(port->dev, 0, port->sense) & 0x04);
  83         } else
  84         if (port->type == 4) {
  85                 return !!(nv_rd32(port->dev, port->sense) & 0x00040000);
  86         } else
  87         if (port->type == 5) {
  88                 if (dev_priv->card_type < NV_D0)
  89                         return !!(nv_rd32(port->dev, port->sense) & 0x01);
  90                 else
  91                         return !!(nv_rd32(port->dev, port->sense) & 0x10);
  92         }
  93         return 0;
  94 }
  95
  96 static int
  97 i2c_sense_sda(void *data)
  98 {
  99         struct nouveau_i2c_chan *port = data;
 100         struct drm_nouveau_private *dev_priv = port->dev->dev_private;
 101         if (port->type == 0) {
 102                 return !!(NVReadVgaCrtc(port->dev, 0, port->sense) & 0x08);
 103         } else
 104         if (port->type == 4) {
 105                 return !!(nv_rd32(port->dev, port->sense) & 0x00080000);
 106         } else
 107         if (port->type == 5) {
 108                 if (dev_priv->card_type < NV_D0)
 109                         return !!(nv_rd32(port->dev, port->sense) & 0x02);
 110                 else
 111                         return !!(nv_rd32(port->dev, port->sense) & 0x20);
 112         }
 113         return 0;
 114 }
 115
 116 static void
 117 i2c_delay(struct nouveau_i2c_chan *port, u32 nsec)
 118 {
 119         udelay((nsec + 500) / 1000);
 120 }
 121
 122 static bool
 123 i2c_raise_scl(struct nouveau_i2c_chan *port)
 124 {
 125         u32 timeout = T_TIMEOUT / T_RISEFALL;
 126
 127         i2c_drive_scl(port, 1);
 128         do {
 129                 i2c_delay(port, T_RISEFALL);
 130         } while (!i2c_sense_scl(port) && --timeout);
 131
 132         return timeout != 0;
 133 }
 134
 135 static int
 136 i2c_start(struct nouveau_i2c_chan *port)
 137 {
 138         int ret = 0;
 139
 140         port->state  = i2c_sense_scl(port);
 141         port->state |= i2c_sense_sda(port) << 1;
 142         if (port->state != 3) {
 143                 i2c_drive_scl(port, 0);
 144                 i2c_drive_sda(port, 1);
 145                 if (!i2c_raise_scl(port))
 146                         ret = -EBUSY;
 147         }
 148
 149         i2c_drive_sda(port, 0);
 150         i2c_delay(port, T_HOLD);
 151         i2c_drive_scl(port, 0);
 152         i2c_delay(port, T_HOLD);
 153         return ret;
 154 }
 155
 156 static void
 157 i2c_stop(struct nouveau_i2c_chan *port)
 158 {
 159         i2c_drive_scl(port, 0);
 160         i2c_drive_sda(port, 0);
 161         i2c_delay(port, T_RISEFALL);
 162
 163         i2c_drive_scl(port, 1);
 164         i2c_delay(port, T_HOLD);
 165         i2c_drive_sda(port, 1);
 166         i2c_delay(port, T_HOLD);
 167 }
 168
 169 static int
 170 i2c_bitw(struct nouveau_i2c_chan *port, int sda)
 171 {
 172         i2c_drive_sda(port, sda);
 173         i2c_delay(port, T_RISEFALL);
 174
 175         if (!i2c_raise_scl(port))
 176                 return -ETIMEDOUT;
 177         i2c_delay(port, T_HOLD);
 178
 179         i2c_drive_scl(port, 0);
 180         i2c_delay(port, T_HOLD);
 181         return 0;
 182 }
 183
 184 static int
 185 i2c_bitr(struct nouveau_i2c_chan *port)
 186 {
 187         int sda;
 188
 189         i2c_drive_sda(port, 1);
 190         i2c_delay(port, T_RISEFALL);
 191
 192         if (!i2c_raise_scl(port))
 193                 return -ETIMEDOUT;
 194         i2c_delay(port, T_HOLD);
 195
 196         sda = i2c_sense_sda(port);
 197
 198         i2c_drive_scl(port, 0);
 199         i2c_delay(port, T_HOLD);
 200         return sda;
 201 }
 202
 203 static int
 204 i2c_get_byte(struct nouveau_i2c_chan *port, u8 *byte, bool last)
 205 {
 206         int i, bit;
 207
 208         *byte = 0;
 209         for (i = 7; i >= 0; i--) {
 210                 bit = i2c_bitr(port);
 211                 if (bit < 0)
 212                         return bit;
 213                 *byte |= bit << i;
 214         }
 215
 216         return i2c_bitw(port, last ? 1 : 0);
 217 }
 218
 219 static int
 220 i2c_put_byte(struct nouveau_i2c_chan *port, u8 byte)
 221 {
 222         int i, ret;
 223         for (i = 7; i >= 0; i--) {
 224                 ret = i2c_bitw(port, !!(byte & (1 << i)));
 225                 if (ret < 0)
 226                         return ret;
 227         }
 228
 229         ret = i2c_bitr(port);
 230         if (ret == 1) /* nack */
 231                 ret = -EIO;
 232         return ret;
 233 }
 234
 235 static int
 236 i2c_addr(struct nouveau_i2c_chan *port, struct i2c_msg *msg)
 237 {
 238         u32 addr = msg->addr << 1;
 239         if (msg->flags & I2C_M_RD)
 240                 addr |= 1;
 241         return i2c_put_byte(port, addr);
 242 }
 243
 244 static int
 245 i2c_bit_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 246 {
 247         struct nouveau_i2c_chan *port = (struct nouveau_i2c_chan *)adap;
 248         struct i2c_msg *msg = msgs;
 249         int ret = 0, mcnt = num;
 250
 251         while (!ret && mcnt--) {
 252                 u8 remaining = msg->len;
 253                 u8 *ptr = msg->buf;
 254
 255                 ret = i2c_start(port);
 256                 if (ret == 0)
 257                         ret = i2c_addr(port, msg);
 258
 259                 if (msg->flags & I2C_M_RD) {
 260                         while (!ret && remaining--)
 261                                 ret = i2c_get_byte(port, ptr++, !remaining);
 262                 } else {
 263                         while (!ret && remaining--)
 264                                 ret = i2c_put_byte(port, *ptr++);
 265                 }
 266
 267                 msg++;
 268         }
 269
 270         i2c_stop(port);
 271         return (ret < 0) ? ret : num;
 272 }
 273
 274 static u32
 275 i2c_bit_func(struct i2c_adapter *adap)
 276 {
 277         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 278 }
 279
 280 const struct i2c_algorithm nouveau_i2c_bit_algo = {
 281         .master_xfer = i2c_bit_xfer,
 282         .functionality = i2c_bit_func
 283 };
 284
 285 static const uint32_t nv50_i2c_port[] = {
 286         0x00e138, 0x00e150, 0x00e168, 0x00e180,
 287         0x00e254, 0x00e274, 0x00e764, 0x00e780,
 288         0x00e79c, 0x00e7b8
 289 };
 290
 291 static u8 *
 292 i2c_table(struct drm_device *dev, u8 *version)
 293 {
 294         u8 *dcb = dcb_table(dev), *i2c = NULL;
 295         if (dcb) {
 296                 if (dcb[0] >= 0x15)
 297                         i2c = ROMPTR(dev, dcb[2]);
 298                 if (dcb[0] >= 0x30)
 299                         i2c = ROMPTR(dev, dcb[4]);
 300         }
 301
 302         /* early revisions had no version number, use dcb version */
 303         if (i2c) {
 304                 *version = dcb[0];
 305                 if (*version >= 0x30)
 306                         *version = i2c[0];
 307         }
 308
 309         return i2c;
 310 }
 311
 312 int
 313 nouveau_i2c_init(struct drm_device *dev)
 314 {
 315         struct drm_nouveau_private *dev_priv = dev->dev_private;
 316         struct nvbios *bios = &dev_priv->vbios;
 317         struct nouveau_i2c_chan *port;
 318         u8 version = 0x00, entries, recordlen;
 319         u8 *i2c, *entry, legacy[2][4] = {};
 320         int ret, i;
 321
 322         INIT_LIST_HEAD(&dev_priv->i2c_ports);
 323
 324         i2c = i2c_table(dev, &version);
 325         if (!i2c) {
 326                 u8 *bmp = &bios->data[bios->offset];
 327                 if (bios->type != NVBIOS_BMP)
 328                         return -ENODEV;
 329
 330                 legacy[0][0] = NV_CIO_CRE_DDC_WR__INDEX;
 331                 legacy[0][1] = NV_CIO_CRE_DDC_STATUS__INDEX;
 332                 legacy[1][0] = NV_CIO_CRE_DDC0_WR__INDEX;
 333                 legacy[1][1] = NV_CIO_CRE_DDC0_STATUS__INDEX;
 334
 335                 /* BMP (from v4.0) has i2c info in the structure, it's in a
 336                  * fixed location on earlier VBIOS
 337                  */
 338                 if (bmp[5] < 4)
 339                         i2c = &bios->data[0x48];
 340                 else
 341                         i2c = &bmp[0x36];
 342
 343                 if (i2c[4]) legacy[0][0] = i2c[4];
 344                 if (i2c[5]) legacy[0][1] = i2c[5];
 345                 if (i2c[6]) legacy[1][0] = i2c[6];
 346                 if (i2c[7]) legacy[1][1] = i2c[7];
 347         }
 348
 349         if (version >= 0x30) {
 350                 entry     = i2c[1] + i2c;
 351                 entries   = i2c[2];
 352                 recordlen = i2c[3];
 353         } else
 354         if (version) {
 355                 entry     = i2c;
 356                 entries   = 16;
 357                 recordlen = 4;
 358         } else {
 359                 entry     = legacy[0];
 360                 entries   = 2;
 361                 recordlen = 4;
 362         }
 363
 364         for (i = 0; i < entries; i++, entry += recordlen) {
 365                 port = kzalloc(sizeof(*port), GFP_KERNEL);
 366                 if (port == NULL) {
 367                         nouveau_i2c_fini(dev);
 368                         return -ENOMEM;
 369                 }
 370
 371                 port->type = entry[3];
 372                 if (version < 0x30) {
 373                         port->type &= 0x07;
 374                         if (port->type == 0x07)
 375                                 port->type = 0xff;
 376                 }
 377
 378                 if (port->type == 0xff) {
 379                         kfree(port);
 380                         continue;
 381                 }
 382
 383                 switch (port->type) {
 384                 case 0: /* NV04:NV50 */
 385                         port->drive = entry[0];
 386                         port->sense = entry[1];
 387                         port->adapter.algo = &nouveau_i2c_bit_algo;
 388                         break;
 389                 case 4: /* NV4E */
 390                         port->drive = 0x600800 + entry[1];
 391                         port->sense = port->drive;
 392                         port->adapter.algo = &nouveau_i2c_bit_algo;
 393                         break;
 394                 case 5: /* NV50- */
 395                         port->drive = entry[0] & 0x0f;
 396                         if (dev_priv->card_type < NV_D0) {
 397                                 if (port->drive >= ARRAY_SIZE(nv50_i2c_port))
 398                                         break;
 399                                 port->drive = nv50_i2c_port[port->drive];
 400                                 port->sense = port->drive;
 401                         } else {
 402                                 port->drive = 0x00d014 + (port->drive * 0x20);
 403                                 port->sense = port->drive;
 404                         }
 405                         port->adapter.algo = &nouveau_i2c_bit_algo;
 406                         break;
 407                 case 6: /* NV50- DP AUX */
 408                         port->drive = entry[0];
 409                         port->sense = port->drive;
 410                         port->adapter.algo = &nouveau_dp_i2c_algo;
 411                         break;
 412                 default:
 413                         break;
 414                 }
 415
 416                 if (!port->adapter.algo) {
 417                         NV_ERROR(dev, "I2C%d: type %d index %x/%x unknown\n",
 418                                  i, port->type, port->drive, port->sense);
 419                         kfree(port);
 420                         continue;
 421                 }
 422
 423                 snprintf(port->adapter.name, sizeof(port->adapter.name),
 424                          "nouveau-%s-%d", pci_name(dev->pdev), i);
 425                 port->adapter.owner = THIS_MODULE;
 426                 port->adapter.dev.parent = &dev->pdev->dev;
 427                 port->dev = dev;
 428                 port->index = i;
 429                 port->dcb = ROM32(entry[0]);
 430                 i2c_set_adapdata(&port->adapter, i2c);
 431
 432                 ret = i2c_add_adapter(&port->adapter);
 433                 if (ret) {
 434                         NV_ERROR(dev, "I2C%d: failed register: %d\n", i, ret);
 435                         kfree(port);
 436                         continue;
 437                 }
 438
 439                 list_add_tail(&port->head, &dev_priv->i2c_ports);
 440         }
 441
 442         return 0;
 443 }
 444
 445 void
 446 nouveau_i2c_fini(struct drm_device *dev)
 447 {
 448         struct drm_nouveau_private *dev_priv = dev->dev_private;
 449         struct nouveau_i2c_chan *port, *tmp;
 450
 451         list_for_each_entry_safe(port, tmp, &dev_priv->i2c_ports, head) {
 452                 i2c_del_adapter(&port->adapter);
 453                 kfree(port);
 454         }
 455 }
 456
 457 struct nouveau_i2c_chan *
 458 nouveau_i2c_find(struct drm_device *dev, u8 index)
 459 {
 460         struct drm_nouveau_private *dev_priv = dev->dev_private;
 461         struct nouveau_i2c_chan *port;
 462
 463         if (index == NV_I2C_DEFAULT(0) ||
 464             index == NV_I2C_DEFAULT(1)) {
 465                 u8 version, *i2c = i2c_table(dev, &version);
 466                 if (i2c && version >= 0x30) {
 467                         if (index == NV_I2C_DEFAULT(0))
 468                                 index = (i2c[4] & 0x0f);
 469                         else
 470                                 index = (i2c[4] & 0xf0) >> 4;
 471                 } else {
 472                         index = 2;
 473                 }
 474         }
 475
 476         list_for_each_entry(port, &dev_priv->i2c_ports, head) {
 477                 if (port->index == index)
 478                         break;
 479         }
 480
 481         if (&port->head == &dev_priv->i2c_ports)
 482                 return NULL;
 483
 484         if (dev_priv->card_type >= NV_50 && (port->dcb & 0x00000100)) {
 485                 u32 reg = 0x00e500, val;
 486                 if (port->type == 6) {
 487                         reg += port->drive * 0x50;
 488                         val  = 0x2002;
 489                 } else {
 490                         reg += ((port->dcb & 0x1e00) >> 9) * 0x50;
 491                         val  = 0xe001;
 492                 }
 493
 494                 /* nfi, but neither auxch or i2c work if it's 1 */
 495                 nv_mask(dev, reg + 0x0c, 0x00000001, 0x00000000);
 496                 /* nfi, but switches auxch vs normal i2c */
 497                 nv_mask(dev, reg + 0x00, 0x0000f003, val);
 498         }
 499
 500         return port;
 501 }
 502
 503 bool
 504 nouveau_probe_i2c_addr(struct nouveau_i2c_chan *i2c, int addr)
 505 {
 506         uint8_t buf[] = { 0 };
 507         struct i2c_msg msgs[] = {
 508                 {
 509                         .addr = addr,
 510                         .flags = 0,
 511                         .len = 1,
 512                         .buf = buf,
 513                 },
 514                 {
 515                         .addr = addr,
 516                         .flags = I2C_M_RD,
 517                         .len = 1,
 518                         .buf = buf,
 519                 }
 520         };
 521
 522         return i2c_transfer(&i2c->adapter, msgs, 2) == 2;
 523 }
 524
 525 int
 526 nouveau_i2c_identify(struct drm_device *dev, const char *what,
 527                      struct i2c_board_info *info,
 528                      bool (*match)(struct nouveau_i2c_chan *,
 529                                    struct i2c_board_info *),
 530                      int index)
 531 {
 532         struct nouveau_i2c_chan *i2c = nouveau_i2c_find(dev, index);
 533         int i;
 534
 535         if (!i2c) {
 536                 NV_DEBUG(dev, "No bus when probing %s on %d\n", what, index);
 537                 return -ENODEV;
 538         }
 539
 540         NV_DEBUG(dev, "Probing %ss on I2C bus: %d\n", what, i2c->index);
 541         for (i = 0; info[i].addr; i++) {
 542                 if (nouveau_probe_i2c_addr(i2c, info[i].addr) &&
 543                     (!match || match(i2c, &info[i]))) {
 544                         NV_INFO(dev, "Detected %s: %s\n", what, info[i].type);
 545                         return i;
 546                 }
 547         }
 548
 549         NV_DEBUG(dev, "No devices found.\n");
 550         return -ENODEV;
 551 }