1 /* 2 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie> 3 * Copyright © 2006-2008,2010 Intel Corporation 4 * Jesse Barnes <jesse.barnes@intel.com> 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 23 * DEALINGS IN THE SOFTWARE. 24 * 25 * Authors: 26 * Eric Anholt <eric@anholt.net> 27 * Chris Wilson <chris@chris-wilson.co.uk> 28 */ 29 30 #include <linux/export.h> 31 #include <linux/i2c-algo-bit.h> 32 #include <linux/i2c.h> 33 34 #include <drm/drm_hdcp.h> 35 36 #include "i915_drv.h" 37 #include "intel_display_types.h" 38 #include "intel_gmbus.h" 39 40 struct gmbus_pin { 41 const char *name; 42 enum i915_gpio gpio; 43 }; 44 45 /* Map gmbus pin pairs to names and registers. */ 46 static const struct gmbus_pin gmbus_pins[] = { 47 [GMBUS_PIN_SSC] = { "ssc", GPIOB }, 48 [GMBUS_PIN_VGADDC] = { "vga", GPIOA }, 49 [GMBUS_PIN_PANEL] = { "panel", GPIOC }, 50 [GMBUS_PIN_DPC] = { "dpc", GPIOD }, 51 [GMBUS_PIN_DPB] = { "dpb", GPIOE }, 52 [GMBUS_PIN_DPD] = { "dpd", GPIOF }, 53 }; 54 55 static const struct gmbus_pin gmbus_pins_bdw[] = { 56 [GMBUS_PIN_VGADDC] = { "vga", GPIOA }, 57 [GMBUS_PIN_DPC] = { "dpc", GPIOD }, 58 [GMBUS_PIN_DPB] = { "dpb", GPIOE }, 59 [GMBUS_PIN_DPD] = { "dpd", GPIOF }, 60 }; 61 62 static const struct gmbus_pin gmbus_pins_skl[] = { 63 [GMBUS_PIN_DPC] = { "dpc", GPIOD }, 64 [GMBUS_PIN_DPB] = { "dpb", GPIOE }, 65 [GMBUS_PIN_DPD] = { "dpd", GPIOF }, 66 }; 67 68 static const struct gmbus_pin gmbus_pins_bxt[] = { 69 [GMBUS_PIN_1_BXT] = { "dpb", GPIOB }, 70 [GMBUS_PIN_2_BXT] = { "dpc", GPIOC }, 71 [GMBUS_PIN_3_BXT] = { "misc", GPIOD }, 72 }; 73 74 static const struct gmbus_pin gmbus_pins_cnp[] = { 75 [GMBUS_PIN_1_BXT] = { "dpb", GPIOB }, 76 [GMBUS_PIN_2_BXT] = { "dpc", GPIOC }, 77 [GMBUS_PIN_3_BXT] = { "misc", GPIOD }, 78 [GMBUS_PIN_4_CNP] = { "dpd", GPIOE }, 79 }; 80 81 static const struct gmbus_pin gmbus_pins_icp[] = { 82 [GMBUS_PIN_1_BXT] = { "dpa", GPIOB }, 83 [GMBUS_PIN_2_BXT] = { "dpb", GPIOC }, 84 [GMBUS_PIN_3_BXT] = { "dpc", GPIOD }, 85 [GMBUS_PIN_9_TC1_ICP] = { "tc1", GPIOJ }, 86 [GMBUS_PIN_10_TC2_ICP] = { "tc2", GPIOK }, 87 [GMBUS_PIN_11_TC3_ICP] = { "tc3", GPIOL }, 88 [GMBUS_PIN_12_TC4_ICP] = { "tc4", GPIOM }, 89 [GMBUS_PIN_13_TC5_TGP] = { "tc5", GPION }, 90 [GMBUS_PIN_14_TC6_TGP] = { "tc6", GPIOO }, 91 }; 92 93 static const struct gmbus_pin gmbus_pins_dg1[] = { 94 [GMBUS_PIN_1_BXT] = { "dpa", GPIOB }, 95 [GMBUS_PIN_2_BXT] = { "dpb", GPIOC }, 96 [GMBUS_PIN_3_BXT] = { "dpc", GPIOD }, 97 [GMBUS_PIN_4_CNP] = { "dpd", GPIOE }, 98 }; 99 100 /* pin is expected to be valid */ 101 static const struct gmbus_pin *get_gmbus_pin(struct drm_i915_private *dev_priv, 102 unsigned int pin) 103 { 104 if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1) 105 return &gmbus_pins_dg1[pin]; 106 else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP) 107 return &gmbus_pins_icp[pin]; 108 else if (HAS_PCH_CNP(dev_priv)) 109 return &gmbus_pins_cnp[pin]; 110 else if (IS_GEN9_LP(dev_priv)) 111 return &gmbus_pins_bxt[pin]; 112 else if (IS_GEN9_BC(dev_priv)) 113 return &gmbus_pins_skl[pin]; 114 else if (IS_BROADWELL(dev_priv)) 115 return &gmbus_pins_bdw[pin]; 116 else 117 return &gmbus_pins[pin]; 118 } 119 120 bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv, 121 unsigned int pin) 122 { 123 unsigned int size; 124 125 if (INTEL_PCH_TYPE(dev_priv) >= PCH_DG1) 126 size = ARRAY_SIZE(gmbus_pins_dg1); 127 else if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP) 128 size = ARRAY_SIZE(gmbus_pins_icp); 129 else if (HAS_PCH_CNP(dev_priv)) 130 size = ARRAY_SIZE(gmbus_pins_cnp); 131 else if (IS_GEN9_LP(dev_priv)) 132 size = ARRAY_SIZE(gmbus_pins_bxt); 133 else if (IS_GEN9_BC(dev_priv)) 134 size = ARRAY_SIZE(gmbus_pins_skl); 135 else if (IS_BROADWELL(dev_priv)) 136 size = ARRAY_SIZE(gmbus_pins_bdw); 137 else 138 size = ARRAY_SIZE(gmbus_pins); 139 140 return pin < size && get_gmbus_pin(dev_priv, pin)->name; 141 } 142 143 /* Intel GPIO access functions */ 144 145 #define I2C_RISEFALL_TIME 10 146 147 static inline struct intel_gmbus * 148 to_intel_gmbus(struct i2c_adapter *i2c) 149 { 150 return container_of(i2c, struct intel_gmbus, adapter); 151 } 152 153 void 154 intel_gmbus_reset(struct drm_i915_private *dev_priv) 155 { 156 intel_de_write(dev_priv, GMBUS0, 0); 157 intel_de_write(dev_priv, GMBUS4, 0); 158 } 159 160 static void pnv_gmbus_clock_gating(struct drm_i915_private *dev_priv, 161 bool enable) 162 { 163 u32 val; 164 165 /* When using bit bashing for I2C, this bit needs to be set to 1 */ 166 val = intel_de_read(dev_priv, DSPCLK_GATE_D); 167 if (!enable) 168 val |= PNV_GMBUSUNIT_CLOCK_GATE_DISABLE; 169 else 170 val &= ~PNV_GMBUSUNIT_CLOCK_GATE_DISABLE; 171 intel_de_write(dev_priv, DSPCLK_GATE_D, val); 172 } 173 174 static void pch_gmbus_clock_gating(struct drm_i915_private *dev_priv, 175 bool enable) 176 { 177 u32 val; 178 179 val = intel_de_read(dev_priv, SOUTH_DSPCLK_GATE_D); 180 if (!enable) 181 val |= PCH_GMBUSUNIT_CLOCK_GATE_DISABLE; 182 else 183 val &= ~PCH_GMBUSUNIT_CLOCK_GATE_DISABLE; 184 intel_de_write(dev_priv, SOUTH_DSPCLK_GATE_D, val); 185 } 186 187 static void bxt_gmbus_clock_gating(struct drm_i915_private *dev_priv, 188 bool enable) 189 { 190 u32 val; 191 192 val = intel_de_read(dev_priv, GEN9_CLKGATE_DIS_4); 193 if (!enable) 194 val |= BXT_GMBUS_GATING_DIS; 195 else 196 val &= ~BXT_GMBUS_GATING_DIS; 197 intel_de_write(dev_priv, GEN9_CLKGATE_DIS_4, val); 198 } 199 200 static u32 get_reserved(struct intel_gmbus *bus) 201 { 202 struct drm_i915_private *i915 = bus->dev_priv; 203 struct intel_uncore *uncore = &i915->uncore; 204 u32 reserved = 0; 205 206 /* On most chips, these bits must be preserved in software. */ 207 if (!IS_I830(i915) && !IS_I845G(i915)) 208 reserved = intel_uncore_read_notrace(uncore, bus->gpio_reg) & 209 (GPIO_DATA_PULLUP_DISABLE | 210 GPIO_CLOCK_PULLUP_DISABLE); 211 212 return reserved; 213 } 214 215 static int get_clock(void *data) 216 { 217 struct intel_gmbus *bus = data; 218 struct intel_uncore *uncore = &bus->dev_priv->uncore; 219 u32 reserved = get_reserved(bus); 220 221 intel_uncore_write_notrace(uncore, 222 bus->gpio_reg, 223 reserved | GPIO_CLOCK_DIR_MASK); 224 intel_uncore_write_notrace(uncore, bus->gpio_reg, reserved); 225 226 return (intel_uncore_read_notrace(uncore, bus->gpio_reg) & 227 GPIO_CLOCK_VAL_IN) != 0; 228 } 229 230 static int get_data(void *data) 231 { 232 struct intel_gmbus *bus = data; 233 struct intel_uncore *uncore = &bus->dev_priv->uncore; 234 u32 reserved = get_reserved(bus); 235 236 intel_uncore_write_notrace(uncore, 237 bus->gpio_reg, 238 reserved | GPIO_DATA_DIR_MASK); 239 intel_uncore_write_notrace(uncore, bus->gpio_reg, reserved); 240 241 return (intel_uncore_read_notrace(uncore, bus->gpio_reg) & 242 GPIO_DATA_VAL_IN) != 0; 243 } 244 245 static void set_clock(void *data, int state_high) 246 { 247 struct intel_gmbus *bus = data; 248 struct intel_uncore *uncore = &bus->dev_priv->uncore; 249 u32 reserved = get_reserved(bus); 250 u32 clock_bits; 251 252 if (state_high) 253 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK; 254 else 255 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK | 256 GPIO_CLOCK_VAL_MASK; 257 258 intel_uncore_write_notrace(uncore, 259 bus->gpio_reg, 260 reserved | clock_bits); 261 intel_uncore_posting_read(uncore, bus->gpio_reg); 262 } 263 264 static void set_data(void *data, int state_high) 265 { 266 struct intel_gmbus *bus = data; 267 struct intel_uncore *uncore = &bus->dev_priv->uncore; 268 u32 reserved = get_reserved(bus); 269 u32 data_bits; 270 271 if (state_high) 272 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK; 273 else 274 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK | 275 GPIO_DATA_VAL_MASK; 276 277 intel_uncore_write_notrace(uncore, bus->gpio_reg, reserved | data_bits); 278 intel_uncore_posting_read(uncore, bus->gpio_reg); 279 } 280 281 static int 282 intel_gpio_pre_xfer(struct i2c_adapter *adapter) 283 { 284 struct intel_gmbus *bus = container_of(adapter, 285 struct intel_gmbus, 286 adapter); 287 struct drm_i915_private *dev_priv = bus->dev_priv; 288 289 intel_gmbus_reset(dev_priv); 290 291 if (IS_PINEVIEW(dev_priv)) 292 pnv_gmbus_clock_gating(dev_priv, false); 293 294 set_data(bus, 1); 295 set_clock(bus, 1); 296 udelay(I2C_RISEFALL_TIME); 297 return 0; 298 } 299 300 static void 301 intel_gpio_post_xfer(struct i2c_adapter *adapter) 302 { 303 struct intel_gmbus *bus = container_of(adapter, 304 struct intel_gmbus, 305 adapter); 306 struct drm_i915_private *dev_priv = bus->dev_priv; 307 308 set_data(bus, 1); 309 set_clock(bus, 1); 310 311 if (IS_PINEVIEW(dev_priv)) 312 pnv_gmbus_clock_gating(dev_priv, true); 313 } 314 315 static void 316 intel_gpio_setup(struct intel_gmbus *bus, unsigned int pin) 317 { 318 struct drm_i915_private *dev_priv = bus->dev_priv; 319 struct i2c_algo_bit_data *algo; 320 321 algo = &bus->bit_algo; 322 323 bus->gpio_reg = GPIO(get_gmbus_pin(dev_priv, pin)->gpio); 324 bus->adapter.algo_data = algo; 325 algo->setsda = set_data; 326 algo->setscl = set_clock; 327 algo->getsda = get_data; 328 algo->getscl = get_clock; 329 algo->pre_xfer = intel_gpio_pre_xfer; 330 algo->post_xfer = intel_gpio_post_xfer; 331 algo->udelay = I2C_RISEFALL_TIME; 332 algo->timeout = usecs_to_jiffies(2200); 333 algo->data = bus; 334 } 335 336 static int gmbus_wait(struct drm_i915_private *dev_priv, u32 status, u32 irq_en) 337 { 338 DEFINE_WAIT(wait); 339 u32 gmbus2; 340 int ret; 341 342 /* Important: The hw handles only the first bit, so set only one! Since 343 * we also need to check for NAKs besides the hw ready/idle signal, we 344 * need to wake up periodically and check that ourselves. 345 */ 346 if (!HAS_GMBUS_IRQ(dev_priv)) 347 irq_en = 0; 348 349 add_wait_queue(&dev_priv->gmbus_wait_queue, &wait); 350 intel_de_write_fw(dev_priv, GMBUS4, irq_en); 351 352 status |= GMBUS_SATOER; 353 ret = wait_for_us((gmbus2 = intel_de_read_fw(dev_priv, GMBUS2)) & status, 354 2); 355 if (ret) 356 ret = wait_for((gmbus2 = intel_de_read_fw(dev_priv, GMBUS2)) & status, 357 50); 358 359 intel_de_write_fw(dev_priv, GMBUS4, 0); 360 remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait); 361 362 if (gmbus2 & GMBUS_SATOER) 363 return -ENXIO; 364 365 return ret; 366 } 367 368 static int 369 gmbus_wait_idle(struct drm_i915_private *dev_priv) 370 { 371 DEFINE_WAIT(wait); 372 u32 irq_enable; 373 int ret; 374 375 /* Important: The hw handles only the first bit, so set only one! */ 376 irq_enable = 0; 377 if (HAS_GMBUS_IRQ(dev_priv)) 378 irq_enable = GMBUS_IDLE_EN; 379 380 add_wait_queue(&dev_priv->gmbus_wait_queue, &wait); 381 intel_de_write_fw(dev_priv, GMBUS4, irq_enable); 382 383 ret = intel_wait_for_register_fw(&dev_priv->uncore, 384 GMBUS2, GMBUS_ACTIVE, 0, 385 10); 386 387 intel_de_write_fw(dev_priv, GMBUS4, 0); 388 remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait); 389 390 return ret; 391 } 392 393 static unsigned int gmbus_max_xfer_size(struct drm_i915_private *dev_priv) 394 { 395 return INTEL_GEN(dev_priv) >= 9 ? GEN9_GMBUS_BYTE_COUNT_MAX : 396 GMBUS_BYTE_COUNT_MAX; 397 } 398 399 static int 400 gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv, 401 unsigned short addr, u8 *buf, unsigned int len, 402 u32 gmbus0_reg, u32 gmbus1_index) 403 { 404 unsigned int size = len; 405 bool burst_read = len > gmbus_max_xfer_size(dev_priv); 406 bool extra_byte_added = false; 407 408 if (burst_read) { 409 /* 410 * As per HW Spec, for 512Bytes need to read extra Byte and 411 * Ignore the extra byte read. 412 */ 413 if (len == 512) { 414 extra_byte_added = true; 415 len++; 416 } 417 size = len % 256 + 256; 418 intel_de_write_fw(dev_priv, GMBUS0, 419 gmbus0_reg | GMBUS_BYTE_CNT_OVERRIDE); 420 } 421 422 intel_de_write_fw(dev_priv, GMBUS1, 423 gmbus1_index | GMBUS_CYCLE_WAIT | (size << GMBUS_BYTE_COUNT_SHIFT) | (addr << GMBUS_SLAVE_ADDR_SHIFT) | GMBUS_SLAVE_READ | GMBUS_SW_RDY); 424 while (len) { 425 int ret; 426 u32 val, loop = 0; 427 428 ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN); 429 if (ret) 430 return ret; 431 432 val = intel_de_read_fw(dev_priv, GMBUS3); 433 do { 434 if (extra_byte_added && len == 1) 435 break; 436 437 *buf++ = val & 0xff; 438 val >>= 8; 439 } while (--len && ++loop < 4); 440 441 if (burst_read && len == size - 4) 442 /* Reset the override bit */ 443 intel_de_write_fw(dev_priv, GMBUS0, gmbus0_reg); 444 } 445 446 return 0; 447 } 448 449 /* 450 * HW spec says that 512Bytes in Burst read need special treatment. 451 * But it doesn't talk about other multiple of 256Bytes. And couldn't locate 452 * an I2C slave, which supports such a lengthy burst read too for experiments. 453 * 454 * So until things get clarified on HW support, to avoid the burst read length 455 * in fold of 256Bytes except 512, max burst read length is fixed at 767Bytes. 456 */ 457 #define INTEL_GMBUS_BURST_READ_MAX_LEN 767U 458 459 static int 460 gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg, 461 u32 gmbus0_reg, u32 gmbus1_index) 462 { 463 u8 *buf = msg->buf; 464 unsigned int rx_size = msg->len; 465 unsigned int len; 466 int ret; 467 468 do { 469 if (HAS_GMBUS_BURST_READ(dev_priv)) 470 len = min(rx_size, INTEL_GMBUS_BURST_READ_MAX_LEN); 471 else 472 len = min(rx_size, gmbus_max_xfer_size(dev_priv)); 473 474 ret = gmbus_xfer_read_chunk(dev_priv, msg->addr, buf, len, 475 gmbus0_reg, gmbus1_index); 476 if (ret) 477 return ret; 478 479 rx_size -= len; 480 buf += len; 481 } while (rx_size != 0); 482 483 return 0; 484 } 485 486 static int 487 gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv, 488 unsigned short addr, u8 *buf, unsigned int len, 489 u32 gmbus1_index) 490 { 491 unsigned int chunk_size = len; 492 u32 val, loop; 493 494 val = loop = 0; 495 while (len && loop < 4) { 496 val |= *buf++ << (8 * loop++); 497 len -= 1; 498 } 499 500 intel_de_write_fw(dev_priv, GMBUS3, val); 501 intel_de_write_fw(dev_priv, GMBUS1, 502 gmbus1_index | GMBUS_CYCLE_WAIT | (chunk_size << GMBUS_BYTE_COUNT_SHIFT) | (addr << GMBUS_SLAVE_ADDR_SHIFT) | GMBUS_SLAVE_WRITE | GMBUS_SW_RDY); 503 while (len) { 504 int ret; 505 506 val = loop = 0; 507 do { 508 val |= *buf++ << (8 * loop); 509 } while (--len && ++loop < 4); 510 511 intel_de_write_fw(dev_priv, GMBUS3, val); 512 513 ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN); 514 if (ret) 515 return ret; 516 } 517 518 return 0; 519 } 520 521 static int 522 gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg, 523 u32 gmbus1_index) 524 { 525 u8 *buf = msg->buf; 526 unsigned int tx_size = msg->len; 527 unsigned int len; 528 int ret; 529 530 do { 531 len = min(tx_size, gmbus_max_xfer_size(dev_priv)); 532 533 ret = gmbus_xfer_write_chunk(dev_priv, msg->addr, buf, len, 534 gmbus1_index); 535 if (ret) 536 return ret; 537 538 buf += len; 539 tx_size -= len; 540 } while (tx_size != 0); 541 542 return 0; 543 } 544 545 /* 546 * The gmbus controller can combine a 1 or 2 byte write with another read/write 547 * that immediately follows it by using an "INDEX" cycle. 548 */ 549 static bool 550 gmbus_is_index_xfer(struct i2c_msg *msgs, int i, int num) 551 { 552 return (i + 1 < num && 553 msgs[i].addr == msgs[i + 1].addr && 554 !(msgs[i].flags & I2C_M_RD) && 555 (msgs[i].len == 1 || msgs[i].len == 2) && 556 msgs[i + 1].len > 0); 557 } 558 559 static int 560 gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs, 561 u32 gmbus0_reg) 562 { 563 u32 gmbus1_index = 0; 564 u32 gmbus5 = 0; 565 int ret; 566 567 if (msgs[0].len == 2) 568 gmbus5 = GMBUS_2BYTE_INDEX_EN | 569 msgs[0].buf[1] | (msgs[0].buf[0] << 8); 570 if (msgs[0].len == 1) 571 gmbus1_index = GMBUS_CYCLE_INDEX | 572 (msgs[0].buf[0] << GMBUS_SLAVE_INDEX_SHIFT); 573 574 /* GMBUS5 holds 16-bit index */ 575 if (gmbus5) 576 intel_de_write_fw(dev_priv, GMBUS5, gmbus5); 577 578 if (msgs[1].flags & I2C_M_RD) 579 ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus0_reg, 580 gmbus1_index); 581 else 582 ret = gmbus_xfer_write(dev_priv, &msgs[1], gmbus1_index); 583 584 /* Clear GMBUS5 after each index transfer */ 585 if (gmbus5) 586 intel_de_write_fw(dev_priv, GMBUS5, 0); 587 588 return ret; 589 } 590 591 static int 592 do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num, 593 u32 gmbus0_source) 594 { 595 struct intel_gmbus *bus = container_of(adapter, 596 struct intel_gmbus, 597 adapter); 598 struct drm_i915_private *dev_priv = bus->dev_priv; 599 int i = 0, inc, try = 0; 600 int ret = 0; 601 602 /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */ 603 if (IS_GEN9_LP(dev_priv)) 604 bxt_gmbus_clock_gating(dev_priv, false); 605 else if (HAS_PCH_SPT(dev_priv) || HAS_PCH_CNP(dev_priv)) 606 pch_gmbus_clock_gating(dev_priv, false); 607 608 retry: 609 intel_de_write_fw(dev_priv, GMBUS0, gmbus0_source | bus->reg0); 610 611 for (; i < num; i += inc) { 612 inc = 1; 613 if (gmbus_is_index_xfer(msgs, i, num)) { 614 ret = gmbus_index_xfer(dev_priv, &msgs[i], 615 gmbus0_source | bus->reg0); 616 inc = 2; /* an index transmission is two msgs */ 617 } else if (msgs[i].flags & I2C_M_RD) { 618 ret = gmbus_xfer_read(dev_priv, &msgs[i], 619 gmbus0_source | bus->reg0, 0); 620 } else { 621 ret = gmbus_xfer_write(dev_priv, &msgs[i], 0); 622 } 623 624 if (!ret) 625 ret = gmbus_wait(dev_priv, 626 GMBUS_HW_WAIT_PHASE, GMBUS_HW_WAIT_EN); 627 if (ret == -ETIMEDOUT) 628 goto timeout; 629 else if (ret) 630 goto clear_err; 631 } 632 633 /* Generate a STOP condition on the bus. Note that gmbus can't generata 634 * a STOP on the very first cycle. To simplify the code we 635 * unconditionally generate the STOP condition with an additional gmbus 636 * cycle. */ 637 intel_de_write_fw(dev_priv, GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY); 638 639 /* Mark the GMBUS interface as disabled after waiting for idle. 640 * We will re-enable it at the start of the next xfer, 641 * till then let it sleep. 642 */ 643 if (gmbus_wait_idle(dev_priv)) { 644 drm_dbg_kms(&dev_priv->drm, 645 "GMBUS [%s] timed out waiting for idle\n", 646 adapter->name); 647 ret = -ETIMEDOUT; 648 } 649 intel_de_write_fw(dev_priv, GMBUS0, 0); 650 ret = ret ?: i; 651 goto out; 652 653 clear_err: 654 /* 655 * Wait for bus to IDLE before clearing NAK. 656 * If we clear the NAK while bus is still active, then it will stay 657 * active and the next transaction may fail. 658 * 659 * If no ACK is received during the address phase of a transaction, the 660 * adapter must report -ENXIO. It is not clear what to return if no ACK 661 * is received at other times. But we have to be careful to not return 662 * spurious -ENXIO because that will prevent i2c and drm edid functions 663 * from retrying. So return -ENXIO only when gmbus properly quiescents - 664 * timing out seems to happen when there _is_ a ddc chip present, but 665 * it's slow responding and only answers on the 2nd retry. 666 */ 667 ret = -ENXIO; 668 if (gmbus_wait_idle(dev_priv)) { 669 drm_dbg_kms(&dev_priv->drm, 670 "GMBUS [%s] timed out after NAK\n", 671 adapter->name); 672 ret = -ETIMEDOUT; 673 } 674 675 /* Toggle the Software Clear Interrupt bit. This has the effect 676 * of resetting the GMBUS controller and so clearing the 677 * BUS_ERROR raised by the slave's NAK. 678 */ 679 intel_de_write_fw(dev_priv, GMBUS1, GMBUS_SW_CLR_INT); 680 intel_de_write_fw(dev_priv, GMBUS1, 0); 681 intel_de_write_fw(dev_priv, GMBUS0, 0); 682 683 drm_dbg_kms(&dev_priv->drm, "GMBUS [%s] NAK for addr: %04x %c(%d)\n", 684 adapter->name, msgs[i].addr, 685 (msgs[i].flags & I2C_M_RD) ? 'r' : 'w', msgs[i].len); 686 687 /* 688 * Passive adapters sometimes NAK the first probe. Retry the first 689 * message once on -ENXIO for GMBUS transfers; the bit banging algorithm 690 * has retries internally. See also the retry loop in 691 * drm_do_probe_ddc_edid, which bails out on the first -ENXIO. 692 */ 693 if (ret == -ENXIO && i == 0 && try++ == 0) { 694 drm_dbg_kms(&dev_priv->drm, 695 "GMBUS [%s] NAK on first message, retry\n", 696 adapter->name); 697 goto retry; 698 } 699 700 goto out; 701 702 timeout: 703 drm_dbg_kms(&dev_priv->drm, 704 "GMBUS [%s] timed out, falling back to bit banging on pin %d\n", 705 bus->adapter.name, bus->reg0 & 0xff); 706 intel_de_write_fw(dev_priv, GMBUS0, 0); 707 708 /* 709 * Hardware may not support GMBUS over these pins? Try GPIO bitbanging 710 * instead. Use EAGAIN to have i2c core retry. 711 */ 712 ret = -EAGAIN; 713 714 out: 715 /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */ 716 if (IS_GEN9_LP(dev_priv)) 717 bxt_gmbus_clock_gating(dev_priv, true); 718 else if (HAS_PCH_SPT(dev_priv) || HAS_PCH_CNP(dev_priv)) 719 pch_gmbus_clock_gating(dev_priv, true); 720 721 return ret; 722 } 723 724 static int 725 gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) 726 { 727 struct intel_gmbus *bus = 728 container_of(adapter, struct intel_gmbus, adapter); 729 struct drm_i915_private *dev_priv = bus->dev_priv; 730 intel_wakeref_t wakeref; 731 int ret; 732 733 wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS); 734 735 if (bus->force_bit) { 736 ret = i2c_bit_algo.master_xfer(adapter, msgs, num); 737 if (ret < 0) 738 bus->force_bit &= ~GMBUS_FORCE_BIT_RETRY; 739 } else { 740 ret = do_gmbus_xfer(adapter, msgs, num, 0); 741 if (ret == -EAGAIN) 742 bus->force_bit |= GMBUS_FORCE_BIT_RETRY; 743 } 744 745 intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref); 746 747 return ret; 748 } 749 750 int intel_gmbus_output_aksv(struct i2c_adapter *adapter) 751 { 752 struct intel_gmbus *bus = 753 container_of(adapter, struct intel_gmbus, adapter); 754 struct drm_i915_private *dev_priv = bus->dev_priv; 755 u8 cmd = DRM_HDCP_DDC_AKSV; 756 u8 buf[DRM_HDCP_KSV_LEN] = { 0 }; 757 struct i2c_msg msgs[] = { 758 { 759 .addr = DRM_HDCP_DDC_ADDR, 760 .flags = 0, 761 .len = sizeof(cmd), 762 .buf = &cmd, 763 }, 764 { 765 .addr = DRM_HDCP_DDC_ADDR, 766 .flags = 0, 767 .len = sizeof(buf), 768 .buf = buf, 769 } 770 }; 771 intel_wakeref_t wakeref; 772 int ret; 773 774 wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS); 775 mutex_lock(&dev_priv->gmbus_mutex); 776 777 /* 778 * In order to output Aksv to the receiver, use an indexed write to 779 * pass the i2c command, and tell GMBUS to use the HW-provided value 780 * instead of sourcing GMBUS3 for the data. 781 */ 782 ret = do_gmbus_xfer(adapter, msgs, ARRAY_SIZE(msgs), GMBUS_AKSV_SELECT); 783 784 mutex_unlock(&dev_priv->gmbus_mutex); 785 intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref); 786 787 return ret; 788 } 789 790 static u32 gmbus_func(struct i2c_adapter *adapter) 791 { 792 return i2c_bit_algo.functionality(adapter) & 793 (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 794 /* I2C_FUNC_10BIT_ADDR | */ 795 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 796 I2C_FUNC_SMBUS_BLOCK_PROC_CALL); 797 } 798 799 static const struct i2c_algorithm gmbus_algorithm = { 800 .master_xfer = gmbus_xfer, 801 .functionality = gmbus_func 802 }; 803 804 static void gmbus_lock_bus(struct i2c_adapter *adapter, 805 unsigned int flags) 806 { 807 struct intel_gmbus *bus = to_intel_gmbus(adapter); 808 struct drm_i915_private *dev_priv = bus->dev_priv; 809 810 mutex_lock(&dev_priv->gmbus_mutex); 811 } 812 813 static int gmbus_trylock_bus(struct i2c_adapter *adapter, 814 unsigned int flags) 815 { 816 struct intel_gmbus *bus = to_intel_gmbus(adapter); 817 struct drm_i915_private *dev_priv = bus->dev_priv; 818 819 return mutex_trylock(&dev_priv->gmbus_mutex); 820 } 821 822 static void gmbus_unlock_bus(struct i2c_adapter *adapter, 823 unsigned int flags) 824 { 825 struct intel_gmbus *bus = to_intel_gmbus(adapter); 826 struct drm_i915_private *dev_priv = bus->dev_priv; 827 828 mutex_unlock(&dev_priv->gmbus_mutex); 829 } 830 831 static const struct i2c_lock_operations gmbus_lock_ops = { 832 .lock_bus = gmbus_lock_bus, 833 .trylock_bus = gmbus_trylock_bus, 834 .unlock_bus = gmbus_unlock_bus, 835 }; 836 837 /** 838 * intel_gmbus_setup - instantiate all Intel i2c GMBuses 839 * @dev_priv: i915 device private 840 */ 841 int intel_gmbus_setup(struct drm_i915_private *dev_priv) 842 { 843 struct pci_dev *pdev = dev_priv->drm.pdev; 844 struct intel_gmbus *bus; 845 unsigned int pin; 846 int ret; 847 848 if (!HAS_DISPLAY(dev_priv)) 849 return 0; 850 851 if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) 852 dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE; 853 else if (!HAS_GMCH(dev_priv)) 854 /* 855 * Broxton uses the same PCH offsets for South Display Engine, 856 * even though it doesn't have a PCH. 857 */ 858 dev_priv->gpio_mmio_base = PCH_DISPLAY_BASE; 859 860 mutex_init(&dev_priv->gmbus_mutex); 861 init_waitqueue_head(&dev_priv->gmbus_wait_queue); 862 863 for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) { 864 if (!intel_gmbus_is_valid_pin(dev_priv, pin)) 865 continue; 866 867 bus = &dev_priv->gmbus[pin]; 868 869 bus->adapter.owner = THIS_MODULE; 870 bus->adapter.class = I2C_CLASS_DDC; 871 snprintf(bus->adapter.name, 872 sizeof(bus->adapter.name), 873 "i915 gmbus %s", 874 get_gmbus_pin(dev_priv, pin)->name); 875 876 bus->adapter.dev.parent = &pdev->dev; 877 bus->dev_priv = dev_priv; 878 879 bus->adapter.algo = &gmbus_algorithm; 880 bus->adapter.lock_ops = &gmbus_lock_ops; 881 882 /* 883 * We wish to retry with bit banging 884 * after a timed out GMBUS attempt. 885 */ 886 bus->adapter.retries = 1; 887 888 /* By default use a conservative clock rate */ 889 bus->reg0 = pin | GMBUS_RATE_100KHZ; 890 891 /* gmbus seems to be broken on i830 */ 892 if (IS_I830(dev_priv)) 893 bus->force_bit = 1; 894 895 intel_gpio_setup(bus, pin); 896 897 ret = i2c_add_adapter(&bus->adapter); 898 if (ret) 899 goto err; 900 } 901 902 intel_gmbus_reset(dev_priv); 903 904 return 0; 905 906 err: 907 while (pin--) { 908 if (!intel_gmbus_is_valid_pin(dev_priv, pin)) 909 continue; 910 911 bus = &dev_priv->gmbus[pin]; 912 i2c_del_adapter(&bus->adapter); 913 } 914 return ret; 915 } 916 917 struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv, 918 unsigned int pin) 919 { 920 if (drm_WARN_ON(&dev_priv->drm, 921 !intel_gmbus_is_valid_pin(dev_priv, pin))) 922 return NULL; 923 924 return &dev_priv->gmbus[pin].adapter; 925 } 926 927 void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed) 928 { 929 struct intel_gmbus *bus = to_intel_gmbus(adapter); 930 931 bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | speed; 932 } 933 934 void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit) 935 { 936 struct intel_gmbus *bus = to_intel_gmbus(adapter); 937 struct drm_i915_private *dev_priv = bus->dev_priv; 938 939 mutex_lock(&dev_priv->gmbus_mutex); 940 941 bus->force_bit += force_bit ? 1 : -1; 942 drm_dbg_kms(&dev_priv->drm, 943 "%sabling bit-banging on %s. force bit now %d\n", 944 force_bit ? "en" : "dis", adapter->name, 945 bus->force_bit); 946 947 mutex_unlock(&dev_priv->gmbus_mutex); 948 } 949 950 bool intel_gmbus_is_forced_bit(struct i2c_adapter *adapter) 951 { 952 struct intel_gmbus *bus = to_intel_gmbus(adapter); 953 954 return bus->force_bit; 955 } 956 957 void intel_gmbus_teardown(struct drm_i915_private *dev_priv) 958 { 959 struct intel_gmbus *bus; 960 unsigned int pin; 961 962 for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) { 963 if (!intel_gmbus_is_valid_pin(dev_priv, pin)) 964 continue; 965 966 bus = &dev_priv->gmbus[pin]; 967 i2c_del_adapter(&bus->adapter); 968 } 969 } 970