1 /* 2 * Freescale i.MX6 PCI Express Root-Complex driver 3 * 4 * Copyright (C) 2013 Marek Vasut <marex@denx.de> 5 * 6 * Based on upstream Linux kernel driver: 7 * pci-imx6.c: Sean Cross <xobs@kosagi.com> 8 * pcie-designware.c: Jingoo Han <jg1.han@samsung.com> 9 * 10 * SPDX-License-Identifier: GPL-2.0 11 */ 12 13 #include <common.h> 14 #include <pci.h> 15 #include <asm/arch/clock.h> 16 #include <asm/arch/iomux.h> 17 #include <asm/arch/crm_regs.h> 18 #include <asm/gpio.h> 19 #include <asm/io.h> 20 #include <linux/sizes.h> 21 #include <errno.h> 22 #include <asm/arch/sys_proto.h> 23 24 #define PCI_ACCESS_READ 0 25 #define PCI_ACCESS_WRITE 1 26 27 #ifdef CONFIG_MX6SX 28 #define MX6_DBI_ADDR 0x08ffc000 29 #define MX6_IO_ADDR 0x08000000 30 #define MX6_MEM_ADDR 0x08100000 31 #define MX6_ROOT_ADDR 0x08f00000 32 #else 33 #define MX6_DBI_ADDR 0x01ffc000 34 #define MX6_IO_ADDR 0x01000000 35 #define MX6_MEM_ADDR 0x01100000 36 #define MX6_ROOT_ADDR 0x01f00000 37 #endif 38 #define MX6_DBI_SIZE 0x4000 39 #define MX6_IO_SIZE 0x100000 40 #define MX6_MEM_SIZE 0xe00000 41 #define MX6_ROOT_SIZE 0xfc000 42 43 /* PCIe Port Logic registers (memory-mapped) */ 44 #define PL_OFFSET 0x700 45 #define PCIE_PL_PFLR (PL_OFFSET + 0x08) 46 #define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16) 47 #define PCIE_PL_PFLR_FORCE_LINK (1 << 15) 48 #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28) 49 #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c) 50 #define PCIE_PHY_DEBUG_R1_LINK_UP (1 << 4) 51 #define PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING (1 << 29) 52 53 #define PCIE_PHY_CTRL (PL_OFFSET + 0x114) 54 #define PCIE_PHY_CTRL_DATA_LOC 0 55 #define PCIE_PHY_CTRL_CAP_ADR_LOC 16 56 #define PCIE_PHY_CTRL_CAP_DAT_LOC 17 57 #define PCIE_PHY_CTRL_WR_LOC 18 58 #define PCIE_PHY_CTRL_RD_LOC 19 59 60 #define PCIE_PHY_STAT (PL_OFFSET + 0x110) 61 #define PCIE_PHY_STAT_DATA_LOC 0 62 #define PCIE_PHY_STAT_ACK_LOC 16 63 64 /* PHY registers (not memory-mapped) */ 65 #define PCIE_PHY_RX_ASIC_OUT 0x100D 66 67 #define PHY_RX_OVRD_IN_LO 0x1005 68 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5) 69 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3) 70 71 #define PCIE_PHY_PUP_REQ (1 << 7) 72 73 /* iATU registers */ 74 #define PCIE_ATU_VIEWPORT 0x900 75 #define PCIE_ATU_REGION_INBOUND (0x1 << 31) 76 #define PCIE_ATU_REGION_OUTBOUND (0x0 << 31) 77 #define PCIE_ATU_REGION_INDEX1 (0x1 << 0) 78 #define PCIE_ATU_REGION_INDEX0 (0x0 << 0) 79 #define PCIE_ATU_CR1 0x904 80 #define PCIE_ATU_TYPE_MEM (0x0 << 0) 81 #define PCIE_ATU_TYPE_IO (0x2 << 0) 82 #define PCIE_ATU_TYPE_CFG0 (0x4 << 0) 83 #define PCIE_ATU_TYPE_CFG1 (0x5 << 0) 84 #define PCIE_ATU_CR2 0x908 85 #define PCIE_ATU_ENABLE (0x1 << 31) 86 #define PCIE_ATU_BAR_MODE_ENABLE (0x1 << 30) 87 #define PCIE_ATU_LOWER_BASE 0x90C 88 #define PCIE_ATU_UPPER_BASE 0x910 89 #define PCIE_ATU_LIMIT 0x914 90 #define PCIE_ATU_LOWER_TARGET 0x918 91 #define PCIE_ATU_BUS(x) (((x) & 0xff) << 24) 92 #define PCIE_ATU_DEV(x) (((x) & 0x1f) << 19) 93 #define PCIE_ATU_FUNC(x) (((x) & 0x7) << 16) 94 #define PCIE_ATU_UPPER_TARGET 0x91C 95 96 /* 97 * PHY access functions 98 */ 99 static int pcie_phy_poll_ack(void __iomem *dbi_base, int exp_val) 100 { 101 u32 val; 102 u32 max_iterations = 10; 103 u32 wait_counter = 0; 104 105 do { 106 val = readl(dbi_base + PCIE_PHY_STAT); 107 val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1; 108 wait_counter++; 109 110 if (val == exp_val) 111 return 0; 112 113 udelay(1); 114 } while (wait_counter < max_iterations); 115 116 return -ETIMEDOUT; 117 } 118 119 static int pcie_phy_wait_ack(void __iomem *dbi_base, int addr) 120 { 121 u32 val; 122 int ret; 123 124 val = addr << PCIE_PHY_CTRL_DATA_LOC; 125 writel(val, dbi_base + PCIE_PHY_CTRL); 126 127 val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC); 128 writel(val, dbi_base + PCIE_PHY_CTRL); 129 130 ret = pcie_phy_poll_ack(dbi_base, 1); 131 if (ret) 132 return ret; 133 134 val = addr << PCIE_PHY_CTRL_DATA_LOC; 135 writel(val, dbi_base + PCIE_PHY_CTRL); 136 137 ret = pcie_phy_poll_ack(dbi_base, 0); 138 if (ret) 139 return ret; 140 141 return 0; 142 } 143 144 /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */ 145 static int pcie_phy_read(void __iomem *dbi_base, int addr , int *data) 146 { 147 u32 val, phy_ctl; 148 int ret; 149 150 ret = pcie_phy_wait_ack(dbi_base, addr); 151 if (ret) 152 return ret; 153 154 /* assert Read signal */ 155 phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC; 156 writel(phy_ctl, dbi_base + PCIE_PHY_CTRL); 157 158 ret = pcie_phy_poll_ack(dbi_base, 1); 159 if (ret) 160 return ret; 161 162 val = readl(dbi_base + PCIE_PHY_STAT); 163 *data = val & 0xffff; 164 165 /* deassert Read signal */ 166 writel(0x00, dbi_base + PCIE_PHY_CTRL); 167 168 ret = pcie_phy_poll_ack(dbi_base, 0); 169 if (ret) 170 return ret; 171 172 return 0; 173 } 174 175 static int pcie_phy_write(void __iomem *dbi_base, int addr, int data) 176 { 177 u32 var; 178 int ret; 179 180 /* write addr */ 181 /* cap addr */ 182 ret = pcie_phy_wait_ack(dbi_base, addr); 183 if (ret) 184 return ret; 185 186 var = data << PCIE_PHY_CTRL_DATA_LOC; 187 writel(var, dbi_base + PCIE_PHY_CTRL); 188 189 /* capture data */ 190 var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC); 191 writel(var, dbi_base + PCIE_PHY_CTRL); 192 193 ret = pcie_phy_poll_ack(dbi_base, 1); 194 if (ret) 195 return ret; 196 197 /* deassert cap data */ 198 var = data << PCIE_PHY_CTRL_DATA_LOC; 199 writel(var, dbi_base + PCIE_PHY_CTRL); 200 201 /* wait for ack de-assertion */ 202 ret = pcie_phy_poll_ack(dbi_base, 0); 203 if (ret) 204 return ret; 205 206 /* assert wr signal */ 207 var = 0x1 << PCIE_PHY_CTRL_WR_LOC; 208 writel(var, dbi_base + PCIE_PHY_CTRL); 209 210 /* wait for ack */ 211 ret = pcie_phy_poll_ack(dbi_base, 1); 212 if (ret) 213 return ret; 214 215 /* deassert wr signal */ 216 var = data << PCIE_PHY_CTRL_DATA_LOC; 217 writel(var, dbi_base + PCIE_PHY_CTRL); 218 219 /* wait for ack de-assertion */ 220 ret = pcie_phy_poll_ack(dbi_base, 0); 221 if (ret) 222 return ret; 223 224 writel(0x0, dbi_base + PCIE_PHY_CTRL); 225 226 return 0; 227 } 228 229 static int imx6_pcie_link_up(void) 230 { 231 u32 rc, ltssm; 232 int rx_valid, temp; 233 234 /* link is debug bit 36, debug register 1 starts at bit 32 */ 235 rc = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1); 236 if ((rc & PCIE_PHY_DEBUG_R1_LINK_UP) && 237 !(rc & PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING)) 238 return -EAGAIN; 239 240 /* 241 * From L0, initiate MAC entry to gen2 if EP/RC supports gen2. 242 * Wait 2ms (LTSSM timeout is 24ms, PHY lock is ~5us in gen2). 243 * If (MAC/LTSSM.state == Recovery.RcvrLock) 244 * && (PHY/rx_valid==0) then pulse PHY/rx_reset. Transition 245 * to gen2 is stuck 246 */ 247 pcie_phy_read((void *)MX6_DBI_ADDR, PCIE_PHY_RX_ASIC_OUT, &rx_valid); 248 ltssm = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0) & 0x3F; 249 250 if (rx_valid & 0x01) 251 return 0; 252 253 if (ltssm != 0x0d) 254 return 0; 255 256 printf("transition to gen2 is stuck, reset PHY!\n"); 257 258 pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp); 259 temp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN); 260 pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp); 261 262 udelay(3000); 263 264 pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp); 265 temp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN); 266 pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp); 267 268 return 0; 269 } 270 271 /* 272 * iATU region setup 273 */ 274 static int imx_pcie_regions_setup(void) 275 { 276 /* 277 * i.MX6 defines 16MB in the AXI address map for PCIe. 278 * 279 * That address space excepted the pcie registers is 280 * split and defined into different regions by iATU, 281 * with sizes and offsets as follows: 282 * 283 * 0x0100_0000 --- 0x010F_FFFF 1MB IORESOURCE_IO 284 * 0x0110_0000 --- 0x01EF_FFFF 14MB IORESOURCE_MEM 285 * 0x01F0_0000 --- 0x01FF_FFFF 1MB Cfg + Registers 286 */ 287 288 /* CMD reg:I/O space, MEM space, and Bus Master Enable */ 289 setbits_le32(MX6_DBI_ADDR | PCI_COMMAND, 290 PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); 291 292 /* Set the CLASS_REV of RC CFG header to PCI_CLASS_BRIDGE_PCI */ 293 setbits_le32(MX6_DBI_ADDR + PCI_CLASS_REVISION, 294 PCI_CLASS_BRIDGE_PCI << 16); 295 296 /* Region #0 is used for Outbound CFG space access. */ 297 writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT); 298 299 writel(MX6_ROOT_ADDR, MX6_DBI_ADDR + PCIE_ATU_LOWER_BASE); 300 writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_BASE); 301 writel(MX6_ROOT_ADDR + MX6_ROOT_SIZE, MX6_DBI_ADDR + PCIE_ATU_LIMIT); 302 303 writel(0, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET); 304 writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_TARGET); 305 writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1); 306 writel(PCIE_ATU_ENABLE, MX6_DBI_ADDR + PCIE_ATU_CR2); 307 308 return 0; 309 } 310 311 /* 312 * PCI Express accessors 313 */ 314 static uint32_t get_bus_address(pci_dev_t d, int where) 315 { 316 uint32_t va_address; 317 318 /* Reconfigure Region #0 */ 319 writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT); 320 321 if (PCI_BUS(d) < 2) 322 writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1); 323 else 324 writel(PCIE_ATU_TYPE_CFG1, MX6_DBI_ADDR + PCIE_ATU_CR1); 325 326 if (PCI_BUS(d) == 0) { 327 va_address = MX6_DBI_ADDR; 328 } else { 329 writel(d << 8, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET); 330 va_address = MX6_IO_ADDR + SZ_16M - SZ_1M; 331 } 332 333 va_address += (where & ~0x3); 334 335 return va_address; 336 } 337 338 static int imx_pcie_addr_valid(pci_dev_t d) 339 { 340 if ((PCI_BUS(d) == 0) && (PCI_DEV(d) > 1)) 341 return -EINVAL; 342 if ((PCI_BUS(d) == 1) && (PCI_DEV(d) > 0)) 343 return -EINVAL; 344 return 0; 345 } 346 347 /* 348 * Replace the original ARM DABT handler with a simple jump-back one. 349 * 350 * The problem here is that if we have a PCIe bridge attached to this PCIe 351 * controller, but no PCIe device is connected to the bridges' downstream 352 * port, the attempt to read/write from/to the config space will produce 353 * a DABT. This is a behavior of the controller and can not be disabled 354 * unfortuatelly. 355 * 356 * To work around the problem, we backup the current DABT handler address 357 * and replace it with our own DABT handler, which only bounces right back 358 * into the code. 359 */ 360 static void imx_pcie_fix_dabt_handler(bool set) 361 { 362 extern uint32_t *_data_abort; 363 uint32_t *data_abort_addr = (uint32_t *)&_data_abort; 364 365 static const uint32_t data_abort_bounce_handler = 0xe25ef004; 366 uint32_t data_abort_bounce_addr = (uint32_t)&data_abort_bounce_handler; 367 368 static uint32_t data_abort_backup; 369 370 if (set) { 371 data_abort_backup = *data_abort_addr; 372 *data_abort_addr = data_abort_bounce_addr; 373 } else { 374 *data_abort_addr = data_abort_backup; 375 } 376 } 377 378 static int imx_pcie_read_config(struct pci_controller *hose, pci_dev_t d, 379 int where, u32 *val) 380 { 381 uint32_t va_address; 382 int ret; 383 384 ret = imx_pcie_addr_valid(d); 385 if (ret) { 386 *val = 0xffffffff; 387 return 0; 388 } 389 390 va_address = get_bus_address(d, where); 391 392 /* 393 * Read the PCIe config space. We must replace the DABT handler 394 * here in case we got data abort from the PCIe controller, see 395 * imx_pcie_fix_dabt_handler() description. Note that writing the 396 * "val" with valid value is also imperative here as in case we 397 * did got DABT, the val would contain random value. 398 */ 399 imx_pcie_fix_dabt_handler(true); 400 writel(0xffffffff, val); 401 *val = readl(va_address); 402 imx_pcie_fix_dabt_handler(false); 403 404 return 0; 405 } 406 407 static int imx_pcie_write_config(struct pci_controller *hose, pci_dev_t d, 408 int where, u32 val) 409 { 410 uint32_t va_address = 0; 411 int ret; 412 413 ret = imx_pcie_addr_valid(d); 414 if (ret) 415 return ret; 416 417 va_address = get_bus_address(d, where); 418 419 /* 420 * Write the PCIe config space. We must replace the DABT handler 421 * here in case we got data abort from the PCIe controller, see 422 * imx_pcie_fix_dabt_handler() description. 423 */ 424 imx_pcie_fix_dabt_handler(true); 425 writel(val, va_address); 426 imx_pcie_fix_dabt_handler(false); 427 428 return 0; 429 } 430 431 /* 432 * Initial bus setup 433 */ 434 static int imx6_pcie_assert_core_reset(bool prepare_for_boot) 435 { 436 struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR; 437 438 if (is_mx6dqp()) 439 setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST); 440 441 #if defined(CONFIG_MX6SX) 442 struct gpc *gpc_regs = (struct gpc *)GPC_BASE_ADDR; 443 444 /* SSP_EN is not used on MX6SX anymore */ 445 setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN); 446 /* Force PCIe PHY reset */ 447 setbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST); 448 /* Power up PCIe PHY */ 449 setbits_le32(&gpc_regs->cntr, PCIE_PHY_PUP_REQ); 450 #else 451 /* 452 * If the bootloader already enabled the link we need some special 453 * handling to get the core back into a state where it is safe to 454 * touch it for configuration. As there is no dedicated reset signal 455 * wired up for MX6QDL, we need to manually force LTSSM into "detect" 456 * state before completely disabling LTSSM, which is a prerequisite 457 * for core configuration. 458 * 459 * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong 460 * indication that the bootloader activated the link. 461 */ 462 if (is_mx6dq() && prepare_for_boot) { 463 u32 val, gpr1, gpr12; 464 465 gpr1 = readl(&iomuxc_regs->gpr[1]); 466 gpr12 = readl(&iomuxc_regs->gpr[12]); 467 if ((gpr1 & IOMUXC_GPR1_PCIE_REF_CLK_EN) && 468 (gpr12 & IOMUXC_GPR12_PCIE_CTL_2)) { 469 val = readl(MX6_DBI_ADDR + PCIE_PL_PFLR); 470 val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; 471 val |= PCIE_PL_PFLR_FORCE_LINK; 472 473 imx_pcie_fix_dabt_handler(true); 474 writel(val, MX6_DBI_ADDR + PCIE_PL_PFLR); 475 imx_pcie_fix_dabt_handler(false); 476 477 gpr12 &= ~IOMUXC_GPR12_PCIE_CTL_2; 478 writel(val, &iomuxc_regs->gpr[12]); 479 } 480 } 481 setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN); 482 clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN); 483 #endif 484 485 return 0; 486 } 487 488 static int imx6_pcie_init_phy(void) 489 { 490 struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR; 491 492 clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE); 493 494 clrsetbits_le32(&iomuxc_regs->gpr[12], 495 IOMUXC_GPR12_DEVICE_TYPE_MASK, 496 IOMUXC_GPR12_DEVICE_TYPE_RC); 497 clrsetbits_le32(&iomuxc_regs->gpr[12], 498 IOMUXC_GPR12_LOS_LEVEL_MASK, 499 IOMUXC_GPR12_LOS_LEVEL_9); 500 501 #ifdef CONFIG_MX6SX 502 clrsetbits_le32(&iomuxc_regs->gpr[12], 503 IOMUXC_GPR12_RX_EQ_MASK, 504 IOMUXC_GPR12_RX_EQ_2); 505 #endif 506 507 writel((0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN1_OFFSET) | 508 (0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_3P5DB_OFFSET) | 509 (20 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_6DB_OFFSET) | 510 (127 << IOMUXC_GPR8_PCS_TX_SWING_FULL_OFFSET) | 511 (127 << IOMUXC_GPR8_PCS_TX_SWING_LOW_OFFSET), 512 &iomuxc_regs->gpr[8]); 513 514 return 0; 515 } 516 517 __weak int imx6_pcie_toggle_power(void) 518 { 519 #ifdef CONFIG_PCIE_IMX_POWER_GPIO 520 gpio_request(CONFIG_PCIE_IMX_POWER_GPIO, "pcie_power"); 521 gpio_direction_output(CONFIG_PCIE_IMX_POWER_GPIO, 0); 522 mdelay(20); 523 gpio_set_value(CONFIG_PCIE_IMX_POWER_GPIO, 1); 524 mdelay(20); 525 gpio_free(CONFIG_PCIE_IMX_POWER_GPIO); 526 #endif 527 return 0; 528 } 529 530 __weak int imx6_pcie_toggle_reset(void) 531 { 532 /* 533 * See 'PCI EXPRESS BASE SPECIFICATION, REV 3.0, SECTION 6.6.1' 534 * for detailed understanding of the PCIe CR reset logic. 535 * 536 * The PCIe #PERST reset line _MUST_ be connected, otherwise your 537 * design does not conform to the specification. You must wait at 538 * least 20 ms after de-asserting the #PERST so the EP device can 539 * do self-initialisation. 540 * 541 * In case your #PERST pin is connected to a plain GPIO pin of the 542 * CPU, you can define CONFIG_PCIE_IMX_PERST_GPIO in your board's 543 * configuration file and the condition below will handle the rest 544 * of the reset toggling. 545 * 546 * In case your #PERST toggling logic is more complex, for example 547 * connected via CPLD or somesuch, you can override this function 548 * in your board file and implement reset logic as needed. You must 549 * not forget to wait at least 20 ms after de-asserting #PERST in 550 * this case either though. 551 * 552 * In case your #PERST line of the PCIe EP device is not connected 553 * at all, your design is broken and you should fix your design, 554 * otherwise you will observe problems like for example the link 555 * not coming up after rebooting the system back from running Linux 556 * that uses the PCIe as well OR the PCIe link might not come up in 557 * Linux at all in the first place since it's in some non-reset 558 * state due to being previously used in U-Boot. 559 */ 560 #ifdef CONFIG_PCIE_IMX_PERST_GPIO 561 gpio_request(CONFIG_PCIE_IMX_PERST_GPIO, "pcie_reset"); 562 gpio_direction_output(CONFIG_PCIE_IMX_PERST_GPIO, 0); 563 mdelay(20); 564 gpio_set_value(CONFIG_PCIE_IMX_PERST_GPIO, 1); 565 mdelay(20); 566 gpio_free(CONFIG_PCIE_IMX_PERST_GPIO); 567 #else 568 puts("WARNING: Make sure the PCIe #PERST line is connected!\n"); 569 #endif 570 return 0; 571 } 572 573 static int imx6_pcie_deassert_core_reset(void) 574 { 575 struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR; 576 577 imx6_pcie_toggle_power(); 578 579 enable_pcie_clock(); 580 581 if (is_mx6dqp()) 582 clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST); 583 584 /* 585 * Wait for the clock to settle a bit, when the clock are sourced 586 * from the CPU, we need about 30 ms to settle. 587 */ 588 mdelay(50); 589 590 #if defined(CONFIG_MX6SX) 591 /* SSP_EN is not used on MX6SX anymore */ 592 clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN); 593 /* Clear PCIe PHY reset bit */ 594 clrbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST); 595 #else 596 /* Enable PCIe */ 597 clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN); 598 setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN); 599 #endif 600 601 imx6_pcie_toggle_reset(); 602 603 return 0; 604 } 605 606 static int imx_pcie_link_up(void) 607 { 608 struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR; 609 uint32_t tmp; 610 int count = 0; 611 612 imx6_pcie_assert_core_reset(false); 613 imx6_pcie_init_phy(); 614 imx6_pcie_deassert_core_reset(); 615 616 imx_pcie_regions_setup(); 617 618 /* 619 * By default, the subordinate is set equally to the secondary 620 * bus (0x01) when the RC boots. 621 * This means that theoretically, only bus 1 is reachable from the RC. 622 * Force the PCIe RC subordinate to 0xff, otherwise no downstream 623 * devices will be detected if the enumeration is applied strictly. 624 */ 625 tmp = readl(MX6_DBI_ADDR + 0x18); 626 tmp |= (0xff << 16); 627 writel(tmp, MX6_DBI_ADDR + 0x18); 628 629 /* 630 * FIXME: Force the PCIe RC to Gen1 operation 631 * The RC must be forced into Gen1 mode before bringing the link 632 * up, otherwise no downstream devices are detected. After the 633 * link is up, a managed Gen1->Gen2 transition can be initiated. 634 */ 635 tmp = readl(MX6_DBI_ADDR + 0x7c); 636 tmp &= ~0xf; 637 tmp |= 0x1; 638 writel(tmp, MX6_DBI_ADDR + 0x7c); 639 640 /* LTSSM enable, starting link. */ 641 setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE); 642 643 while (!imx6_pcie_link_up()) { 644 udelay(10); 645 count++; 646 if (count >= 4000) { 647 #ifdef CONFIG_PCI_SCAN_SHOW 648 puts("PCI: pcie phy link never came up\n"); 649 #endif 650 debug("DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n", 651 readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0), 652 readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1)); 653 return -EINVAL; 654 } 655 } 656 657 return 0; 658 } 659 660 void imx_pcie_init(void) 661 { 662 /* Static instance of the controller. */ 663 static struct pci_controller pcc; 664 struct pci_controller *hose = &pcc; 665 int ret; 666 667 memset(&pcc, 0, sizeof(pcc)); 668 669 /* PCI I/O space */ 670 pci_set_region(&hose->regions[0], 671 MX6_IO_ADDR, MX6_IO_ADDR, 672 MX6_IO_SIZE, PCI_REGION_IO); 673 674 /* PCI memory space */ 675 pci_set_region(&hose->regions[1], 676 MX6_MEM_ADDR, MX6_MEM_ADDR, 677 MX6_MEM_SIZE, PCI_REGION_MEM); 678 679 /* System memory space */ 680 pci_set_region(&hose->regions[2], 681 MMDC0_ARB_BASE_ADDR, MMDC0_ARB_BASE_ADDR, 682 0xefffffff, PCI_REGION_MEM | PCI_REGION_SYS_MEMORY); 683 684 hose->region_count = 3; 685 686 pci_set_ops(hose, 687 pci_hose_read_config_byte_via_dword, 688 pci_hose_read_config_word_via_dword, 689 imx_pcie_read_config, 690 pci_hose_write_config_byte_via_dword, 691 pci_hose_write_config_word_via_dword, 692 imx_pcie_write_config); 693 694 /* Start the controller. */ 695 ret = imx_pcie_link_up(); 696 697 if (!ret) { 698 pci_register_hose(hose); 699 hose->last_busno = pci_hose_scan(hose); 700 } 701 } 702 703 void imx_pcie_remove(void) 704 { 705 imx6_pcie_assert_core_reset(true); 706 } 707 708 /* Probe function. */ 709 void pci_init_board(void) 710 { 711 imx_pcie_init(); 712 } 713