xref: /openbmc/u-boot/drivers/pci/pcie_imx.c (revision 274bced8)
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_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
46 #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
47 #define PCIE_PHY_DEBUG_R1_LINK_UP		(1 << 4)
48 #define PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING	(1 << 29)
49 
50 #define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
51 #define PCIE_PHY_CTRL_DATA_LOC 0
52 #define PCIE_PHY_CTRL_CAP_ADR_LOC 16
53 #define PCIE_PHY_CTRL_CAP_DAT_LOC 17
54 #define PCIE_PHY_CTRL_WR_LOC 18
55 #define PCIE_PHY_CTRL_RD_LOC 19
56 
57 #define PCIE_PHY_STAT (PL_OFFSET + 0x110)
58 #define PCIE_PHY_STAT_DATA_LOC 0
59 #define PCIE_PHY_STAT_ACK_LOC 16
60 
61 /* PHY registers (not memory-mapped) */
62 #define PCIE_PHY_RX_ASIC_OUT 0x100D
63 
64 #define PHY_RX_OVRD_IN_LO 0x1005
65 #define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
66 #define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
67 
68 #define PCIE_PHY_PUP_REQ		(1 << 7)
69 
70 /* iATU registers */
71 #define PCIE_ATU_VIEWPORT		0x900
72 #define PCIE_ATU_REGION_INBOUND		(0x1 << 31)
73 #define PCIE_ATU_REGION_OUTBOUND	(0x0 << 31)
74 #define PCIE_ATU_REGION_INDEX1		(0x1 << 0)
75 #define PCIE_ATU_REGION_INDEX0		(0x0 << 0)
76 #define PCIE_ATU_CR1			0x904
77 #define PCIE_ATU_TYPE_MEM		(0x0 << 0)
78 #define PCIE_ATU_TYPE_IO		(0x2 << 0)
79 #define PCIE_ATU_TYPE_CFG0		(0x4 << 0)
80 #define PCIE_ATU_TYPE_CFG1		(0x5 << 0)
81 #define PCIE_ATU_CR2			0x908
82 #define PCIE_ATU_ENABLE			(0x1 << 31)
83 #define PCIE_ATU_BAR_MODE_ENABLE	(0x1 << 30)
84 #define PCIE_ATU_LOWER_BASE		0x90C
85 #define PCIE_ATU_UPPER_BASE		0x910
86 #define PCIE_ATU_LIMIT			0x914
87 #define PCIE_ATU_LOWER_TARGET		0x918
88 #define PCIE_ATU_BUS(x)			(((x) & 0xff) << 24)
89 #define PCIE_ATU_DEV(x)			(((x) & 0x1f) << 19)
90 #define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
91 #define PCIE_ATU_UPPER_TARGET		0x91C
92 
93 /*
94  * PHY access functions
95  */
96 static int pcie_phy_poll_ack(void __iomem *dbi_base, int exp_val)
97 {
98 	u32 val;
99 	u32 max_iterations = 10;
100 	u32 wait_counter = 0;
101 
102 	do {
103 		val = readl(dbi_base + PCIE_PHY_STAT);
104 		val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1;
105 		wait_counter++;
106 
107 		if (val == exp_val)
108 			return 0;
109 
110 		udelay(1);
111 	} while (wait_counter < max_iterations);
112 
113 	return -ETIMEDOUT;
114 }
115 
116 static int pcie_phy_wait_ack(void __iomem *dbi_base, int addr)
117 {
118 	u32 val;
119 	int ret;
120 
121 	val = addr << PCIE_PHY_CTRL_DATA_LOC;
122 	writel(val, dbi_base + PCIE_PHY_CTRL);
123 
124 	val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
125 	writel(val, dbi_base + PCIE_PHY_CTRL);
126 
127 	ret = pcie_phy_poll_ack(dbi_base, 1);
128 	if (ret)
129 		return ret;
130 
131 	val = addr << PCIE_PHY_CTRL_DATA_LOC;
132 	writel(val, dbi_base + PCIE_PHY_CTRL);
133 
134 	ret = pcie_phy_poll_ack(dbi_base, 0);
135 	if (ret)
136 		return ret;
137 
138 	return 0;
139 }
140 
141 /* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
142 static int pcie_phy_read(void __iomem *dbi_base, int addr , int *data)
143 {
144 	u32 val, phy_ctl;
145 	int ret;
146 
147 	ret = pcie_phy_wait_ack(dbi_base, addr);
148 	if (ret)
149 		return ret;
150 
151 	/* assert Read signal */
152 	phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
153 	writel(phy_ctl, dbi_base + PCIE_PHY_CTRL);
154 
155 	ret = pcie_phy_poll_ack(dbi_base, 1);
156 	if (ret)
157 		return ret;
158 
159 	val = readl(dbi_base + PCIE_PHY_STAT);
160 	*data = val & 0xffff;
161 
162 	/* deassert Read signal */
163 	writel(0x00, dbi_base + PCIE_PHY_CTRL);
164 
165 	ret = pcie_phy_poll_ack(dbi_base, 0);
166 	if (ret)
167 		return ret;
168 
169 	return 0;
170 }
171 
172 static int pcie_phy_write(void __iomem *dbi_base, int addr, int data)
173 {
174 	u32 var;
175 	int ret;
176 
177 	/* write addr */
178 	/* cap addr */
179 	ret = pcie_phy_wait_ack(dbi_base, addr);
180 	if (ret)
181 		return ret;
182 
183 	var = data << PCIE_PHY_CTRL_DATA_LOC;
184 	writel(var, dbi_base + PCIE_PHY_CTRL);
185 
186 	/* capture data */
187 	var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
188 	writel(var, dbi_base + PCIE_PHY_CTRL);
189 
190 	ret = pcie_phy_poll_ack(dbi_base, 1);
191 	if (ret)
192 		return ret;
193 
194 	/* deassert cap data */
195 	var = data << PCIE_PHY_CTRL_DATA_LOC;
196 	writel(var, dbi_base + PCIE_PHY_CTRL);
197 
198 	/* wait for ack de-assertion */
199 	ret = pcie_phy_poll_ack(dbi_base, 0);
200 	if (ret)
201 		return ret;
202 
203 	/* assert wr signal */
204 	var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
205 	writel(var, dbi_base + PCIE_PHY_CTRL);
206 
207 	/* wait for ack */
208 	ret = pcie_phy_poll_ack(dbi_base, 1);
209 	if (ret)
210 		return ret;
211 
212 	/* deassert wr signal */
213 	var = data << PCIE_PHY_CTRL_DATA_LOC;
214 	writel(var, dbi_base + PCIE_PHY_CTRL);
215 
216 	/* wait for ack de-assertion */
217 	ret = pcie_phy_poll_ack(dbi_base, 0);
218 	if (ret)
219 		return ret;
220 
221 	writel(0x0, dbi_base + PCIE_PHY_CTRL);
222 
223 	return 0;
224 }
225 
226 static int imx6_pcie_link_up(void)
227 {
228 	u32 rc, ltssm;
229 	int rx_valid, temp;
230 
231 	/* link is debug bit 36, debug register 1 starts at bit 32 */
232 	rc = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1);
233 	if ((rc & PCIE_PHY_DEBUG_R1_LINK_UP) &&
234 	    !(rc & PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING))
235 		return -EAGAIN;
236 
237 	/*
238 	 * From L0, initiate MAC entry to gen2 if EP/RC supports gen2.
239 	 * Wait 2ms (LTSSM timeout is 24ms, PHY lock is ~5us in gen2).
240 	 * If (MAC/LTSSM.state == Recovery.RcvrLock)
241 	 * && (PHY/rx_valid==0) then pulse PHY/rx_reset. Transition
242 	 * to gen2 is stuck
243 	 */
244 	pcie_phy_read((void *)MX6_DBI_ADDR, PCIE_PHY_RX_ASIC_OUT, &rx_valid);
245 	ltssm = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0) & 0x3F;
246 
247 	if (rx_valid & 0x01)
248 		return 0;
249 
250 	if (ltssm != 0x0d)
251 		return 0;
252 
253 	printf("transition to gen2 is stuck, reset PHY!\n");
254 
255 	pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp);
256 	temp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN);
257 	pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp);
258 
259 	udelay(3000);
260 
261 	pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp);
262 	temp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN);
263 	pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp);
264 
265 	return 0;
266 }
267 
268 /*
269  * iATU region setup
270  */
271 static int imx_pcie_regions_setup(void)
272 {
273 	/*
274 	 * i.MX6 defines 16MB in the AXI address map for PCIe.
275 	 *
276 	 * That address space excepted the pcie registers is
277 	 * split and defined into different regions by iATU,
278 	 * with sizes and offsets as follows:
279 	 *
280 	 * 0x0100_0000 --- 0x010F_FFFF 1MB IORESOURCE_IO
281 	 * 0x0110_0000 --- 0x01EF_FFFF 14MB IORESOURCE_MEM
282 	 * 0x01F0_0000 --- 0x01FF_FFFF 1MB Cfg + Registers
283 	 */
284 
285 	/* CMD reg:I/O space, MEM space, and Bus Master Enable */
286 	setbits_le32(MX6_DBI_ADDR | PCI_COMMAND,
287 		     PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
288 
289 	/* Set the CLASS_REV of RC CFG header to PCI_CLASS_BRIDGE_PCI */
290 	setbits_le32(MX6_DBI_ADDR + PCI_CLASS_REVISION,
291 		     PCI_CLASS_BRIDGE_PCI << 16);
292 
293 	/* Region #0 is used for Outbound CFG space access. */
294 	writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT);
295 
296 	writel(MX6_ROOT_ADDR, MX6_DBI_ADDR + PCIE_ATU_LOWER_BASE);
297 	writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_BASE);
298 	writel(MX6_ROOT_ADDR + MX6_ROOT_SIZE, MX6_DBI_ADDR + PCIE_ATU_LIMIT);
299 
300 	writel(0, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET);
301 	writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_TARGET);
302 	writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1);
303 	writel(PCIE_ATU_ENABLE, MX6_DBI_ADDR + PCIE_ATU_CR2);
304 
305 	return 0;
306 }
307 
308 /*
309  * PCI Express accessors
310  */
311 static uint32_t get_bus_address(pci_dev_t d, int where)
312 {
313 	uint32_t va_address;
314 
315 	/* Reconfigure Region #0 */
316 	writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT);
317 
318 	if (PCI_BUS(d) < 2)
319 		writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1);
320 	else
321 		writel(PCIE_ATU_TYPE_CFG1, MX6_DBI_ADDR + PCIE_ATU_CR1);
322 
323 	if (PCI_BUS(d) == 0) {
324 		va_address = MX6_DBI_ADDR;
325 	} else {
326 		writel(d << 8, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET);
327 		va_address = MX6_IO_ADDR + SZ_16M - SZ_1M;
328 	}
329 
330 	va_address += (where & ~0x3);
331 
332 	return va_address;
333 }
334 
335 static int imx_pcie_addr_valid(pci_dev_t d)
336 {
337 	if ((PCI_BUS(d) == 0) && (PCI_DEV(d) > 1))
338 		return -EINVAL;
339 	if ((PCI_BUS(d) == 1) && (PCI_DEV(d) > 0))
340 		return -EINVAL;
341 	return 0;
342 }
343 
344 /*
345  * Replace the original ARM DABT handler with a simple jump-back one.
346  *
347  * The problem here is that if we have a PCIe bridge attached to this PCIe
348  * controller, but no PCIe device is connected to the bridges' downstream
349  * port, the attempt to read/write from/to the config space will produce
350  * a DABT. This is a behavior of the controller and can not be disabled
351  * unfortuatelly.
352  *
353  * To work around the problem, we backup the current DABT handler address
354  * and replace it with our own DABT handler, which only bounces right back
355  * into the code.
356  */
357 static void imx_pcie_fix_dabt_handler(bool set)
358 {
359 	extern uint32_t *_data_abort;
360 	uint32_t *data_abort_addr = (uint32_t *)&_data_abort;
361 
362 	static const uint32_t data_abort_bounce_handler = 0xe25ef004;
363 	uint32_t data_abort_bounce_addr = (uint32_t)&data_abort_bounce_handler;
364 
365 	static uint32_t data_abort_backup;
366 
367 	if (set) {
368 		data_abort_backup = *data_abort_addr;
369 		*data_abort_addr = data_abort_bounce_addr;
370 	} else {
371 		*data_abort_addr = data_abort_backup;
372 	}
373 }
374 
375 static int imx_pcie_read_config(struct pci_controller *hose, pci_dev_t d,
376 				int where, u32 *val)
377 {
378 	uint32_t va_address;
379 	int ret;
380 
381 	ret = imx_pcie_addr_valid(d);
382 	if (ret) {
383 		*val = 0xffffffff;
384 		return 0;
385 	}
386 
387 	va_address = get_bus_address(d, where);
388 
389 	/*
390 	 * Read the PCIe config space. We must replace the DABT handler
391 	 * here in case we got data abort from the PCIe controller, see
392 	 * imx_pcie_fix_dabt_handler() description. Note that writing the
393 	 * "val" with valid value is also imperative here as in case we
394 	 * did got DABT, the val would contain random value.
395 	 */
396 	imx_pcie_fix_dabt_handler(true);
397 	writel(0xffffffff, val);
398 	*val = readl(va_address);
399 	imx_pcie_fix_dabt_handler(false);
400 
401 	return 0;
402 }
403 
404 static int imx_pcie_write_config(struct pci_controller *hose, pci_dev_t d,
405 			int where, u32 val)
406 {
407 	uint32_t va_address = 0;
408 	int ret;
409 
410 	ret = imx_pcie_addr_valid(d);
411 	if (ret)
412 		return ret;
413 
414 	va_address = get_bus_address(d, where);
415 
416 	/*
417 	 * Write the PCIe config space. We must replace the DABT handler
418 	 * here in case we got data abort from the PCIe controller, see
419 	 * imx_pcie_fix_dabt_handler() description.
420 	 */
421 	imx_pcie_fix_dabt_handler(true);
422 	writel(val, va_address);
423 	imx_pcie_fix_dabt_handler(false);
424 
425 	return 0;
426 }
427 
428 /*
429  * Initial bus setup
430  */
431 static int imx6_pcie_assert_core_reset(void)
432 {
433 	struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
434 
435 	if (is_mx6dqp())
436 		setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
437 
438 #if defined(CONFIG_MX6SX)
439 	struct gpc *gpc_regs = (struct gpc *)GPC_BASE_ADDR;
440 
441 	/* SSP_EN is not used on MX6SX anymore */
442 	setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN);
443 	/* Force PCIe PHY reset */
444 	setbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST);
445 	/* Power up PCIe PHY */
446 	setbits_le32(&gpc_regs->cntr, PCIE_PHY_PUP_REQ);
447 #else
448 	setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
449 	clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
450 #endif
451 
452 	return 0;
453 }
454 
455 static int imx6_pcie_init_phy(void)
456 {
457 	struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
458 
459 	clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE);
460 
461 	clrsetbits_le32(&iomuxc_regs->gpr[12],
462 			IOMUXC_GPR12_DEVICE_TYPE_MASK,
463 			IOMUXC_GPR12_DEVICE_TYPE_RC);
464 	clrsetbits_le32(&iomuxc_regs->gpr[12],
465 			IOMUXC_GPR12_LOS_LEVEL_MASK,
466 			IOMUXC_GPR12_LOS_LEVEL_9);
467 
468 #ifdef CONFIG_MX6SX
469 	clrsetbits_le32(&iomuxc_regs->gpr[12],
470 			IOMUXC_GPR12_RX_EQ_MASK,
471 			IOMUXC_GPR12_RX_EQ_2);
472 #endif
473 
474 	writel((0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN1_OFFSET) |
475 	       (0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_3P5DB_OFFSET) |
476 	       (20 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_6DB_OFFSET) |
477 	       (127 << IOMUXC_GPR8_PCS_TX_SWING_FULL_OFFSET) |
478 	       (127 << IOMUXC_GPR8_PCS_TX_SWING_LOW_OFFSET),
479 	       &iomuxc_regs->gpr[8]);
480 
481 	return 0;
482 }
483 
484 __weak int imx6_pcie_toggle_power(void)
485 {
486 #ifdef CONFIG_PCIE_IMX_POWER_GPIO
487 	gpio_direction_output(CONFIG_PCIE_IMX_POWER_GPIO, 0);
488 	mdelay(20);
489 	gpio_set_value(CONFIG_PCIE_IMX_POWER_GPIO, 1);
490 	mdelay(20);
491 #endif
492 	return 0;
493 }
494 
495 __weak int imx6_pcie_toggle_reset(void)
496 {
497 	/*
498 	 * See 'PCI EXPRESS BASE SPECIFICATION, REV 3.0, SECTION 6.6.1'
499 	 * for detailed understanding of the PCIe CR reset logic.
500 	 *
501 	 * The PCIe #PERST reset line _MUST_ be connected, otherwise your
502 	 * design does not conform to the specification. You must wait at
503 	 * least 20 ms after de-asserting the #PERST so the EP device can
504 	 * do self-initialisation.
505 	 *
506 	 * In case your #PERST pin is connected to a plain GPIO pin of the
507 	 * CPU, you can define CONFIG_PCIE_IMX_PERST_GPIO in your board's
508 	 * configuration file and the condition below will handle the rest
509 	 * of the reset toggling.
510 	 *
511 	 * In case your #PERST toggling logic is more complex, for example
512 	 * connected via CPLD or somesuch, you can override this function
513 	 * in your board file and implement reset logic as needed. You must
514 	 * not forget to wait at least 20 ms after de-asserting #PERST in
515 	 * this case either though.
516 	 *
517 	 * In case your #PERST line of the PCIe EP device is not connected
518 	 * at all, your design is broken and you should fix your design,
519 	 * otherwise you will observe problems like for example the link
520 	 * not coming up after rebooting the system back from running Linux
521 	 * that uses the PCIe as well OR the PCIe link might not come up in
522 	 * Linux at all in the first place since it's in some non-reset
523 	 * state due to being previously used in U-Boot.
524 	 */
525 #ifdef CONFIG_PCIE_IMX_PERST_GPIO
526 	gpio_direction_output(CONFIG_PCIE_IMX_PERST_GPIO, 0);
527 	mdelay(20);
528 	gpio_set_value(CONFIG_PCIE_IMX_PERST_GPIO, 1);
529 	mdelay(20);
530 #else
531 	puts("WARNING: Make sure the PCIe #PERST line is connected!\n");
532 #endif
533 	return 0;
534 }
535 
536 static int imx6_pcie_deassert_core_reset(void)
537 {
538 	struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
539 
540 	imx6_pcie_toggle_power();
541 
542 	enable_pcie_clock();
543 
544 	if (is_mx6dqp())
545 		clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
546 
547 	/*
548 	 * Wait for the clock to settle a bit, when the clock are sourced
549 	 * from the CPU, we need about 30 ms to settle.
550 	 */
551 	mdelay(50);
552 
553 #if defined(CONFIG_MX6SX)
554 	/* SSP_EN is not used on MX6SX anymore */
555 	clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN);
556 	/* Clear PCIe PHY reset bit */
557 	clrbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST);
558 #else
559 	/* Enable PCIe */
560 	clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
561 	setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
562 #endif
563 
564 	imx6_pcie_toggle_reset();
565 
566 	return 0;
567 }
568 
569 static int imx_pcie_link_up(void)
570 {
571 	struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
572 	uint32_t tmp;
573 	int count = 0;
574 
575 	imx6_pcie_assert_core_reset();
576 	imx6_pcie_init_phy();
577 	imx6_pcie_deassert_core_reset();
578 
579 	imx_pcie_regions_setup();
580 
581 	/*
582 	 * FIXME: Force the PCIe RC to Gen1 operation
583 	 * The RC must be forced into Gen1 mode before bringing the link
584 	 * up, otherwise no downstream devices are detected. After the
585 	 * link is up, a managed Gen1->Gen2 transition can be initiated.
586 	 */
587 	tmp = readl(MX6_DBI_ADDR + 0x7c);
588 	tmp &= ~0xf;
589 	tmp |= 0x1;
590 	writel(tmp, MX6_DBI_ADDR + 0x7c);
591 
592 	/* LTSSM enable, starting link. */
593 	setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE);
594 
595 	while (!imx6_pcie_link_up()) {
596 		udelay(10);
597 		count++;
598 		if (count >= 4000) {
599 #ifdef CONFIG_PCI_SCAN_SHOW
600 			puts("PCI:   pcie phy link never came up\n");
601 #endif
602 			debug("DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
603 			      readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0),
604 			      readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1));
605 			return -EINVAL;
606 		}
607 	}
608 
609 	return 0;
610 }
611 
612 void imx_pcie_init(void)
613 {
614 	/* Static instance of the controller. */
615 	static struct pci_controller	pcc;
616 	struct pci_controller		*hose = &pcc;
617 	int ret;
618 
619 	memset(&pcc, 0, sizeof(pcc));
620 
621 	/* PCI I/O space */
622 	pci_set_region(&hose->regions[0],
623 		       MX6_IO_ADDR, MX6_IO_ADDR,
624 		       MX6_IO_SIZE, PCI_REGION_IO);
625 
626 	/* PCI memory space */
627 	pci_set_region(&hose->regions[1],
628 		       MX6_MEM_ADDR, MX6_MEM_ADDR,
629 		       MX6_MEM_SIZE, PCI_REGION_MEM);
630 
631 	/* System memory space */
632 	pci_set_region(&hose->regions[2],
633 		       MMDC0_ARB_BASE_ADDR, MMDC0_ARB_BASE_ADDR,
634 		       0xefffffff, PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
635 
636 	hose->region_count = 3;
637 
638 	pci_set_ops(hose,
639 		    pci_hose_read_config_byte_via_dword,
640 		    pci_hose_read_config_word_via_dword,
641 		    imx_pcie_read_config,
642 		    pci_hose_write_config_byte_via_dword,
643 		    pci_hose_write_config_word_via_dword,
644 		    imx_pcie_write_config);
645 
646 	/* Start the controller. */
647 	ret = imx_pcie_link_up();
648 
649 	if (!ret) {
650 		pci_register_hose(hose);
651 		hose->last_busno = pci_hose_scan(hose);
652 	}
653 }
654 
655 /* Probe function. */
656 void pci_init_board(void)
657 {
658 	imx_pcie_init();
659 }
660