1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PCIe driver for Marvell Armada 370 and Armada XP SoCs
4  *
5  * Author: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/pci.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/gpio.h>
13 #include <linux/init.h>
14 #include <linux/mbus.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/of_address.h>
18 #include <linux/of_irq.h>
19 #include <linux/of_gpio.h>
20 #include <linux/of_pci.h>
21 #include <linux/of_platform.h>
22 
23 #include "../pci.h"
24 #include "../pci-bridge-emul.h"
25 
26 /*
27  * PCIe unit register offsets.
28  */
29 #define PCIE_DEV_ID_OFF		0x0000
30 #define PCIE_CMD_OFF		0x0004
31 #define PCIE_DEV_REV_OFF	0x0008
32 #define PCIE_BAR_LO_OFF(n)	(0x0010 + ((n) << 3))
33 #define PCIE_BAR_HI_OFF(n)	(0x0014 + ((n) << 3))
34 #define PCIE_CAP_PCIEXP		0x0060
35 #define PCIE_HEADER_LOG_4_OFF	0x0128
36 #define PCIE_BAR_CTRL_OFF(n)	(0x1804 + (((n) - 1) * 4))
37 #define PCIE_WIN04_CTRL_OFF(n)	(0x1820 + ((n) << 4))
38 #define PCIE_WIN04_BASE_OFF(n)	(0x1824 + ((n) << 4))
39 #define PCIE_WIN04_REMAP_OFF(n)	(0x182c + ((n) << 4))
40 #define PCIE_WIN5_CTRL_OFF	0x1880
41 #define PCIE_WIN5_BASE_OFF	0x1884
42 #define PCIE_WIN5_REMAP_OFF	0x188c
43 #define PCIE_CONF_ADDR_OFF	0x18f8
44 #define  PCIE_CONF_ADDR_EN		0x80000000
45 #define  PCIE_CONF_REG(r)		((((r) & 0xf00) << 16) | ((r) & 0xfc))
46 #define  PCIE_CONF_BUS(b)		(((b) & 0xff) << 16)
47 #define  PCIE_CONF_DEV(d)		(((d) & 0x1f) << 11)
48 #define  PCIE_CONF_FUNC(f)		(((f) & 0x7) << 8)
49 #define  PCIE_CONF_ADDR(bus, devfn, where) \
50 	(PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn))    | \
51 	 PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where) | \
52 	 PCIE_CONF_ADDR_EN)
53 #define PCIE_CONF_DATA_OFF	0x18fc
54 #define PCIE_MASK_OFF		0x1910
55 #define  PCIE_MASK_ENABLE_INTS          0x0f000000
56 #define PCIE_CTRL_OFF		0x1a00
57 #define  PCIE_CTRL_X1_MODE		0x0001
58 #define PCIE_STAT_OFF		0x1a04
59 #define  PCIE_STAT_BUS                  0xff00
60 #define  PCIE_STAT_DEV                  0x1f0000
61 #define  PCIE_STAT_LINK_DOWN		BIT(0)
62 #define PCIE_RC_RTSTA		0x1a14
63 #define PCIE_DEBUG_CTRL         0x1a60
64 #define  PCIE_DEBUG_SOFT_RESET		BIT(20)
65 
66 struct mvebu_pcie_port;
67 
68 /* Structure representing all PCIe interfaces */
69 struct mvebu_pcie {
70 	struct platform_device *pdev;
71 	struct mvebu_pcie_port *ports;
72 	struct resource io;
73 	struct resource realio;
74 	struct resource mem;
75 	struct resource busn;
76 	int nports;
77 };
78 
79 struct mvebu_pcie_window {
80 	phys_addr_t base;
81 	phys_addr_t remap;
82 	size_t size;
83 };
84 
85 /* Structure representing one PCIe interface */
86 struct mvebu_pcie_port {
87 	char *name;
88 	void __iomem *base;
89 	u32 port;
90 	u32 lane;
91 	int devfn;
92 	unsigned int mem_target;
93 	unsigned int mem_attr;
94 	unsigned int io_target;
95 	unsigned int io_attr;
96 	struct clk *clk;
97 	struct gpio_desc *reset_gpio;
98 	char *reset_name;
99 	struct pci_bridge_emul bridge;
100 	struct device_node *dn;
101 	struct mvebu_pcie *pcie;
102 	struct mvebu_pcie_window memwin;
103 	struct mvebu_pcie_window iowin;
104 	u32 saved_pcie_stat;
105 	struct resource regs;
106 };
107 
108 static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg)
109 {
110 	writel(val, port->base + reg);
111 }
112 
113 static inline u32 mvebu_readl(struct mvebu_pcie_port *port, u32 reg)
114 {
115 	return readl(port->base + reg);
116 }
117 
118 static inline bool mvebu_has_ioport(struct mvebu_pcie_port *port)
119 {
120 	return port->io_target != -1 && port->io_attr != -1;
121 }
122 
123 static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
124 {
125 	return !(mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_LINK_DOWN);
126 }
127 
128 static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie_port *port, int nr)
129 {
130 	u32 stat;
131 
132 	stat = mvebu_readl(port, PCIE_STAT_OFF);
133 	stat &= ~PCIE_STAT_BUS;
134 	stat |= nr << 8;
135 	mvebu_writel(port, stat, PCIE_STAT_OFF);
136 }
137 
138 static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
139 {
140 	u32 stat;
141 
142 	stat = mvebu_readl(port, PCIE_STAT_OFF);
143 	stat &= ~PCIE_STAT_DEV;
144 	stat |= nr << 16;
145 	mvebu_writel(port, stat, PCIE_STAT_OFF);
146 }
147 
148 /*
149  * Setup PCIE BARs and Address Decode Wins:
150  * BAR[0] -> internal registers (needed for MSI)
151  * BAR[1] -> covers all DRAM banks
152  * BAR[2] -> Disabled
153  * WIN[0-3] -> DRAM bank[0-3]
154  */
155 static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
156 {
157 	const struct mbus_dram_target_info *dram;
158 	u32 size;
159 	int i;
160 
161 	dram = mv_mbus_dram_info();
162 
163 	/* First, disable and clear BARs and windows. */
164 	for (i = 1; i < 3; i++) {
165 		mvebu_writel(port, 0, PCIE_BAR_CTRL_OFF(i));
166 		mvebu_writel(port, 0, PCIE_BAR_LO_OFF(i));
167 		mvebu_writel(port, 0, PCIE_BAR_HI_OFF(i));
168 	}
169 
170 	for (i = 0; i < 5; i++) {
171 		mvebu_writel(port, 0, PCIE_WIN04_CTRL_OFF(i));
172 		mvebu_writel(port, 0, PCIE_WIN04_BASE_OFF(i));
173 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
174 	}
175 
176 	mvebu_writel(port, 0, PCIE_WIN5_CTRL_OFF);
177 	mvebu_writel(port, 0, PCIE_WIN5_BASE_OFF);
178 	mvebu_writel(port, 0, PCIE_WIN5_REMAP_OFF);
179 
180 	/* Setup windows for DDR banks.  Count total DDR size on the fly. */
181 	size = 0;
182 	for (i = 0; i < dram->num_cs; i++) {
183 		const struct mbus_dram_window *cs = dram->cs + i;
184 
185 		mvebu_writel(port, cs->base & 0xffff0000,
186 			     PCIE_WIN04_BASE_OFF(i));
187 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
188 		mvebu_writel(port,
189 			     ((cs->size - 1) & 0xffff0000) |
190 			     (cs->mbus_attr << 8) |
191 			     (dram->mbus_dram_target_id << 4) | 1,
192 			     PCIE_WIN04_CTRL_OFF(i));
193 
194 		size += cs->size;
195 	}
196 
197 	/* Round up 'size' to the nearest power of two. */
198 	if ((size & (size - 1)) != 0)
199 		size = 1 << fls(size);
200 
201 	/* Setup BAR[1] to all DRAM banks. */
202 	mvebu_writel(port, dram->cs[0].base, PCIE_BAR_LO_OFF(1));
203 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1));
204 	mvebu_writel(port, ((size - 1) & 0xffff0000) | 1,
205 		     PCIE_BAR_CTRL_OFF(1));
206 
207 	/*
208 	 * Point BAR[0] to the device's internal registers.
209 	 */
210 	mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0));
211 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
212 }
213 
214 static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
215 {
216 	u32 cmd, mask;
217 
218 	/* Point PCIe unit MBUS decode windows to DRAM space. */
219 	mvebu_pcie_setup_wins(port);
220 
221 	/* Master + slave enable. */
222 	cmd = mvebu_readl(port, PCIE_CMD_OFF);
223 	cmd |= PCI_COMMAND_IO;
224 	cmd |= PCI_COMMAND_MEMORY;
225 	cmd |= PCI_COMMAND_MASTER;
226 	mvebu_writel(port, cmd, PCIE_CMD_OFF);
227 
228 	/* Enable interrupt lines A-D. */
229 	mask = mvebu_readl(port, PCIE_MASK_OFF);
230 	mask |= PCIE_MASK_ENABLE_INTS;
231 	mvebu_writel(port, mask, PCIE_MASK_OFF);
232 }
233 
234 static int mvebu_pcie_hw_rd_conf(struct mvebu_pcie_port *port,
235 				 struct pci_bus *bus,
236 				 u32 devfn, int where, int size, u32 *val)
237 {
238 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
239 
240 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
241 		     PCIE_CONF_ADDR_OFF);
242 
243 	switch (size) {
244 	case 1:
245 		*val = readb_relaxed(conf_data + (where & 3));
246 		break;
247 	case 2:
248 		*val = readw_relaxed(conf_data + (where & 2));
249 		break;
250 	case 4:
251 		*val = readl_relaxed(conf_data);
252 		break;
253 	}
254 
255 	return PCIBIOS_SUCCESSFUL;
256 }
257 
258 static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
259 				 struct pci_bus *bus,
260 				 u32 devfn, int where, int size, u32 val)
261 {
262 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
263 
264 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
265 		     PCIE_CONF_ADDR_OFF);
266 
267 	switch (size) {
268 	case 1:
269 		writeb(val, conf_data + (where & 3));
270 		break;
271 	case 2:
272 		writew(val, conf_data + (where & 2));
273 		break;
274 	case 4:
275 		writel(val, conf_data);
276 		break;
277 	default:
278 		return PCIBIOS_BAD_REGISTER_NUMBER;
279 	}
280 
281 	return PCIBIOS_SUCCESSFUL;
282 }
283 
284 /*
285  * Remove windows, starting from the largest ones to the smallest
286  * ones.
287  */
288 static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
289 				   phys_addr_t base, size_t size)
290 {
291 	while (size) {
292 		size_t sz = 1 << (fls(size) - 1);
293 
294 		mvebu_mbus_del_window(base, sz);
295 		base += sz;
296 		size -= sz;
297 	}
298 }
299 
300 /*
301  * MBus windows can only have a power of two size, but PCI BARs do not
302  * have this constraint. Therefore, we have to split the PCI BAR into
303  * areas each having a power of two size. We start from the largest
304  * one (i.e highest order bit set in the size).
305  */
306 static void mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
307 				   unsigned int target, unsigned int attribute,
308 				   phys_addr_t base, size_t size,
309 				   phys_addr_t remap)
310 {
311 	size_t size_mapped = 0;
312 
313 	while (size) {
314 		size_t sz = 1 << (fls(size) - 1);
315 		int ret;
316 
317 		ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
318 							sz, remap);
319 		if (ret) {
320 			phys_addr_t end = base + sz - 1;
321 
322 			dev_err(&port->pcie->pdev->dev,
323 				"Could not create MBus window at [mem %pa-%pa]: %d\n",
324 				&base, &end, ret);
325 			mvebu_pcie_del_windows(port, base - size_mapped,
326 					       size_mapped);
327 			return;
328 		}
329 
330 		size -= sz;
331 		size_mapped += sz;
332 		base += sz;
333 		if (remap != MVEBU_MBUS_NO_REMAP)
334 			remap += sz;
335 	}
336 }
337 
338 static void mvebu_pcie_set_window(struct mvebu_pcie_port *port,
339 				  unsigned int target, unsigned int attribute,
340 				  const struct mvebu_pcie_window *desired,
341 				  struct mvebu_pcie_window *cur)
342 {
343 	if (desired->base == cur->base && desired->remap == cur->remap &&
344 	    desired->size == cur->size)
345 		return;
346 
347 	if (cur->size != 0) {
348 		mvebu_pcie_del_windows(port, cur->base, cur->size);
349 		cur->size = 0;
350 		cur->base = 0;
351 
352 		/*
353 		 * If something tries to change the window while it is enabled
354 		 * the change will not be done atomically. That would be
355 		 * difficult to do in the general case.
356 		 */
357 	}
358 
359 	if (desired->size == 0)
360 		return;
361 
362 	mvebu_pcie_add_windows(port, target, attribute, desired->base,
363 			       desired->size, desired->remap);
364 	*cur = *desired;
365 }
366 
367 static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
368 {
369 	struct mvebu_pcie_window desired = {};
370 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
371 
372 	/* Are the new iobase/iolimit values invalid? */
373 	if (conf->iolimit < conf->iobase ||
374 	    conf->iolimitupper < conf->iobaseupper ||
375 	    !(conf->command & PCI_COMMAND_IO)) {
376 		mvebu_pcie_set_window(port, port->io_target, port->io_attr,
377 				      &desired, &port->iowin);
378 		return;
379 	}
380 
381 	if (!mvebu_has_ioport(port)) {
382 		dev_WARN(&port->pcie->pdev->dev,
383 			 "Attempt to set IO when IO is disabled\n");
384 		return;
385 	}
386 
387 	/*
388 	 * We read the PCI-to-PCI bridge emulated registers, and
389 	 * calculate the base address and size of the address decoding
390 	 * window to setup, according to the PCI-to-PCI bridge
391 	 * specifications. iobase is the bus address, port->iowin_base
392 	 * is the CPU address.
393 	 */
394 	desired.remap = ((conf->iobase & 0xF0) << 8) |
395 			(conf->iobaseupper << 16);
396 	desired.base = port->pcie->io.start + desired.remap;
397 	desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
398 			 (conf->iolimitupper << 16)) -
399 			desired.remap) +
400 		       1;
401 
402 	mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
403 			      &port->iowin);
404 }
405 
406 static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
407 {
408 	struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
409 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
410 
411 	/* Are the new membase/memlimit values invalid? */
412 	if (conf->memlimit < conf->membase ||
413 	    !(conf->command & PCI_COMMAND_MEMORY)) {
414 		mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
415 				      &desired, &port->memwin);
416 		return;
417 	}
418 
419 	/*
420 	 * We read the PCI-to-PCI bridge emulated registers, and
421 	 * calculate the base address and size of the address decoding
422 	 * window to setup, according to the PCI-to-PCI bridge
423 	 * specifications.
424 	 */
425 	desired.base = ((conf->membase & 0xFFF0) << 16);
426 	desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
427 		       desired.base + 1;
428 
429 	mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
430 			      &port->memwin);
431 }
432 
433 static pci_bridge_emul_read_status_t
434 mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
435 				     int reg, u32 *value)
436 {
437 	struct mvebu_pcie_port *port = bridge->data;
438 
439 	switch (reg) {
440 	case PCI_EXP_DEVCAP:
441 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
442 		break;
443 
444 	case PCI_EXP_DEVCTL:
445 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL) &
446 				 ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
447 				   PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
448 		break;
449 
450 	case PCI_EXP_LNKCAP:
451 		/*
452 		 * PCIe requires the clock power management capability to be
453 		 * hard-wired to zero for downstream ports
454 		 */
455 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
456 			 ~PCI_EXP_LNKCAP_CLKPM;
457 		break;
458 
459 	case PCI_EXP_LNKCTL:
460 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
461 		break;
462 
463 	case PCI_EXP_SLTCTL:
464 		*value = PCI_EXP_SLTSTA_PDS << 16;
465 		break;
466 
467 	case PCI_EXP_RTSTA:
468 		*value = mvebu_readl(port, PCIE_RC_RTSTA);
469 		break;
470 
471 	default:
472 		return PCI_BRIDGE_EMUL_NOT_HANDLED;
473 	}
474 
475 	return PCI_BRIDGE_EMUL_HANDLED;
476 }
477 
478 static void
479 mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
480 				      int reg, u32 old, u32 new, u32 mask)
481 {
482 	struct mvebu_pcie_port *port = bridge->data;
483 	struct pci_bridge_emul_conf *conf = &bridge->conf;
484 
485 	switch (reg) {
486 	case PCI_COMMAND:
487 	{
488 		if (!mvebu_has_ioport(port))
489 			conf->command &= ~PCI_COMMAND_IO;
490 
491 		if ((old ^ new) & PCI_COMMAND_IO)
492 			mvebu_pcie_handle_iobase_change(port);
493 		if ((old ^ new) & PCI_COMMAND_MEMORY)
494 			mvebu_pcie_handle_membase_change(port);
495 
496 		break;
497 	}
498 
499 	case PCI_IO_BASE:
500 		/*
501 		 * We keep bit 1 set, it is a read-only bit that
502 		 * indicates we support 32 bits addressing for the
503 		 * I/O
504 		 */
505 		conf->iobase |= PCI_IO_RANGE_TYPE_32;
506 		conf->iolimit |= PCI_IO_RANGE_TYPE_32;
507 		mvebu_pcie_handle_iobase_change(port);
508 		break;
509 
510 	case PCI_MEMORY_BASE:
511 		mvebu_pcie_handle_membase_change(port);
512 		break;
513 
514 	case PCI_IO_BASE_UPPER16:
515 		mvebu_pcie_handle_iobase_change(port);
516 		break;
517 
518 	case PCI_PRIMARY_BUS:
519 		mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
520 		break;
521 
522 	default:
523 		break;
524 	}
525 }
526 
527 static void
528 mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
529 				      int reg, u32 old, u32 new, u32 mask)
530 {
531 	struct mvebu_pcie_port *port = bridge->data;
532 
533 	switch (reg) {
534 	case PCI_EXP_DEVCTL:
535 		/*
536 		 * Armada370 data says these bits must always
537 		 * be zero when in root complex mode.
538 		 */
539 		new &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
540 			 PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
541 
542 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
543 		break;
544 
545 	case PCI_EXP_LNKCTL:
546 		/*
547 		 * If we don't support CLKREQ, we must ensure that the
548 		 * CLKREQ enable bit always reads zero.  Since we haven't
549 		 * had this capability, and it's dependent on board wiring,
550 		 * disable it for the time being.
551 		 */
552 		new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
553 
554 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
555 		break;
556 
557 	case PCI_EXP_RTSTA:
558 		mvebu_writel(port, new, PCIE_RC_RTSTA);
559 		break;
560 	}
561 }
562 
563 static struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
564 	.write_base = mvebu_pci_bridge_emul_base_conf_write,
565 	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
566 	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
567 };
568 
569 /*
570  * Initialize the configuration space of the PCI-to-PCI bridge
571  * associated with the given PCIe interface.
572  */
573 static void mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
574 {
575 	struct pci_bridge_emul *bridge = &port->bridge;
576 
577 	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
578 	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
579 	bridge->conf.class_revision =
580 		mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
581 
582 	if (mvebu_has_ioport(port)) {
583 		/* We support 32 bits I/O addressing */
584 		bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
585 		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
586 	}
587 
588 	bridge->has_pcie = true;
589 	bridge->data = port;
590 	bridge->ops = &mvebu_pci_bridge_emul_ops;
591 
592 	pci_bridge_emul_init(bridge, PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR);
593 }
594 
595 static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
596 {
597 	return sys->private_data;
598 }
599 
600 static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
601 						    struct pci_bus *bus,
602 						    int devfn)
603 {
604 	int i;
605 
606 	for (i = 0; i < pcie->nports; i++) {
607 		struct mvebu_pcie_port *port = &pcie->ports[i];
608 
609 		if (bus->number == 0 && port->devfn == devfn)
610 			return port;
611 		if (bus->number != 0 &&
612 		    bus->number >= port->bridge.conf.secondary_bus &&
613 		    bus->number <= port->bridge.conf.subordinate_bus)
614 			return port;
615 	}
616 
617 	return NULL;
618 }
619 
620 /* PCI configuration space write function */
621 static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
622 			      int where, int size, u32 val)
623 {
624 	struct mvebu_pcie *pcie = bus->sysdata;
625 	struct mvebu_pcie_port *port;
626 	int ret;
627 
628 	port = mvebu_pcie_find_port(pcie, bus, devfn);
629 	if (!port)
630 		return PCIBIOS_DEVICE_NOT_FOUND;
631 
632 	/* Access the emulated PCI-to-PCI bridge */
633 	if (bus->number == 0)
634 		return pci_bridge_emul_conf_write(&port->bridge, where,
635 						  size, val);
636 
637 	if (!mvebu_pcie_link_up(port))
638 		return PCIBIOS_DEVICE_NOT_FOUND;
639 
640 	/* Access the real PCIe interface */
641 	ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
642 				    where, size, val);
643 
644 	return ret;
645 }
646 
647 /* PCI configuration space read function */
648 static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
649 			      int size, u32 *val)
650 {
651 	struct mvebu_pcie *pcie = bus->sysdata;
652 	struct mvebu_pcie_port *port;
653 	int ret;
654 
655 	port = mvebu_pcie_find_port(pcie, bus, devfn);
656 	if (!port) {
657 		*val = 0xffffffff;
658 		return PCIBIOS_DEVICE_NOT_FOUND;
659 	}
660 
661 	/* Access the emulated PCI-to-PCI bridge */
662 	if (bus->number == 0)
663 		return pci_bridge_emul_conf_read(&port->bridge, where,
664 						 size, val);
665 
666 	if (!mvebu_pcie_link_up(port)) {
667 		*val = 0xffffffff;
668 		return PCIBIOS_DEVICE_NOT_FOUND;
669 	}
670 
671 	/* Access the real PCIe interface */
672 	ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
673 				    where, size, val);
674 
675 	return ret;
676 }
677 
678 static struct pci_ops mvebu_pcie_ops = {
679 	.read = mvebu_pcie_rd_conf,
680 	.write = mvebu_pcie_wr_conf,
681 };
682 
683 static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
684 						 const struct resource *res,
685 						 resource_size_t start,
686 						 resource_size_t size,
687 						 resource_size_t align)
688 {
689 	if (dev->bus->number != 0)
690 		return start;
691 
692 	/*
693 	 * On the PCI-to-PCI bridge side, the I/O windows must have at
694 	 * least a 64 KB size and the memory windows must have at
695 	 * least a 1 MB size. Moreover, MBus windows need to have a
696 	 * base address aligned on their size, and their size must be
697 	 * a power of two. This means that if the BAR doesn't have a
698 	 * power of two size, several MBus windows will actually be
699 	 * created. We need to ensure that the biggest MBus window
700 	 * (which will be the first one) is aligned on its size, which
701 	 * explains the rounddown_pow_of_two() being done here.
702 	 */
703 	if (res->flags & IORESOURCE_IO)
704 		return round_up(start, max_t(resource_size_t, SZ_64K,
705 					     rounddown_pow_of_two(size)));
706 	else if (res->flags & IORESOURCE_MEM)
707 		return round_up(start, max_t(resource_size_t, SZ_1M,
708 					     rounddown_pow_of_two(size)));
709 	else
710 		return start;
711 }
712 
713 static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
714 					      struct device_node *np,
715 					      struct mvebu_pcie_port *port)
716 {
717 	int ret = 0;
718 
719 	ret = of_address_to_resource(np, 0, &port->regs);
720 	if (ret)
721 		return (void __iomem *)ERR_PTR(ret);
722 
723 	return devm_ioremap_resource(&pdev->dev, &port->regs);
724 }
725 
726 #define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
727 #define    DT_TYPE_IO                 0x1
728 #define    DT_TYPE_MEM32              0x2
729 #define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
730 #define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)
731 
732 static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
733 			      unsigned long type,
734 			      unsigned int *tgt,
735 			      unsigned int *attr)
736 {
737 	const int na = 3, ns = 2;
738 	const __be32 *range;
739 	int rlen, nranges, rangesz, pna, i;
740 
741 	*tgt = -1;
742 	*attr = -1;
743 
744 	range = of_get_property(np, "ranges", &rlen);
745 	if (!range)
746 		return -EINVAL;
747 
748 	pna = of_n_addr_cells(np);
749 	rangesz = pna + na + ns;
750 	nranges = rlen / sizeof(__be32) / rangesz;
751 
752 	for (i = 0; i < nranges; i++, range += rangesz) {
753 		u32 flags = of_read_number(range, 1);
754 		u32 slot = of_read_number(range + 1, 1);
755 		u64 cpuaddr = of_read_number(range + na, pna);
756 		unsigned long rtype;
757 
758 		if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
759 			rtype = IORESOURCE_IO;
760 		else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
761 			rtype = IORESOURCE_MEM;
762 		else
763 			continue;
764 
765 		if (slot == PCI_SLOT(devfn) && type == rtype) {
766 			*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
767 			*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
768 			return 0;
769 		}
770 	}
771 
772 	return -ENOENT;
773 }
774 
775 #ifdef CONFIG_PM_SLEEP
776 static int mvebu_pcie_suspend(struct device *dev)
777 {
778 	struct mvebu_pcie *pcie;
779 	int i;
780 
781 	pcie = dev_get_drvdata(dev);
782 	for (i = 0; i < pcie->nports; i++) {
783 		struct mvebu_pcie_port *port = pcie->ports + i;
784 		port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
785 	}
786 
787 	return 0;
788 }
789 
790 static int mvebu_pcie_resume(struct device *dev)
791 {
792 	struct mvebu_pcie *pcie;
793 	int i;
794 
795 	pcie = dev_get_drvdata(dev);
796 	for (i = 0; i < pcie->nports; i++) {
797 		struct mvebu_pcie_port *port = pcie->ports + i;
798 		mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
799 		mvebu_pcie_setup_hw(port);
800 	}
801 
802 	return 0;
803 }
804 #endif
805 
806 static void mvebu_pcie_port_clk_put(void *data)
807 {
808 	struct mvebu_pcie_port *port = data;
809 
810 	clk_put(port->clk);
811 }
812 
813 static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
814 	struct mvebu_pcie_port *port, struct device_node *child)
815 {
816 	struct device *dev = &pcie->pdev->dev;
817 	enum of_gpio_flags flags;
818 	int reset_gpio, ret;
819 
820 	port->pcie = pcie;
821 
822 	if (of_property_read_u32(child, "marvell,pcie-port", &port->port)) {
823 		dev_warn(dev, "ignoring %pOF, missing pcie-port property\n",
824 			 child);
825 		goto skip;
826 	}
827 
828 	if (of_property_read_u32(child, "marvell,pcie-lane", &port->lane))
829 		port->lane = 0;
830 
831 	port->name = devm_kasprintf(dev, GFP_KERNEL, "pcie%d.%d", port->port,
832 				    port->lane);
833 	if (!port->name) {
834 		ret = -ENOMEM;
835 		goto err;
836 	}
837 
838 	port->devfn = of_pci_get_devfn(child);
839 	if (port->devfn < 0)
840 		goto skip;
841 
842 	ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM,
843 				 &port->mem_target, &port->mem_attr);
844 	if (ret < 0) {
845 		dev_err(dev, "%s: cannot get tgt/attr for mem window\n",
846 			port->name);
847 		goto skip;
848 	}
849 
850 	if (resource_size(&pcie->io) != 0) {
851 		mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_IO,
852 				   &port->io_target, &port->io_attr);
853 	} else {
854 		port->io_target = -1;
855 		port->io_attr = -1;
856 	}
857 
858 	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
859 	if (reset_gpio == -EPROBE_DEFER) {
860 		ret = reset_gpio;
861 		goto err;
862 	}
863 
864 	if (gpio_is_valid(reset_gpio)) {
865 		unsigned long gpio_flags;
866 
867 		port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
868 						  port->name);
869 		if (!port->reset_name) {
870 			ret = -ENOMEM;
871 			goto err;
872 		}
873 
874 		if (flags & OF_GPIO_ACTIVE_LOW) {
875 			dev_info(dev, "%pOF: reset gpio is active low\n",
876 				 child);
877 			gpio_flags = GPIOF_ACTIVE_LOW |
878 				     GPIOF_OUT_INIT_LOW;
879 		} else {
880 			gpio_flags = GPIOF_OUT_INIT_HIGH;
881 		}
882 
883 		ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
884 					    port->reset_name);
885 		if (ret) {
886 			if (ret == -EPROBE_DEFER)
887 				goto err;
888 			goto skip;
889 		}
890 
891 		port->reset_gpio = gpio_to_desc(reset_gpio);
892 	}
893 
894 	port->clk = of_clk_get_by_name(child, NULL);
895 	if (IS_ERR(port->clk)) {
896 		dev_err(dev, "%s: cannot get clock\n", port->name);
897 		goto skip;
898 	}
899 
900 	ret = devm_add_action(dev, mvebu_pcie_port_clk_put, port);
901 	if (ret < 0) {
902 		clk_put(port->clk);
903 		goto err;
904 	}
905 
906 	return 1;
907 
908 skip:
909 	ret = 0;
910 
911 	/* In the case of skipping, we need to free these */
912 	devm_kfree(dev, port->reset_name);
913 	port->reset_name = NULL;
914 	devm_kfree(dev, port->name);
915 	port->name = NULL;
916 
917 err:
918 	return ret;
919 }
920 
921 /*
922  * Power up a PCIe port.  PCIe requires the refclk to be stable for 100µs
923  * prior to releasing PERST.  See table 2-4 in section 2.6.2 AC Specifications
924  * of the PCI Express Card Electromechanical Specification, 1.1.
925  */
926 static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
927 {
928 	int ret;
929 
930 	ret = clk_prepare_enable(port->clk);
931 	if (ret < 0)
932 		return ret;
933 
934 	if (port->reset_gpio) {
935 		u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
936 
937 		of_property_read_u32(port->dn, "reset-delay-us",
938 				     &reset_udelay);
939 
940 		udelay(100);
941 
942 		gpiod_set_value_cansleep(port->reset_gpio, 0);
943 		msleep(reset_udelay / 1000);
944 	}
945 
946 	return 0;
947 }
948 
949 /*
950  * Power down a PCIe port.  Strictly, PCIe requires us to place the card
951  * in D3hot state before asserting PERST#.
952  */
953 static void mvebu_pcie_powerdown(struct mvebu_pcie_port *port)
954 {
955 	gpiod_set_value_cansleep(port->reset_gpio, 1);
956 
957 	clk_disable_unprepare(port->clk);
958 }
959 
960 /*
961  * devm_of_pci_get_host_bridge_resources() only sets up translateable resources,
962  * so we need extra resource setup parsing our special DT properties encoding
963  * the MEM and IO apertures.
964  */
965 static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
966 {
967 	struct device *dev = &pcie->pdev->dev;
968 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
969 	int ret;
970 
971 	/* Get the PCIe memory aperture */
972 	mvebu_mbus_get_pcie_mem_aperture(&pcie->mem);
973 	if (resource_size(&pcie->mem) == 0) {
974 		dev_err(dev, "invalid memory aperture size\n");
975 		return -EINVAL;
976 	}
977 
978 	pcie->mem.name = "PCI MEM";
979 	pci_add_resource(&bridge->windows, &pcie->mem);
980 	ret = devm_request_resource(dev, &iomem_resource, &pcie->mem);
981 	if (ret)
982 		return ret;
983 
984 	/* Get the PCIe IO aperture */
985 	mvebu_mbus_get_pcie_io_aperture(&pcie->io);
986 
987 	if (resource_size(&pcie->io) != 0) {
988 		pcie->realio.flags = pcie->io.flags;
989 		pcie->realio.start = PCIBIOS_MIN_IO;
990 		pcie->realio.end = min_t(resource_size_t,
991 					 IO_SPACE_LIMIT - SZ_64K,
992 					 resource_size(&pcie->io) - 1);
993 		pcie->realio.name = "PCI I/O";
994 
995 		pci_add_resource(&bridge->windows, &pcie->realio);
996 		ret = devm_request_resource(dev, &ioport_resource, &pcie->realio);
997 		if (ret)
998 			return ret;
999 	}
1000 
1001 	return 0;
1002 }
1003 
1004 /*
1005  * This is a copy of pci_host_probe(), except that it does the I/O
1006  * remap as the last step, once we are sure we won't fail.
1007  *
1008  * It should be removed once the I/O remap error handling issue has
1009  * been sorted out.
1010  */
1011 static int mvebu_pci_host_probe(struct pci_host_bridge *bridge)
1012 {
1013 	struct mvebu_pcie *pcie;
1014 	struct pci_bus *bus, *child;
1015 	int ret;
1016 
1017 	ret = pci_scan_root_bus_bridge(bridge);
1018 	if (ret < 0) {
1019 		dev_err(bridge->dev.parent, "Scanning root bridge failed");
1020 		return ret;
1021 	}
1022 
1023 	pcie = pci_host_bridge_priv(bridge);
1024 	if (resource_size(&pcie->io) != 0) {
1025 		unsigned int i;
1026 
1027 		for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)
1028 			pci_ioremap_io(i, pcie->io.start + i);
1029 	}
1030 
1031 	bus = bridge->bus;
1032 
1033 	/*
1034 	 * We insert PCI resources into the iomem_resource and
1035 	 * ioport_resource trees in either pci_bus_claim_resources()
1036 	 * or pci_bus_assign_resources().
1037 	 */
1038 	if (pci_has_flag(PCI_PROBE_ONLY)) {
1039 		pci_bus_claim_resources(bus);
1040 	} else {
1041 		pci_bus_size_bridges(bus);
1042 		pci_bus_assign_resources(bus);
1043 
1044 		list_for_each_entry(child, &bus->children, node)
1045 			pcie_bus_configure_settings(child);
1046 	}
1047 
1048 	pci_bus_add_devices(bus);
1049 	return 0;
1050 }
1051 
1052 static int mvebu_pcie_probe(struct platform_device *pdev)
1053 {
1054 	struct device *dev = &pdev->dev;
1055 	struct mvebu_pcie *pcie;
1056 	struct pci_host_bridge *bridge;
1057 	struct device_node *np = dev->of_node;
1058 	struct device_node *child;
1059 	int num, i, ret;
1060 
1061 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct mvebu_pcie));
1062 	if (!bridge)
1063 		return -ENOMEM;
1064 
1065 	pcie = pci_host_bridge_priv(bridge);
1066 	pcie->pdev = pdev;
1067 	platform_set_drvdata(pdev, pcie);
1068 
1069 	ret = mvebu_pcie_parse_request_resources(pcie);
1070 	if (ret)
1071 		return ret;
1072 
1073 	num = of_get_available_child_count(np);
1074 
1075 	pcie->ports = devm_kcalloc(dev, num, sizeof(*pcie->ports), GFP_KERNEL);
1076 	if (!pcie->ports)
1077 		return -ENOMEM;
1078 
1079 	i = 0;
1080 	for_each_available_child_of_node(np, child) {
1081 		struct mvebu_pcie_port *port = &pcie->ports[i];
1082 
1083 		ret = mvebu_pcie_parse_port(pcie, port, child);
1084 		if (ret < 0) {
1085 			of_node_put(child);
1086 			return ret;
1087 		} else if (ret == 0) {
1088 			continue;
1089 		}
1090 
1091 		port->dn = child;
1092 		i++;
1093 	}
1094 	pcie->nports = i;
1095 
1096 	for (i = 0; i < pcie->nports; i++) {
1097 		struct mvebu_pcie_port *port = &pcie->ports[i];
1098 
1099 		child = port->dn;
1100 		if (!child)
1101 			continue;
1102 
1103 		ret = mvebu_pcie_powerup(port);
1104 		if (ret < 0)
1105 			continue;
1106 
1107 		port->base = mvebu_pcie_map_registers(pdev, child, port);
1108 		if (IS_ERR(port->base)) {
1109 			dev_err(dev, "%s: cannot map registers\n", port->name);
1110 			port->base = NULL;
1111 			mvebu_pcie_powerdown(port);
1112 			continue;
1113 		}
1114 
1115 		mvebu_pcie_setup_hw(port);
1116 		mvebu_pcie_set_local_dev_nr(port, 1);
1117 		mvebu_pci_bridge_emul_init(port);
1118 	}
1119 
1120 	pcie->nports = i;
1121 
1122 	bridge->sysdata = pcie;
1123 	bridge->ops = &mvebu_pcie_ops;
1124 	bridge->align_resource = mvebu_pcie_align_resource;
1125 
1126 	return mvebu_pci_host_probe(bridge);
1127 }
1128 
1129 static const struct of_device_id mvebu_pcie_of_match_table[] = {
1130 	{ .compatible = "marvell,armada-xp-pcie", },
1131 	{ .compatible = "marvell,armada-370-pcie", },
1132 	{ .compatible = "marvell,dove-pcie", },
1133 	{ .compatible = "marvell,kirkwood-pcie", },
1134 	{},
1135 };
1136 
1137 static const struct dev_pm_ops mvebu_pcie_pm_ops = {
1138 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_pcie_suspend, mvebu_pcie_resume)
1139 };
1140 
1141 static struct platform_driver mvebu_pcie_driver = {
1142 	.driver = {
1143 		.name = "mvebu-pcie",
1144 		.of_match_table = mvebu_pcie_of_match_table,
1145 		/* driver unloading/unbinding currently not supported */
1146 		.suppress_bind_attrs = true,
1147 		.pm = &mvebu_pcie_pm_ops,
1148 	},
1149 	.probe = mvebu_pcie_probe,
1150 };
1151 builtin_platform_driver(mvebu_pcie_driver);
1152