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/module.h>
10 #include <linux/pci.h>
11 #include <linux/clk.h>
12 #include <linux/delay.h>
13 #include <linux/gpio.h>
14 #include <linux/init.h>
15 #include <linux/mbus.h>
16 #include <linux/slab.h>
17 #include <linux/platform_device.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_gpio.h>
21 #include <linux/of_pci.h>
22 #include <linux/of_platform.h>
23 
24 #include "../pci.h"
25 #include "../pci-bridge-emul.h"
26 
27 /*
28  * PCIe unit register offsets.
29  */
30 #define PCIE_DEV_ID_OFF		0x0000
31 #define PCIE_CMD_OFF		0x0004
32 #define PCIE_DEV_REV_OFF	0x0008
33 #define PCIE_BAR_LO_OFF(n)	(0x0010 + ((n) << 3))
34 #define PCIE_BAR_HI_OFF(n)	(0x0014 + ((n) << 3))
35 #define PCIE_CAP_PCIEXP		0x0060
36 #define PCIE_HEADER_LOG_4_OFF	0x0128
37 #define PCIE_BAR_CTRL_OFF(n)	(0x1804 + (((n) - 1) * 4))
38 #define PCIE_WIN04_CTRL_OFF(n)	(0x1820 + ((n) << 4))
39 #define PCIE_WIN04_BASE_OFF(n)	(0x1824 + ((n) << 4))
40 #define PCIE_WIN04_REMAP_OFF(n)	(0x182c + ((n) << 4))
41 #define PCIE_WIN5_CTRL_OFF	0x1880
42 #define PCIE_WIN5_BASE_OFF	0x1884
43 #define PCIE_WIN5_REMAP_OFF	0x188c
44 #define PCIE_CONF_ADDR_OFF	0x18f8
45 #define  PCIE_CONF_ADDR_EN		0x80000000
46 #define  PCIE_CONF_REG(r)		((((r) & 0xf00) << 16) | ((r) & 0xfc))
47 #define  PCIE_CONF_BUS(b)		(((b) & 0xff) << 16)
48 #define  PCIE_CONF_DEV(d)		(((d) & 0x1f) << 11)
49 #define  PCIE_CONF_FUNC(f)		(((f) & 0x7) << 8)
50 #define  PCIE_CONF_ADDR(bus, devfn, where) \
51 	(PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn))    | \
52 	 PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where) | \
53 	 PCIE_CONF_ADDR_EN)
54 #define PCIE_CONF_DATA_OFF	0x18fc
55 #define PCIE_INT_CAUSE_OFF	0x1900
56 #define  PCIE_INT_PM_PME		BIT(28)
57 #define PCIE_MASK_OFF		0x1910
58 #define  PCIE_MASK_ENABLE_INTS          0x0f000000
59 #define PCIE_CTRL_OFF		0x1a00
60 #define  PCIE_CTRL_X1_MODE		0x0001
61 #define  PCIE_CTRL_RC_MODE		BIT(1)
62 #define  PCIE_CTRL_MASTER_HOT_RESET	BIT(24)
63 #define PCIE_STAT_OFF		0x1a04
64 #define  PCIE_STAT_BUS                  0xff00
65 #define  PCIE_STAT_DEV                  0x1f0000
66 #define  PCIE_STAT_LINK_DOWN		BIT(0)
67 #define PCIE_RC_RTSTA		0x1a14
68 #define PCIE_DEBUG_CTRL         0x1a60
69 #define  PCIE_DEBUG_SOFT_RESET		BIT(20)
70 
71 struct mvebu_pcie_port;
72 
73 /* Structure representing all PCIe interfaces */
74 struct mvebu_pcie {
75 	struct platform_device *pdev;
76 	struct mvebu_pcie_port *ports;
77 	struct resource io;
78 	struct resource realio;
79 	struct resource mem;
80 	struct resource busn;
81 	int nports;
82 };
83 
84 struct mvebu_pcie_window {
85 	phys_addr_t base;
86 	phys_addr_t remap;
87 	size_t size;
88 };
89 
90 /* Structure representing one PCIe interface */
91 struct mvebu_pcie_port {
92 	char *name;
93 	void __iomem *base;
94 	u32 port;
95 	u32 lane;
96 	int devfn;
97 	unsigned int mem_target;
98 	unsigned int mem_attr;
99 	unsigned int io_target;
100 	unsigned int io_attr;
101 	struct clk *clk;
102 	struct gpio_desc *reset_gpio;
103 	char *reset_name;
104 	struct pci_bridge_emul bridge;
105 	struct device_node *dn;
106 	struct mvebu_pcie *pcie;
107 	struct mvebu_pcie_window memwin;
108 	struct mvebu_pcie_window iowin;
109 	u32 saved_pcie_stat;
110 	struct resource regs;
111 };
112 
113 static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg)
114 {
115 	writel(val, port->base + reg);
116 }
117 
118 static inline u32 mvebu_readl(struct mvebu_pcie_port *port, u32 reg)
119 {
120 	return readl(port->base + reg);
121 }
122 
123 static inline bool mvebu_has_ioport(struct mvebu_pcie_port *port)
124 {
125 	return port->io_target != -1 && port->io_attr != -1;
126 }
127 
128 static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
129 {
130 	return !(mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_LINK_DOWN);
131 }
132 
133 static u8 mvebu_pcie_get_local_bus_nr(struct mvebu_pcie_port *port)
134 {
135 	return (mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_BUS) >> 8;
136 }
137 
138 static void mvebu_pcie_set_local_bus_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_BUS;
144 	stat |= nr << 8;
145 	mvebu_writel(port, stat, PCIE_STAT_OFF);
146 }
147 
148 static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
149 {
150 	u32 stat;
151 
152 	stat = mvebu_readl(port, PCIE_STAT_OFF);
153 	stat &= ~PCIE_STAT_DEV;
154 	stat |= nr << 16;
155 	mvebu_writel(port, stat, PCIE_STAT_OFF);
156 }
157 
158 static void mvebu_pcie_disable_wins(struct mvebu_pcie_port *port)
159 {
160 	int i;
161 
162 	mvebu_writel(port, 0, PCIE_BAR_LO_OFF(0));
163 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
164 
165 	for (i = 1; i < 3; i++) {
166 		mvebu_writel(port, 0, PCIE_BAR_CTRL_OFF(i));
167 		mvebu_writel(port, 0, PCIE_BAR_LO_OFF(i));
168 		mvebu_writel(port, 0, PCIE_BAR_HI_OFF(i));
169 	}
170 
171 	for (i = 0; i < 5; i++) {
172 		mvebu_writel(port, 0, PCIE_WIN04_CTRL_OFF(i));
173 		mvebu_writel(port, 0, PCIE_WIN04_BASE_OFF(i));
174 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
175 	}
176 
177 	mvebu_writel(port, 0, PCIE_WIN5_CTRL_OFF);
178 	mvebu_writel(port, 0, PCIE_WIN5_BASE_OFF);
179 	mvebu_writel(port, 0, PCIE_WIN5_REMAP_OFF);
180 }
181 
182 /*
183  * Setup PCIE BARs and Address Decode Wins:
184  * BAR[0] -> internal registers (needed for MSI)
185  * BAR[1] -> covers all DRAM banks
186  * BAR[2] -> Disabled
187  * WIN[0-3] -> DRAM bank[0-3]
188  */
189 static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
190 {
191 	const struct mbus_dram_target_info *dram;
192 	u32 size;
193 	int i;
194 
195 	dram = mv_mbus_dram_info();
196 
197 	/* First, disable and clear BARs and windows. */
198 	mvebu_pcie_disable_wins(port);
199 
200 	/* Setup windows for DDR banks.  Count total DDR size on the fly. */
201 	size = 0;
202 	for (i = 0; i < dram->num_cs; i++) {
203 		const struct mbus_dram_window *cs = dram->cs + i;
204 
205 		mvebu_writel(port, cs->base & 0xffff0000,
206 			     PCIE_WIN04_BASE_OFF(i));
207 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
208 		mvebu_writel(port,
209 			     ((cs->size - 1) & 0xffff0000) |
210 			     (cs->mbus_attr << 8) |
211 			     (dram->mbus_dram_target_id << 4) | 1,
212 			     PCIE_WIN04_CTRL_OFF(i));
213 
214 		size += cs->size;
215 	}
216 
217 	/* Round up 'size' to the nearest power of two. */
218 	if ((size & (size - 1)) != 0)
219 		size = 1 << fls(size);
220 
221 	/* Setup BAR[1] to all DRAM banks. */
222 	mvebu_writel(port, dram->cs[0].base, PCIE_BAR_LO_OFF(1));
223 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1));
224 	mvebu_writel(port, ((size - 1) & 0xffff0000) | 1,
225 		     PCIE_BAR_CTRL_OFF(1));
226 
227 	/*
228 	 * Point BAR[0] to the device's internal registers.
229 	 */
230 	mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0));
231 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
232 }
233 
234 static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
235 {
236 	u32 ctrl, cmd, dev_rev, mask;
237 
238 	/* Setup PCIe controller to Root Complex mode. */
239 	ctrl = mvebu_readl(port, PCIE_CTRL_OFF);
240 	ctrl |= PCIE_CTRL_RC_MODE;
241 	mvebu_writel(port, ctrl, PCIE_CTRL_OFF);
242 
243 	/* Disable Root Bridge I/O space, memory space and bus mastering. */
244 	cmd = mvebu_readl(port, PCIE_CMD_OFF);
245 	cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
246 	mvebu_writel(port, cmd, PCIE_CMD_OFF);
247 
248 	/*
249 	 * Change Class Code of PCI Bridge device to PCI Bridge (0x6004)
250 	 * because default value is Memory controller (0x5080).
251 	 *
252 	 * Note that this mvebu PCI Bridge does not have compliant Type 1
253 	 * Configuration Space. Header Type is reported as Type 0 and it
254 	 * has format of Type 0 config space.
255 	 *
256 	 * Moreover Type 0 BAR registers (ranges 0x10 - 0x28 and 0x30 - 0x34)
257 	 * have the same format in Marvell's specification as in PCIe
258 	 * specification, but their meaning is totally different and they do
259 	 * different things: they are aliased into internal mvebu registers
260 	 * (e.g. PCIE_BAR_LO_OFF) and these should not be changed or
261 	 * reconfigured by pci device drivers.
262 	 *
263 	 * Therefore driver uses emulation of PCI Bridge which emulates
264 	 * access to configuration space via internal mvebu registers or
265 	 * emulated configuration buffer. Driver access these PCI Bridge
266 	 * directly for simplification, but these registers can be accessed
267 	 * also via standard mvebu way for accessing PCI config space.
268 	 */
269 	dev_rev = mvebu_readl(port, PCIE_DEV_REV_OFF);
270 	dev_rev &= ~0xffffff00;
271 	dev_rev |= (PCI_CLASS_BRIDGE_PCI << 8) << 8;
272 	mvebu_writel(port, dev_rev, PCIE_DEV_REV_OFF);
273 
274 	/* Point PCIe unit MBUS decode windows to DRAM space. */
275 	mvebu_pcie_setup_wins(port);
276 
277 	/* Enable interrupt lines A-D. */
278 	mask = mvebu_readl(port, PCIE_MASK_OFF);
279 	mask |= PCIE_MASK_ENABLE_INTS;
280 	mvebu_writel(port, mask, PCIE_MASK_OFF);
281 }
282 
283 static int mvebu_pcie_hw_rd_conf(struct mvebu_pcie_port *port,
284 				 struct pci_bus *bus,
285 				 u32 devfn, int where, int size, u32 *val)
286 {
287 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
288 
289 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
290 		     PCIE_CONF_ADDR_OFF);
291 
292 	switch (size) {
293 	case 1:
294 		*val = readb_relaxed(conf_data + (where & 3));
295 		break;
296 	case 2:
297 		*val = readw_relaxed(conf_data + (where & 2));
298 		break;
299 	case 4:
300 		*val = readl_relaxed(conf_data);
301 		break;
302 	default:
303 		*val = 0xffffffff;
304 		return PCIBIOS_BAD_REGISTER_NUMBER;
305 	}
306 
307 	return PCIBIOS_SUCCESSFUL;
308 }
309 
310 static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
311 				 struct pci_bus *bus,
312 				 u32 devfn, int where, int size, u32 val)
313 {
314 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
315 
316 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
317 		     PCIE_CONF_ADDR_OFF);
318 
319 	switch (size) {
320 	case 1:
321 		writeb(val, conf_data + (where & 3));
322 		break;
323 	case 2:
324 		writew(val, conf_data + (where & 2));
325 		break;
326 	case 4:
327 		writel(val, conf_data);
328 		break;
329 	default:
330 		return PCIBIOS_BAD_REGISTER_NUMBER;
331 	}
332 
333 	return PCIBIOS_SUCCESSFUL;
334 }
335 
336 /*
337  * Remove windows, starting from the largest ones to the smallest
338  * ones.
339  */
340 static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
341 				   phys_addr_t base, size_t size)
342 {
343 	while (size) {
344 		size_t sz = 1 << (fls(size) - 1);
345 
346 		mvebu_mbus_del_window(base, sz);
347 		base += sz;
348 		size -= sz;
349 	}
350 }
351 
352 /*
353  * MBus windows can only have a power of two size, but PCI BARs do not
354  * have this constraint. Therefore, we have to split the PCI BAR into
355  * areas each having a power of two size. We start from the largest
356  * one (i.e highest order bit set in the size).
357  */
358 static int mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
359 				   unsigned int target, unsigned int attribute,
360 				   phys_addr_t base, size_t size,
361 				   phys_addr_t remap)
362 {
363 	size_t size_mapped = 0;
364 
365 	while (size) {
366 		size_t sz = 1 << (fls(size) - 1);
367 		int ret;
368 
369 		ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
370 							sz, remap);
371 		if (ret) {
372 			phys_addr_t end = base + sz - 1;
373 
374 			dev_err(&port->pcie->pdev->dev,
375 				"Could not create MBus window at [mem %pa-%pa]: %d\n",
376 				&base, &end, ret);
377 			mvebu_pcie_del_windows(port, base - size_mapped,
378 					       size_mapped);
379 			return ret;
380 		}
381 
382 		size -= sz;
383 		size_mapped += sz;
384 		base += sz;
385 		if (remap != MVEBU_MBUS_NO_REMAP)
386 			remap += sz;
387 	}
388 
389 	return 0;
390 }
391 
392 static int mvebu_pcie_set_window(struct mvebu_pcie_port *port,
393 				  unsigned int target, unsigned int attribute,
394 				  const struct mvebu_pcie_window *desired,
395 				  struct mvebu_pcie_window *cur)
396 {
397 	int ret;
398 
399 	if (desired->base == cur->base && desired->remap == cur->remap &&
400 	    desired->size == cur->size)
401 		return 0;
402 
403 	if (cur->size != 0) {
404 		mvebu_pcie_del_windows(port, cur->base, cur->size);
405 		cur->size = 0;
406 		cur->base = 0;
407 
408 		/*
409 		 * If something tries to change the window while it is enabled
410 		 * the change will not be done atomically. That would be
411 		 * difficult to do in the general case.
412 		 */
413 	}
414 
415 	if (desired->size == 0)
416 		return 0;
417 
418 	ret = mvebu_pcie_add_windows(port, target, attribute, desired->base,
419 				     desired->size, desired->remap);
420 	if (ret) {
421 		cur->size = 0;
422 		cur->base = 0;
423 		return ret;
424 	}
425 
426 	*cur = *desired;
427 	return 0;
428 }
429 
430 static int mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
431 {
432 	struct mvebu_pcie_window desired = {};
433 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
434 
435 	/* Are the new iobase/iolimit values invalid? */
436 	if (conf->iolimit < conf->iobase ||
437 	    conf->iolimitupper < conf->iobaseupper)
438 		return mvebu_pcie_set_window(port, port->io_target, port->io_attr,
439 					     &desired, &port->iowin);
440 
441 	if (!mvebu_has_ioport(port)) {
442 		dev_WARN(&port->pcie->pdev->dev,
443 			 "Attempt to set IO when IO is disabled\n");
444 		return -EOPNOTSUPP;
445 	}
446 
447 	/*
448 	 * We read the PCI-to-PCI bridge emulated registers, and
449 	 * calculate the base address and size of the address decoding
450 	 * window to setup, according to the PCI-to-PCI bridge
451 	 * specifications. iobase is the bus address, port->iowin_base
452 	 * is the CPU address.
453 	 */
454 	desired.remap = ((conf->iobase & 0xF0) << 8) |
455 			(conf->iobaseupper << 16);
456 	desired.base = port->pcie->io.start + desired.remap;
457 	desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
458 			 (conf->iolimitupper << 16)) -
459 			desired.remap) +
460 		       1;
461 
462 	return mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
463 				     &port->iowin);
464 }
465 
466 static int mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
467 {
468 	struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
469 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
470 
471 	/* Are the new membase/memlimit values invalid? */
472 	if (conf->memlimit < conf->membase)
473 		return mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
474 					     &desired, &port->memwin);
475 
476 	/*
477 	 * We read the PCI-to-PCI bridge emulated registers, and
478 	 * calculate the base address and size of the address decoding
479 	 * window to setup, according to the PCI-to-PCI bridge
480 	 * specifications.
481 	 */
482 	desired.base = ((conf->membase & 0xFFF0) << 16);
483 	desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
484 		       desired.base + 1;
485 
486 	return mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
487 				     &port->memwin);
488 }
489 
490 static pci_bridge_emul_read_status_t
491 mvebu_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge,
492 				     int reg, u32 *value)
493 {
494 	struct mvebu_pcie_port *port = bridge->data;
495 
496 	switch (reg) {
497 	case PCI_COMMAND:
498 		*value = mvebu_readl(port, PCIE_CMD_OFF);
499 		break;
500 
501 	case PCI_PRIMARY_BUS: {
502 		/*
503 		 * From the whole 32bit register we support reading from HW only
504 		 * secondary bus number which is mvebu local bus number.
505 		 * Other bits are retrieved only from emulated config buffer.
506 		 */
507 		__le32 *cfgspace = (__le32 *)&bridge->conf;
508 		u32 val = le32_to_cpu(cfgspace[PCI_PRIMARY_BUS / 4]);
509 		val &= ~0xff00;
510 		val |= mvebu_pcie_get_local_bus_nr(port) << 8;
511 		*value = val;
512 		break;
513 	}
514 
515 	case PCI_INTERRUPT_LINE: {
516 		/*
517 		 * From the whole 32bit register we support reading from HW only
518 		 * one bit: PCI_BRIDGE_CTL_BUS_RESET.
519 		 * Other bits are retrieved only from emulated config buffer.
520 		 */
521 		__le32 *cfgspace = (__le32 *)&bridge->conf;
522 		u32 val = le32_to_cpu(cfgspace[PCI_INTERRUPT_LINE / 4]);
523 		if (mvebu_readl(port, PCIE_CTRL_OFF) & PCIE_CTRL_MASTER_HOT_RESET)
524 			val |= PCI_BRIDGE_CTL_BUS_RESET << 16;
525 		else
526 			val &= ~(PCI_BRIDGE_CTL_BUS_RESET << 16);
527 		*value = val;
528 		break;
529 	}
530 
531 	default:
532 		return PCI_BRIDGE_EMUL_NOT_HANDLED;
533 	}
534 
535 	return PCI_BRIDGE_EMUL_HANDLED;
536 }
537 
538 static pci_bridge_emul_read_status_t
539 mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
540 				     int reg, u32 *value)
541 {
542 	struct mvebu_pcie_port *port = bridge->data;
543 
544 	switch (reg) {
545 	case PCI_EXP_DEVCAP:
546 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
547 		break;
548 
549 	case PCI_EXP_DEVCTL:
550 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
551 		break;
552 
553 	case PCI_EXP_LNKCAP:
554 		/*
555 		 * PCIe requires the clock power management capability to be
556 		 * hard-wired to zero for downstream ports
557 		 */
558 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
559 			 ~PCI_EXP_LNKCAP_CLKPM;
560 		break;
561 
562 	case PCI_EXP_LNKCTL:
563 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
564 		break;
565 
566 	case PCI_EXP_SLTCTL:
567 		*value = PCI_EXP_SLTSTA_PDS << 16;
568 		break;
569 
570 	case PCI_EXP_RTSTA:
571 		*value = mvebu_readl(port, PCIE_RC_RTSTA);
572 		break;
573 
574 	case PCI_EXP_DEVCAP2:
575 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP2);
576 		break;
577 
578 	case PCI_EXP_DEVCTL2:
579 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
580 		break;
581 
582 	case PCI_EXP_LNKCTL2:
583 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
584 		break;
585 
586 	default:
587 		return PCI_BRIDGE_EMUL_NOT_HANDLED;
588 	}
589 
590 	return PCI_BRIDGE_EMUL_HANDLED;
591 }
592 
593 static void
594 mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
595 				      int reg, u32 old, u32 new, u32 mask)
596 {
597 	struct mvebu_pcie_port *port = bridge->data;
598 	struct pci_bridge_emul_conf *conf = &bridge->conf;
599 
600 	switch (reg) {
601 	case PCI_COMMAND:
602 		if (!mvebu_has_ioport(port)) {
603 			conf->command = cpu_to_le16(
604 				le16_to_cpu(conf->command) & ~PCI_COMMAND_IO);
605 			new &= ~PCI_COMMAND_IO;
606 		}
607 
608 		mvebu_writel(port, new, PCIE_CMD_OFF);
609 		break;
610 
611 	case PCI_IO_BASE:
612 		if ((mask & 0xffff) && mvebu_pcie_handle_iobase_change(port)) {
613 			/* On error disable IO range */
614 			conf->iobase &= ~0xf0;
615 			conf->iolimit &= ~0xf0;
616 			conf->iobaseupper = cpu_to_le16(0x0000);
617 			conf->iolimitupper = cpu_to_le16(0x0000);
618 			if (mvebu_has_ioport(port))
619 				conf->iobase |= 0xf0;
620 		}
621 		break;
622 
623 	case PCI_MEMORY_BASE:
624 		if (mvebu_pcie_handle_membase_change(port)) {
625 			/* On error disable mem range */
626 			conf->membase = cpu_to_le16(le16_to_cpu(conf->membase) & ~0xfff0);
627 			conf->memlimit = cpu_to_le16(le16_to_cpu(conf->memlimit) & ~0xfff0);
628 			conf->membase = cpu_to_le16(le16_to_cpu(conf->membase) | 0xfff0);
629 		}
630 		break;
631 
632 	case PCI_IO_BASE_UPPER16:
633 		if (mvebu_pcie_handle_iobase_change(port)) {
634 			/* On error disable IO range */
635 			conf->iobase &= ~0xf0;
636 			conf->iolimit &= ~0xf0;
637 			conf->iobaseupper = cpu_to_le16(0x0000);
638 			conf->iolimitupper = cpu_to_le16(0x0000);
639 			if (mvebu_has_ioport(port))
640 				conf->iobase |= 0xf0;
641 		}
642 		break;
643 
644 	case PCI_PRIMARY_BUS:
645 		if (mask & 0xff00)
646 			mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
647 		break;
648 
649 	case PCI_INTERRUPT_LINE:
650 		if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) {
651 			u32 ctrl = mvebu_readl(port, PCIE_CTRL_OFF);
652 			if (new & (PCI_BRIDGE_CTL_BUS_RESET << 16))
653 				ctrl |= PCIE_CTRL_MASTER_HOT_RESET;
654 			else
655 				ctrl &= ~PCIE_CTRL_MASTER_HOT_RESET;
656 			mvebu_writel(port, ctrl, PCIE_CTRL_OFF);
657 		}
658 		break;
659 
660 	default:
661 		break;
662 	}
663 }
664 
665 static void
666 mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
667 				      int reg, u32 old, u32 new, u32 mask)
668 {
669 	struct mvebu_pcie_port *port = bridge->data;
670 
671 	switch (reg) {
672 	case PCI_EXP_DEVCTL:
673 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
674 		break;
675 
676 	case PCI_EXP_LNKCTL:
677 		/*
678 		 * If we don't support CLKREQ, we must ensure that the
679 		 * CLKREQ enable bit always reads zero.  Since we haven't
680 		 * had this capability, and it's dependent on board wiring,
681 		 * disable it for the time being.
682 		 */
683 		new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
684 
685 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
686 		break;
687 
688 	case PCI_EXP_RTSTA:
689 		/*
690 		 * PME Status bit in Root Status Register (PCIE_RC_RTSTA)
691 		 * is read-only and can be cleared only by writing 0b to the
692 		 * Interrupt Cause RW0C register (PCIE_INT_CAUSE_OFF). So
693 		 * clear PME via Interrupt Cause.
694 		 */
695 		if (new & PCI_EXP_RTSTA_PME)
696 			mvebu_writel(port, ~PCIE_INT_PM_PME, PCIE_INT_CAUSE_OFF);
697 		break;
698 
699 	case PCI_EXP_DEVCTL2:
700 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
701 		break;
702 
703 	case PCI_EXP_LNKCTL2:
704 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
705 		break;
706 
707 	default:
708 		break;
709 	}
710 }
711 
712 static struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
713 	.read_base = mvebu_pci_bridge_emul_base_conf_read,
714 	.write_base = mvebu_pci_bridge_emul_base_conf_write,
715 	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
716 	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
717 };
718 
719 /*
720  * Initialize the configuration space of the PCI-to-PCI bridge
721  * associated with the given PCIe interface.
722  */
723 static int mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
724 {
725 	struct pci_bridge_emul *bridge = &port->bridge;
726 	u32 pcie_cap = mvebu_readl(port, PCIE_CAP_PCIEXP);
727 	u8 pcie_cap_ver = ((pcie_cap >> 16) & PCI_EXP_FLAGS_VERS);
728 
729 	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
730 	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
731 	bridge->conf.class_revision =
732 		mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
733 
734 	if (mvebu_has_ioport(port)) {
735 		/* We support 32 bits I/O addressing */
736 		bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
737 		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
738 	}
739 
740 	/*
741 	 * Older mvebu hardware provides PCIe Capability structure only in
742 	 * version 1. New hardware provides it in version 2.
743 	 */
744 	bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver);
745 
746 	bridge->has_pcie = true;
747 	bridge->data = port;
748 	bridge->ops = &mvebu_pci_bridge_emul_ops;
749 
750 	return pci_bridge_emul_init(bridge, PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR);
751 }
752 
753 static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
754 {
755 	return sys->private_data;
756 }
757 
758 static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
759 						    struct pci_bus *bus,
760 						    int devfn)
761 {
762 	int i;
763 
764 	for (i = 0; i < pcie->nports; i++) {
765 		struct mvebu_pcie_port *port = &pcie->ports[i];
766 
767 		if (!port->base)
768 			continue;
769 
770 		if (bus->number == 0 && port->devfn == devfn)
771 			return port;
772 		if (bus->number != 0 &&
773 		    bus->number >= port->bridge.conf.secondary_bus &&
774 		    bus->number <= port->bridge.conf.subordinate_bus)
775 			return port;
776 	}
777 
778 	return NULL;
779 }
780 
781 /* PCI configuration space write function */
782 static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
783 			      int where, int size, u32 val)
784 {
785 	struct mvebu_pcie *pcie = bus->sysdata;
786 	struct mvebu_pcie_port *port;
787 	int ret;
788 
789 	port = mvebu_pcie_find_port(pcie, bus, devfn);
790 	if (!port)
791 		return PCIBIOS_DEVICE_NOT_FOUND;
792 
793 	/* Access the emulated PCI-to-PCI bridge */
794 	if (bus->number == 0)
795 		return pci_bridge_emul_conf_write(&port->bridge, where,
796 						  size, val);
797 
798 	if (!mvebu_pcie_link_up(port))
799 		return PCIBIOS_DEVICE_NOT_FOUND;
800 
801 	/* Access the real PCIe interface */
802 	ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
803 				    where, size, val);
804 
805 	return ret;
806 }
807 
808 /* PCI configuration space read function */
809 static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
810 			      int size, u32 *val)
811 {
812 	struct mvebu_pcie *pcie = bus->sysdata;
813 	struct mvebu_pcie_port *port;
814 	int ret;
815 
816 	port = mvebu_pcie_find_port(pcie, bus, devfn);
817 	if (!port)
818 		return PCIBIOS_DEVICE_NOT_FOUND;
819 
820 	/* Access the emulated PCI-to-PCI bridge */
821 	if (bus->number == 0)
822 		return pci_bridge_emul_conf_read(&port->bridge, where,
823 						 size, val);
824 
825 	if (!mvebu_pcie_link_up(port))
826 		return PCIBIOS_DEVICE_NOT_FOUND;
827 
828 	/* Access the real PCIe interface */
829 	ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
830 				    where, size, val);
831 
832 	return ret;
833 }
834 
835 static struct pci_ops mvebu_pcie_ops = {
836 	.read = mvebu_pcie_rd_conf,
837 	.write = mvebu_pcie_wr_conf,
838 };
839 
840 static int mvebu_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
841 {
842 	/* Interrupt support on mvebu emulated bridges is not implemented yet */
843 	if (dev->bus->number == 0)
844 		return 0; /* Proper return code 0 == NO_IRQ */
845 
846 	return of_irq_parse_and_map_pci(dev, slot, pin);
847 }
848 
849 static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
850 						 const struct resource *res,
851 						 resource_size_t start,
852 						 resource_size_t size,
853 						 resource_size_t align)
854 {
855 	if (dev->bus->number != 0)
856 		return start;
857 
858 	/*
859 	 * On the PCI-to-PCI bridge side, the I/O windows must have at
860 	 * least a 64 KB size and the memory windows must have at
861 	 * least a 1 MB size. Moreover, MBus windows need to have a
862 	 * base address aligned on their size, and their size must be
863 	 * a power of two. This means that if the BAR doesn't have a
864 	 * power of two size, several MBus windows will actually be
865 	 * created. We need to ensure that the biggest MBus window
866 	 * (which will be the first one) is aligned on its size, which
867 	 * explains the rounddown_pow_of_two() being done here.
868 	 */
869 	if (res->flags & IORESOURCE_IO)
870 		return round_up(start, max_t(resource_size_t, SZ_64K,
871 					     rounddown_pow_of_two(size)));
872 	else if (res->flags & IORESOURCE_MEM)
873 		return round_up(start, max_t(resource_size_t, SZ_1M,
874 					     rounddown_pow_of_two(size)));
875 	else
876 		return start;
877 }
878 
879 static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
880 					      struct device_node *np,
881 					      struct mvebu_pcie_port *port)
882 {
883 	int ret = 0;
884 
885 	ret = of_address_to_resource(np, 0, &port->regs);
886 	if (ret)
887 		return (void __iomem *)ERR_PTR(ret);
888 
889 	return devm_ioremap_resource(&pdev->dev, &port->regs);
890 }
891 
892 #define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
893 #define    DT_TYPE_IO                 0x1
894 #define    DT_TYPE_MEM32              0x2
895 #define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
896 #define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)
897 
898 static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
899 			      unsigned long type,
900 			      unsigned int *tgt,
901 			      unsigned int *attr)
902 {
903 	const int na = 3, ns = 2;
904 	const __be32 *range;
905 	int rlen, nranges, rangesz, pna, i;
906 
907 	*tgt = -1;
908 	*attr = -1;
909 
910 	range = of_get_property(np, "ranges", &rlen);
911 	if (!range)
912 		return -EINVAL;
913 
914 	pna = of_n_addr_cells(np);
915 	rangesz = pna + na + ns;
916 	nranges = rlen / sizeof(__be32) / rangesz;
917 
918 	for (i = 0; i < nranges; i++, range += rangesz) {
919 		u32 flags = of_read_number(range, 1);
920 		u32 slot = of_read_number(range + 1, 1);
921 		u64 cpuaddr = of_read_number(range + na, pna);
922 		unsigned long rtype;
923 
924 		if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
925 			rtype = IORESOURCE_IO;
926 		else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
927 			rtype = IORESOURCE_MEM;
928 		else
929 			continue;
930 
931 		if (slot == PCI_SLOT(devfn) && type == rtype) {
932 			*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
933 			*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
934 			return 0;
935 		}
936 	}
937 
938 	return -ENOENT;
939 }
940 
941 #ifdef CONFIG_PM_SLEEP
942 static int mvebu_pcie_suspend(struct device *dev)
943 {
944 	struct mvebu_pcie *pcie;
945 	int i;
946 
947 	pcie = dev_get_drvdata(dev);
948 	for (i = 0; i < pcie->nports; i++) {
949 		struct mvebu_pcie_port *port = pcie->ports + i;
950 		if (!port->base)
951 			continue;
952 		port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
953 	}
954 
955 	return 0;
956 }
957 
958 static int mvebu_pcie_resume(struct device *dev)
959 {
960 	struct mvebu_pcie *pcie;
961 	int i;
962 
963 	pcie = dev_get_drvdata(dev);
964 	for (i = 0; i < pcie->nports; i++) {
965 		struct mvebu_pcie_port *port = pcie->ports + i;
966 		if (!port->base)
967 			continue;
968 		mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
969 		mvebu_pcie_setup_hw(port);
970 	}
971 
972 	return 0;
973 }
974 #endif
975 
976 static void mvebu_pcie_port_clk_put(void *data)
977 {
978 	struct mvebu_pcie_port *port = data;
979 
980 	clk_put(port->clk);
981 }
982 
983 static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
984 	struct mvebu_pcie_port *port, struct device_node *child)
985 {
986 	struct device *dev = &pcie->pdev->dev;
987 	enum of_gpio_flags flags;
988 	int reset_gpio, ret;
989 
990 	port->pcie = pcie;
991 
992 	if (of_property_read_u32(child, "marvell,pcie-port", &port->port)) {
993 		dev_warn(dev, "ignoring %pOF, missing pcie-port property\n",
994 			 child);
995 		goto skip;
996 	}
997 
998 	if (of_property_read_u32(child, "marvell,pcie-lane", &port->lane))
999 		port->lane = 0;
1000 
1001 	port->name = devm_kasprintf(dev, GFP_KERNEL, "pcie%d.%d", port->port,
1002 				    port->lane);
1003 	if (!port->name) {
1004 		ret = -ENOMEM;
1005 		goto err;
1006 	}
1007 
1008 	port->devfn = of_pci_get_devfn(child);
1009 	if (port->devfn < 0)
1010 		goto skip;
1011 	if (PCI_FUNC(port->devfn) != 0) {
1012 		dev_err(dev, "%s: invalid function number, must be zero\n",
1013 			port->name);
1014 		goto skip;
1015 	}
1016 
1017 	ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM,
1018 				 &port->mem_target, &port->mem_attr);
1019 	if (ret < 0) {
1020 		dev_err(dev, "%s: cannot get tgt/attr for mem window\n",
1021 			port->name);
1022 		goto skip;
1023 	}
1024 
1025 	if (resource_size(&pcie->io) != 0) {
1026 		mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_IO,
1027 				   &port->io_target, &port->io_attr);
1028 	} else {
1029 		port->io_target = -1;
1030 		port->io_attr = -1;
1031 	}
1032 
1033 	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
1034 	if (reset_gpio == -EPROBE_DEFER) {
1035 		ret = reset_gpio;
1036 		goto err;
1037 	}
1038 
1039 	if (gpio_is_valid(reset_gpio)) {
1040 		unsigned long gpio_flags;
1041 
1042 		port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
1043 						  port->name);
1044 		if (!port->reset_name) {
1045 			ret = -ENOMEM;
1046 			goto err;
1047 		}
1048 
1049 		if (flags & OF_GPIO_ACTIVE_LOW) {
1050 			dev_info(dev, "%pOF: reset gpio is active low\n",
1051 				 child);
1052 			gpio_flags = GPIOF_ACTIVE_LOW |
1053 				     GPIOF_OUT_INIT_LOW;
1054 		} else {
1055 			gpio_flags = GPIOF_OUT_INIT_HIGH;
1056 		}
1057 
1058 		ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
1059 					    port->reset_name);
1060 		if (ret) {
1061 			if (ret == -EPROBE_DEFER)
1062 				goto err;
1063 			goto skip;
1064 		}
1065 
1066 		port->reset_gpio = gpio_to_desc(reset_gpio);
1067 	}
1068 
1069 	port->clk = of_clk_get_by_name(child, NULL);
1070 	if (IS_ERR(port->clk)) {
1071 		dev_err(dev, "%s: cannot get clock\n", port->name);
1072 		goto skip;
1073 	}
1074 
1075 	ret = devm_add_action(dev, mvebu_pcie_port_clk_put, port);
1076 	if (ret < 0) {
1077 		clk_put(port->clk);
1078 		goto err;
1079 	}
1080 
1081 	return 1;
1082 
1083 skip:
1084 	ret = 0;
1085 
1086 	/* In the case of skipping, we need to free these */
1087 	devm_kfree(dev, port->reset_name);
1088 	port->reset_name = NULL;
1089 	devm_kfree(dev, port->name);
1090 	port->name = NULL;
1091 
1092 err:
1093 	return ret;
1094 }
1095 
1096 /*
1097  * Power up a PCIe port.  PCIe requires the refclk to be stable for 100µs
1098  * prior to releasing PERST.  See table 2-4 in section 2.6.2 AC Specifications
1099  * of the PCI Express Card Electromechanical Specification, 1.1.
1100  */
1101 static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
1102 {
1103 	int ret;
1104 
1105 	ret = clk_prepare_enable(port->clk);
1106 	if (ret < 0)
1107 		return ret;
1108 
1109 	if (port->reset_gpio) {
1110 		u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
1111 
1112 		of_property_read_u32(port->dn, "reset-delay-us",
1113 				     &reset_udelay);
1114 
1115 		udelay(100);
1116 
1117 		gpiod_set_value_cansleep(port->reset_gpio, 0);
1118 		msleep(reset_udelay / 1000);
1119 	}
1120 
1121 	return 0;
1122 }
1123 
1124 /*
1125  * Power down a PCIe port.  Strictly, PCIe requires us to place the card
1126  * in D3hot state before asserting PERST#.
1127  */
1128 static void mvebu_pcie_powerdown(struct mvebu_pcie_port *port)
1129 {
1130 	gpiod_set_value_cansleep(port->reset_gpio, 1);
1131 
1132 	clk_disable_unprepare(port->clk);
1133 }
1134 
1135 /*
1136  * devm_of_pci_get_host_bridge_resources() only sets up translateable resources,
1137  * so we need extra resource setup parsing our special DT properties encoding
1138  * the MEM and IO apertures.
1139  */
1140 static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
1141 {
1142 	struct device *dev = &pcie->pdev->dev;
1143 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
1144 	int ret;
1145 
1146 	/* Get the PCIe memory aperture */
1147 	mvebu_mbus_get_pcie_mem_aperture(&pcie->mem);
1148 	if (resource_size(&pcie->mem) == 0) {
1149 		dev_err(dev, "invalid memory aperture size\n");
1150 		return -EINVAL;
1151 	}
1152 
1153 	pcie->mem.name = "PCI MEM";
1154 	pci_add_resource(&bridge->windows, &pcie->mem);
1155 	ret = devm_request_resource(dev, &iomem_resource, &pcie->mem);
1156 	if (ret)
1157 		return ret;
1158 
1159 	/* Get the PCIe IO aperture */
1160 	mvebu_mbus_get_pcie_io_aperture(&pcie->io);
1161 
1162 	if (resource_size(&pcie->io) != 0) {
1163 		pcie->realio.flags = pcie->io.flags;
1164 		pcie->realio.start = PCIBIOS_MIN_IO;
1165 		pcie->realio.end = min_t(resource_size_t,
1166 					 IO_SPACE_LIMIT - SZ_64K,
1167 					 resource_size(&pcie->io) - 1);
1168 		pcie->realio.name = "PCI I/O";
1169 
1170 		ret = devm_pci_remap_iospace(dev, &pcie->realio, pcie->io.start);
1171 		if (ret)
1172 			return ret;
1173 
1174 		pci_add_resource(&bridge->windows, &pcie->realio);
1175 		ret = devm_request_resource(dev, &ioport_resource, &pcie->realio);
1176 		if (ret)
1177 			return ret;
1178 	}
1179 
1180 	return 0;
1181 }
1182 
1183 static int mvebu_pcie_probe(struct platform_device *pdev)
1184 {
1185 	struct device *dev = &pdev->dev;
1186 	struct mvebu_pcie *pcie;
1187 	struct pci_host_bridge *bridge;
1188 	struct device_node *np = dev->of_node;
1189 	struct device_node *child;
1190 	int num, i, ret;
1191 
1192 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct mvebu_pcie));
1193 	if (!bridge)
1194 		return -ENOMEM;
1195 
1196 	pcie = pci_host_bridge_priv(bridge);
1197 	pcie->pdev = pdev;
1198 	platform_set_drvdata(pdev, pcie);
1199 
1200 	ret = mvebu_pcie_parse_request_resources(pcie);
1201 	if (ret)
1202 		return ret;
1203 
1204 	num = of_get_available_child_count(np);
1205 
1206 	pcie->ports = devm_kcalloc(dev, num, sizeof(*pcie->ports), GFP_KERNEL);
1207 	if (!pcie->ports)
1208 		return -ENOMEM;
1209 
1210 	i = 0;
1211 	for_each_available_child_of_node(np, child) {
1212 		struct mvebu_pcie_port *port = &pcie->ports[i];
1213 
1214 		ret = mvebu_pcie_parse_port(pcie, port, child);
1215 		if (ret < 0) {
1216 			of_node_put(child);
1217 			return ret;
1218 		} else if (ret == 0) {
1219 			continue;
1220 		}
1221 
1222 		port->dn = child;
1223 		i++;
1224 	}
1225 	pcie->nports = i;
1226 
1227 	for (i = 0; i < pcie->nports; i++) {
1228 		struct mvebu_pcie_port *port = &pcie->ports[i];
1229 
1230 		child = port->dn;
1231 		if (!child)
1232 			continue;
1233 
1234 		ret = mvebu_pcie_powerup(port);
1235 		if (ret < 0)
1236 			continue;
1237 
1238 		port->base = mvebu_pcie_map_registers(pdev, child, port);
1239 		if (IS_ERR(port->base)) {
1240 			dev_err(dev, "%s: cannot map registers\n", port->name);
1241 			port->base = NULL;
1242 			mvebu_pcie_powerdown(port);
1243 			continue;
1244 		}
1245 
1246 		ret = mvebu_pci_bridge_emul_init(port);
1247 		if (ret < 0) {
1248 			dev_err(dev, "%s: cannot init emulated bridge\n",
1249 				port->name);
1250 			devm_iounmap(dev, port->base);
1251 			port->base = NULL;
1252 			mvebu_pcie_powerdown(port);
1253 			continue;
1254 		}
1255 
1256 		/*
1257 		 * PCIe topology exported by mvebu hw is quite complicated. In
1258 		 * reality has something like N fully independent host bridges
1259 		 * where each host bridge has one PCIe Root Port (which acts as
1260 		 * PCI Bridge device). Each host bridge has its own independent
1261 		 * internal registers, independent access to PCI config space,
1262 		 * independent interrupt lines, independent window and memory
1263 		 * access configuration. But additionally there is some kind of
1264 		 * peer-to-peer support between PCIe devices behind different
1265 		 * host bridges limited just to forwarding of memory and I/O
1266 		 * transactions (forwarding of error messages and config cycles
1267 		 * is not supported). So we could say there are N independent
1268 		 * PCIe Root Complexes.
1269 		 *
1270 		 * For this kind of setup DT should have been structured into
1271 		 * N independent PCIe controllers / host bridges. But instead
1272 		 * structure in past was defined to put PCIe Root Ports of all
1273 		 * host bridges into one bus zero, like in classic multi-port
1274 		 * Root Complex setup with just one host bridge.
1275 		 *
1276 		 * This means that pci-mvebu.c driver provides "virtual" bus 0
1277 		 * on which registers all PCIe Root Ports (PCI Bridge devices)
1278 		 * specified in DT by their BDF addresses and virtually routes
1279 		 * PCI config access of each PCI bridge device to specific PCIe
1280 		 * host bridge.
1281 		 *
1282 		 * Normally PCI Bridge should choose between Type 0 and Type 1
1283 		 * config requests based on primary and secondary bus numbers
1284 		 * configured on the bridge itself. But because mvebu PCI Bridge
1285 		 * does not have registers for primary and secondary bus numbers
1286 		 * in its config space, it determinates type of config requests
1287 		 * via its own custom way.
1288 		 *
1289 		 * There are two options how mvebu determinate type of config
1290 		 * request.
1291 		 *
1292 		 * 1. If Secondary Bus Number Enable bit is not set or is not
1293 		 * available (applies for pre-XP PCIe controllers) then Type 0
1294 		 * is used if target bus number equals Local Bus Number (bits
1295 		 * [15:8] in register 0x1a04) and target device number differs
1296 		 * from Local Device Number (bits [20:16] in register 0x1a04).
1297 		 * Type 1 is used if target bus number differs from Local Bus
1298 		 * Number. And when target bus number equals Local Bus Number
1299 		 * and target device equals Local Device Number then request is
1300 		 * routed to Local PCI Bridge (PCIe Root Port).
1301 		 *
1302 		 * 2. If Secondary Bus Number Enable bit is set (bit 7 in
1303 		 * register 0x1a2c) then mvebu hw determinate type of config
1304 		 * request like compliant PCI Bridge based on primary bus number
1305 		 * which is configured via Local Bus Number (bits [15:8] in
1306 		 * register 0x1a04) and secondary bus number which is configured
1307 		 * via Secondary Bus Number (bits [7:0] in register 0x1a2c).
1308 		 * Local PCI Bridge (PCIe Root Port) is available on primary bus
1309 		 * as device with Local Device Number (bits [20:16] in register
1310 		 * 0x1a04).
1311 		 *
1312 		 * Secondary Bus Number Enable bit is disabled by default and
1313 		 * option 2. is not available on pre-XP PCIe controllers. Hence
1314 		 * this driver always use option 1.
1315 		 *
1316 		 * Basically it means that primary and secondary buses shares
1317 		 * one virtual number configured via Local Bus Number bits and
1318 		 * Local Device Number bits determinates if accessing primary
1319 		 * or secondary bus. Set Local Device Number to 1 and redirect
1320 		 * all writes of PCI Bridge Secondary Bus Number register to
1321 		 * Local Bus Number (bits [15:8] in register 0x1a04).
1322 		 *
1323 		 * So when accessing devices on buses behind secondary bus
1324 		 * number it would work correctly. And also when accessing
1325 		 * device 0 at secondary bus number via config space would be
1326 		 * correctly routed to secondary bus. Due to issues described
1327 		 * in mvebu_pcie_setup_hw(), PCI Bridges at primary bus (zero)
1328 		 * are not accessed directly via PCI config space but rarher
1329 		 * indirectly via kernel emulated PCI bridge driver.
1330 		 */
1331 		mvebu_pcie_setup_hw(port);
1332 		mvebu_pcie_set_local_dev_nr(port, 0);
1333 	}
1334 
1335 	pcie->nports = i;
1336 
1337 	bridge->sysdata = pcie;
1338 	bridge->ops = &mvebu_pcie_ops;
1339 	bridge->align_resource = mvebu_pcie_align_resource;
1340 	bridge->map_irq = mvebu_pcie_map_irq;
1341 
1342 	return pci_host_probe(bridge);
1343 }
1344 
1345 static int mvebu_pcie_remove(struct platform_device *pdev)
1346 {
1347 	struct mvebu_pcie *pcie = platform_get_drvdata(pdev);
1348 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
1349 	u32 cmd;
1350 	int i;
1351 
1352 	/* Remove PCI bus with all devices. */
1353 	pci_lock_rescan_remove();
1354 	pci_stop_root_bus(bridge->bus);
1355 	pci_remove_root_bus(bridge->bus);
1356 	pci_unlock_rescan_remove();
1357 
1358 	for (i = 0; i < pcie->nports; i++) {
1359 		struct mvebu_pcie_port *port = &pcie->ports[i];
1360 
1361 		if (!port->base)
1362 			continue;
1363 
1364 		/* Disable Root Bridge I/O space, memory space and bus mastering. */
1365 		cmd = mvebu_readl(port, PCIE_CMD_OFF);
1366 		cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
1367 		mvebu_writel(port, cmd, PCIE_CMD_OFF);
1368 
1369 		/* Mask all interrupt sources. */
1370 		mvebu_writel(port, 0, PCIE_MASK_OFF);
1371 
1372 		/* Free config space for emulated root bridge. */
1373 		pci_bridge_emul_cleanup(&port->bridge);
1374 
1375 		/* Disable and clear BARs and windows. */
1376 		mvebu_pcie_disable_wins(port);
1377 
1378 		/* Delete PCIe IO and MEM windows. */
1379 		if (port->iowin.size)
1380 			mvebu_pcie_del_windows(port, port->iowin.base, port->iowin.size);
1381 		if (port->memwin.size)
1382 			mvebu_pcie_del_windows(port, port->memwin.base, port->memwin.size);
1383 
1384 		/* Power down card and disable clocks. Must be the last step. */
1385 		mvebu_pcie_powerdown(port);
1386 	}
1387 
1388 	return 0;
1389 }
1390 
1391 static const struct of_device_id mvebu_pcie_of_match_table[] = {
1392 	{ .compatible = "marvell,armada-xp-pcie", },
1393 	{ .compatible = "marvell,armada-370-pcie", },
1394 	{ .compatible = "marvell,dove-pcie", },
1395 	{ .compatible = "marvell,kirkwood-pcie", },
1396 	{},
1397 };
1398 
1399 static const struct dev_pm_ops mvebu_pcie_pm_ops = {
1400 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_pcie_suspend, mvebu_pcie_resume)
1401 };
1402 
1403 static struct platform_driver mvebu_pcie_driver = {
1404 	.driver = {
1405 		.name = "mvebu-pcie",
1406 		.of_match_table = mvebu_pcie_of_match_table,
1407 		.pm = &mvebu_pcie_pm_ops,
1408 	},
1409 	.probe = mvebu_pcie_probe,
1410 	.remove = mvebu_pcie_remove,
1411 };
1412 module_platform_driver(mvebu_pcie_driver);
1413 
1414 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@bootlin.com>");
1415 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
1416 MODULE_DESCRIPTION("Marvell EBU PCIe controller");
1417 MODULE_LICENSE("GPL v2");
1418