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/msi.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_MASK_OFF		0x1910
56 #define  PCIE_MASK_ENABLE_INTS          0x0f000000
57 #define PCIE_CTRL_OFF		0x1a00
58 #define  PCIE_CTRL_X1_MODE		0x0001
59 #define PCIE_STAT_OFF		0x1a04
60 #define  PCIE_STAT_BUS                  0xff00
61 #define  PCIE_STAT_DEV                  0x1f0000
62 #define  PCIE_STAT_LINK_DOWN		BIT(0)
63 #define PCIE_RC_RTSTA		0x1a14
64 #define PCIE_DEBUG_CTRL         0x1a60
65 #define  PCIE_DEBUG_SOFT_RESET		BIT(20)
66 
67 struct mvebu_pcie_port;
68 
69 /* Structure representing all PCIe interfaces */
70 struct mvebu_pcie {
71 	struct platform_device *pdev;
72 	struct mvebu_pcie_port *ports;
73 	struct msi_controller *msi;
74 	struct resource io;
75 	struct resource realio;
76 	struct resource mem;
77 	struct resource busn;
78 	int nports;
79 };
80 
81 struct mvebu_pcie_window {
82 	phys_addr_t base;
83 	phys_addr_t remap;
84 	size_t size;
85 };
86 
87 /* Structure representing one PCIe interface */
88 struct mvebu_pcie_port {
89 	char *name;
90 	void __iomem *base;
91 	u32 port;
92 	u32 lane;
93 	int devfn;
94 	unsigned int mem_target;
95 	unsigned int mem_attr;
96 	unsigned int io_target;
97 	unsigned int io_attr;
98 	struct clk *clk;
99 	struct gpio_desc *reset_gpio;
100 	char *reset_name;
101 	struct pci_bridge_emul bridge;
102 	struct device_node *dn;
103 	struct mvebu_pcie *pcie;
104 	struct mvebu_pcie_window memwin;
105 	struct mvebu_pcie_window iowin;
106 	u32 saved_pcie_stat;
107 	struct resource regs;
108 };
109 
110 static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg)
111 {
112 	writel(val, port->base + reg);
113 }
114 
115 static inline u32 mvebu_readl(struct mvebu_pcie_port *port, u32 reg)
116 {
117 	return readl(port->base + reg);
118 }
119 
120 static inline bool mvebu_has_ioport(struct mvebu_pcie_port *port)
121 {
122 	return port->io_target != -1 && port->io_attr != -1;
123 }
124 
125 static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
126 {
127 	return !(mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_LINK_DOWN);
128 }
129 
130 static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie_port *port, int nr)
131 {
132 	u32 stat;
133 
134 	stat = mvebu_readl(port, PCIE_STAT_OFF);
135 	stat &= ~PCIE_STAT_BUS;
136 	stat |= nr << 8;
137 	mvebu_writel(port, stat, PCIE_STAT_OFF);
138 }
139 
140 static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
141 {
142 	u32 stat;
143 
144 	stat = mvebu_readl(port, PCIE_STAT_OFF);
145 	stat &= ~PCIE_STAT_DEV;
146 	stat |= nr << 16;
147 	mvebu_writel(port, stat, PCIE_STAT_OFF);
148 }
149 
150 /*
151  * Setup PCIE BARs and Address Decode Wins:
152  * BAR[0] -> internal registers (needed for MSI)
153  * BAR[1] -> covers all DRAM banks
154  * BAR[2] -> Disabled
155  * WIN[0-3] -> DRAM bank[0-3]
156  */
157 static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
158 {
159 	const struct mbus_dram_target_info *dram;
160 	u32 size;
161 	int i;
162 
163 	dram = mv_mbus_dram_info();
164 
165 	/* First, disable and clear BARs and windows. */
166 	for (i = 1; i < 3; i++) {
167 		mvebu_writel(port, 0, PCIE_BAR_CTRL_OFF(i));
168 		mvebu_writel(port, 0, PCIE_BAR_LO_OFF(i));
169 		mvebu_writel(port, 0, PCIE_BAR_HI_OFF(i));
170 	}
171 
172 	for (i = 0; i < 5; i++) {
173 		mvebu_writel(port, 0, PCIE_WIN04_CTRL_OFF(i));
174 		mvebu_writel(port, 0, PCIE_WIN04_BASE_OFF(i));
175 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
176 	}
177 
178 	mvebu_writel(port, 0, PCIE_WIN5_CTRL_OFF);
179 	mvebu_writel(port, 0, PCIE_WIN5_BASE_OFF);
180 	mvebu_writel(port, 0, PCIE_WIN5_REMAP_OFF);
181 
182 	/* Setup windows for DDR banks.  Count total DDR size on the fly. */
183 	size = 0;
184 	for (i = 0; i < dram->num_cs; i++) {
185 		const struct mbus_dram_window *cs = dram->cs + i;
186 
187 		mvebu_writel(port, cs->base & 0xffff0000,
188 			     PCIE_WIN04_BASE_OFF(i));
189 		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
190 		mvebu_writel(port,
191 			     ((cs->size - 1) & 0xffff0000) |
192 			     (cs->mbus_attr << 8) |
193 			     (dram->mbus_dram_target_id << 4) | 1,
194 			     PCIE_WIN04_CTRL_OFF(i));
195 
196 		size += cs->size;
197 	}
198 
199 	/* Round up 'size' to the nearest power of two. */
200 	if ((size & (size - 1)) != 0)
201 		size = 1 << fls(size);
202 
203 	/* Setup BAR[1] to all DRAM banks. */
204 	mvebu_writel(port, dram->cs[0].base, PCIE_BAR_LO_OFF(1));
205 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1));
206 	mvebu_writel(port, ((size - 1) & 0xffff0000) | 1,
207 		     PCIE_BAR_CTRL_OFF(1));
208 
209 	/*
210 	 * Point BAR[0] to the device's internal registers.
211 	 */
212 	mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0));
213 	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
214 }
215 
216 static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
217 {
218 	u32 cmd, mask;
219 
220 	/* Point PCIe unit MBUS decode windows to DRAM space. */
221 	mvebu_pcie_setup_wins(port);
222 
223 	/* Master + slave enable. */
224 	cmd = mvebu_readl(port, PCIE_CMD_OFF);
225 	cmd |= PCI_COMMAND_IO;
226 	cmd |= PCI_COMMAND_MEMORY;
227 	cmd |= PCI_COMMAND_MASTER;
228 	mvebu_writel(port, cmd, PCIE_CMD_OFF);
229 
230 	/* Enable interrupt lines A-D. */
231 	mask = mvebu_readl(port, PCIE_MASK_OFF);
232 	mask |= PCIE_MASK_ENABLE_INTS;
233 	mvebu_writel(port, mask, PCIE_MASK_OFF);
234 }
235 
236 static int mvebu_pcie_hw_rd_conf(struct mvebu_pcie_port *port,
237 				 struct pci_bus *bus,
238 				 u32 devfn, int where, int size, u32 *val)
239 {
240 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
241 
242 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
243 		     PCIE_CONF_ADDR_OFF);
244 
245 	switch (size) {
246 	case 1:
247 		*val = readb_relaxed(conf_data + (where & 3));
248 		break;
249 	case 2:
250 		*val = readw_relaxed(conf_data + (where & 2));
251 		break;
252 	case 4:
253 		*val = readl_relaxed(conf_data);
254 		break;
255 	}
256 
257 	return PCIBIOS_SUCCESSFUL;
258 }
259 
260 static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
261 				 struct pci_bus *bus,
262 				 u32 devfn, int where, int size, u32 val)
263 {
264 	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
265 
266 	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
267 		     PCIE_CONF_ADDR_OFF);
268 
269 	switch (size) {
270 	case 1:
271 		writeb(val, conf_data + (where & 3));
272 		break;
273 	case 2:
274 		writew(val, conf_data + (where & 2));
275 		break;
276 	case 4:
277 		writel(val, conf_data);
278 		break;
279 	default:
280 		return PCIBIOS_BAD_REGISTER_NUMBER;
281 	}
282 
283 	return PCIBIOS_SUCCESSFUL;
284 }
285 
286 /*
287  * Remove windows, starting from the largest ones to the smallest
288  * ones.
289  */
290 static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
291 				   phys_addr_t base, size_t size)
292 {
293 	while (size) {
294 		size_t sz = 1 << (fls(size) - 1);
295 
296 		mvebu_mbus_del_window(base, sz);
297 		base += sz;
298 		size -= sz;
299 	}
300 }
301 
302 /*
303  * MBus windows can only have a power of two size, but PCI BARs do not
304  * have this constraint. Therefore, we have to split the PCI BAR into
305  * areas each having a power of two size. We start from the largest
306  * one (i.e highest order bit set in the size).
307  */
308 static void mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
309 				   unsigned int target, unsigned int attribute,
310 				   phys_addr_t base, size_t size,
311 				   phys_addr_t remap)
312 {
313 	size_t size_mapped = 0;
314 
315 	while (size) {
316 		size_t sz = 1 << (fls(size) - 1);
317 		int ret;
318 
319 		ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
320 							sz, remap);
321 		if (ret) {
322 			phys_addr_t end = base + sz - 1;
323 
324 			dev_err(&port->pcie->pdev->dev,
325 				"Could not create MBus window at [mem %pa-%pa]: %d\n",
326 				&base, &end, ret);
327 			mvebu_pcie_del_windows(port, base - size_mapped,
328 					       size_mapped);
329 			return;
330 		}
331 
332 		size -= sz;
333 		size_mapped += sz;
334 		base += sz;
335 		if (remap != MVEBU_MBUS_NO_REMAP)
336 			remap += sz;
337 	}
338 }
339 
340 static void mvebu_pcie_set_window(struct mvebu_pcie_port *port,
341 				  unsigned int target, unsigned int attribute,
342 				  const struct mvebu_pcie_window *desired,
343 				  struct mvebu_pcie_window *cur)
344 {
345 	if (desired->base == cur->base && desired->remap == cur->remap &&
346 	    desired->size == cur->size)
347 		return;
348 
349 	if (cur->size != 0) {
350 		mvebu_pcie_del_windows(port, cur->base, cur->size);
351 		cur->size = 0;
352 		cur->base = 0;
353 
354 		/*
355 		 * If something tries to change the window while it is enabled
356 		 * the change will not be done atomically. That would be
357 		 * difficult to do in the general case.
358 		 */
359 	}
360 
361 	if (desired->size == 0)
362 		return;
363 
364 	mvebu_pcie_add_windows(port, target, attribute, desired->base,
365 			       desired->size, desired->remap);
366 	*cur = *desired;
367 }
368 
369 static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
370 {
371 	struct mvebu_pcie_window desired = {};
372 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
373 
374 	/* Are the new iobase/iolimit values invalid? */
375 	if (conf->iolimit < conf->iobase ||
376 	    conf->iolimitupper < conf->iobaseupper ||
377 	    !(conf->command & PCI_COMMAND_IO)) {
378 		mvebu_pcie_set_window(port, port->io_target, port->io_attr,
379 				      &desired, &port->iowin);
380 		return;
381 	}
382 
383 	if (!mvebu_has_ioport(port)) {
384 		dev_WARN(&port->pcie->pdev->dev,
385 			 "Attempt to set IO when IO is disabled\n");
386 		return;
387 	}
388 
389 	/*
390 	 * We read the PCI-to-PCI bridge emulated registers, and
391 	 * calculate the base address and size of the address decoding
392 	 * window to setup, according to the PCI-to-PCI bridge
393 	 * specifications. iobase is the bus address, port->iowin_base
394 	 * is the CPU address.
395 	 */
396 	desired.remap = ((conf->iobase & 0xF0) << 8) |
397 			(conf->iobaseupper << 16);
398 	desired.base = port->pcie->io.start + desired.remap;
399 	desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
400 			 (conf->iolimitupper << 16)) -
401 			desired.remap) +
402 		       1;
403 
404 	mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
405 			      &port->iowin);
406 }
407 
408 static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
409 {
410 	struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
411 	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
412 
413 	/* Are the new membase/memlimit values invalid? */
414 	if (conf->memlimit < conf->membase ||
415 	    !(conf->command & PCI_COMMAND_MEMORY)) {
416 		mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
417 				      &desired, &port->memwin);
418 		return;
419 	}
420 
421 	/*
422 	 * We read the PCI-to-PCI bridge emulated registers, and
423 	 * calculate the base address and size of the address decoding
424 	 * window to setup, according to the PCI-to-PCI bridge
425 	 * specifications.
426 	 */
427 	desired.base = ((conf->membase & 0xFFF0) << 16);
428 	desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
429 		       desired.base + 1;
430 
431 	mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
432 			      &port->memwin);
433 }
434 
435 static pci_bridge_emul_read_status_t
436 mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
437 				     int reg, u32 *value)
438 {
439 	struct mvebu_pcie_port *port = bridge->data;
440 
441 	switch (reg) {
442 	case PCI_EXP_DEVCAP:
443 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
444 		break;
445 
446 	case PCI_EXP_DEVCTL:
447 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL) &
448 				 ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
449 				   PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
450 		break;
451 
452 	case PCI_EXP_LNKCAP:
453 		/*
454 		 * PCIe requires the clock power management capability to be
455 		 * hard-wired to zero for downstream ports
456 		 */
457 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
458 			 ~PCI_EXP_LNKCAP_CLKPM;
459 		break;
460 
461 	case PCI_EXP_LNKCTL:
462 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
463 		break;
464 
465 	case PCI_EXP_SLTCTL:
466 		*value = PCI_EXP_SLTSTA_PDS << 16;
467 		break;
468 
469 	case PCI_EXP_RTSTA:
470 		*value = mvebu_readl(port, PCIE_RC_RTSTA);
471 		break;
472 
473 	default:
474 		return PCI_BRIDGE_EMUL_NOT_HANDLED;
475 	}
476 
477 	return PCI_BRIDGE_EMUL_HANDLED;
478 }
479 
480 static void
481 mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
482 				      int reg, u32 old, u32 new, u32 mask)
483 {
484 	struct mvebu_pcie_port *port = bridge->data;
485 	struct pci_bridge_emul_conf *conf = &bridge->conf;
486 
487 	switch (reg) {
488 	case PCI_COMMAND:
489 	{
490 		if (!mvebu_has_ioport(port))
491 			conf->command &= ~PCI_COMMAND_IO;
492 
493 		if ((old ^ new) & PCI_COMMAND_IO)
494 			mvebu_pcie_handle_iobase_change(port);
495 		if ((old ^ new) & PCI_COMMAND_MEMORY)
496 			mvebu_pcie_handle_membase_change(port);
497 
498 		break;
499 	}
500 
501 	case PCI_IO_BASE:
502 		/*
503 		 * We keep bit 1 set, it is a read-only bit that
504 		 * indicates we support 32 bits addressing for the
505 		 * I/O
506 		 */
507 		conf->iobase |= PCI_IO_RANGE_TYPE_32;
508 		conf->iolimit |= PCI_IO_RANGE_TYPE_32;
509 		mvebu_pcie_handle_iobase_change(port);
510 		break;
511 
512 	case PCI_MEMORY_BASE:
513 		mvebu_pcie_handle_membase_change(port);
514 		break;
515 
516 	case PCI_IO_BASE_UPPER16:
517 		mvebu_pcie_handle_iobase_change(port);
518 		break;
519 
520 	case PCI_PRIMARY_BUS:
521 		mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
522 		break;
523 
524 	default:
525 		break;
526 	}
527 }
528 
529 static void
530 mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
531 				      int reg, u32 old, u32 new, u32 mask)
532 {
533 	struct mvebu_pcie_port *port = bridge->data;
534 
535 	switch (reg) {
536 	case PCI_EXP_DEVCTL:
537 		/*
538 		 * Armada370 data says these bits must always
539 		 * be zero when in root complex mode.
540 		 */
541 		new &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
542 			 PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
543 
544 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
545 		break;
546 
547 	case PCI_EXP_LNKCTL:
548 		/*
549 		 * If we don't support CLKREQ, we must ensure that the
550 		 * CLKREQ enable bit always reads zero.  Since we haven't
551 		 * had this capability, and it's dependent on board wiring,
552 		 * disable it for the time being.
553 		 */
554 		new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
555 
556 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
557 		break;
558 
559 	case PCI_EXP_RTSTA:
560 		mvebu_writel(port, new, PCIE_RC_RTSTA);
561 		break;
562 	}
563 }
564 
565 static struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
566 	.write_base = mvebu_pci_bridge_emul_base_conf_write,
567 	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
568 	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
569 };
570 
571 /*
572  * Initialize the configuration space of the PCI-to-PCI bridge
573  * associated with the given PCIe interface.
574  */
575 static void mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
576 {
577 	struct pci_bridge_emul *bridge = &port->bridge;
578 
579 	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
580 	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
581 	bridge->conf.class_revision =
582 		mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
583 
584 	if (mvebu_has_ioport(port)) {
585 		/* We support 32 bits I/O addressing */
586 		bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
587 		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
588 	}
589 
590 	bridge->has_pcie = true;
591 	bridge->data = port;
592 	bridge->ops = &mvebu_pci_bridge_emul_ops;
593 
594 	pci_bridge_emul_init(bridge, PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR);
595 }
596 
597 static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
598 {
599 	return sys->private_data;
600 }
601 
602 static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
603 						    struct pci_bus *bus,
604 						    int devfn)
605 {
606 	int i;
607 
608 	for (i = 0; i < pcie->nports; i++) {
609 		struct mvebu_pcie_port *port = &pcie->ports[i];
610 
611 		if (bus->number == 0 && port->devfn == devfn)
612 			return port;
613 		if (bus->number != 0 &&
614 		    bus->number >= port->bridge.conf.secondary_bus &&
615 		    bus->number <= port->bridge.conf.subordinate_bus)
616 			return port;
617 	}
618 
619 	return NULL;
620 }
621 
622 /* PCI configuration space write function */
623 static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
624 			      int where, int size, u32 val)
625 {
626 	struct mvebu_pcie *pcie = bus->sysdata;
627 	struct mvebu_pcie_port *port;
628 	int ret;
629 
630 	port = mvebu_pcie_find_port(pcie, bus, devfn);
631 	if (!port)
632 		return PCIBIOS_DEVICE_NOT_FOUND;
633 
634 	/* Access the emulated PCI-to-PCI bridge */
635 	if (bus->number == 0)
636 		return pci_bridge_emul_conf_write(&port->bridge, where,
637 						  size, val);
638 
639 	if (!mvebu_pcie_link_up(port))
640 		return PCIBIOS_DEVICE_NOT_FOUND;
641 
642 	/* Access the real PCIe interface */
643 	ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
644 				    where, size, val);
645 
646 	return ret;
647 }
648 
649 /* PCI configuration space read function */
650 static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
651 			      int size, u32 *val)
652 {
653 	struct mvebu_pcie *pcie = bus->sysdata;
654 	struct mvebu_pcie_port *port;
655 	int ret;
656 
657 	port = mvebu_pcie_find_port(pcie, bus, devfn);
658 	if (!port) {
659 		*val = 0xffffffff;
660 		return PCIBIOS_DEVICE_NOT_FOUND;
661 	}
662 
663 	/* Access the emulated PCI-to-PCI bridge */
664 	if (bus->number == 0)
665 		return pci_bridge_emul_conf_read(&port->bridge, where,
666 						 size, val);
667 
668 	if (!mvebu_pcie_link_up(port)) {
669 		*val = 0xffffffff;
670 		return PCIBIOS_DEVICE_NOT_FOUND;
671 	}
672 
673 	/* Access the real PCIe interface */
674 	ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
675 				    where, size, val);
676 
677 	return ret;
678 }
679 
680 static struct pci_ops mvebu_pcie_ops = {
681 	.read = mvebu_pcie_rd_conf,
682 	.write = mvebu_pcie_wr_conf,
683 };
684 
685 static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
686 						 const struct resource *res,
687 						 resource_size_t start,
688 						 resource_size_t size,
689 						 resource_size_t align)
690 {
691 	if (dev->bus->number != 0)
692 		return start;
693 
694 	/*
695 	 * On the PCI-to-PCI bridge side, the I/O windows must have at
696 	 * least a 64 KB size and the memory windows must have at
697 	 * least a 1 MB size. Moreover, MBus windows need to have a
698 	 * base address aligned on their size, and their size must be
699 	 * a power of two. This means that if the BAR doesn't have a
700 	 * power of two size, several MBus windows will actually be
701 	 * created. We need to ensure that the biggest MBus window
702 	 * (which will be the first one) is aligned on its size, which
703 	 * explains the rounddown_pow_of_two() being done here.
704 	 */
705 	if (res->flags & IORESOURCE_IO)
706 		return round_up(start, max_t(resource_size_t, SZ_64K,
707 					     rounddown_pow_of_two(size)));
708 	else if (res->flags & IORESOURCE_MEM)
709 		return round_up(start, max_t(resource_size_t, SZ_1M,
710 					     rounddown_pow_of_two(size)));
711 	else
712 		return start;
713 }
714 
715 static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
716 					      struct device_node *np,
717 					      struct mvebu_pcie_port *port)
718 {
719 	int ret = 0;
720 
721 	ret = of_address_to_resource(np, 0, &port->regs);
722 	if (ret)
723 		return (void __iomem *)ERR_PTR(ret);
724 
725 	return devm_ioremap_resource(&pdev->dev, &port->regs);
726 }
727 
728 #define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
729 #define    DT_TYPE_IO                 0x1
730 #define    DT_TYPE_MEM32              0x2
731 #define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
732 #define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)
733 
734 static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
735 			      unsigned long type,
736 			      unsigned int *tgt,
737 			      unsigned int *attr)
738 {
739 	const int na = 3, ns = 2;
740 	const __be32 *range;
741 	int rlen, nranges, rangesz, pna, i;
742 
743 	*tgt = -1;
744 	*attr = -1;
745 
746 	range = of_get_property(np, "ranges", &rlen);
747 	if (!range)
748 		return -EINVAL;
749 
750 	pna = of_n_addr_cells(np);
751 	rangesz = pna + na + ns;
752 	nranges = rlen / sizeof(__be32) / rangesz;
753 
754 	for (i = 0; i < nranges; i++, range += rangesz) {
755 		u32 flags = of_read_number(range, 1);
756 		u32 slot = of_read_number(range + 1, 1);
757 		u64 cpuaddr = of_read_number(range + na, pna);
758 		unsigned long rtype;
759 
760 		if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
761 			rtype = IORESOURCE_IO;
762 		else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
763 			rtype = IORESOURCE_MEM;
764 		else
765 			continue;
766 
767 		if (slot == PCI_SLOT(devfn) && type == rtype) {
768 			*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
769 			*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
770 			return 0;
771 		}
772 	}
773 
774 	return -ENOENT;
775 }
776 
777 #ifdef CONFIG_PM_SLEEP
778 static int mvebu_pcie_suspend(struct device *dev)
779 {
780 	struct mvebu_pcie *pcie;
781 	int i;
782 
783 	pcie = dev_get_drvdata(dev);
784 	for (i = 0; i < pcie->nports; i++) {
785 		struct mvebu_pcie_port *port = pcie->ports + i;
786 		port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
787 	}
788 
789 	return 0;
790 }
791 
792 static int mvebu_pcie_resume(struct device *dev)
793 {
794 	struct mvebu_pcie *pcie;
795 	int i;
796 
797 	pcie = dev_get_drvdata(dev);
798 	for (i = 0; i < pcie->nports; i++) {
799 		struct mvebu_pcie_port *port = pcie->ports + i;
800 		mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
801 		mvebu_pcie_setup_hw(port);
802 	}
803 
804 	return 0;
805 }
806 #endif
807 
808 static void mvebu_pcie_port_clk_put(void *data)
809 {
810 	struct mvebu_pcie_port *port = data;
811 
812 	clk_put(port->clk);
813 }
814 
815 static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
816 	struct mvebu_pcie_port *port, struct device_node *child)
817 {
818 	struct device *dev = &pcie->pdev->dev;
819 	enum of_gpio_flags flags;
820 	int reset_gpio, ret;
821 
822 	port->pcie = pcie;
823 
824 	if (of_property_read_u32(child, "marvell,pcie-port", &port->port)) {
825 		dev_warn(dev, "ignoring %pOF, missing pcie-port property\n",
826 			 child);
827 		goto skip;
828 	}
829 
830 	if (of_property_read_u32(child, "marvell,pcie-lane", &port->lane))
831 		port->lane = 0;
832 
833 	port->name = devm_kasprintf(dev, GFP_KERNEL, "pcie%d.%d", port->port,
834 				    port->lane);
835 	if (!port->name) {
836 		ret = -ENOMEM;
837 		goto err;
838 	}
839 
840 	port->devfn = of_pci_get_devfn(child);
841 	if (port->devfn < 0)
842 		goto skip;
843 
844 	ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM,
845 				 &port->mem_target, &port->mem_attr);
846 	if (ret < 0) {
847 		dev_err(dev, "%s: cannot get tgt/attr for mem window\n",
848 			port->name);
849 		goto skip;
850 	}
851 
852 	if (resource_size(&pcie->io) != 0) {
853 		mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_IO,
854 				   &port->io_target, &port->io_attr);
855 	} else {
856 		port->io_target = -1;
857 		port->io_attr = -1;
858 	}
859 
860 	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
861 	if (reset_gpio == -EPROBE_DEFER) {
862 		ret = reset_gpio;
863 		goto err;
864 	}
865 
866 	if (gpio_is_valid(reset_gpio)) {
867 		unsigned long gpio_flags;
868 
869 		port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
870 						  port->name);
871 		if (!port->reset_name) {
872 			ret = -ENOMEM;
873 			goto err;
874 		}
875 
876 		if (flags & OF_GPIO_ACTIVE_LOW) {
877 			dev_info(dev, "%pOF: reset gpio is active low\n",
878 				 child);
879 			gpio_flags = GPIOF_ACTIVE_LOW |
880 				     GPIOF_OUT_INIT_LOW;
881 		} else {
882 			gpio_flags = GPIOF_OUT_INIT_HIGH;
883 		}
884 
885 		ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
886 					    port->reset_name);
887 		if (ret) {
888 			if (ret == -EPROBE_DEFER)
889 				goto err;
890 			goto skip;
891 		}
892 
893 		port->reset_gpio = gpio_to_desc(reset_gpio);
894 	}
895 
896 	port->clk = of_clk_get_by_name(child, NULL);
897 	if (IS_ERR(port->clk)) {
898 		dev_err(dev, "%s: cannot get clock\n", port->name);
899 		goto skip;
900 	}
901 
902 	ret = devm_add_action(dev, mvebu_pcie_port_clk_put, port);
903 	if (ret < 0) {
904 		clk_put(port->clk);
905 		goto err;
906 	}
907 
908 	return 1;
909 
910 skip:
911 	ret = 0;
912 
913 	/* In the case of skipping, we need to free these */
914 	devm_kfree(dev, port->reset_name);
915 	port->reset_name = NULL;
916 	devm_kfree(dev, port->name);
917 	port->name = NULL;
918 
919 err:
920 	return ret;
921 }
922 
923 /*
924  * Power up a PCIe port.  PCIe requires the refclk to be stable for 100µs
925  * prior to releasing PERST.  See table 2-4 in section 2.6.2 AC Specifications
926  * of the PCI Express Card Electromechanical Specification, 1.1.
927  */
928 static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
929 {
930 	int ret;
931 
932 	ret = clk_prepare_enable(port->clk);
933 	if (ret < 0)
934 		return ret;
935 
936 	if (port->reset_gpio) {
937 		u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
938 
939 		of_property_read_u32(port->dn, "reset-delay-us",
940 				     &reset_udelay);
941 
942 		udelay(100);
943 
944 		gpiod_set_value_cansleep(port->reset_gpio, 0);
945 		msleep(reset_udelay / 1000);
946 	}
947 
948 	return 0;
949 }
950 
951 /*
952  * Power down a PCIe port.  Strictly, PCIe requires us to place the card
953  * in D3hot state before asserting PERST#.
954  */
955 static void mvebu_pcie_powerdown(struct mvebu_pcie_port *port)
956 {
957 	gpiod_set_value_cansleep(port->reset_gpio, 1);
958 
959 	clk_disable_unprepare(port->clk);
960 }
961 
962 /*
963  * We can't use devm_of_pci_get_host_bridge_resources() because we
964  * need to parse our special DT properties encoding the MEM and IO
965  * apertures.
966  */
967 static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
968 {
969 	struct device *dev = &pcie->pdev->dev;
970 	struct device_node *np = dev->of_node;
971 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
972 	int ret;
973 
974 	/* Get the bus range */
975 	ret = of_pci_parse_bus_range(np, &pcie->busn);
976 	if (ret) {
977 		dev_err(dev, "failed to parse bus-range property: %d\n", ret);
978 		return ret;
979 	}
980 	pci_add_resource(&bridge->windows, &pcie->busn);
981 
982 	/* Get the PCIe memory aperture */
983 	mvebu_mbus_get_pcie_mem_aperture(&pcie->mem);
984 	if (resource_size(&pcie->mem) == 0) {
985 		dev_err(dev, "invalid memory aperture size\n");
986 		return -EINVAL;
987 	}
988 
989 	pcie->mem.name = "PCI MEM";
990 	pci_add_resource(&bridge->windows, &pcie->mem);
991 
992 	/* Get the PCIe IO aperture */
993 	mvebu_mbus_get_pcie_io_aperture(&pcie->io);
994 
995 	if (resource_size(&pcie->io) != 0) {
996 		pcie->realio.flags = pcie->io.flags;
997 		pcie->realio.start = PCIBIOS_MIN_IO;
998 		pcie->realio.end = min_t(resource_size_t,
999 					 IO_SPACE_LIMIT - SZ_64K,
1000 					 resource_size(&pcie->io) - 1);
1001 		pcie->realio.name = "PCI I/O";
1002 
1003 		pci_add_resource(&bridge->windows, &pcie->realio);
1004 	}
1005 
1006 	return devm_request_pci_bus_resources(dev, &bridge->windows);
1007 }
1008 
1009 /*
1010  * This is a copy of pci_host_probe(), except that it does the I/O
1011  * remap as the last step, once we are sure we won't fail.
1012  *
1013  * It should be removed once the I/O remap error handling issue has
1014  * been sorted out.
1015  */
1016 static int mvebu_pci_host_probe(struct pci_host_bridge *bridge)
1017 {
1018 	struct mvebu_pcie *pcie;
1019 	struct pci_bus *bus, *child;
1020 	int ret;
1021 
1022 	ret = pci_scan_root_bus_bridge(bridge);
1023 	if (ret < 0) {
1024 		dev_err(bridge->dev.parent, "Scanning root bridge failed");
1025 		return ret;
1026 	}
1027 
1028 	pcie = pci_host_bridge_priv(bridge);
1029 	if (resource_size(&pcie->io) != 0) {
1030 		unsigned int i;
1031 
1032 		for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)
1033 			pci_ioremap_io(i, pcie->io.start + i);
1034 	}
1035 
1036 	bus = bridge->bus;
1037 
1038 	/*
1039 	 * We insert PCI resources into the iomem_resource and
1040 	 * ioport_resource trees in either pci_bus_claim_resources()
1041 	 * or pci_bus_assign_resources().
1042 	 */
1043 	if (pci_has_flag(PCI_PROBE_ONLY)) {
1044 		pci_bus_claim_resources(bus);
1045 	} else {
1046 		pci_bus_size_bridges(bus);
1047 		pci_bus_assign_resources(bus);
1048 
1049 		list_for_each_entry(child, &bus->children, node)
1050 			pcie_bus_configure_settings(child);
1051 	}
1052 
1053 	pci_bus_add_devices(bus);
1054 	return 0;
1055 }
1056 
1057 static int mvebu_pcie_probe(struct platform_device *pdev)
1058 {
1059 	struct device *dev = &pdev->dev;
1060 	struct mvebu_pcie *pcie;
1061 	struct pci_host_bridge *bridge;
1062 	struct device_node *np = dev->of_node;
1063 	struct device_node *child;
1064 	int num, i, ret;
1065 
1066 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct mvebu_pcie));
1067 	if (!bridge)
1068 		return -ENOMEM;
1069 
1070 	pcie = pci_host_bridge_priv(bridge);
1071 	pcie->pdev = pdev;
1072 	platform_set_drvdata(pdev, pcie);
1073 
1074 	ret = mvebu_pcie_parse_request_resources(pcie);
1075 	if (ret)
1076 		return ret;
1077 
1078 	num = of_get_available_child_count(np);
1079 
1080 	pcie->ports = devm_kcalloc(dev, num, sizeof(*pcie->ports), GFP_KERNEL);
1081 	if (!pcie->ports)
1082 		return -ENOMEM;
1083 
1084 	i = 0;
1085 	for_each_available_child_of_node(np, child) {
1086 		struct mvebu_pcie_port *port = &pcie->ports[i];
1087 
1088 		ret = mvebu_pcie_parse_port(pcie, port, child);
1089 		if (ret < 0) {
1090 			of_node_put(child);
1091 			return ret;
1092 		} else if (ret == 0) {
1093 			continue;
1094 		}
1095 
1096 		port->dn = child;
1097 		i++;
1098 	}
1099 	pcie->nports = i;
1100 
1101 	for (i = 0; i < pcie->nports; i++) {
1102 		struct mvebu_pcie_port *port = &pcie->ports[i];
1103 
1104 		child = port->dn;
1105 		if (!child)
1106 			continue;
1107 
1108 		ret = mvebu_pcie_powerup(port);
1109 		if (ret < 0)
1110 			continue;
1111 
1112 		port->base = mvebu_pcie_map_registers(pdev, child, port);
1113 		if (IS_ERR(port->base)) {
1114 			dev_err(dev, "%s: cannot map registers\n", port->name);
1115 			port->base = NULL;
1116 			mvebu_pcie_powerdown(port);
1117 			continue;
1118 		}
1119 
1120 		mvebu_pcie_setup_hw(port);
1121 		mvebu_pcie_set_local_dev_nr(port, 1);
1122 		mvebu_pci_bridge_emul_init(port);
1123 	}
1124 
1125 	pcie->nports = i;
1126 
1127 	bridge->sysdata = pcie;
1128 	bridge->ops = &mvebu_pcie_ops;
1129 	bridge->align_resource = mvebu_pcie_align_resource;
1130 	bridge->msi = pcie->msi;
1131 
1132 	return mvebu_pci_host_probe(bridge);
1133 }
1134 
1135 static const struct of_device_id mvebu_pcie_of_match_table[] = {
1136 	{ .compatible = "marvell,armada-xp-pcie", },
1137 	{ .compatible = "marvell,armada-370-pcie", },
1138 	{ .compatible = "marvell,dove-pcie", },
1139 	{ .compatible = "marvell,kirkwood-pcie", },
1140 	{},
1141 };
1142 
1143 static const struct dev_pm_ops mvebu_pcie_pm_ops = {
1144 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_pcie_suspend, mvebu_pcie_resume)
1145 };
1146 
1147 static struct platform_driver mvebu_pcie_driver = {
1148 	.driver = {
1149 		.name = "mvebu-pcie",
1150 		.of_match_table = mvebu_pcie_of_match_table,
1151 		/* driver unloading/unbinding currently not supported */
1152 		.suppress_bind_attrs = true,
1153 		.pm = &mvebu_pcie_pm_ops,
1154 	},
1155 	.probe = mvebu_pcie_probe,
1156 };
1157 builtin_platform_driver(mvebu_pcie_driver);
1158