xref: /openbmc/linux/arch/sh/drivers/pci/pcie-sh7786.c (revision 7fe2f639)
1 /*
2  * Low-Level PCI Express Support for the SH7786
3  *
4  *  Copyright (C) 2009 - 2011  Paul Mundt
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #define pr_fmt(fmt) "PCI: " fmt
11 
12 #include <linux/pci.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/io.h>
16 #include <linux/async.h>
17 #include <linux/delay.h>
18 #include <linux/slab.h>
19 #include <linux/clk.h>
20 #include <linux/sh_clk.h>
21 #include "pcie-sh7786.h"
22 #include <asm/sizes.h>
23 
24 struct sh7786_pcie_port {
25 	struct pci_channel	*hose;
26 	struct clk		*fclk, phy_clk;
27 	unsigned int		index;
28 	int			endpoint;
29 	int			link;
30 };
31 
32 static struct sh7786_pcie_port *sh7786_pcie_ports;
33 static unsigned int nr_ports;
34 
35 static struct sh7786_pcie_hwops {
36 	int (*core_init)(void);
37 	async_func_ptr *port_init_hw;
38 } *sh7786_pcie_hwops;
39 
40 static struct resource sh7786_pci0_resources[] = {
41 	{
42 		.name	= "PCIe0 IO",
43 		.start	= 0xfd000000,
44 		.end	= 0xfd000000 + SZ_8M - 1,
45 		.flags	= IORESOURCE_IO,
46 	}, {
47 		.name	= "PCIe0 MEM 0",
48 		.start	= 0xc0000000,
49 		.end	= 0xc0000000 + SZ_512M - 1,
50 		.flags	= IORESOURCE_MEM | IORESOURCE_MEM_32BIT,
51 	}, {
52 		.name	= "PCIe0 MEM 1",
53 		.start	= 0x10000000,
54 		.end	= 0x10000000 + SZ_64M - 1,
55 		.flags	= IORESOURCE_MEM,
56 	}, {
57 		.name	= "PCIe0 MEM 2",
58 		.start	= 0xfe100000,
59 		.end	= 0xfe100000 + SZ_1M - 1,
60 		.flags	= IORESOURCE_MEM,
61 	},
62 };
63 
64 static struct resource sh7786_pci1_resources[] = {
65 	{
66 		.name	= "PCIe1 IO",
67 		.start	= 0xfd800000,
68 		.end	= 0xfd800000 + SZ_8M - 1,
69 		.flags	= IORESOURCE_IO,
70 	}, {
71 		.name	= "PCIe1 MEM 0",
72 		.start	= 0xa0000000,
73 		.end	= 0xa0000000 + SZ_512M - 1,
74 		.flags	= IORESOURCE_MEM | IORESOURCE_MEM_32BIT,
75 	}, {
76 		.name	= "PCIe1 MEM 1",
77 		.start	= 0x30000000,
78 		.end	= 0x30000000 + SZ_256M - 1,
79 		.flags	= IORESOURCE_MEM | IORESOURCE_MEM_32BIT,
80 	}, {
81 		.name	= "PCIe1 MEM 2",
82 		.start	= 0xfe300000,
83 		.end	= 0xfe300000 + SZ_1M - 1,
84 		.flags	= IORESOURCE_MEM,
85 	},
86 };
87 
88 static struct resource sh7786_pci2_resources[] = {
89 	{
90 		.name	= "PCIe2 IO",
91 		.start	= 0xfc800000,
92 		.end	= 0xfc800000 + SZ_4M - 1,
93 		.flags	= IORESOURCE_IO,
94 	}, {
95 		.name	= "PCIe2 MEM 0",
96 		.start	= 0x80000000,
97 		.end	= 0x80000000 + SZ_512M - 1,
98 		.flags	= IORESOURCE_MEM | IORESOURCE_MEM_32BIT,
99 	}, {
100 		.name	= "PCIe2 MEM 1",
101 		.start	= 0x20000000,
102 		.end	= 0x20000000 + SZ_256M - 1,
103 		.flags	= IORESOURCE_MEM | IORESOURCE_MEM_32BIT,
104 	}, {
105 		.name	= "PCIe2 MEM 2",
106 		.start	= 0xfcd00000,
107 		.end	= 0xfcd00000 + SZ_1M - 1,
108 		.flags	= IORESOURCE_MEM,
109 	},
110 };
111 
112 extern struct pci_ops sh7786_pci_ops;
113 
114 #define DEFINE_CONTROLLER(start, idx)					\
115 {									\
116 	.pci_ops	= &sh7786_pci_ops,				\
117 	.resources	= sh7786_pci##idx##_resources,			\
118 	.nr_resources	= ARRAY_SIZE(sh7786_pci##idx##_resources),	\
119 	.reg_base	= start,					\
120 	.mem_offset	= 0,						\
121 	.io_offset	= 0,						\
122 }
123 
124 static struct pci_channel sh7786_pci_channels[] = {
125 	DEFINE_CONTROLLER(0xfe000000, 0),
126 	DEFINE_CONTROLLER(0xfe200000, 1),
127 	DEFINE_CONTROLLER(0xfcc00000, 2),
128 };
129 
130 static struct clk fixed_pciexclkp = {
131 	.rate = 100000000,	/* 100 MHz reference clock */
132 };
133 
134 static void __devinit sh7786_pci_fixup(struct pci_dev *dev)
135 {
136 	/*
137 	 * Prevent enumeration of root complex resources.
138 	 */
139 	if (pci_is_root_bus(dev->bus) && dev->devfn == 0) {
140 		int i;
141 
142 		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
143 			dev->resource[i].start	= 0;
144 			dev->resource[i].end	= 0;
145 			dev->resource[i].flags	= 0;
146 		}
147 	}
148 }
149 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_RENESAS, PCI_DEVICE_ID_RENESAS_SH7786,
150 			 sh7786_pci_fixup);
151 
152 static int __init phy_wait_for_ack(struct pci_channel *chan)
153 {
154 	unsigned int timeout = 100;
155 
156 	while (timeout--) {
157 		if (pci_read_reg(chan, SH4A_PCIEPHYADRR) & (1 << BITS_ACK))
158 			return 0;
159 
160 		udelay(100);
161 	}
162 
163 	return -ETIMEDOUT;
164 }
165 
166 static int __init pci_wait_for_irq(struct pci_channel *chan, unsigned int mask)
167 {
168 	unsigned int timeout = 100;
169 
170 	while (timeout--) {
171 		if ((pci_read_reg(chan, SH4A_PCIEINTR) & mask) == mask)
172 			return 0;
173 
174 		udelay(100);
175 	}
176 
177 	return -ETIMEDOUT;
178 }
179 
180 static void __init phy_write_reg(struct pci_channel *chan, unsigned int addr,
181 				 unsigned int lane, unsigned int data)
182 {
183 	unsigned long phyaddr;
184 
185 	phyaddr = (1 << BITS_CMD) + ((lane & 0xf) << BITS_LANE) +
186 			((addr & 0xff) << BITS_ADR);
187 
188 	/* Set write data */
189 	pci_write_reg(chan, data, SH4A_PCIEPHYDOUTR);
190 	pci_write_reg(chan, phyaddr, SH4A_PCIEPHYADRR);
191 
192 	phy_wait_for_ack(chan);
193 
194 	/* Clear command */
195 	pci_write_reg(chan, 0, SH4A_PCIEPHYDOUTR);
196 	pci_write_reg(chan, 0, SH4A_PCIEPHYADRR);
197 
198 	phy_wait_for_ack(chan);
199 }
200 
201 static int __init pcie_clk_init(struct sh7786_pcie_port *port)
202 {
203 	struct pci_channel *chan = port->hose;
204 	struct clk *clk;
205 	char fclk_name[16];
206 	int ret;
207 
208 	/*
209 	 * First register the fixed clock
210 	 */
211 	ret = clk_register(&fixed_pciexclkp);
212 	if (unlikely(ret != 0))
213 		return ret;
214 
215 	/*
216 	 * Grab the port's function clock, which the PHY clock depends
217 	 * on. clock lookups don't help us much at this point, since no
218 	 * dev_id is available this early. Lame.
219 	 */
220 	snprintf(fclk_name, sizeof(fclk_name), "pcie%d_fck", port->index);
221 
222 	port->fclk = clk_get(NULL, fclk_name);
223 	if (IS_ERR(port->fclk)) {
224 		ret = PTR_ERR(port->fclk);
225 		goto err_fclk;
226 	}
227 
228 	clk_enable(port->fclk);
229 
230 	/*
231 	 * And now, set up the PHY clock
232 	 */
233 	clk = &port->phy_clk;
234 
235 	memset(clk, 0, sizeof(struct clk));
236 
237 	clk->parent = &fixed_pciexclkp;
238 	clk->enable_reg = (void __iomem *)(chan->reg_base + SH4A_PCIEPHYCTLR);
239 	clk->enable_bit = BITS_CKE;
240 
241 	ret = sh_clk_mstp32_register(clk, 1);
242 	if (unlikely(ret < 0))
243 		goto err_phy;
244 
245 	return 0;
246 
247 err_phy:
248 	clk_disable(port->fclk);
249 	clk_put(port->fclk);
250 err_fclk:
251 	clk_unregister(&fixed_pciexclkp);
252 
253 	return ret;
254 }
255 
256 static int __init phy_init(struct sh7786_pcie_port *port)
257 {
258 	struct pci_channel *chan = port->hose;
259 	unsigned int timeout = 100;
260 
261 	clk_enable(&port->phy_clk);
262 
263 	/* Initialize the phy */
264 	phy_write_reg(chan, 0x60, 0xf, 0x004b008b);
265 	phy_write_reg(chan, 0x61, 0xf, 0x00007b41);
266 	phy_write_reg(chan, 0x64, 0xf, 0x00ff4f00);
267 	phy_write_reg(chan, 0x65, 0xf, 0x09070907);
268 	phy_write_reg(chan, 0x66, 0xf, 0x00000010);
269 	phy_write_reg(chan, 0x74, 0xf, 0x0007001c);
270 	phy_write_reg(chan, 0x79, 0xf, 0x01fc000d);
271 	phy_write_reg(chan, 0xb0, 0xf, 0x00000610);
272 
273 	/* Deassert Standby */
274 	phy_write_reg(chan, 0x67, 0x1, 0x00000400);
275 
276 	/* Disable clock */
277 	clk_disable(&port->phy_clk);
278 
279 	while (timeout--) {
280 		if (pci_read_reg(chan, SH4A_PCIEPHYSR))
281 			return 0;
282 
283 		udelay(100);
284 	}
285 
286 	return -ETIMEDOUT;
287 }
288 
289 static void __init pcie_reset(struct sh7786_pcie_port *port)
290 {
291 	struct pci_channel *chan = port->hose;
292 
293 	pci_write_reg(chan, 1, SH4A_PCIESRSTR);
294 	pci_write_reg(chan, 0, SH4A_PCIETCTLR);
295 	pci_write_reg(chan, 0, SH4A_PCIESRSTR);
296 	pci_write_reg(chan, 0, SH4A_PCIETXVC0SR);
297 }
298 
299 static int __init pcie_init(struct sh7786_pcie_port *port)
300 {
301 	struct pci_channel *chan = port->hose;
302 	unsigned int data;
303 	phys_addr_t memphys;
304 	size_t memsize;
305 	int ret, i, win;
306 
307 	/* Begin initialization */
308 	pcie_reset(port);
309 
310 	/*
311 	 * Initial header for port config space is type 1, set the device
312 	 * class to match. Hardware takes care of propagating the IDSETR
313 	 * settings, so there is no need to bother with a quirk.
314 	 */
315 	pci_write_reg(chan, PCI_CLASS_BRIDGE_PCI << 16, SH4A_PCIEIDSETR1);
316 
317 	/* Initialize default capabilities. */
318 	data = pci_read_reg(chan, SH4A_PCIEEXPCAP0);
319 	data &= ~(PCI_EXP_FLAGS_TYPE << 16);
320 
321 	if (port->endpoint)
322 		data |= PCI_EXP_TYPE_ENDPOINT << 20;
323 	else
324 		data |= PCI_EXP_TYPE_ROOT_PORT << 20;
325 
326 	data |= PCI_CAP_ID_EXP;
327 	pci_write_reg(chan, data, SH4A_PCIEEXPCAP0);
328 
329 	/* Enable data link layer active state reporting */
330 	pci_write_reg(chan, PCI_EXP_LNKCAP_DLLLARC, SH4A_PCIEEXPCAP3);
331 
332 	/* Enable extended sync and ASPM L0s support */
333 	data = pci_read_reg(chan, SH4A_PCIEEXPCAP4);
334 	data &= ~PCI_EXP_LNKCTL_ASPMC;
335 	data |= PCI_EXP_LNKCTL_ES | 1;
336 	pci_write_reg(chan, data, SH4A_PCIEEXPCAP4);
337 
338 	/* Write out the physical slot number */
339 	data = pci_read_reg(chan, SH4A_PCIEEXPCAP5);
340 	data &= ~PCI_EXP_SLTCAP_PSN;
341 	data |= (port->index + 1) << 19;
342 	pci_write_reg(chan, data, SH4A_PCIEEXPCAP5);
343 
344 	/* Set the completion timer timeout to the maximum 32ms. */
345 	data = pci_read_reg(chan, SH4A_PCIETLCTLR);
346 	data &= ~0x3f00;
347 	data |= 0x32 << 8;
348 	pci_write_reg(chan, data, SH4A_PCIETLCTLR);
349 
350 	/*
351 	 * Set fast training sequences to the maximum 255,
352 	 * and enable MAC data scrambling.
353 	 */
354 	data = pci_read_reg(chan, SH4A_PCIEMACCTLR);
355 	data &= ~PCIEMACCTLR_SCR_DIS;
356 	data |= (0xff << 16);
357 	pci_write_reg(chan, data, SH4A_PCIEMACCTLR);
358 
359 	memphys = __pa(memory_start);
360 	memsize = roundup_pow_of_two(memory_end - memory_start);
361 
362 	/*
363 	 * If there's more than 512MB of memory, we need to roll over to
364 	 * LAR1/LAMR1.
365 	 */
366 	if (memsize > SZ_512M) {
367 		pci_write_reg(chan, memphys + SZ_512M, SH4A_PCIELAR1);
368 		pci_write_reg(chan, ((memsize - SZ_512M) - SZ_256) | 1,
369 			      SH4A_PCIELAMR1);
370 		memsize = SZ_512M;
371 	} else {
372 		/*
373 		 * Otherwise just zero it out and disable it.
374 		 */
375 		pci_write_reg(chan, 0, SH4A_PCIELAR1);
376 		pci_write_reg(chan, 0, SH4A_PCIELAMR1);
377 	}
378 
379 	/*
380 	 * LAR0/LAMR0 covers up to the first 512MB, which is enough to
381 	 * cover all of lowmem on most platforms.
382 	 */
383 	pci_write_reg(chan, memphys, SH4A_PCIELAR0);
384 	pci_write_reg(chan, (memsize - SZ_256) | 1, SH4A_PCIELAMR0);
385 
386 	/* Finish initialization */
387 	data = pci_read_reg(chan, SH4A_PCIETCTLR);
388 	data |= 0x1;
389 	pci_write_reg(chan, data, SH4A_PCIETCTLR);
390 
391 	/* Let things settle down a bit.. */
392 	mdelay(100);
393 
394 	/* Enable DL_Active Interrupt generation */
395 	data = pci_read_reg(chan, SH4A_PCIEDLINTENR);
396 	data |= PCIEDLINTENR_DLL_ACT_ENABLE;
397 	pci_write_reg(chan, data, SH4A_PCIEDLINTENR);
398 
399 	/* Disable MAC data scrambling. */
400 	data = pci_read_reg(chan, SH4A_PCIEMACCTLR);
401 	data |= PCIEMACCTLR_SCR_DIS | (0xff << 16);
402 	pci_write_reg(chan, data, SH4A_PCIEMACCTLR);
403 
404 	/*
405 	 * This will timeout if we don't have a link, but we permit the
406 	 * port to register anyways in order to support hotplug on future
407 	 * hardware.
408 	 */
409 	ret = pci_wait_for_irq(chan, MASK_INT_TX_CTRL);
410 
411 	data = pci_read_reg(chan, SH4A_PCIEPCICONF1);
412 	data &= ~(PCI_STATUS_DEVSEL_MASK << 16);
413 	data |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
414 		(PCI_STATUS_CAP_LIST | PCI_STATUS_DEVSEL_FAST) << 16;
415 	pci_write_reg(chan, data, SH4A_PCIEPCICONF1);
416 
417 	pci_write_reg(chan, 0x80888000, SH4A_PCIETXVC0DCTLR);
418 	pci_write_reg(chan, 0x00222000, SH4A_PCIERXVC0DCTLR);
419 
420 	wmb();
421 
422 	if (ret == 0) {
423 		data = pci_read_reg(chan, SH4A_PCIEMACSR);
424 		printk(KERN_NOTICE "PCI: PCIe#%d x%d link detected\n",
425 		       port->index, (data >> 20) & 0x3f);
426 	} else
427 		printk(KERN_NOTICE "PCI: PCIe#%d link down\n",
428 		       port->index);
429 
430 	for (i = win = 0; i < chan->nr_resources; i++) {
431 		struct resource *res = chan->resources + i;
432 		resource_size_t size;
433 		u32 mask;
434 
435 		/*
436 		 * We can't use the 32-bit mode windows in legacy 29-bit
437 		 * mode, so just skip them entirely.
438 		 */
439 		if ((res->flags & IORESOURCE_MEM_32BIT) && __in_29bit_mode())
440 			continue;
441 
442 		pci_write_reg(chan, 0x00000000, SH4A_PCIEPTCTLR(win));
443 
444 		/*
445 		 * The PAMR mask is calculated in units of 256kB, which
446 		 * keeps things pretty simple.
447 		 */
448 		size = resource_size(res);
449 		mask = (roundup_pow_of_two(size) / SZ_256K) - 1;
450 		pci_write_reg(chan, mask << 18, SH4A_PCIEPAMR(win));
451 
452 		pci_write_reg(chan, upper_32_bits(res->start),
453 			      SH4A_PCIEPARH(win));
454 		pci_write_reg(chan, lower_32_bits(res->start),
455 			      SH4A_PCIEPARL(win));
456 
457 		mask = MASK_PARE;
458 		if (res->flags & IORESOURCE_IO)
459 			mask |= MASK_SPC;
460 
461 		pci_write_reg(chan, mask, SH4A_PCIEPTCTLR(win));
462 
463 		win++;
464 	}
465 
466 	return 0;
467 }
468 
469 int __init pcibios_map_platform_irq(struct pci_dev *pdev, u8 slot, u8 pin)
470 {
471         return 71;
472 }
473 
474 static int __init sh7786_pcie_core_init(void)
475 {
476 	/* Return the number of ports */
477 	return test_mode_pin(MODE_PIN12) ? 3 : 2;
478 }
479 
480 static void __init sh7786_pcie_init_hw(void *data, async_cookie_t cookie)
481 {
482 	struct sh7786_pcie_port *port = data;
483 	int ret;
484 
485 	/*
486 	 * Check if we are configured in endpoint or root complex mode,
487 	 * this is a fixed pin setting that applies to all PCIe ports.
488 	 */
489 	port->endpoint = test_mode_pin(MODE_PIN11);
490 
491 	/*
492 	 * Setup clocks, needed both for PHY and PCIe registers.
493 	 */
494 	ret = pcie_clk_init(port);
495 	if (unlikely(ret < 0)) {
496 		pr_err("clock initialization failed for port#%d\n",
497 		       port->index);
498 		return;
499 	}
500 
501 	ret = phy_init(port);
502 	if (unlikely(ret < 0)) {
503 		pr_err("phy initialization failed for port#%d\n",
504 		       port->index);
505 		return;
506 	}
507 
508 	ret = pcie_init(port);
509 	if (unlikely(ret < 0)) {
510 		pr_err("core initialization failed for port#%d\n",
511 			       port->index);
512 		return;
513 	}
514 
515 	/* In the interest of preserving device ordering, synchronize */
516 	async_synchronize_cookie(cookie);
517 
518 	register_pci_controller(port->hose);
519 }
520 
521 static struct sh7786_pcie_hwops sh7786_65nm_pcie_hwops __initdata = {
522 	.core_init	= sh7786_pcie_core_init,
523 	.port_init_hw	= sh7786_pcie_init_hw,
524 };
525 
526 static int __init sh7786_pcie_init(void)
527 {
528 	struct clk *platclk;
529 	int i;
530 
531 	printk(KERN_NOTICE "PCI: Starting initialization.\n");
532 
533 	sh7786_pcie_hwops = &sh7786_65nm_pcie_hwops;
534 
535 	nr_ports = sh7786_pcie_hwops->core_init();
536 	BUG_ON(nr_ports > ARRAY_SIZE(sh7786_pci_channels));
537 
538 	if (unlikely(nr_ports == 0))
539 		return -ENODEV;
540 
541 	sh7786_pcie_ports = kzalloc(nr_ports * sizeof(struct sh7786_pcie_port),
542 				    GFP_KERNEL);
543 	if (unlikely(!sh7786_pcie_ports))
544 		return -ENOMEM;
545 
546 	/*
547 	 * Fetch any optional platform clock associated with this block.
548 	 *
549 	 * This is a rather nasty hack for boards with spec-mocking FPGAs
550 	 * that have a secondary set of clocks outside of the on-chip
551 	 * ones that need to be accounted for before there is any chance
552 	 * of touching the existing MSTP bits or CPG clocks.
553 	 */
554 	platclk = clk_get(NULL, "pcie_plat_clk");
555 	if (IS_ERR(platclk)) {
556 		/* Sane hardware should probably get a WARN_ON.. */
557 		platclk = NULL;
558 	}
559 
560 	clk_enable(platclk);
561 
562 	printk(KERN_NOTICE "PCI: probing %d ports.\n", nr_ports);
563 
564 	for (i = 0; i < nr_ports; i++) {
565 		struct sh7786_pcie_port *port = sh7786_pcie_ports + i;
566 
567 		port->index		= i;
568 		port->hose		= sh7786_pci_channels + i;
569 		port->hose->io_map_base	= port->hose->resources[0].start;
570 
571 		async_schedule(sh7786_pcie_hwops->port_init_hw, port);
572 	}
573 
574 	async_synchronize_full();
575 
576 	return 0;
577 }
578 arch_initcall(sh7786_pcie_init);
579