1/*
2 *  Ralink RT3662/RT3883 SoC PCI support
3 *
4 *  Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
5 *
6 *  Parts of this file are based on Ralink's 2.6.21 BSP
7 *
8 *  This program is free software; you can redistribute it and/or modify it
9 *  under the terms of the GNU General Public License version 2 as published
10 *  by the Free Software Foundation.
11 */
12
13#include <linux/types.h>
14#include <linux/pci.h>
15#include <linux/io.h>
16#include <linux/init.h>
17#include <linux/delay.h>
18#include <linux/interrupt.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/of_irq.h>
22#include <linux/of_pci.h>
23#include <linux/platform_device.h>
24
25#include <asm/mach-ralink/rt3883.h>
26#include <asm/mach-ralink/ralink_regs.h>
27
28#define RT3883_MEMORY_BASE		0x00000000
29#define RT3883_MEMORY_SIZE		0x02000000
30
31#define RT3883_PCI_REG_PCICFG		0x00
32#define   RT3883_PCICFG_P2P_BR_DEVNUM_M 0xf
33#define   RT3883_PCICFG_P2P_BR_DEVNUM_S 16
34#define   RT3883_PCICFG_PCIRST		BIT(1)
35#define RT3883_PCI_REG_PCIRAW		0x04
36#define RT3883_PCI_REG_PCIINT		0x08
37#define RT3883_PCI_REG_PCIENA		0x0c
38
39#define RT3883_PCI_REG_CFGADDR		0x20
40#define RT3883_PCI_REG_CFGDATA		0x24
41#define RT3883_PCI_REG_MEMBASE		0x28
42#define RT3883_PCI_REG_IOBASE		0x2c
43#define RT3883_PCI_REG_ARBCTL		0x80
44
45#define RT3883_PCI_REG_BASE(_x)		(0x1000 + (_x) * 0x1000)
46#define RT3883_PCI_REG_BAR0SETUP(_x)	(RT3883_PCI_REG_BASE((_x)) + 0x10)
47#define RT3883_PCI_REG_IMBASEBAR0(_x)	(RT3883_PCI_REG_BASE((_x)) + 0x18)
48#define RT3883_PCI_REG_ID(_x)		(RT3883_PCI_REG_BASE((_x)) + 0x30)
49#define RT3883_PCI_REG_CLASS(_x)	(RT3883_PCI_REG_BASE((_x)) + 0x34)
50#define RT3883_PCI_REG_SUBID(_x)	(RT3883_PCI_REG_BASE((_x)) + 0x38)
51#define RT3883_PCI_REG_STATUS(_x)	(RT3883_PCI_REG_BASE((_x)) + 0x50)
52
53#define RT3883_PCI_MODE_NONE	0
54#define RT3883_PCI_MODE_PCI	BIT(0)
55#define RT3883_PCI_MODE_PCIE	BIT(1)
56#define RT3883_PCI_MODE_BOTH	(RT3883_PCI_MODE_PCI | RT3883_PCI_MODE_PCIE)
57
58#define RT3883_PCI_IRQ_COUNT	32
59
60#define RT3883_P2P_BR_DEVNUM	1
61
62struct rt3883_pci_controller {
63	void __iomem *base;
64
65	struct device_node *intc_of_node;
66	struct irq_domain *irq_domain;
67
68	struct pci_controller pci_controller;
69	struct resource io_res;
70	struct resource mem_res;
71
72	bool pcie_ready;
73};
74
75static inline struct rt3883_pci_controller *
76pci_bus_to_rt3883_controller(struct pci_bus *bus)
77{
78	struct pci_controller *hose;
79
80	hose = (struct pci_controller *) bus->sysdata;
81	return container_of(hose, struct rt3883_pci_controller, pci_controller);
82}
83
84static inline u32 rt3883_pci_r32(struct rt3883_pci_controller *rpc,
85				 unsigned reg)
86{
87	return ioread32(rpc->base + reg);
88}
89
90static inline void rt3883_pci_w32(struct rt3883_pci_controller *rpc,
91				  u32 val, unsigned reg)
92{
93	iowrite32(val, rpc->base + reg);
94}
95
96static inline u32 rt3883_pci_get_cfgaddr(unsigned int bus, unsigned int slot,
97					 unsigned int func, unsigned int where)
98{
99	return (bus << 16) | (slot << 11) | (func << 8) | (where & 0xfc) |
100	       0x80000000;
101}
102
103static u32 rt3883_pci_read_cfg32(struct rt3883_pci_controller *rpc,
104			       unsigned bus, unsigned slot,
105			       unsigned func, unsigned reg)
106{
107	unsigned long flags;
108	u32 address;
109	u32 ret;
110
111	address = rt3883_pci_get_cfgaddr(bus, slot, func, reg);
112
113	rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
114	ret = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
115
116	return ret;
117}
118
119static void rt3883_pci_write_cfg32(struct rt3883_pci_controller *rpc,
120				 unsigned bus, unsigned slot,
121				 unsigned func, unsigned reg, u32 val)
122{
123	unsigned long flags;
124	u32 address;
125
126	address = rt3883_pci_get_cfgaddr(bus, slot, func, reg);
127
128	rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
129	rt3883_pci_w32(rpc, val, RT3883_PCI_REG_CFGDATA);
130}
131
132static void rt3883_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
133{
134	struct rt3883_pci_controller *rpc;
135	u32 pending;
136
137	rpc = irq_get_handler_data(irq);
138
139	pending = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIINT) &
140		  rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
141
142	if (!pending) {
143		spurious_interrupt();
144		return;
145	}
146
147	while (pending) {
148		unsigned bit = __ffs(pending);
149
150		irq = irq_find_mapping(rpc->irq_domain, bit);
151		generic_handle_irq(irq);
152
153		pending &= ~BIT(bit);
154	}
155}
156
157static void rt3883_pci_irq_unmask(struct irq_data *d)
158{
159	struct rt3883_pci_controller *rpc;
160	u32 t;
161
162	rpc = irq_data_get_irq_chip_data(d);
163
164	t = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
165	rt3883_pci_w32(rpc, t | BIT(d->hwirq), RT3883_PCI_REG_PCIENA);
166	/* flush write */
167	rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
168}
169
170static void rt3883_pci_irq_mask(struct irq_data *d)
171{
172	struct rt3883_pci_controller *rpc;
173	u32 t;
174
175	rpc = irq_data_get_irq_chip_data(d);
176
177	t = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
178	rt3883_pci_w32(rpc, t & ~BIT(d->hwirq), RT3883_PCI_REG_PCIENA);
179	/* flush write */
180	rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
181}
182
183static struct irq_chip rt3883_pci_irq_chip = {
184	.name		= "RT3883 PCI",
185	.irq_mask	= rt3883_pci_irq_mask,
186	.irq_unmask	= rt3883_pci_irq_unmask,
187	.irq_mask_ack	= rt3883_pci_irq_mask,
188};
189
190static int rt3883_pci_irq_map(struct irq_domain *d, unsigned int irq,
191			      irq_hw_number_t hw)
192{
193	irq_set_chip_and_handler(irq, &rt3883_pci_irq_chip, handle_level_irq);
194	irq_set_chip_data(irq, d->host_data);
195
196	return 0;
197}
198
199static const struct irq_domain_ops rt3883_pci_irq_domain_ops = {
200	.map = rt3883_pci_irq_map,
201	.xlate = irq_domain_xlate_onecell,
202};
203
204static int rt3883_pci_irq_init(struct device *dev,
205			       struct rt3883_pci_controller *rpc)
206{
207	int irq;
208
209	irq = irq_of_parse_and_map(rpc->intc_of_node, 0);
210	if (irq == 0) {
211		dev_err(dev, "%s has no IRQ",
212			of_node_full_name(rpc->intc_of_node));
213		return -EINVAL;
214	}
215
216	/* disable all interrupts */
217	rt3883_pci_w32(rpc, 0, RT3883_PCI_REG_PCIENA);
218
219	rpc->irq_domain =
220		irq_domain_add_linear(rpc->intc_of_node, RT3883_PCI_IRQ_COUNT,
221				      &rt3883_pci_irq_domain_ops,
222				      rpc);
223	if (!rpc->irq_domain) {
224		dev_err(dev, "unable to add IRQ domain\n");
225		return -ENODEV;
226	}
227
228	irq_set_handler_data(irq, rpc);
229	irq_set_chained_handler(irq, rt3883_pci_irq_handler);
230
231	return 0;
232}
233
234static int rt3883_pci_config_read(struct pci_bus *bus, unsigned int devfn,
235				  int where, int size, u32 *val)
236{
237	struct rt3883_pci_controller *rpc;
238	unsigned long flags;
239	u32 address;
240	u32 data;
241
242	rpc = pci_bus_to_rt3883_controller(bus);
243
244	if (!rpc->pcie_ready && bus->number == 1)
245		return PCIBIOS_DEVICE_NOT_FOUND;
246
247	address = rt3883_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
248					 PCI_FUNC(devfn), where);
249
250	rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
251	data = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
252
253	switch (size) {
254	case 1:
255		*val = (data >> ((where & 3) << 3)) & 0xff;
256		break;
257	case 2:
258		*val = (data >> ((where & 3) << 3)) & 0xffff;
259		break;
260	case 4:
261		*val = data;
262		break;
263	}
264
265	return PCIBIOS_SUCCESSFUL;
266}
267
268static int rt3883_pci_config_write(struct pci_bus *bus, unsigned int devfn,
269				   int where, int size, u32 val)
270{
271	struct rt3883_pci_controller *rpc;
272	unsigned long flags;
273	u32 address;
274	u32 data;
275
276	rpc = pci_bus_to_rt3883_controller(bus);
277
278	if (!rpc->pcie_ready && bus->number == 1)
279		return PCIBIOS_DEVICE_NOT_FOUND;
280
281	address = rt3883_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
282					 PCI_FUNC(devfn), where);
283
284	rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
285	data = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
286
287	switch (size) {
288	case 1:
289		data = (data & ~(0xff << ((where & 3) << 3))) |
290		       (val << ((where & 3) << 3));
291		break;
292	case 2:
293		data = (data & ~(0xffff << ((where & 3) << 3))) |
294		       (val << ((where & 3) << 3));
295		break;
296	case 4:
297		data = val;
298		break;
299	}
300
301	rt3883_pci_w32(rpc, data, RT3883_PCI_REG_CFGDATA);
302
303	return PCIBIOS_SUCCESSFUL;
304}
305
306static struct pci_ops rt3883_pci_ops = {
307	.read	= rt3883_pci_config_read,
308	.write	= rt3883_pci_config_write,
309};
310
311static void rt3883_pci_preinit(struct rt3883_pci_controller *rpc, unsigned mode)
312{
313	u32 syscfg1;
314	u32 rstctrl;
315	u32 clkcfg1;
316	u32 t;
317
318	rstctrl = rt_sysc_r32(RT3883_SYSC_REG_RSTCTRL);
319	syscfg1 = rt_sysc_r32(RT3883_SYSC_REG_SYSCFG1);
320	clkcfg1 = rt_sysc_r32(RT3883_SYSC_REG_CLKCFG1);
321
322	if (mode & RT3883_PCI_MODE_PCIE) {
323		rstctrl |= RT3883_RSTCTRL_PCIE;
324		rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
325
326		/* setup PCI PAD drive mode */
327		syscfg1 &= ~(0x30);
328		syscfg1 |= (2 << 4);
329		rt_sysc_w32(syscfg1, RT3883_SYSC_REG_SYSCFG1);
330
331		t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
332		t &= ~BIT(31);
333		rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
334
335		t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN1);
336		t &= 0x80ffffff;
337		rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN1);
338
339		t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN1);
340		t |= 0xa << 24;
341		rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN1);
342
343		t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
344		t |= BIT(31);
345		rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
346
347		msleep(50);
348
349		rstctrl &= ~RT3883_RSTCTRL_PCIE;
350		rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
351	}
352
353	syscfg1 |= (RT3883_SYSCFG1_PCIE_RC_MODE | RT3883_SYSCFG1_PCI_HOST_MODE);
354
355	clkcfg1 &= ~(RT3883_CLKCFG1_PCI_CLK_EN | RT3883_CLKCFG1_PCIE_CLK_EN);
356
357	if (mode & RT3883_PCI_MODE_PCI) {
358		clkcfg1 |= RT3883_CLKCFG1_PCI_CLK_EN;
359		rstctrl &= ~RT3883_RSTCTRL_PCI;
360	}
361
362	if (mode & RT3883_PCI_MODE_PCIE) {
363		clkcfg1 |= RT3883_CLKCFG1_PCIE_CLK_EN;
364		rstctrl &= ~RT3883_RSTCTRL_PCIE;
365	}
366
367	rt_sysc_w32(syscfg1, RT3883_SYSC_REG_SYSCFG1);
368	rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
369	rt_sysc_w32(clkcfg1, RT3883_SYSC_REG_CLKCFG1);
370
371	msleep(500);
372
373	/*
374	 * setup the device number of the P2P bridge
375	 * and de-assert the reset line
376	 */
377	t = (RT3883_P2P_BR_DEVNUM << RT3883_PCICFG_P2P_BR_DEVNUM_S);
378	rt3883_pci_w32(rpc, t, RT3883_PCI_REG_PCICFG);
379
380	/* flush write */
381	rt3883_pci_r32(rpc, RT3883_PCI_REG_PCICFG);
382	msleep(500);
383
384	if (mode & RT3883_PCI_MODE_PCIE) {
385		msleep(500);
386
387		t = rt3883_pci_r32(rpc, RT3883_PCI_REG_STATUS(1));
388
389		rpc->pcie_ready = t & BIT(0);
390
391		if (!rpc->pcie_ready) {
392			/* reset the PCIe block */
393			t = rt_sysc_r32(RT3883_SYSC_REG_RSTCTRL);
394			t |= RT3883_RSTCTRL_PCIE;
395			rt_sysc_w32(t, RT3883_SYSC_REG_RSTCTRL);
396			t &= ~RT3883_RSTCTRL_PCIE;
397			rt_sysc_w32(t, RT3883_SYSC_REG_RSTCTRL);
398
399			/* turn off PCIe clock */
400			t = rt_sysc_r32(RT3883_SYSC_REG_CLKCFG1);
401			t &= ~RT3883_CLKCFG1_PCIE_CLK_EN;
402			rt_sysc_w32(t, RT3883_SYSC_REG_CLKCFG1);
403
404			t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
405			t &= ~0xf000c080;
406			rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
407		}
408	}
409
410	/* enable PCI arbiter */
411	rt3883_pci_w32(rpc, 0x79, RT3883_PCI_REG_ARBCTL);
412}
413
414static int rt3883_pci_probe(struct platform_device *pdev)
415{
416	struct rt3883_pci_controller *rpc;
417	struct device *dev = &pdev->dev;
418	struct device_node *np = dev->of_node;
419	struct resource *res;
420	struct device_node *child;
421	u32 val;
422	int err;
423	int mode;
424
425	rpc = devm_kzalloc(dev, sizeof(*rpc), GFP_KERNEL);
426	if (!rpc)
427		return -ENOMEM;
428
429	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
430	rpc->base = devm_ioremap_resource(dev, res);
431	if (IS_ERR(rpc->base))
432		return PTR_ERR(rpc->base);
433
434	/* find the interrupt controller child node */
435	for_each_child_of_node(np, child) {
436		if (of_get_property(child, "interrupt-controller", NULL) &&
437		    of_node_get(child)) {
438			rpc->intc_of_node = child;
439			break;
440		}
441	}
442
443	if (!rpc->intc_of_node) {
444		dev_err(dev, "%s has no %s child node",
445			of_node_full_name(rpc->intc_of_node),
446			"interrupt controller");
447		return -EINVAL;
448	}
449
450	/* find the PCI host bridge child node */
451	for_each_child_of_node(np, child) {
452		if (child->type &&
453		    of_node_cmp(child->type, "pci") == 0 &&
454		    of_node_get(child)) {
455			rpc->pci_controller.of_node = child;
456			break;
457		}
458	}
459
460	if (!rpc->pci_controller.of_node) {
461		dev_err(dev, "%s has no %s child node",
462			of_node_full_name(rpc->intc_of_node),
463			"PCI host bridge");
464		err = -EINVAL;
465		goto err_put_intc_node;
466	}
467
468	mode = RT3883_PCI_MODE_NONE;
469	for_each_available_child_of_node(rpc->pci_controller.of_node, child) {
470		int devfn;
471
472		if (!child->type ||
473		    of_node_cmp(child->type, "pci") != 0)
474			continue;
475
476		devfn = of_pci_get_devfn(child);
477		if (devfn < 0)
478			continue;
479
480		switch (PCI_SLOT(devfn)) {
481		case 1:
482			mode |= RT3883_PCI_MODE_PCIE;
483			break;
484
485		case 17:
486		case 18:
487			mode |= RT3883_PCI_MODE_PCI;
488			break;
489		}
490	}
491
492	if (mode == RT3883_PCI_MODE_NONE) {
493		dev_err(dev, "unable to determine PCI mode\n");
494		err = -EINVAL;
495		goto err_put_hb_node;
496	}
497
498	dev_info(dev, "mode:%s%s\n",
499		 (mode & RT3883_PCI_MODE_PCI) ? " PCI" : "",
500		 (mode & RT3883_PCI_MODE_PCIE) ? " PCIe" : "");
501
502	rt3883_pci_preinit(rpc, mode);
503
504	rpc->pci_controller.pci_ops = &rt3883_pci_ops;
505	rpc->pci_controller.io_resource = &rpc->io_res;
506	rpc->pci_controller.mem_resource = &rpc->mem_res;
507
508	/* Load PCI I/O and memory resources from DT */
509	pci_load_of_ranges(&rpc->pci_controller,
510			   rpc->pci_controller.of_node);
511
512	rt3883_pci_w32(rpc, rpc->mem_res.start, RT3883_PCI_REG_MEMBASE);
513	rt3883_pci_w32(rpc, rpc->io_res.start, RT3883_PCI_REG_IOBASE);
514
515	ioport_resource.start = rpc->io_res.start;
516	ioport_resource.end = rpc->io_res.end;
517
518	/* PCI */
519	rt3883_pci_w32(rpc, 0x03ff0000, RT3883_PCI_REG_BAR0SETUP(0));
520	rt3883_pci_w32(rpc, RT3883_MEMORY_BASE, RT3883_PCI_REG_IMBASEBAR0(0));
521	rt3883_pci_w32(rpc, 0x08021814, RT3883_PCI_REG_ID(0));
522	rt3883_pci_w32(rpc, 0x00800001, RT3883_PCI_REG_CLASS(0));
523	rt3883_pci_w32(rpc, 0x28801814, RT3883_PCI_REG_SUBID(0));
524
525	/* PCIe */
526	rt3883_pci_w32(rpc, 0x03ff0000, RT3883_PCI_REG_BAR0SETUP(1));
527	rt3883_pci_w32(rpc, RT3883_MEMORY_BASE, RT3883_PCI_REG_IMBASEBAR0(1));
528	rt3883_pci_w32(rpc, 0x08021814, RT3883_PCI_REG_ID(1));
529	rt3883_pci_w32(rpc, 0x06040001, RT3883_PCI_REG_CLASS(1));
530	rt3883_pci_w32(rpc, 0x28801814, RT3883_PCI_REG_SUBID(1));
531
532	err = rt3883_pci_irq_init(dev, rpc);
533	if (err)
534		goto err_put_hb_node;
535
536	/* PCIe */
537	val = rt3883_pci_read_cfg32(rpc, 0, 0x01, 0, PCI_COMMAND);
538	val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
539	rt3883_pci_write_cfg32(rpc, 0, 0x01, 0, PCI_COMMAND, val);
540
541	/* PCI */
542	val = rt3883_pci_read_cfg32(rpc, 0, 0x00, 0, PCI_COMMAND);
543	val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
544	rt3883_pci_write_cfg32(rpc, 0, 0x00, 0, PCI_COMMAND, val);
545
546	if (mode == RT3883_PCI_MODE_PCIE) {
547		rt3883_pci_w32(rpc, 0x03ff0001, RT3883_PCI_REG_BAR0SETUP(0));
548		rt3883_pci_w32(rpc, 0x03ff0001, RT3883_PCI_REG_BAR0SETUP(1));
549
550		rt3883_pci_write_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
551				       PCI_BASE_ADDRESS_0,
552				       RT3883_MEMORY_BASE);
553		/* flush write */
554		rt3883_pci_read_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
555				      PCI_BASE_ADDRESS_0);
556	} else {
557		rt3883_pci_write_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
558				       PCI_IO_BASE, 0x00000101);
559	}
560
561	register_pci_controller(&rpc->pci_controller);
562
563	return 0;
564
565err_put_hb_node:
566	of_node_put(rpc->pci_controller.of_node);
567err_put_intc_node:
568	of_node_put(rpc->intc_of_node);
569	return err;
570}
571
572int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
573{
574	return of_irq_parse_and_map_pci(dev, slot, pin);
575}
576
577int pcibios_plat_dev_init(struct pci_dev *dev)
578{
579	return 0;
580}
581
582static const struct of_device_id rt3883_pci_ids[] = {
583	{ .compatible = "ralink,rt3883-pci" },
584	{},
585};
586MODULE_DEVICE_TABLE(of, rt3883_pci_ids);
587
588static struct platform_driver rt3883_pci_driver = {
589	.probe = rt3883_pci_probe,
590	.driver = {
591		.name = "rt3883-pci",
592		.of_match_table = of_match_ptr(rt3883_pci_ids),
593	},
594};
595
596static int __init rt3883_pci_init(void)
597{
598	return platform_driver_register(&rt3883_pci_driver);
599}
600
601postcore_initcall(rt3883_pci_init);
602