1/*
2 * Alchemy PCI host mode support.
3 *
4 * Copyright 2001-2003, 2007-2008 MontaVista Software Inc.
5 * Author: MontaVista Software, Inc. <source@mvista.com>
6 *
7 * Support for all devices (greater than 16) added by David Gathright.
8 */
9
10#include <linux/clk.h>
11#include <linux/export.h>
12#include <linux/types.h>
13#include <linux/pci.h>
14#include <linux/platform_device.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/syscore_ops.h>
18#include <linux/vmalloc.h>
19
20#include <asm/dma-coherence.h>
21#include <asm/mach-au1x00/au1000.h>
22#include <asm/tlbmisc.h>
23
24#ifdef CONFIG_PCI_DEBUG
25#define DBG(x...) printk(KERN_DEBUG x)
26#else
27#define DBG(x...) do {} while (0)
28#endif
29
30#define PCI_ACCESS_READ		0
31#define PCI_ACCESS_WRITE	1
32
33struct alchemy_pci_context {
34	struct pci_controller alchemy_pci_ctrl; /* leave as first member! */
35	void __iomem *regs;			/* ctrl base */
36	/* tools for wired entry for config space access */
37	unsigned long last_elo0;
38	unsigned long last_elo1;
39	int wired_entry;
40	struct vm_struct *pci_cfg_vm;
41
42	unsigned long pm[12];
43
44	int (*board_map_irq)(const struct pci_dev *d, u8 slot, u8 pin);
45	int (*board_pci_idsel)(unsigned int devsel, int assert);
46};
47
48/* for syscore_ops. There's only one PCI controller on Alchemy chips, so this
49 * should suffice for now.
50 */
51static struct alchemy_pci_context *__alchemy_pci_ctx;
52
53
54/* IO/MEM resources for PCI. Keep the memres in sync with __fixup_bigphys_addr
55 * in arch/mips/alchemy/common/setup.c
56 */
57static struct resource alchemy_pci_def_memres = {
58	.start	= ALCHEMY_PCI_MEMWIN_START,
59	.end	= ALCHEMY_PCI_MEMWIN_END,
60	.name	= "PCI memory space",
61	.flags	= IORESOURCE_MEM
62};
63
64static struct resource alchemy_pci_def_iores = {
65	.start	= ALCHEMY_PCI_IOWIN_START,
66	.end	= ALCHEMY_PCI_IOWIN_END,
67	.name	= "PCI IO space",
68	.flags	= IORESOURCE_IO
69};
70
71static void mod_wired_entry(int entry, unsigned long entrylo0,
72		unsigned long entrylo1, unsigned long entryhi,
73		unsigned long pagemask)
74{
75	unsigned long old_pagemask;
76	unsigned long old_ctx;
77
78	/* Save old context and create impossible VPN2 value */
79	old_ctx = read_c0_entryhi() & 0xff;
80	old_pagemask = read_c0_pagemask();
81	write_c0_index(entry);
82	write_c0_pagemask(pagemask);
83	write_c0_entryhi(entryhi);
84	write_c0_entrylo0(entrylo0);
85	write_c0_entrylo1(entrylo1);
86	tlb_write_indexed();
87	write_c0_entryhi(old_ctx);
88	write_c0_pagemask(old_pagemask);
89}
90
91static void alchemy_pci_wired_entry(struct alchemy_pci_context *ctx)
92{
93	ctx->wired_entry = read_c0_wired();
94	add_wired_entry(0, 0, (unsigned long)ctx->pci_cfg_vm->addr, PM_4K);
95	ctx->last_elo0 = ctx->last_elo1 = ~0;
96}
97
98static int config_access(unsigned char access_type, struct pci_bus *bus,
99			 unsigned int dev_fn, unsigned char where, u32 *data)
100{
101	struct alchemy_pci_context *ctx = bus->sysdata;
102	unsigned int device = PCI_SLOT(dev_fn);
103	unsigned int function = PCI_FUNC(dev_fn);
104	unsigned long offset, status, cfg_base, flags, entryLo0, entryLo1, r;
105	int error = PCIBIOS_SUCCESSFUL;
106
107	if (device > 19) {
108		*data = 0xffffffff;
109		return -1;
110	}
111
112	local_irq_save(flags);
113	r = __raw_readl(ctx->regs + PCI_REG_STATCMD) & 0x0000ffff;
114	r |= PCI_STATCMD_STATUS(0x2000);
115	__raw_writel(r, ctx->regs + PCI_REG_STATCMD);
116	wmb();
117
118	/* Allow board vendors to implement their own off-chip IDSEL.
119	 * If it doesn't succeed, may as well bail out at this point.
120	 */
121	if (ctx->board_pci_idsel(device, 1) == 0) {
122		*data = 0xffffffff;
123		local_irq_restore(flags);
124		return -1;
125	}
126
127	/* Setup the config window */
128	if (bus->number == 0)
129		cfg_base = (1 << device) << 11;
130	else
131		cfg_base = 0x80000000 | (bus->number << 16) | (device << 11);
132
133	/* Setup the lower bits of the 36-bit address */
134	offset = (function << 8) | (where & ~0x3);
135	/* Pick up any address that falls below the page mask */
136	offset |= cfg_base & ~PAGE_MASK;
137
138	/* Page boundary */
139	cfg_base = cfg_base & PAGE_MASK;
140
141	/* To improve performance, if the current device is the same as
142	 * the last device accessed, we don't touch the TLB.
143	 */
144	entryLo0 = (6 << 26) | (cfg_base >> 6) | (2 << 3) | 7;
145	entryLo1 = (6 << 26) | (cfg_base >> 6) | (0x1000 >> 6) | (2 << 3) | 7;
146	if ((entryLo0 != ctx->last_elo0) || (entryLo1 != ctx->last_elo1)) {
147		mod_wired_entry(ctx->wired_entry, entryLo0, entryLo1,
148				(unsigned long)ctx->pci_cfg_vm->addr, PM_4K);
149		ctx->last_elo0 = entryLo0;
150		ctx->last_elo1 = entryLo1;
151	}
152
153	if (access_type == PCI_ACCESS_WRITE)
154		__raw_writel(*data, ctx->pci_cfg_vm->addr + offset);
155	else
156		*data = __raw_readl(ctx->pci_cfg_vm->addr + offset);
157	wmb();
158
159	DBG("alchemy-pci: cfg access %d bus %u dev %u at %x dat %x conf %lx\n",
160	    access_type, bus->number, device, where, *data, offset);
161
162	/* check for errors, master abort */
163	status = __raw_readl(ctx->regs + PCI_REG_STATCMD);
164	if (status & (1 << 29)) {
165		*data = 0xffffffff;
166		error = -1;
167		DBG("alchemy-pci: master abort on cfg access %d bus %d dev %d\n",
168		    access_type, bus->number, device);
169	} else if ((status >> 28) & 0xf) {
170		DBG("alchemy-pci: PCI ERR detected: dev %d, status %lx\n",
171		    device, (status >> 28) & 0xf);
172
173		/* clear errors */
174		__raw_writel(status & 0xf000ffff, ctx->regs + PCI_REG_STATCMD);
175
176		*data = 0xffffffff;
177		error = -1;
178	}
179
180	/* Take away the IDSEL. */
181	(void)ctx->board_pci_idsel(device, 0);
182
183	local_irq_restore(flags);
184	return error;
185}
186
187static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
188			    int where,	u8 *val)
189{
190	u32 data;
191	int ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
192
193	if (where & 1)
194		data >>= 8;
195	if (where & 2)
196		data >>= 16;
197	*val = data & 0xff;
198	return ret;
199}
200
201static int read_config_word(struct pci_bus *bus, unsigned int devfn,
202			    int where, u16 *val)
203{
204	u32 data;
205	int ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
206
207	if (where & 2)
208		data >>= 16;
209	*val = data & 0xffff;
210	return ret;
211}
212
213static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
214			     int where, u32 *val)
215{
216	return config_access(PCI_ACCESS_READ, bus, devfn, where, val);
217}
218
219static int write_config_byte(struct pci_bus *bus, unsigned int devfn,
220			     int where, u8 val)
221{
222	u32 data = 0;
223
224	if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
225		return -1;
226
227	data = (data & ~(0xff << ((where & 3) << 3))) |
228	       (val << ((where & 3) << 3));
229
230	if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
231		return -1;
232
233	return PCIBIOS_SUCCESSFUL;
234}
235
236static int write_config_word(struct pci_bus *bus, unsigned int devfn,
237			     int where, u16 val)
238{
239	u32 data = 0;
240
241	if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
242		return -1;
243
244	data = (data & ~(0xffff << ((where & 3) << 3))) |
245	       (val << ((where & 3) << 3));
246
247	if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
248		return -1;
249
250	return PCIBIOS_SUCCESSFUL;
251}
252
253static int write_config_dword(struct pci_bus *bus, unsigned int devfn,
254			      int where, u32 val)
255{
256	return config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val);
257}
258
259static int alchemy_pci_read(struct pci_bus *bus, unsigned int devfn,
260		       int where, int size, u32 *val)
261{
262	switch (size) {
263	case 1: {
264			u8 _val;
265			int rc = read_config_byte(bus, devfn, where, &_val);
266
267			*val = _val;
268			return rc;
269		}
270	case 2: {
271			u16 _val;
272			int rc = read_config_word(bus, devfn, where, &_val);
273
274			*val = _val;
275			return rc;
276		}
277	default:
278		return read_config_dword(bus, devfn, where, val);
279	}
280}
281
282static int alchemy_pci_write(struct pci_bus *bus, unsigned int devfn,
283			     int where, int size, u32 val)
284{
285	switch (size) {
286	case 1:
287		return write_config_byte(bus, devfn, where, (u8) val);
288	case 2:
289		return write_config_word(bus, devfn, where, (u16) val);
290	default:
291		return write_config_dword(bus, devfn, where, val);
292	}
293}
294
295static struct pci_ops alchemy_pci_ops = {
296	.read	= alchemy_pci_read,
297	.write	= alchemy_pci_write,
298};
299
300static int alchemy_pci_def_idsel(unsigned int devsel, int assert)
301{
302	return 1;	/* success */
303}
304
305/* save PCI controller register contents. */
306static int alchemy_pci_suspend(void)
307{
308	struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
309	if (!ctx)
310		return 0;
311
312	ctx->pm[0]  = __raw_readl(ctx->regs + PCI_REG_CMEM);
313	ctx->pm[1]  = __raw_readl(ctx->regs + PCI_REG_CONFIG) & 0x0009ffff;
314	ctx->pm[2]  = __raw_readl(ctx->regs + PCI_REG_B2BMASK_CCH);
315	ctx->pm[3]  = __raw_readl(ctx->regs + PCI_REG_B2BBASE0_VID);
316	ctx->pm[4]  = __raw_readl(ctx->regs + PCI_REG_B2BBASE1_SID);
317	ctx->pm[5]  = __raw_readl(ctx->regs + PCI_REG_MWMASK_DEV);
318	ctx->pm[6]  = __raw_readl(ctx->regs + PCI_REG_MWBASE_REV_CCL);
319	ctx->pm[7]  = __raw_readl(ctx->regs + PCI_REG_ID);
320	ctx->pm[8]  = __raw_readl(ctx->regs + PCI_REG_CLASSREV);
321	ctx->pm[9]  = __raw_readl(ctx->regs + PCI_REG_PARAM);
322	ctx->pm[10] = __raw_readl(ctx->regs + PCI_REG_MBAR);
323	ctx->pm[11] = __raw_readl(ctx->regs + PCI_REG_TIMEOUT);
324
325	return 0;
326}
327
328static void alchemy_pci_resume(void)
329{
330	struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
331	if (!ctx)
332		return;
333
334	__raw_writel(ctx->pm[0],  ctx->regs + PCI_REG_CMEM);
335	__raw_writel(ctx->pm[2],  ctx->regs + PCI_REG_B2BMASK_CCH);
336	__raw_writel(ctx->pm[3],  ctx->regs + PCI_REG_B2BBASE0_VID);
337	__raw_writel(ctx->pm[4],  ctx->regs + PCI_REG_B2BBASE1_SID);
338	__raw_writel(ctx->pm[5],  ctx->regs + PCI_REG_MWMASK_DEV);
339	__raw_writel(ctx->pm[6],  ctx->regs + PCI_REG_MWBASE_REV_CCL);
340	__raw_writel(ctx->pm[7],  ctx->regs + PCI_REG_ID);
341	__raw_writel(ctx->pm[8],  ctx->regs + PCI_REG_CLASSREV);
342	__raw_writel(ctx->pm[9],  ctx->regs + PCI_REG_PARAM);
343	__raw_writel(ctx->pm[10], ctx->regs + PCI_REG_MBAR);
344	__raw_writel(ctx->pm[11], ctx->regs + PCI_REG_TIMEOUT);
345	wmb();
346	__raw_writel(ctx->pm[1],  ctx->regs + PCI_REG_CONFIG);
347	wmb();
348
349	/* YAMON on all db1xxx boards wipes the TLB and writes zero to C0_wired
350	 * on resume, making it necessary to recreate it as soon as possible.
351	 */
352	ctx->wired_entry = 8191;	/* impossibly high value */
353	alchemy_pci_wired_entry(ctx);	/* install it */
354}
355
356static struct syscore_ops alchemy_pci_pmops = {
357	.suspend	= alchemy_pci_suspend,
358	.resume		= alchemy_pci_resume,
359};
360
361static int alchemy_pci_probe(struct platform_device *pdev)
362{
363	struct alchemy_pci_platdata *pd = pdev->dev.platform_data;
364	struct alchemy_pci_context *ctx;
365	void __iomem *virt_io;
366	unsigned long val;
367	struct resource *r;
368	struct clk *c;
369	int ret;
370
371	/* need at least PCI IRQ mapping table */
372	if (!pd) {
373		dev_err(&pdev->dev, "need platform data for PCI setup\n");
374		ret = -ENODEV;
375		goto out;
376	}
377
378	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
379	if (!ctx) {
380		dev_err(&pdev->dev, "no memory for pcictl context\n");
381		ret = -ENOMEM;
382		goto out;
383	}
384
385	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
386	if (!r) {
387		dev_err(&pdev->dev, "no	 pcictl ctrl regs resource\n");
388		ret = -ENODEV;
389		goto out1;
390	}
391
392	if (!request_mem_region(r->start, resource_size(r), pdev->name)) {
393		dev_err(&pdev->dev, "cannot claim pci regs\n");
394		ret = -ENODEV;
395		goto out1;
396	}
397
398	c = clk_get(&pdev->dev, "pci_clko");
399	if (IS_ERR(c)) {
400		dev_err(&pdev->dev, "unable to find PCI clock\n");
401		ret = PTR_ERR(c);
402		goto out2;
403	}
404
405	ret = clk_prepare_enable(c);
406	if (ret) {
407		dev_err(&pdev->dev, "cannot enable PCI clock\n");
408		goto out6;
409	}
410
411	ctx->regs = ioremap_nocache(r->start, resource_size(r));
412	if (!ctx->regs) {
413		dev_err(&pdev->dev, "cannot map pci regs\n");
414		ret = -ENODEV;
415		goto out5;
416	}
417
418	/* map parts of the PCI IO area */
419	/* REVISIT: if this changes with a newer variant (doubt it) make this
420	 * a platform resource.
421	 */
422	virt_io = ioremap(AU1500_PCI_IO_PHYS_ADDR, 0x00100000);
423	if (!virt_io) {
424		dev_err(&pdev->dev, "cannot remap pci io space\n");
425		ret = -ENODEV;
426		goto out3;
427	}
428	ctx->alchemy_pci_ctrl.io_map_base = (unsigned long)virt_io;
429
430	/* Au1500 revisions older than AD have borked coherent PCI */
431	if ((alchemy_get_cputype() == ALCHEMY_CPU_AU1500) &&
432	    (read_c0_prid() < 0x01030202) && !coherentio) {
433		val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
434		val |= PCI_CONFIG_NC;
435		__raw_writel(val, ctx->regs + PCI_REG_CONFIG);
436		wmb();
437		dev_info(&pdev->dev, "non-coherent PCI on Au1500 AA/AB/AC\n");
438	}
439
440	if (pd->board_map_irq)
441		ctx->board_map_irq = pd->board_map_irq;
442
443	if (pd->board_pci_idsel)
444		ctx->board_pci_idsel = pd->board_pci_idsel;
445	else
446		ctx->board_pci_idsel = alchemy_pci_def_idsel;
447
448	/* fill in relevant pci_controller members */
449	ctx->alchemy_pci_ctrl.pci_ops = &alchemy_pci_ops;
450	ctx->alchemy_pci_ctrl.mem_resource = &alchemy_pci_def_memres;
451	ctx->alchemy_pci_ctrl.io_resource = &alchemy_pci_def_iores;
452
453	/* we can't ioremap the entire pci config space because it's too large,
454	 * nor can we dynamically ioremap it because some drivers use the
455	 * PCI config routines from within atomic contex and that becomes a
456	 * problem in get_vm_area().  Instead we use one wired TLB entry to
457	 * handle all config accesses for all busses.
458	 */
459	ctx->pci_cfg_vm = get_vm_area(0x2000, VM_IOREMAP);
460	if (!ctx->pci_cfg_vm) {
461		dev_err(&pdev->dev, "unable to get vm area\n");
462		ret = -ENOMEM;
463		goto out4;
464	}
465	ctx->wired_entry = 8191;	/* impossibly high value */
466	alchemy_pci_wired_entry(ctx);	/* install it */
467
468	set_io_port_base((unsigned long)ctx->alchemy_pci_ctrl.io_map_base);
469
470	/* board may want to modify bits in the config register, do it now */
471	val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
472	val &= ~pd->pci_cfg_clr;
473	val |= pd->pci_cfg_set;
474	val &= ~PCI_CONFIG_PD;		/* clear disable bit */
475	__raw_writel(val, ctx->regs + PCI_REG_CONFIG);
476	wmb();
477
478	__alchemy_pci_ctx = ctx;
479	platform_set_drvdata(pdev, ctx);
480	register_syscore_ops(&alchemy_pci_pmops);
481	register_pci_controller(&ctx->alchemy_pci_ctrl);
482
483	dev_info(&pdev->dev, "PCI controller at %ld MHz\n",
484		 clk_get_rate(c) / 1000000);
485
486	return 0;
487
488out4:
489	iounmap(virt_io);
490out3:
491	iounmap(ctx->regs);
492out5:
493	clk_disable_unprepare(c);
494out6:
495	clk_put(c);
496out2:
497	release_mem_region(r->start, resource_size(r));
498out1:
499	kfree(ctx);
500out:
501	return ret;
502}
503
504static struct platform_driver alchemy_pcictl_driver = {
505	.probe		= alchemy_pci_probe,
506	.driver = {
507		.name	= "alchemy-pci",
508	},
509};
510
511static int __init alchemy_pci_init(void)
512{
513	/* Au1500/Au1550 have PCI */
514	switch (alchemy_get_cputype()) {
515	case ALCHEMY_CPU_AU1500:
516	case ALCHEMY_CPU_AU1550:
517		return platform_driver_register(&alchemy_pcictl_driver);
518	}
519	return 0;
520}
521arch_initcall(alchemy_pci_init);
522
523
524int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
525{
526	struct alchemy_pci_context *ctx = dev->sysdata;
527	if (ctx && ctx->board_map_irq)
528		return ctx->board_map_irq(dev, slot, pin);
529	return -1;
530}
531
532int pcibios_plat_dev_init(struct pci_dev *dev)
533{
534	return 0;
535}
536