1/* ASB2305 PCI support
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from arch/i386/kernel/pci-pc.c
6 *	(c) 1999--2000 Martin Mares <mj@suse.cz>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public Licence
10 * as published by the Free Software Foundation; either version
11 * 2 of the Licence, or (at your option) any later version.
12 */
13#include <linux/types.h>
14#include <linux/kernel.h>
15#include <linux/sched.h>
16#include <linux/pci.h>
17#include <linux/init.h>
18#include <linux/ioport.h>
19#include <linux/delay.h>
20#include <linux/irq.h>
21#include <asm/io.h>
22#include <asm/irq.h>
23#include "pci-asb2305.h"
24
25unsigned int pci_probe = 1;
26
27struct pci_ops *pci_root_ops;
28
29/*
30 * The accessible PCI window does not cover the entire CPU address space, but
31 * there are devices we want to access outside of that window, so we need to
32 * insert specific PCI bus resources instead of using the platform-level bus
33 * resources directly for the PCI root bus.
34 *
35 * These are configured and inserted by pcibios_init().
36 */
37static struct resource pci_ioport_resource = {
38	.name	= "PCI IO",
39	.start	= 0xbe000000,
40	.end	= 0xbe03ffff,
41	.flags	= IORESOURCE_IO,
42};
43
44static struct resource pci_iomem_resource = {
45	.name	= "PCI mem",
46	.start	= 0xb8000000,
47	.end	= 0xbbffffff,
48	.flags	= IORESOURCE_MEM,
49};
50
51/*
52 * Functions for accessing PCI configuration space
53 */
54
55#define CONFIG_CMD(bus, devfn, where) \
56	(0x80000000 | (bus->number << 16) | (devfn << 8) | (where & ~3))
57
58#define MEM_PAGING_REG	(*(volatile __u32 *) 0xBFFFFFF4)
59#define CONFIG_ADDRESS	(*(volatile __u32 *) 0xBFFFFFF8)
60#define CONFIG_DATAL(X)	(*(volatile __u32 *) 0xBFFFFFFC)
61#define CONFIG_DATAW(X)	(*(volatile __u16 *) (0xBFFFFFFC + ((X) & 2)))
62#define CONFIG_DATAB(X)	(*(volatile __u8  *) (0xBFFFFFFC + ((X) & 3)))
63
64#define BRIDGEREGB(X)	(*(volatile __u8  *) (0xBE040000 + (X)))
65#define BRIDGEREGW(X)	(*(volatile __u16 *) (0xBE040000 + (X)))
66#define BRIDGEREGL(X)	(*(volatile __u32 *) (0xBE040000 + (X)))
67
68static inline int __query(const struct pci_bus *bus, unsigned int devfn)
69{
70#if 0
71	return bus->number == 0 && (devfn == PCI_DEVFN(0, 0));
72	return bus->number == 1;
73	return bus->number == 0 &&
74		(devfn == PCI_DEVFN(2, 0) || devfn == PCI_DEVFN(3, 0));
75#endif
76	return 1;
77}
78
79/*
80 *
81 */
82static int pci_ampci_read_config_byte(struct pci_bus *bus, unsigned int devfn,
83				      int where, u32 *_value)
84{
85	u32 rawval, value;
86
87	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
88		value = BRIDGEREGB(where);
89		__pcbdebug("=> %02hx", &BRIDGEREGL(where), value);
90	} else {
91		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
92		rawval = CONFIG_ADDRESS;
93		value = CONFIG_DATAB(where);
94		if (__query(bus, devfn))
95			__pcidebug("=> %02hx", bus, devfn, where, value);
96	}
97
98	*_value = value;
99	return PCIBIOS_SUCCESSFUL;
100}
101
102static int pci_ampci_read_config_word(struct pci_bus *bus, unsigned int devfn,
103				      int where, u32 *_value)
104{
105	u32 rawval, value;
106
107	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
108		value = BRIDGEREGW(where);
109		__pcbdebug("=> %04hx", &BRIDGEREGL(where), value);
110	} else {
111		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
112		rawval = CONFIG_ADDRESS;
113		value = CONFIG_DATAW(where);
114		if (__query(bus, devfn))
115			__pcidebug("=> %04hx", bus, devfn, where, value);
116	}
117
118	*_value = value;
119	return PCIBIOS_SUCCESSFUL;
120}
121
122static int pci_ampci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
123				       int where, u32 *_value)
124{
125	u32 rawval, value;
126
127	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
128		value = BRIDGEREGL(where);
129		__pcbdebug("=> %08x", &BRIDGEREGL(where), value);
130	} else {
131		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
132		rawval = CONFIG_ADDRESS;
133		value = CONFIG_DATAL(where);
134		if (__query(bus, devfn))
135			__pcidebug("=> %08x", bus, devfn, where, value);
136	}
137
138	*_value = value;
139	return PCIBIOS_SUCCESSFUL;
140}
141
142static int pci_ampci_write_config_byte(struct pci_bus *bus, unsigned int devfn,
143				       int where, u8 value)
144{
145	u32 rawval;
146
147	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
148		__pcbdebug("<= %02x", &BRIDGEREGB(where), value);
149		BRIDGEREGB(where) = value;
150	} else {
151		if (bus->number == 0 &&
152		    (devfn == PCI_DEVFN(2, 0) || devfn == PCI_DEVFN(3, 0))
153		    )
154			__pcidebug("<= %02x", bus, devfn, where, value);
155		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
156		rawval = CONFIG_ADDRESS;
157		CONFIG_DATAB(where) = value;
158	}
159	return PCIBIOS_SUCCESSFUL;
160}
161
162static int pci_ampci_write_config_word(struct pci_bus *bus, unsigned int devfn,
163				       int where, u16 value)
164{
165	u32 rawval;
166
167	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
168		__pcbdebug("<= %04hx", &BRIDGEREGW(where), value);
169		BRIDGEREGW(where) = value;
170	} else {
171		if (__query(bus, devfn))
172			__pcidebug("<= %04hx", bus, devfn, where, value);
173		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
174		rawval = CONFIG_ADDRESS;
175		CONFIG_DATAW(where) = value;
176	}
177	return PCIBIOS_SUCCESSFUL;
178}
179
180static int pci_ampci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
181					int where, u32 value)
182{
183	u32 rawval;
184
185	if (bus->number == 0 && devfn == PCI_DEVFN(0, 0)) {
186		__pcbdebug("<= %08x", &BRIDGEREGL(where), value);
187		BRIDGEREGL(where) = value;
188	} else {
189		if (__query(bus, devfn))
190			__pcidebug("<= %08x", bus, devfn, where, value);
191		CONFIG_ADDRESS = CONFIG_CMD(bus, devfn, where);
192		rawval = CONFIG_ADDRESS;
193		CONFIG_DATAL(where) = value;
194	}
195	return PCIBIOS_SUCCESSFUL;
196}
197
198static int pci_ampci_read_config(struct pci_bus *bus, unsigned int devfn,
199				 int where, int size, u32 *val)
200{
201	switch (size) {
202	case 1:
203		return pci_ampci_read_config_byte(bus, devfn, where, val);
204	case 2:
205		return pci_ampci_read_config_word(bus, devfn, where, val);
206	case 4:
207		return pci_ampci_read_config_dword(bus, devfn, where, val);
208	default:
209		BUG();
210		return -EOPNOTSUPP;
211	}
212}
213
214static int pci_ampci_write_config(struct pci_bus *bus, unsigned int devfn,
215				  int where, int size, u32 val)
216{
217	switch (size) {
218	case 1:
219		return pci_ampci_write_config_byte(bus, devfn, where, val);
220	case 2:
221		return pci_ampci_write_config_word(bus, devfn, where, val);
222	case 4:
223		return pci_ampci_write_config_dword(bus, devfn, where, val);
224	default:
225		BUG();
226		return -EOPNOTSUPP;
227	}
228}
229
230static struct pci_ops pci_direct_ampci = {
231	.read = pci_ampci_read_config,
232	.write = pci_ampci_write_config,
233};
234
235/*
236 * Before we decide to use direct hardware access mechanisms, we try to do some
237 * trivial checks to ensure it at least _seems_ to be working -- we just test
238 * whether bus 00 contains a host bridge (this is similar to checking
239 * techniques used in XFree86, but ours should be more reliable since we
240 * attempt to make use of direct access hints provided by the PCI BIOS).
241 *
242 * This should be close to trivial, but it isn't, because there are buggy
243 * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
244 */
245static int __init pci_sanity_check(struct pci_ops *o)
246{
247	struct pci_bus bus;		/* Fake bus and device */
248	u32 x;
249
250	bus.number = 0;
251
252	if ((!o->read(&bus, 0, PCI_CLASS_DEVICE, 2, &x) &&
253	     (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)) ||
254	    (!o->read(&bus, 0, PCI_VENDOR_ID, 2, &x) &&
255	     (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)))
256		return 1;
257
258	printk(KERN_ERR "PCI: Sanity check failed\n");
259	return 0;
260}
261
262static int __init pci_check_direct(void)
263{
264	unsigned long flags;
265
266	local_irq_save(flags);
267
268	/*
269	 * Check if access works.
270	 */
271	if (pci_sanity_check(&pci_direct_ampci)) {
272		local_irq_restore(flags);
273		printk(KERN_INFO "PCI: Using configuration ampci\n");
274		request_mem_region(0xBE040000, 256, "AMPCI bridge");
275		request_mem_region(0xBFFFFFF4, 12, "PCI ampci");
276		request_mem_region(0xBC000000, 32 * 1024 * 1024, "PCI SRAM");
277		return 0;
278	}
279
280	local_irq_restore(flags);
281	return -ENODEV;
282}
283
284static void pcibios_fixup_device_resources(struct pci_dev *dev)
285{
286	int idx;
287
288	if (!dev->bus)
289		return;
290
291	for (idx = 0; idx < PCI_BRIDGE_RESOURCES; idx++) {
292		struct resource *r = &dev->resource[idx];
293
294		if (!r->flags || r->parent || !r->start)
295			continue;
296
297		pci_claim_resource(dev, idx);
298	}
299}
300
301static void pcibios_fixup_bridge_resources(struct pci_dev *dev)
302{
303	int idx;
304
305	if (!dev->bus)
306		return;
307
308	for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
309		struct resource *r = &dev->resource[idx];
310
311		if (!r->flags || r->parent || !r->start)
312			continue;
313
314		pci_claim_bridge_resource(dev, idx);
315	}
316}
317
318/*
319 *  Called after each bus is probed, but before its children
320 *  are examined.
321 */
322void pcibios_fixup_bus(struct pci_bus *bus)
323{
324	struct pci_dev *dev;
325
326	if (bus->self) {
327		pci_read_bridge_bases(bus);
328		pcibios_fixup_bridge_resources(bus->self);
329	}
330
331	list_for_each_entry(dev, &bus->devices, bus_list)
332		pcibios_fixup_device_resources(dev);
333}
334
335/*
336 * Initialization. Try all known PCI access methods. Note that we support
337 * using both PCI BIOS and direct access: in such cases, we use I/O ports
338 * to access config space, but we still keep BIOS order of cards to be
339 * compatible with 2.0.X. This should go away some day.
340 */
341static int __init pcibios_init(void)
342{
343	resource_size_t io_offset, mem_offset;
344	LIST_HEAD(resources);
345	struct pci_bus *bus;
346
347	ioport_resource.start	= 0xA0000000;
348	ioport_resource.end	= 0xDFFFFFFF;
349	iomem_resource.start	= 0xA0000000;
350	iomem_resource.end	= 0xDFFFFFFF;
351
352	if (insert_resource(&iomem_resource, &pci_iomem_resource) < 0)
353		panic("Unable to insert PCI IOMEM resource\n");
354	if (insert_resource(&ioport_resource, &pci_ioport_resource) < 0)
355		panic("Unable to insert PCI IOPORT resource\n");
356
357	if (!pci_probe)
358		return 0;
359
360	if (pci_check_direct() < 0) {
361		printk(KERN_WARNING "PCI: No PCI bus detected\n");
362		return 0;
363	}
364
365	printk(KERN_INFO "PCI: Probing PCI hardware [mempage %08x]\n",
366	       MEM_PAGING_REG);
367
368	io_offset = pci_ioport_resource.start -
369	    (pci_ioport_resource.start & 0x00ffffff);
370	mem_offset = pci_iomem_resource.start -
371	    ((pci_iomem_resource.start & 0x03ffffff) | MEM_PAGING_REG);
372
373	pci_add_resource_offset(&resources, &pci_ioport_resource, io_offset);
374	pci_add_resource_offset(&resources, &pci_iomem_resource, mem_offset);
375	bus = pci_scan_root_bus(NULL, 0, &pci_direct_ampci, NULL, &resources);
376	if (!bus)
377		return 0;
378
379	pcibios_irq_init();
380	pcibios_fixup_irqs();
381	pcibios_resource_survey();
382	pci_bus_add_devices(bus);
383	return 0;
384}
385
386arch_initcall(pcibios_init);
387
388char *__init pcibios_setup(char *str)
389{
390	if (!strcmp(str, "off")) {
391		pci_probe = 0;
392		return NULL;
393	}
394
395	return str;
396}
397
398int pcibios_enable_device(struct pci_dev *dev, int mask)
399{
400	int err;
401
402	err = pci_enable_resources(dev, mask);
403	if (err == 0)
404		pcibios_enable_irq(dev);
405	return err;
406}
407
408/*
409 * disable the ethernet chipset
410 */
411static void __init unit_disable_pcnet(struct pci_bus *bus, struct pci_ops *o)
412{
413	u32 x;
414
415	bus->number = 0;
416
417	o->read (bus, PCI_DEVFN(2, 0), PCI_VENDOR_ID,		4, &x);
418	o->read (bus, PCI_DEVFN(2, 0), PCI_COMMAND,		2, &x);
419	x |= PCI_COMMAND_MASTER |
420		PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
421		PCI_COMMAND_SERR | PCI_COMMAND_PARITY;
422	o->write(bus, PCI_DEVFN(2, 0), PCI_COMMAND,		2, x);
423	o->read (bus, PCI_DEVFN(2, 0), PCI_COMMAND,		2, &x);
424	o->write(bus, PCI_DEVFN(2, 0), PCI_BASE_ADDRESS_0,	4, 0x00030001);
425	o->read (bus, PCI_DEVFN(2, 0), PCI_BASE_ADDRESS_0,	4, &x);
426
427#define RDP (*(volatile u32 *) 0xBE030010)
428#define RAP (*(volatile u32 *) 0xBE030014)
429#define __set_RAP(X) do { RAP = (X); x = RAP; } while (0)
430#define __set_RDP(X) do { RDP = (X); x = RDP; } while (0)
431#define __get_RDP() ({ RDP & 0xffff; })
432
433	__set_RAP(0);
434	__set_RDP(0x0004);	/* CSR0 = STOP */
435
436	__set_RAP(88);		/* check CSR88 indicates an Am79C973 */
437	BUG_ON(__get_RDP() != 0x5003);
438
439	for (x = 0; x < 100; x++)
440		asm volatile("nop");
441
442	__set_RDP(0x0004);	/* CSR0 = STOP */
443}
444
445/*
446 * initialise the unit hardware
447 */
448asmlinkage void __init unit_pci_init(void)
449{
450	struct pci_bus bus;		/* Fake bus and device */
451	struct pci_ops *o = &pci_direct_ampci;
452	u32 x;
453
454	set_intr_level(XIRQ1, NUM2GxICR_LEVEL(CONFIG_PCI_IRQ_LEVEL));
455
456	memset(&bus, 0, sizeof(bus));
457
458	MEM_PAGING_REG = 0xE8000000;
459
460	/* we need to set up the bridge _now_ or we won't be able to access the
461	 * PCI config registers
462	 */
463	BRIDGEREGW(PCI_COMMAND) |=
464		PCI_COMMAND_SERR | PCI_COMMAND_PARITY |
465		PCI_COMMAND_MEMORY | PCI_COMMAND_IO | PCI_COMMAND_MASTER;
466	BRIDGEREGW(PCI_STATUS)		= 0xF800;
467	BRIDGEREGB(PCI_LATENCY_TIMER)	= 0x10;
468	BRIDGEREGL(PCI_BASE_ADDRESS_0)	= 0x80000000;
469	BRIDGEREGB(PCI_INTERRUPT_LINE)	= 1;
470	BRIDGEREGL(0x48)		= 0x98000000;	/* AMPCI base addr */
471	BRIDGEREGB(0x41)		= 0x00;		/* secondary bus
472							 * number */
473	BRIDGEREGB(0x42)		= 0x01;		/* subordinate bus
474							 * number */
475	BRIDGEREGB(0x44)		= 0x01;
476	BRIDGEREGL(0x50)		= 0x00000001;
477	BRIDGEREGL(0x58)		= 0x00001002;
478	BRIDGEREGL(0x5C)		= 0x00000011;
479
480	/* we also need to set up the PCI-PCI bridge */
481	bus.number = 0;
482
483	/* IO: 0x00000000-0x00020000 */
484	o->read (&bus, PCI_DEVFN(3, 0), PCI_COMMAND,		2, &x);
485	x |= PCI_COMMAND_MASTER |
486		PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
487		PCI_COMMAND_SERR | PCI_COMMAND_PARITY;
488	o->write(&bus, PCI_DEVFN(3, 0), PCI_COMMAND,		2, x);
489
490	o->read (&bus, PCI_DEVFN(3, 0), PCI_IO_BASE,		1, &x);
491	o->read (&bus, PCI_DEVFN(3, 0), PCI_IO_BASE_UPPER16,	4, &x);
492	o->read (&bus, PCI_DEVFN(3, 0), PCI_MEMORY_BASE,	4, &x);
493	o->read (&bus, PCI_DEVFN(3, 0), PCI_PREF_MEMORY_BASE,	4, &x);
494
495	o->write(&bus, PCI_DEVFN(3, 0), PCI_IO_BASE,		1, 0x01);
496	o->read (&bus, PCI_DEVFN(3, 0), PCI_IO_BASE,		1, &x);
497	o->write(&bus, PCI_DEVFN(3, 0), PCI_IO_BASE_UPPER16,	4, 0x00020000);
498	o->read (&bus, PCI_DEVFN(3, 0), PCI_IO_BASE_UPPER16,	4, &x);
499	o->write(&bus, PCI_DEVFN(3, 0), PCI_MEMORY_BASE,	4, 0xEBB0EA00);
500	o->read (&bus, PCI_DEVFN(3, 0), PCI_MEMORY_BASE,	4, &x);
501	o->write(&bus, PCI_DEVFN(3, 0), PCI_PREF_MEMORY_BASE,	4, 0xE9F0E800);
502	o->read (&bus, PCI_DEVFN(3, 0), PCI_PREF_MEMORY_BASE,	4, &x);
503
504	unit_disable_pcnet(&bus, o);
505}
506