1/*
2 *  linux/arch/arm/kernel/dec21285.c: PCI functions for DC21285
3 *
4 *  Copyright (C) 1998-2001 Russell King
5 *  Copyright (C) 1998-2000 Phil Blundell
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/kernel.h>
12#include <linux/pci.h>
13#include <linux/interrupt.h>
14#include <linux/mm.h>
15#include <linux/slab.h>
16#include <linux/init.h>
17#include <linux/ioport.h>
18#include <linux/irq.h>
19
20#include <asm/io.h>
21#include <asm/irq.h>
22#include <asm/system.h>
23#include <asm/mach/pci.h>
24#include <asm/hardware/dec21285.h>
25
26#define MAX_SLOTS		21
27
28#define PCICMD_ABORT		((PCI_STATUS_REC_MASTER_ABORT| \
29				  PCI_STATUS_REC_TARGET_ABORT)<<16)
30
31#define PCICMD_ERROR_BITS	((PCI_STATUS_DETECTED_PARITY | \
32				  PCI_STATUS_REC_MASTER_ABORT | \
33				  PCI_STATUS_REC_TARGET_ABORT | \
34				  PCI_STATUS_PARITY) << 16)
35
36extern int setup_arm_irq(int, struct irqaction *);
37extern void pcibios_report_status(u_int status_mask, int warn);
38
39static unsigned long
40dc21285_base_address(struct pci_bus *bus, unsigned int devfn)
41{
42	unsigned long addr = 0;
43
44	if (bus->number == 0) {
45		if (PCI_SLOT(devfn) == 0)
46			/*
47			 * For devfn 0, point at the 21285
48			 */
49			addr = ARMCSR_BASE;
50		else {
51			devfn -= 1 << 3;
52
53			if (devfn < PCI_DEVFN(MAX_SLOTS, 0))
54				addr = PCICFG0_BASE | 0xc00000 | (devfn << 8);
55		}
56	} else
57		addr = PCICFG1_BASE | (bus->number << 16) | (devfn << 8);
58
59	return addr;
60}
61
62static int
63dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
64		    int size, u32 *value)
65{
66	unsigned long addr = dc21285_base_address(bus, devfn);
67	u32 v = 0xffffffff;
68
69	if (addr)
70		switch (size) {
71		case 1:
72			asm("ldrb	%0, [%1, %2]"
73				: "=r" (v) : "r" (addr), "r" (where) : "cc");
74			break;
75		case 2:
76			asm("ldrh	%0, [%1, %2]"
77				: "=r" (v) : "r" (addr), "r" (where) : "cc");
78			break;
79		case 4:
80			asm("ldr	%0, [%1, %2]"
81				: "=r" (v) : "r" (addr), "r" (where) : "cc");
82			break;
83		}
84
85	*value = v;
86
87	v = *CSR_PCICMD;
88	if (v & PCICMD_ABORT) {
89		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
90		return -1;
91	}
92
93	return PCIBIOS_SUCCESSFUL;
94}
95
96static int
97dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
98		     int size, u32 value)
99{
100	unsigned long addr = dc21285_base_address(bus, devfn);
101	u32 v;
102
103	if (addr)
104		switch (size) {
105		case 1:
106			asm("strb	%0, [%1, %2]"
107				: : "r" (value), "r" (addr), "r" (where)
108				: "cc");
109			break;
110		case 2:
111			asm("strh	%0, [%1, %2]"
112				: : "r" (value), "r" (addr), "r" (where)
113				: "cc");
114			break;
115		case 4:
116			asm("str	%0, [%1, %2]"
117				: : "r" (value), "r" (addr), "r" (where)
118				: "cc");
119			break;
120		}
121
122	v = *CSR_PCICMD;
123	if (v & PCICMD_ABORT) {
124		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
125		return -1;
126	}
127
128	return PCIBIOS_SUCCESSFUL;
129}
130
131static struct pci_ops dc21285_ops = {
132	.read	= dc21285_read_config,
133	.write	= dc21285_write_config,
134};
135
136static struct timer_list serr_timer;
137static struct timer_list perr_timer;
138
139static void dc21285_enable_error(unsigned long __data)
140{
141	switch (__data) {
142	case IRQ_PCI_SERR:
143		del_timer(&serr_timer);
144		break;
145
146	case IRQ_PCI_PERR:
147		del_timer(&perr_timer);
148		break;
149	}
150
151	enable_irq(__data);
152}
153
154/*
155 * Warn on PCI errors.
156 */
157static irqreturn_t dc21285_abort_irq(int irq, void *dev_id)
158{
159	unsigned int cmd;
160	unsigned int status;
161
162	cmd = *CSR_PCICMD;
163	status = cmd >> 16;
164	cmd = cmd & 0xffff;
165
166	if (status & PCI_STATUS_REC_MASTER_ABORT) {
167		printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n",
168			instruction_pointer(get_irq_regs()));
169		cmd |= PCI_STATUS_REC_MASTER_ABORT << 16;
170	}
171
172	if (status & PCI_STATUS_REC_TARGET_ABORT) {
173		printk(KERN_DEBUG "PCI: target abort: ");
174		pcibios_report_status(PCI_STATUS_REC_MASTER_ABORT |
175				      PCI_STATUS_SIG_TARGET_ABORT |
176				      PCI_STATUS_REC_TARGET_ABORT, 1);
177		printk("\n");
178
179		cmd |= PCI_STATUS_REC_TARGET_ABORT << 16;
180	}
181
182	*CSR_PCICMD = cmd;
183
184	return IRQ_HANDLED;
185}
186
187static irqreturn_t dc21285_serr_irq(int irq, void *dev_id)
188{
189	struct timer_list *timer = dev_id;
190	unsigned int cntl;
191
192	printk(KERN_DEBUG "PCI: system error received: ");
193	pcibios_report_status(PCI_STATUS_SIG_SYSTEM_ERROR, 1);
194	printk("\n");
195
196	cntl = *CSR_SA110_CNTL & 0xffffdf07;
197	*CSR_SA110_CNTL = cntl | SA110_CNTL_RXSERR;
198
199	/*
200	 * back off this interrupt
201	 */
202	disable_irq(irq);
203	timer->expires = jiffies + HZ;
204	add_timer(timer);
205
206	return IRQ_HANDLED;
207}
208
209static irqreturn_t dc21285_discard_irq(int irq, void *dev_id)
210{
211	printk(KERN_DEBUG "PCI: discard timer expired\n");
212	*CSR_SA110_CNTL &= 0xffffde07;
213
214	return IRQ_HANDLED;
215}
216
217static irqreturn_t dc21285_dparity_irq(int irq, void *dev_id)
218{
219	unsigned int cmd;
220
221	printk(KERN_DEBUG "PCI: data parity error detected: ");
222	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
223	printk("\n");
224
225	cmd = *CSR_PCICMD & 0xffff;
226	*CSR_PCICMD = cmd | 1 << 24;
227
228	return IRQ_HANDLED;
229}
230
231static irqreturn_t dc21285_parity_irq(int irq, void *dev_id)
232{
233	struct timer_list *timer = dev_id;
234	unsigned int cmd;
235
236	printk(KERN_DEBUG "PCI: parity error detected: ");
237	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
238	printk("\n");
239
240	cmd = *CSR_PCICMD & 0xffff;
241	*CSR_PCICMD = cmd | 1 << 31;
242
243	/*
244	 * back off this interrupt
245	 */
246	disable_irq(irq);
247	timer->expires = jiffies + HZ;
248	add_timer(timer);
249
250	return IRQ_HANDLED;
251}
252
253int __init dc21285_setup(int nr, struct pci_sys_data *sys)
254{
255	struct resource *res;
256
257	if (nr || !footbridge_cfn_mode())
258		return 0;
259
260	res = kzalloc(sizeof(struct resource) * 2, GFP_KERNEL);
261	if (!res) {
262		printk("out of memory for root bus resources");
263		return 0;
264	}
265
266	res[0].flags = IORESOURCE_MEM;
267	res[0].name  = "Footbridge non-prefetch";
268	res[1].flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
269	res[1].name  = "Footbridge prefetch";
270
271	allocate_resource(&iomem_resource, &res[1], 0x20000000,
272			  0xa0000000, 0xffffffff, 0x20000000, NULL, NULL);
273	allocate_resource(&iomem_resource, &res[0], 0x40000000,
274			  0x80000000, 0xffffffff, 0x40000000, NULL, NULL);
275
276	sys->resource[0] = &ioport_resource;
277	sys->resource[1] = &res[0];
278	sys->resource[2] = &res[1];
279	sys->mem_offset  = DC21285_PCI_MEM;
280
281	return 1;
282}
283
284struct pci_bus * __init dc21285_scan_bus(int nr, struct pci_sys_data *sys)
285{
286	return pci_scan_bus(0, &dc21285_ops, sys);
287}
288
289void __init dc21285_preinit(void)
290{
291	unsigned int mem_size, mem_mask;
292	int cfn_mode;
293
294	mem_size = (unsigned int)high_memory - PAGE_OFFSET;
295	for (mem_mask = 0x00100000; mem_mask < 0x10000000; mem_mask <<= 1)
296		if (mem_mask >= mem_size)
297			break;
298
299	/*
300	 * These registers need to be set up whether we're the
301	 * central function or not.
302	 */
303	*CSR_SDRAMBASEMASK    = (mem_mask - 1) & 0x0ffc0000;
304	*CSR_SDRAMBASEOFFSET  = 0;
305	*CSR_ROMBASEMASK      = 0x80000000;
306	*CSR_CSRBASEMASK      = 0;
307	*CSR_CSRBASEOFFSET    = 0;
308	*CSR_PCIADDR_EXTN     = 0;
309
310	cfn_mode = __footbridge_cfn_mode();
311
312	printk(KERN_INFO "PCI: DC21285 footbridge, revision %02lX, in "
313		"%s mode\n", *CSR_CLASSREV & 0xff, cfn_mode ?
314		"central function" : "addin");
315
316	if (footbridge_cfn_mode()) {
317		/*
318		 * Clear any existing errors - we aren't
319		 * interested in historical data...
320		 */
321		*CSR_SA110_CNTL	= (*CSR_SA110_CNTL & 0xffffde07) |
322				  SA110_CNTL_RXSERR;
323		*CSR_PCICMD = (*CSR_PCICMD & 0xffff) | PCICMD_ERROR_BITS;
324	}
325
326	init_timer(&serr_timer);
327	init_timer(&perr_timer);
328
329	serr_timer.data = IRQ_PCI_SERR;
330	serr_timer.function = dc21285_enable_error;
331	perr_timer.data = IRQ_PCI_PERR;
332	perr_timer.function = dc21285_enable_error;
333
334	/*
335	 * We don't care if these fail.
336	 */
337	request_irq(IRQ_PCI_SERR, dc21285_serr_irq, IRQF_DISABLED,
338		    "PCI system error", &serr_timer);
339	request_irq(IRQ_PCI_PERR, dc21285_parity_irq, IRQF_DISABLED,
340		    "PCI parity error", &perr_timer);
341	request_irq(IRQ_PCI_ABORT, dc21285_abort_irq, IRQF_DISABLED,
342		    "PCI abort", NULL);
343	request_irq(IRQ_DISCARD_TIMER, dc21285_discard_irq, IRQF_DISABLED,
344		    "Discard timer", NULL);
345	request_irq(IRQ_PCI_DPERR, dc21285_dparity_irq, IRQF_DISABLED,
346		    "PCI data parity", NULL);
347
348	if (cfn_mode) {
349		static struct resource csrio;
350
351		csrio.flags  = IORESOURCE_IO;
352		csrio.name   = "Footbridge";
353
354		allocate_resource(&ioport_resource, &csrio, 128,
355				  0xff00, 0xffff, 128, NULL, NULL);
356
357		/*
358		 * Map our SDRAM at a known address in PCI space, just in case
359		 * the firmware had other ideas.  Using a nonzero base is
360		 * necessary, since some VGA cards forcefully use PCI addresses
361		 * in the range 0x000a0000 to 0x000c0000. (eg, S3 cards).
362		 */
363		*CSR_PCICSRBASE       = 0xf4000000;
364		*CSR_PCICSRIOBASE     = csrio.start;
365		*CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
366		*CSR_PCIROMBASE       = 0;
367		*CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
368			      PCI_COMMAND_INVALIDATE | PCICMD_ERROR_BITS;
369	} else if (footbridge_cfn_mode() != 0) {
370		/*
371		 * If we are not compiled to accept "add-in" mode, then
372		 * we are using a constant virt_to_bus translation which
373		 * can not hope to cater for the way the host BIOS  has
374		 * set up the machine.
375		 */
376		panic("PCI: this kernel is compiled for central "
377			"function mode only");
378	}
379}
380
381void __init dc21285_postinit(void)
382{
383	register_isa_ports(DC21285_PCI_MEM, DC21285_PCI_IO, 0);
384}
385