aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-ixp4xx/common-pci.c
blob: 3b32f7014bf6685d8254c02e6edc0542f37346c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
/*
 * arch/arm/mach-ixp4xx/common-pci.c 
 *
 * IXP4XX PCI routines for all platforms
 *
 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright (C) 2002 Intel Corporation.
 * Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
 * Copyright (C) 2003-2004 MontaVista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <asm/dma-mapping.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/sizes.h>
#include <asm/system.h>
#include <asm/mach/pci.h>
#include <asm/arch/hardware.h>


/*
 * IXP4xx PCI read function is dependent on whether we are 
 * running A0 or B0 (AppleGate) silicon.
 */
int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);

/*
 * Base address for PCI regsiter region
 */
unsigned long ixp4xx_pci_reg_base = 0;

/*
 * PCI cfg an I/O routines are done by programming a 
 * command/byte enable register, and then read/writing
 * the data from a data regsiter. We need to ensure
 * these transactions are atomic or we will end up
 * with corrupt data on the bus or in a driver.
 */
static DEFINE_SPINLOCK(ixp4xx_pci_lock);

/*
 * Read from PCI config space
 */
static void crp_read(u32 ad_cbe, u32 *data)
{
	unsigned long flags;
	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
	*PCI_CRP_AD_CBE = ad_cbe;
	*data = *PCI_CRP_RDATA;
	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
}

/*
 * Write to PCI config space
 */
static void crp_write(u32 ad_cbe, u32 data)
{ 
	unsigned long flags;
	spin_lock_irqsave(&ixp4xx_pci_lock, flags);
	*PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE | ad_cbe;
	*PCI_CRP_WDATA = data;
	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
}

static inline int check_master_abort(void)
{
	/* check Master Abort bit after access */
	unsigned long isr = *PCI_ISR;

	if (isr & PCI_ISR_PFE) {
		/* make sure the Master Abort bit is reset */    
		*PCI_ISR = PCI_ISR_PFE;
		pr_debug("%s failed\n", __func__);
		return 1;
	}

	return 0;
}

int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
{
	unsigned long flags;
	int retval = 0;
	int i;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/* 
	 * PCI workaround  - only works if NP PCI space reads have 
	 * no side effects!!! Read 8 times. last one will be good.
	 */
	for (i = 0; i < 8; i++) {
		*PCI_NP_CBE = cmd;
		*data = *PCI_NP_RDATA;
		*data = *PCI_NP_RDATA;
	}

	if(check_master_abort())
		retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
}

int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
{
	unsigned long flags;
	int retval = 0;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/* set up and execute the read */    
	*PCI_NP_CBE = cmd;

	/* the result of the read is now in NP_RDATA */
	*data = *PCI_NP_RDATA; 

	if(check_master_abort())
		retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
}

int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
{    
	unsigned long flags;
	int retval = 0;

	spin_lock_irqsave(&ixp4xx_pci_lock, flags);

	*PCI_NP_AD = addr;

	/* set up the write */
	*PCI_NP_CBE = cmd;

	/* execute the write by writing to NP_WDATA */
	*PCI_NP_WDATA = data;

	if(check_master_abort())
		retval = 1;

	spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
	return retval;
}

static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
{
	u32 addr;
	if (!bus_num) {
		/* type 0 */
		addr = BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) | 
		    (where & ~3);	
	} else {
		/* type 1 */
		addr = (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) | 
			((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
	}
	return addr;
}

/*
 * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
 * 0 and 3 are not valid indexes...
 */
static u32 bytemask[] = {
	/*0*/	0,
	/*1*/	0xff,
	/*2*/	0xffff,
	/*3*/	0,
	/*4*/	0xffffffff,
};

static u32 local_byte_lane_enable_bits(u32 n, int size)
{
	if (size == 1)
		return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
	if (size == 2)
		return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
	if (size == 4)
		return 0;
	return 0xffffffff;
}

static int local_read_config(int where, int size, u32 *value)
{ 
	u32 n, data;
	pr_debug("local_read_config from %d size %d\n", where, size);
	n = where % 4;
	crp_read(where & ~3, &data);
	*value = (data >> (8*n)) & bytemask[size];
	pr_debug("local_read_config read %#x\n", *value);
	return PCIBIOS_SUCCESSFUL;
}

static int local_write_config(int where, int size, u32 value)
{
	u32 n, byte_enables, data;
	pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
	n = where % 4;
	byte_enables = local_byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
		return PCIBIOS_BAD_REGISTER_NUMBER;
	data = value << (8*n);
	crp_write((where & ~3) | byte_enables, data);
	return PCIBIOS_SUCCESSFUL;
}

static u32 byte_lane_enable_bits(u32 n, int size)
{
	if (size == 1)
		return (0xf & ~BIT(n)) << 4;
	if (size == 2)
		return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
	if (size == 4)
		return 0;
	return 0xffffffff;
}

static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
	u32 n, byte_enables, addr, data;
	u8 bus_num = bus->number;

	pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
		bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

	*value = 0xffffffff;
	n = where % 4;
	byte_enables = byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	addr = ixp4xx_config_addr(bus_num, devfn, where);
	if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_CONFIGREAD, &data))
		return PCIBIOS_DEVICE_NOT_FOUND;

	*value = (data >> (8*n)) & bytemask[size];
	pr_debug("read_config_byte read %#x\n", *value);
	return PCIBIOS_SUCCESSFUL;
}

static int ixp4xx_pci_write_config(struct pci_bus *bus,  unsigned int devfn, int where, int size, u32 value)
{
	u32 n, byte_enables, addr, data;
	u8 bus_num = bus->number;

	pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
		size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));

	n = where % 4;
	byte_enables = byte_lane_enable_bits(n, size);
	if (byte_enables == 0xffffffff)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	addr = ixp4xx_config_addr(bus_num, devfn, where);
	data = value << (8*n);
	if (ixp4xx_pci_write(addr, byte_enables | NP_CMD_CONFIGWRITE, data))
		return PCIBIOS_DEVICE_NOT_FOUND;

	return PCIBIOS_SUCCESSFUL;
}

struct pci_ops ixp4xx_ops = {
	.read =  ixp4xx_pci_read_config,
	.write = ixp4xx_pci_write_config,
};

/*
 * PCI abort handler
 */
static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
	u32 isr, status;

	isr = *PCI_ISR;
	local_read_config(PCI_STATUS, 2, &status);
	pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
		"status = %#x\n", addr, isr, status);

	/* make sure the Master Abort bit is reset */    
	*PCI_ISR = PCI_ISR_PFE;
	status |= PCI_STATUS_REC_MASTER_ABORT;
	local_write_config(PCI_STATUS, 2, status);

	/*
	 * If it was an imprecise abort, then we need to correct the
	 * return address to be _after_ the instruction.
	 */
	if (fsr & (1 << 10))
		regs->ARM_pc += 4;

	return 0;
}


/*
 * Setup DMA mask to 64MB on PCI devices. Ignore all other devices.
 */
static int ixp4xx_pci_platform_notify(struct device *dev)
{
	if(dev->bus == &pci_bus_type) {
		*dev->dma_mask =  SZ_64M - 1;
		dev->coherent_dma_mask = SZ_64M - 1;
		dmabounce_register_dev(dev, 2048, 4096);
	}
	return 0;
}

static int ixp4xx_pci_platform_notify_remove(struct device *dev)
{
	if(dev->bus == &pci_bus_type) {
		dmabounce_unregister_dev(dev);
	}
	return 0;
}

int dma_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
{
	return (dev->bus == &pci_bus_type ) && ((dma_addr + size) >= SZ_64M);
}

/*
 * Only first 64MB of memory can be accessed via PCI.
 * We use GFP_DMA to allocate safe buffers to do map/unmap.
 * This is really ugly and we need a better way of specifying
 * DMA-capable regions of memory.
 */
void __init ixp4xx_adjust_zones(int node, unsigned long *zone_size,
	unsigned long *zhole_size)
{
	unsigned int sz = SZ_64M >> PAGE_SHIFT;

	/*
	 * Only adjust if > 64M on current system
	 */
	if (node || (zone_size[0] <= sz))
		return;

	zone_size[1] = zone_size[0] - sz;
	zone_size[0] = sz;
	zhole_size[1] = zhole_size[0];
	zhole_size[0] = 0;
}

void __init ixp4xx_pci_preinit(void)
{  
	unsigned long processor_id;

	asm("mrc p15, 0, %0, cr0, cr0, 0;" : "=r"(processor_id) :);

	/*
	 * Determine which PCI read method to use.
	 * Rev 0 IXP425 requires workaround.
	 */
	if (!(processor_id & 0xf) && cpu_is_ixp42x()) {
		printk("PCI: IXP42x A0 silicon detected - "
			"PCI Non-Prefetch Workaround Enabled\n");
		ixp4xx_pci_read = ixp4xx_pci_read_errata;
	} else
		ixp4xx_pci_read = ixp4xx_pci_read_no_errata;


	/* hook in our fault handler for PCI errors */
	hook_fault_code(16+6, abort_handler, SIGBUS, "imprecise external abort");

	pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");

	/* 
	 * We use identity AHB->PCI address translation
	 * in the 0x48000000 to 0x4bffffff address space
	 */
	*PCI_PCIMEMBASE = 0x48494A4B;

	/* 
	 * We also use identity PCI->AHB address translation
	 * in 4 16MB BARs that begin at the physical memory start
	 */
	*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) + 
		((PHYS_OFFSET & 0xFF000000) >> 8) +
		((PHYS_OFFSET & 0xFF000000) >> 16) +
		((PHYS_OFFSET & 0xFF000000) >> 24) +
		0x00010203;

	if (*PCI_CSR & PCI_CSR_HOST) {
		printk("PCI: IXP4xx is host\n");

		pr_debug("setup BARs in controller\n");

		/*
		 * We configure the PCI inbound memory windows to be 
		 * 1:1 mapped to SDRAM
		 */
		local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET + 0x00000000);
		local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + 0x01000000);
		local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + 0x02000000);
		local_write_config(PCI_BASE_ADDRESS_3, 4, PHYS_OFFSET + 0x03000000);

		/*
		 * Enable CSR window at 0xff000000.
		 */
		local_write_config(PCI_BASE_ADDRESS_4, 4, 0xff000008);

		/*
		 * Enable the IO window to be way up high, at 0xfffffc00
		 */
		local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
	} else {
		printk("PCI: IXP4xx is target - No bus scan performed\n");
	}

	printk("PCI: IXP4xx Using %s access for memory space\n",
#ifndef CONFIG_IXP4XX_INDIRECT_PCI
			"direct"
#else
			"indirect"
#endif
		);

	pr_debug("clear error bits in ISR\n");
	*PCI_ISR = PCI_ISR_PSE | PCI_ISR_PFE | PCI_ISR_PPE | PCI_ISR_AHBE;

	/*
	 * Set Initialize Complete in PCI Control Register: allow IXP4XX to
	 * respond to PCI configuration cycles. Specify that the AHB bus is
	 * operating in big endian mode. Set up byte lane swapping between 
	 * little-endian PCI and the big-endian AHB bus 
	 */
#ifdef __ARMEB__
	*PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE | PCI_CSR_PDS | PCI_CSR_ADS;
#else
	*PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE;
#endif

	pr_debug("DONE\n");
}

int ixp4xx_setup(int nr, struct pci_sys_data *sys)
{
	struct resource *res;

	if (nr >= 1)
		return 0;

	res = kzalloc(sizeof(*res) * 2, GFP_KERNEL);
	if (res == NULL) {
		/* 
		 * If we're out of memory this early, something is wrong,
		 * so we might as well catch it here.
		 */
		panic("PCI: unable to allocate resources?\n");
	}

	local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);

	res[0].name = "PCI I/O Space";
	res[0].start = 0x00000000;
	res[0].end = 0x0000ffff;
	res[0].flags = IORESOURCE_IO;

	res[1].name = "PCI Memory Space";
	res[1].start = PCIBIOS_MIN_MEM;
#ifndef CONFIG_IXP4XX_INDIRECT_PCI
	res[1].end = 0x4bffffff;
#else
	res[1].end = 0x4fffffff;
#endif
	res[1].flags = IORESOURCE_MEM;

	request_resource(&ioport_resource, &res[0]);
	request_resource(&iomem_resource, &res[1]);

	sys->resource[0] = &res[0];
	sys->resource[1] = &res[1];
	sys->resource[2] = NULL;

	platform_notify = ixp4xx_pci_platform_notify;
	platform_notify_remove = ixp4xx_pci_platform_notify_remove;

	return 1;
}

struct pci_bus *ixp4xx_scan_bus(int nr, struct pci_sys_data *sys)
{
	return pci_scan_bus(sys->busnr, &ixp4xx_ops, sys);
}

/*
 * We override these so we properly do dmabounce otherwise drivers
 * are able to set the dma_mask to 0xffffffff and we can no longer
 * trap bounces. :(
 *
 * We just return true on everyhing except for < 64MB in which case 
 * we will fail miseralby and die since we can't handle that case.
 */
int
pci_set_dma_mask(struct pci_dev *dev, u64 mask)
{
	if (mask >= SZ_64M - 1 )
		return 0;

	return -EIO;
}
    
int
pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
{
	if (mask >= SZ_64M - 1 )
		return 0;

	return -EIO;
}

EXPORT_SYMBOL(ixp4xx_pci_read);
EXPORT_SYMBOL(ixp4xx_pci_write);