summaryrefslogtreecommitdiff
path: root/arch/mips/sni/rm200.c
blob: d84744ca871d72b9f8b358ef5d4653af252bf6d5 (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
/*
 * RM200 specific code
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
 *
 * i8259 parts ripped out of arch/mips/kernel/i8259.c
 */

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/serial_8250.h>
#include <linux/io.h>

#include <asm/sni.h>
#include <asm/time.h>
#include <asm/irq_cpu.h>

#define RM200_I8259A_IRQ_BASE 32

#define MEMPORT(_base,_irq)				\
	{						\
		.mapbase	= _base,		\
		.irq		= _irq,			\
		.uartclk	= 1843200,		\
		.iotype		= UPIO_MEM,		\
		.flags		= UPF_BOOT_AUTOCONF|UPF_IOREMAP, \
	}

static struct plat_serial8250_port rm200_data[] = {
	MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE + 4),
	MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE + 3),
	{ },
};

static struct platform_device rm200_serial8250_device = {
	.name			= "serial8250",
	.id			= PLAT8250_DEV_PLATFORM,
	.dev			= {
		.platform_data	= rm200_data,
	},
};

static struct resource rm200_ds1216_rsrc[] = {
	{
		.start = 0x1cd41ffc,
		.end   = 0x1cd41fff,
		.flags = IORESOURCE_MEM
	}
};

static struct platform_device rm200_ds1216_device = {
	.name		= "rtc-ds1216",
	.num_resources	= ARRAY_SIZE(rm200_ds1216_rsrc),
	.resource	= rm200_ds1216_rsrc
};

static struct resource snirm_82596_rm200_rsrc[] = {
	{
		.start = 0x18000000,
		.end   = 0x180fffff,
		.flags = IORESOURCE_MEM
	},
	{
		.start = 0x1b000000,
		.end   = 0x1b000004,
		.flags = IORESOURCE_MEM
	},
	{
		.start = 0x1ff00000,
		.end   = 0x1ff00020,
		.flags = IORESOURCE_MEM
	},
	{
		.start = 27,
		.end   = 27,
		.flags = IORESOURCE_IRQ
	},
	{
		.flags = 0x00
	}
};

static struct platform_device snirm_82596_rm200_pdev = {
	.name		= "snirm_82596",
	.num_resources	= ARRAY_SIZE(snirm_82596_rm200_rsrc),
	.resource	= snirm_82596_rm200_rsrc
};

static struct resource snirm_53c710_rm200_rsrc[] = {
	{
		.start = 0x19000000,
		.end   = 0x190fffff,
		.flags = IORESOURCE_MEM
	},
	{
		.start = 26,
		.end   = 26,
		.flags = IORESOURCE_IRQ
	}
};

static struct platform_device snirm_53c710_rm200_pdev = {
	.name		= "snirm_53c710",
	.num_resources	= ARRAY_SIZE(snirm_53c710_rm200_rsrc),
	.resource	= snirm_53c710_rm200_rsrc
};

static int __init snirm_setup_devinit(void)
{
	if (sni_brd_type == SNI_BRD_RM200) {
		platform_device_register(&rm200_serial8250_device);
		platform_device_register(&rm200_ds1216_device);
		platform_device_register(&snirm_82596_rm200_pdev);
		platform_device_register(&snirm_53c710_rm200_pdev);
		sni_eisa_root_init();
	}
	return 0;
}

device_initcall(snirm_setup_devinit);

/*
 * RM200 has an ISA and an EISA bus. The iSA bus is only used
 * for onboard devices and also has twi i8259 PICs. Since these
 * PICs are no accessible via inb/outb the following code uses
 * readb/writeb to access them
 */

static DEFINE_RAW_SPINLOCK(sni_rm200_i8259A_lock);
#define PIC_CMD	   0x00
#define PIC_IMR	   0x01
#define PIC_ISR	   PIC_CMD
#define PIC_POLL   PIC_ISR
#define PIC_OCW3   PIC_ISR

/* i8259A PIC related value */
#define PIC_CASCADE_IR		2
#define MASTER_ICW4_DEFAULT	0x01
#define SLAVE_ICW4_DEFAULT	0x01

/*
 * This contains the irq mask for both 8259A irq controllers,
 */
static unsigned int rm200_cached_irq_mask = 0xffff;
static __iomem u8 *rm200_pic_master;
static __iomem u8 *rm200_pic_slave;

#define cached_master_mask	(rm200_cached_irq_mask)
#define cached_slave_mask	(rm200_cached_irq_mask >> 8)

static void sni_rm200_disable_8259A_irq(struct irq_data *d)
{
	unsigned int mask, irq = d->irq - RM200_I8259A_IRQ_BASE;
	unsigned long flags;

	mask = 1 << irq;
	raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
	rm200_cached_irq_mask |= mask;
	if (irq & 8)
		writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
	else
		writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
	raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}

static void sni_rm200_enable_8259A_irq(struct irq_data *d)
{
	unsigned int mask, irq = d->irq - RM200_I8259A_IRQ_BASE;
	unsigned long flags;

	mask = ~(1 << irq);
	raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
	rm200_cached_irq_mask &= mask;
	if (irq & 8)
		writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
	else
		writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
	raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}

static inline int sni_rm200_i8259A_irq_real(unsigned int irq)
{
	int value;
	int irqmask = 1 << irq;

	if (irq < 8) {
		writeb(0x0B, rm200_pic_master + PIC_CMD);
		value = readb(rm200_pic_master + PIC_CMD) & irqmask;
		writeb(0x0A, rm200_pic_master + PIC_CMD);
		return value;
	}
	writeb(0x0B, rm200_pic_slave + PIC_CMD); /* ISR register */
	value = readb(rm200_pic_slave + PIC_CMD) & (irqmask >> 8);
	writeb(0x0A, rm200_pic_slave + PIC_CMD);
	return value;
}

/*
 * Careful! The 8259A is a fragile beast, it pretty
 * much _has_ to be done exactly like this (mask it
 * first, _then_ send the EOI, and the order of EOI
 * to the two 8259s is important!
 */
void sni_rm200_mask_and_ack_8259A(struct irq_data *d)
{
	unsigned int irqmask, irq = d->irq - RM200_I8259A_IRQ_BASE;
	unsigned long flags;

	irqmask = 1 << irq;
	raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
	/*
	 * Lightweight spurious IRQ detection. We do not want
	 * to overdo spurious IRQ handling - it's usually a sign
	 * of hardware problems, so we only do the checks we can
	 * do without slowing down good hardware unnecessarily.
	 *
	 * Note that IRQ7 and IRQ15 (the two spurious IRQs
	 * usually resulting from the 8259A-1|2 PICs) occur
	 * even if the IRQ is masked in the 8259A. Thus we
	 * can check spurious 8259A IRQs without doing the
	 * quite slow i8259A_irq_real() call for every IRQ.
	 * This does not cover 100% of spurious interrupts,
	 * but should be enough to warn the user that there
	 * is something bad going on ...
	 */
	if (rm200_cached_irq_mask & irqmask)
		goto spurious_8259A_irq;
	rm200_cached_irq_mask |= irqmask;

handle_real_irq:
	if (irq & 8) {
		readb(rm200_pic_slave + PIC_IMR);
		writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
		writeb(0x60+(irq & 7), rm200_pic_slave + PIC_CMD);
		writeb(0x60+PIC_CASCADE_IR, rm200_pic_master + PIC_CMD);
	} else {
		readb(rm200_pic_master + PIC_IMR);
		writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
		writeb(0x60+irq, rm200_pic_master + PIC_CMD);
	}
	raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
	return;

spurious_8259A_irq:
	/*
	 * this is the slow path - should happen rarely.
	 */
	if (sni_rm200_i8259A_irq_real(irq))
		/*
		 * oops, the IRQ _is_ in service according to the
		 * 8259A - not spurious, go handle it.
		 */
		goto handle_real_irq;

	{
		static int spurious_irq_mask;
		/*
		 * At this point we can be sure the IRQ is spurious,
		 * let's ACK and report it. [once per IRQ]
		 */
		if (!(spurious_irq_mask & irqmask)) {
			printk(KERN_DEBUG
			       "spurious RM200 8259A interrupt: IRQ%d.\n", irq);
			spurious_irq_mask |= irqmask;
		}
		atomic_inc(&irq_err_count);
		/*
		 * Theoretically we do not have to handle this IRQ,
		 * but in Linux this does not cause problems and is
		 * simpler for us.
		 */
		goto handle_real_irq;
	}
}

static struct irq_chip sni_rm200_i8259A_chip = {
	.name		= "RM200-XT-PIC",
	.irq_mask	= sni_rm200_disable_8259A_irq,
	.irq_unmask	= sni_rm200_enable_8259A_irq,
	.irq_mask_ack	= sni_rm200_mask_and_ack_8259A,
};

/*
 * Do the traditional i8259 interrupt polling thing.  This is for the few
 * cases where no better interrupt acknowledge method is available and we
 * absolutely must touch the i8259.
 */
static inline int sni_rm200_i8259_irq(void)
{
	int irq;

	raw_spin_lock(&sni_rm200_i8259A_lock);

	/* Perform an interrupt acknowledge cycle on controller 1. */
	writeb(0x0C, rm200_pic_master + PIC_CMD);	/* prepare for poll */
	irq = readb(rm200_pic_master + PIC_CMD) & 7;
	if (irq == PIC_CASCADE_IR) {
		/*
		 * Interrupt is cascaded so perform interrupt
		 * acknowledge on controller 2.
		 */
		writeb(0x0C, rm200_pic_slave + PIC_CMD); /* prepare for poll */
		irq = (readb(rm200_pic_slave + PIC_CMD) & 7) + 8;
	}

	if (unlikely(irq == 7)) {
		/*
		 * This may be a spurious interrupt.
		 *
		 * Read the interrupt status register (ISR). If the most
		 * significant bit is not set then there is no valid
		 * interrupt.
		 */
		writeb(0x0B, rm200_pic_master + PIC_ISR); /* ISR register */
		if (~readb(rm200_pic_master + PIC_ISR) & 0x80)
			irq = -1;
	}

	raw_spin_unlock(&sni_rm200_i8259A_lock);

	return likely(irq >= 0) ? irq + RM200_I8259A_IRQ_BASE : irq;
}

void sni_rm200_init_8259A(void)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);

	writeb(0xff, rm200_pic_master + PIC_IMR);
	writeb(0xff, rm200_pic_slave + PIC_IMR);

	writeb(0x11, rm200_pic_master + PIC_CMD);
	writeb(0, rm200_pic_master + PIC_IMR);
	writeb(1U << PIC_CASCADE_IR, rm200_pic_master + PIC_IMR);
	writeb(MASTER_ICW4_DEFAULT, rm200_pic_master + PIC_IMR);
	writeb(0x11, rm200_pic_slave + PIC_CMD);
	writeb(8, rm200_pic_slave + PIC_IMR);
	writeb(PIC_CASCADE_IR, rm200_pic_slave + PIC_IMR);
	writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR);
	udelay(100);		/* wait for 8259A to initialize */

	writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
	writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);

	raw_spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
}

/*
 * IRQ2 is cascade interrupt to second interrupt controller
 */

static struct resource sni_rm200_pic1_resource = {
	.name = "onboard ISA pic1",
	.start = 0x16000020,
	.end = 0x16000023,
	.flags = IORESOURCE_BUSY
};

static struct resource sni_rm200_pic2_resource = {
	.name = "onboard ISA pic2",
	.start = 0x160000a0,
	.end = 0x160000a3,
	.flags = IORESOURCE_BUSY
};

/* ISA irq handler */
static irqreturn_t sni_rm200_i8259A_irq_handler(int dummy, void *p)
{
	int irq;

	irq = sni_rm200_i8259_irq();
	if (unlikely(irq < 0))
		return IRQ_NONE;

	do_IRQ(irq);
	return IRQ_HANDLED;
}

void __init sni_rm200_i8259_irqs(void)
{
	int i;

	rm200_pic_master = ioremap(0x16000020, 4);
	if (!rm200_pic_master)
		return;
	rm200_pic_slave = ioremap(0x160000a0, 4);
	if (!rm200_pic_slave) {
		iounmap(rm200_pic_master);
		return;
	}

	insert_resource(&iomem_resource, &sni_rm200_pic1_resource);
	insert_resource(&iomem_resource, &sni_rm200_pic2_resource);

	sni_rm200_init_8259A();

	for (i = RM200_I8259A_IRQ_BASE; i < RM200_I8259A_IRQ_BASE + 16; i++)
		irq_set_chip_and_handler(i, &sni_rm200_i8259A_chip,
					 handle_level_irq);

	if (request_irq(RM200_I8259A_IRQ_BASE + PIC_CASCADE_IR, no_action,
			IRQF_NO_THREAD, "cascade", NULL))
		pr_err("Failed to register cascade interrupt\n");
}


#define SNI_RM200_INT_STAT_REG	CKSEG1ADDR(0xbc000000)
#define SNI_RM200_INT_ENA_REG	CKSEG1ADDR(0xbc080000)

#define SNI_RM200_INT_START  24
#define SNI_RM200_INT_END    28

static void enable_rm200_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq - SNI_RM200_INT_START);

	*(volatile u8 *)SNI_RM200_INT_ENA_REG &= ~mask;
}

void disable_rm200_irq(struct irq_data *d)
{
	unsigned int mask = 1 << (d->irq - SNI_RM200_INT_START);

	*(volatile u8 *)SNI_RM200_INT_ENA_REG |= mask;
}

static struct irq_chip rm200_irq_type = {
	.name = "RM200",
	.irq_mask = disable_rm200_irq,
	.irq_unmask = enable_rm200_irq,
};

static void sni_rm200_hwint(void)
{
	u32 pending = read_c0_cause() & read_c0_status();
	u8 mask;
	u8 stat;
	int irq;

	if (pending & C_IRQ5)
		do_IRQ(MIPS_CPU_IRQ_BASE + 7);
	else if (pending & C_IRQ0) {
		clear_c0_status(IE_IRQ0);
		mask = *(volatile u8 *)SNI_RM200_INT_ENA_REG ^ 0x1f;
		stat = *(volatile u8 *)SNI_RM200_INT_STAT_REG ^ 0x14;
		irq = ffs(stat & mask & 0x1f);

		if (likely(irq > 0))
			do_IRQ(irq + SNI_RM200_INT_START - 1);
		set_c0_status(IE_IRQ0);
	}
}

void __init sni_rm200_irq_init(void)
{
	int i;

	* (volatile u8 *)SNI_RM200_INT_ENA_REG = 0x1f;

	sni_rm200_i8259_irqs();
	mips_cpu_irq_init();
	/* Actually we've got more interrupts to handle ...  */
	for (i = SNI_RM200_INT_START; i <= SNI_RM200_INT_END; i++)
		irq_set_chip_and_handler(i, &rm200_irq_type, handle_level_irq);
	sni_hwint = sni_rm200_hwint;
	change_c0_status(ST0_IM, IE_IRQ0);
	if (request_irq(SNI_RM200_INT_START + 0, sni_rm200_i8259A_irq_handler,
			0, "onboard ISA", NULL))
		pr_err("Failed to register onboard ISA interrupt\n");
	if (request_irq(SNI_RM200_INT_START + 1, sni_isa_irq_handler, 0, "ISA",
			NULL))
		pr_err("Failed to register ISA interrupt\n");
}

void __init sni_rm200_init(void)
{
}