1 /*
2 * RM200 specific code
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
9 *
10 * i8259 parts ripped out of arch/mips/kernel/i8259.c
11 */
12
13 #include <linux/delay.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/serial_8250.h>
18 #include <linux/io.h>
19
20 #include <asm/sni.h>
21 #include <asm/time.h>
22 #include <asm/irq_cpu.h>
23
24 #define RM200_I8259A_IRQ_BASE 32
25
26 #define MEMPORT(_base,_irq) \
27 { \
28 .mapbase = _base, \
29 .irq = _irq, \
30 .uartclk = 1843200, \
31 .iotype = UPIO_MEM, \
32 .flags = UPF_BOOT_AUTOCONF|UPF_IOREMAP, \
33 }
34
35 static struct plat_serial8250_port rm200_data[] = {
36 MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE + 4),
37 MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE + 3),
38 { },
39 };
40
41 static struct platform_device rm200_serial8250_device = {
42 .name = "serial8250",
43 .id = PLAT8250_DEV_PLATFORM,
44 .dev = {
45 .platform_data = rm200_data,
46 },
47 };
48
49 static struct resource rm200_ds1216_rsrc[] = {
50 {
51 .start = 0x1cd41ffc,
52 .end = 0x1cd41fff,
53 .flags = IORESOURCE_MEM
54 }
55 };
56
57 static struct platform_device rm200_ds1216_device = {
58 .name = "rtc-ds1216",
59 .num_resources = ARRAY_SIZE(rm200_ds1216_rsrc),
60 .resource = rm200_ds1216_rsrc
61 };
62
63 static struct resource snirm_82596_rm200_rsrc[] = {
64 {
65 .start = 0x18000000,
66 .end = 0x180fffff,
67 .flags = IORESOURCE_MEM
68 },
69 {
70 .start = 0x1b000000,
71 .end = 0x1b000004,
72 .flags = IORESOURCE_MEM
73 },
74 {
75 .start = 0x1ff00000,
76 .end = 0x1ff00020,
77 .flags = IORESOURCE_MEM
78 },
79 {
80 .start = 27,
81 .end = 27,
82 .flags = IORESOURCE_IRQ
83 },
84 {
85 .flags = 0x00
86 }
87 };
88
89 static struct platform_device snirm_82596_rm200_pdev = {
90 .name = "snirm_82596",
91 .num_resources = ARRAY_SIZE(snirm_82596_rm200_rsrc),
92 .resource = snirm_82596_rm200_rsrc
93 };
94
95 static struct resource snirm_53c710_rm200_rsrc[] = {
96 {
97 .start = 0x19000000,
98 .end = 0x190fffff,
99 .flags = IORESOURCE_MEM
100 },
101 {
102 .start = 26,
103 .end = 26,
104 .flags = IORESOURCE_IRQ
105 }
106 };
107
108 static struct platform_device snirm_53c710_rm200_pdev = {
109 .name = "snirm_53c710",
110 .num_resources = ARRAY_SIZE(snirm_53c710_rm200_rsrc),
111 .resource = snirm_53c710_rm200_rsrc
112 };
113
snirm_setup_devinit(void)114 static int __init snirm_setup_devinit(void)
115 {
116 if (sni_brd_type == SNI_BRD_RM200) {
117 platform_device_register(&rm200_serial8250_device);
118 platform_device_register(&rm200_ds1216_device);
119 platform_device_register(&snirm_82596_rm200_pdev);
120 platform_device_register(&snirm_53c710_rm200_pdev);
121 sni_eisa_root_init();
122 }
123 return 0;
124 }
125
126 device_initcall(snirm_setup_devinit);
127
128 /*
129 * RM200 has an ISA and an EISA bus. The iSA bus is only used
130 * for onboard devices and also has twi i8259 PICs. Since these
131 * PICs are no accessible via inb/outb the following code uses
132 * readb/writeb to access them
133 */
134
135 DEFINE_SPINLOCK(sni_rm200_i8259A_lock);
136 #define PIC_CMD 0x00
137 #define PIC_IMR 0x01
138 #define PIC_ISR PIC_CMD
139 #define PIC_POLL PIC_ISR
140 #define PIC_OCW3 PIC_ISR
141
142 /* i8259A PIC related value */
143 #define PIC_CASCADE_IR 2
144 #define MASTER_ICW4_DEFAULT 0x01
145 #define SLAVE_ICW4_DEFAULT 0x01
146
147 /*
148 * This contains the irq mask for both 8259A irq controllers,
149 */
150 static unsigned int rm200_cached_irq_mask = 0xffff;
151 static __iomem u8 *rm200_pic_master;
152 static __iomem u8 *rm200_pic_slave;
153
154 #define cached_master_mask (rm200_cached_irq_mask)
155 #define cached_slave_mask (rm200_cached_irq_mask >> 8)
156
sni_rm200_disable_8259A_irq(unsigned int irq)157 static void sni_rm200_disable_8259A_irq(unsigned int irq)
158 {
159 unsigned int mask;
160 unsigned long flags;
161
162 irq -= RM200_I8259A_IRQ_BASE;
163 mask = 1 << irq;
164 spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
165 rm200_cached_irq_mask |= mask;
166 if (irq & 8)
167 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
168 else
169 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
170 spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
171 }
172
sni_rm200_enable_8259A_irq(unsigned int irq)173 static void sni_rm200_enable_8259A_irq(unsigned int irq)
174 {
175 unsigned int mask;
176 unsigned long flags;
177
178 irq -= RM200_I8259A_IRQ_BASE;
179 mask = ~(1 << irq);
180 spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
181 rm200_cached_irq_mask &= mask;
182 if (irq & 8)
183 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
184 else
185 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
186 spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
187 }
188
sni_rm200_i8259A_irq_real(unsigned int irq)189 static inline int sni_rm200_i8259A_irq_real(unsigned int irq)
190 {
191 int value;
192 int irqmask = 1 << irq;
193
194 if (irq < 8) {
195 writeb(0x0B, rm200_pic_master + PIC_CMD);
196 value = readb(rm200_pic_master + PIC_CMD) & irqmask;
197 writeb(0x0A, rm200_pic_master + PIC_CMD);
198 return value;
199 }
200 writeb(0x0B, rm200_pic_slave + PIC_CMD); /* ISR register */
201 value = readb(rm200_pic_slave + PIC_CMD) & (irqmask >> 8);
202 writeb(0x0A, rm200_pic_slave + PIC_CMD);
203 return value;
204 }
205
206 /*
207 * Careful! The 8259A is a fragile beast, it pretty
208 * much _has_ to be done exactly like this (mask it
209 * first, _then_ send the EOI, and the order of EOI
210 * to the two 8259s is important!
211 */
sni_rm200_mask_and_ack_8259A(unsigned int irq)212 void sni_rm200_mask_and_ack_8259A(unsigned int irq)
213 {
214 unsigned int irqmask;
215 unsigned long flags;
216
217 irq -= RM200_I8259A_IRQ_BASE;
218 irqmask = 1 << irq;
219 spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
220 /*
221 * Lightweight spurious IRQ detection. We do not want
222 * to overdo spurious IRQ handling - it's usually a sign
223 * of hardware problems, so we only do the checks we can
224 * do without slowing down good hardware unnecessarily.
225 *
226 * Note that IRQ7 and IRQ15 (the two spurious IRQs
227 * usually resulting from the 8259A-1|2 PICs) occur
228 * even if the IRQ is masked in the 8259A. Thus we
229 * can check spurious 8259A IRQs without doing the
230 * quite slow i8259A_irq_real() call for every IRQ.
231 * This does not cover 100% of spurious interrupts,
232 * but should be enough to warn the user that there
233 * is something bad going on ...
234 */
235 if (rm200_cached_irq_mask & irqmask)
236 goto spurious_8259A_irq;
237 rm200_cached_irq_mask |= irqmask;
238
239 handle_real_irq:
240 if (irq & 8) {
241 readb(rm200_pic_slave + PIC_IMR);
242 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
243 writeb(0x60+(irq & 7), rm200_pic_slave + PIC_CMD);
244 writeb(0x60+PIC_CASCADE_IR, rm200_pic_master + PIC_CMD);
245 } else {
246 readb(rm200_pic_master + PIC_IMR);
247 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
248 writeb(0x60+irq, rm200_pic_master + PIC_CMD);
249 }
250 spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
251 return;
252
253 spurious_8259A_irq:
254 /*
255 * this is the slow path - should happen rarely.
256 */
257 if (sni_rm200_i8259A_irq_real(irq))
258 /*
259 * oops, the IRQ _is_ in service according to the
260 * 8259A - not spurious, go handle it.
261 */
262 goto handle_real_irq;
263
264 {
265 static int spurious_irq_mask;
266 /*
267 * At this point we can be sure the IRQ is spurious,
268 * lets ACK and report it. [once per IRQ]
269 */
270 if (!(spurious_irq_mask & irqmask)) {
271 printk(KERN_DEBUG
272 "spurious RM200 8259A interrupt: IRQ%d.\n", irq);
273 spurious_irq_mask |= irqmask;
274 }
275 atomic_inc(&irq_err_count);
276 /*
277 * Theoretically we do not have to handle this IRQ,
278 * but in Linux this does not cause problems and is
279 * simpler for us.
280 */
281 goto handle_real_irq;
282 }
283 }
284
285 static struct irq_chip sni_rm200_i8259A_chip = {
286 .name = "RM200-XT-PIC",
287 .mask = sni_rm200_disable_8259A_irq,
288 .unmask = sni_rm200_enable_8259A_irq,
289 .mask_ack = sni_rm200_mask_and_ack_8259A,
290 };
291
292 /*
293 * Do the traditional i8259 interrupt polling thing. This is for the few
294 * cases where no better interrupt acknowledge method is available and we
295 * absolutely must touch the i8259.
296 */
sni_rm200_i8259_irq(void)297 static inline int sni_rm200_i8259_irq(void)
298 {
299 int irq;
300
301 spin_lock(&sni_rm200_i8259A_lock);
302
303 /* Perform an interrupt acknowledge cycle on controller 1. */
304 writeb(0x0C, rm200_pic_master + PIC_CMD); /* prepare for poll */
305 irq = readb(rm200_pic_master + PIC_CMD) & 7;
306 if (irq == PIC_CASCADE_IR) {
307 /*
308 * Interrupt is cascaded so perform interrupt
309 * acknowledge on controller 2.
310 */
311 writeb(0x0C, rm200_pic_slave + PIC_CMD); /* prepare for poll */
312 irq = (readb(rm200_pic_slave + PIC_CMD) & 7) + 8;
313 }
314
315 if (unlikely(irq == 7)) {
316 /*
317 * This may be a spurious interrupt.
318 *
319 * Read the interrupt status register (ISR). If the most
320 * significant bit is not set then there is no valid
321 * interrupt.
322 */
323 writeb(0x0B, rm200_pic_master + PIC_ISR); /* ISR register */
324 if (~readb(rm200_pic_master + PIC_ISR) & 0x80)
325 irq = -1;
326 }
327
328 spin_unlock(&sni_rm200_i8259A_lock);
329
330 return likely(irq >= 0) ? irq + RM200_I8259A_IRQ_BASE : irq;
331 }
332
sni_rm200_init_8259A(void)333 void sni_rm200_init_8259A(void)
334 {
335 unsigned long flags;
336
337 spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
338
339 writeb(0xff, rm200_pic_master + PIC_IMR);
340 writeb(0xff, rm200_pic_slave + PIC_IMR);
341
342 writeb(0x11, rm200_pic_master + PIC_CMD);
343 writeb(0, rm200_pic_master + PIC_IMR);
344 writeb(1U << PIC_CASCADE_IR, rm200_pic_master + PIC_IMR);
345 writeb(MASTER_ICW4_DEFAULT, rm200_pic_master + PIC_IMR);
346 writeb(0x11, rm200_pic_slave + PIC_CMD);
347 writeb(8, rm200_pic_slave + PIC_IMR);
348 writeb(PIC_CASCADE_IR, rm200_pic_slave + PIC_IMR);
349 writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR);
350 udelay(100); /* wait for 8259A to initialize */
351
352 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
353 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
354
355 spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
356 }
357
358 /*
359 * IRQ2 is cascade interrupt to second interrupt controller
360 */
361 static struct irqaction sni_rm200_irq2 = {
362 no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL
363 };
364
365 static struct resource sni_rm200_pic1_resource = {
366 .name = "onboard ISA pic1",
367 .start = 0x16000020,
368 .end = 0x16000023,
369 .flags = IORESOURCE_BUSY
370 };
371
372 static struct resource sni_rm200_pic2_resource = {
373 .name = "onboard ISA pic2",
374 .start = 0x160000a0,
375 .end = 0x160000a3,
376 .flags = IORESOURCE_BUSY
377 };
378
379 /* ISA irq handler */
sni_rm200_i8259A_irq_handler(int dummy,void * p)380 static irqreturn_t sni_rm200_i8259A_irq_handler(int dummy, void *p)
381 {
382 int irq;
383
384 irq = sni_rm200_i8259_irq();
385 if (unlikely(irq < 0))
386 return IRQ_NONE;
387
388 do_IRQ(irq);
389 return IRQ_HANDLED;
390 }
391
392 struct irqaction sni_rm200_i8259A_irq = {
393 .handler = sni_rm200_i8259A_irq_handler,
394 .name = "onboard ISA",
395 .flags = IRQF_SHARED
396 };
397
sni_rm200_i8259_irqs(void)398 void __init sni_rm200_i8259_irqs(void)
399 {
400 int i;
401
402 rm200_pic_master = ioremap_nocache(0x16000020, 4);
403 if (!rm200_pic_master)
404 return;
405 rm200_pic_slave = ioremap_nocache(0x160000a0, 4);
406 if (!rm200_pic_master) {
407 iounmap(rm200_pic_master);
408 return;
409 }
410
411 insert_resource(&iomem_resource, &sni_rm200_pic1_resource);
412 insert_resource(&iomem_resource, &sni_rm200_pic2_resource);
413
414 sni_rm200_init_8259A();
415
416 for (i = RM200_I8259A_IRQ_BASE; i < RM200_I8259A_IRQ_BASE + 16; i++)
417 set_irq_chip_and_handler(i, &sni_rm200_i8259A_chip,
418 handle_level_irq);
419
420 setup_irq(RM200_I8259A_IRQ_BASE + PIC_CASCADE_IR, &sni_rm200_irq2);
421 }
422
423
424 #define SNI_RM200_INT_STAT_REG CKSEG1ADDR(0xbc000000)
425 #define SNI_RM200_INT_ENA_REG CKSEG1ADDR(0xbc080000)
426
427 #define SNI_RM200_INT_START 24
428 #define SNI_RM200_INT_END 28
429
enable_rm200_irq(unsigned int irq)430 static void enable_rm200_irq(unsigned int irq)
431 {
432 unsigned int mask = 1 << (irq - SNI_RM200_INT_START);
433
434 *(volatile u8 *)SNI_RM200_INT_ENA_REG &= ~mask;
435 }
436
disable_rm200_irq(unsigned int irq)437 void disable_rm200_irq(unsigned int irq)
438 {
439 unsigned int mask = 1 << (irq - SNI_RM200_INT_START);
440
441 *(volatile u8 *)SNI_RM200_INT_ENA_REG |= mask;
442 }
443
end_rm200_irq(unsigned int irq)444 void end_rm200_irq(unsigned int irq)
445 {
446 if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
447 enable_rm200_irq(irq);
448 }
449
450 static struct irq_chip rm200_irq_type = {
451 .typename = "RM200",
452 .ack = disable_rm200_irq,
453 .mask = disable_rm200_irq,
454 .mask_ack = disable_rm200_irq,
455 .unmask = enable_rm200_irq,
456 .end = end_rm200_irq,
457 };
458
sni_rm200_hwint(void)459 static void sni_rm200_hwint(void)
460 {
461 u32 pending = read_c0_cause() & read_c0_status();
462 u8 mask;
463 u8 stat;
464 int irq;
465
466 if (pending & C_IRQ5)
467 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
468 else if (pending & C_IRQ0) {
469 clear_c0_status(IE_IRQ0);
470 mask = *(volatile u8 *)SNI_RM200_INT_ENA_REG ^ 0x1f;
471 stat = *(volatile u8 *)SNI_RM200_INT_STAT_REG ^ 0x14;
472 irq = ffs(stat & mask & 0x1f);
473
474 if (likely(irq > 0))
475 do_IRQ(irq + SNI_RM200_INT_START - 1);
476 set_c0_status(IE_IRQ0);
477 }
478 }
479
sni_rm200_irq_init(void)480 void __init sni_rm200_irq_init(void)
481 {
482 int i;
483
484 * (volatile u8 *)SNI_RM200_INT_ENA_REG = 0x1f;
485
486 sni_rm200_i8259_irqs();
487 mips_cpu_irq_init();
488 /* Actually we've got more interrupts to handle ... */
489 for (i = SNI_RM200_INT_START; i <= SNI_RM200_INT_END; i++)
490 set_irq_chip(i, &rm200_irq_type);
491 sni_hwint = sni_rm200_hwint;
492 change_c0_status(ST0_IM, IE_IRQ0);
493 setup_irq(SNI_RM200_INT_START + 0, &sni_rm200_i8259A_irq);
494 setup_irq(SNI_RM200_INT_START + 1, &sni_isa_irq);
495 }
496
sni_rm200_init(void)497 void __init sni_rm200_init(void)
498 {
499 }
500