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
8 * Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
10 * i8259 parts ripped out of arch/mips/kernel/i8259.c
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>
22 #include <asm/irq_cpu.h>
24 #define RM200_I8259A_IRQ_BASE 32
26 #define MEMPORT(_base,_irq) \
32 .flags = UPF_BOOT_AUTOCONF|UPF_IOREMAP, \
35 static struct plat_serial8250_port rm200_data
[] = {
36 MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE
+ 4),
37 MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE
+ 3),
41 static struct platform_device rm200_serial8250_device
= {
43 .id
= PLAT8250_DEV_PLATFORM
,
45 .platform_data
= rm200_data
,
49 static struct resource rm200_ds1216_rsrc
[] = {
53 .flags
= IORESOURCE_MEM
57 static struct platform_device rm200_ds1216_device
= {
59 .num_resources
= ARRAY_SIZE(rm200_ds1216_rsrc
),
60 .resource
= rm200_ds1216_rsrc
63 static struct resource snirm_82596_rm200_rsrc
[] = {
67 .flags
= IORESOURCE_MEM
72 .flags
= IORESOURCE_MEM
77 .flags
= IORESOURCE_MEM
82 .flags
= IORESOURCE_IRQ
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
95 static struct resource snirm_53c710_rm200_rsrc
[] = {
99 .flags
= IORESOURCE_MEM
104 .flags
= IORESOURCE_IRQ
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
114 static int __init
snirm_setup_devinit(void)
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();
126 device_initcall(snirm_setup_devinit
);
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
135 DEFINE_SPINLOCK(sni_rm200_i8259A_lock
);
138 #define PIC_ISR PIC_CMD
139 #define PIC_POLL PIC_ISR
140 #define PIC_OCW3 PIC_ISR
142 /* i8259A PIC related value */
143 #define PIC_CASCADE_IR 2
144 #define MASTER_ICW4_DEFAULT 0x01
145 #define SLAVE_ICW4_DEFAULT 0x01
148 * This contains the irq mask for both 8259A irq controllers,
150 static unsigned int rm200_cached_irq_mask
= 0xffff;
151 static __iomem u8
*rm200_pic_master
;
152 static __iomem u8
*rm200_pic_slave
;
154 #define cached_master_mask (rm200_cached_irq_mask)
155 #define cached_slave_mask (rm200_cached_irq_mask >> 8)
157 static void sni_rm200_disable_8259A_irq(unsigned int irq
)
162 irq
-= RM200_I8259A_IRQ_BASE
;
164 spin_lock_irqsave(&sni_rm200_i8259A_lock
, flags
);
165 rm200_cached_irq_mask
|= mask
;
167 writeb(cached_slave_mask
, rm200_pic_slave
+ PIC_IMR
);
169 writeb(cached_master_mask
, rm200_pic_master
+ PIC_IMR
);
170 spin_unlock_irqrestore(&sni_rm200_i8259A_lock
, flags
);
173 static void sni_rm200_enable_8259A_irq(unsigned int irq
)
178 irq
-= RM200_I8259A_IRQ_BASE
;
180 spin_lock_irqsave(&sni_rm200_i8259A_lock
, flags
);
181 rm200_cached_irq_mask
&= mask
;
183 writeb(cached_slave_mask
, rm200_pic_slave
+ PIC_IMR
);
185 writeb(cached_master_mask
, rm200_pic_master
+ PIC_IMR
);
186 spin_unlock_irqrestore(&sni_rm200_i8259A_lock
, flags
);
189 static inline int sni_rm200_i8259A_irq_real(unsigned int irq
)
192 int irqmask
= 1 << irq
;
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
);
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
);
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!
212 void sni_rm200_mask_and_ack_8259A(unsigned int irq
)
214 unsigned int irqmask
;
217 irq
-= RM200_I8259A_IRQ_BASE
;
219 spin_lock_irqsave(&sni_rm200_i8259A_lock
, flags
);
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.
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 ...
235 if (rm200_cached_irq_mask
& irqmask
)
236 goto spurious_8259A_irq
;
237 rm200_cached_irq_mask
|= irqmask
;
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
);
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
);
250 spin_unlock_irqrestore(&sni_rm200_i8259A_lock
, flags
);
255 * this is the slow path - should happen rarely.
257 if (sni_rm200_i8259A_irq_real(irq
))
259 * oops, the IRQ _is_ in service according to the
260 * 8259A - not spurious, go handle it.
262 goto handle_real_irq
;
265 static int spurious_irq_mask
;
267 * At this point we can be sure the IRQ is spurious,
268 * lets ACK and report it. [once per IRQ]
270 if (!(spurious_irq_mask
& irqmask
)) {
272 "spurious RM200 8259A interrupt: IRQ%d.\n", irq
);
273 spurious_irq_mask
|= irqmask
;
275 atomic_inc(&irq_err_count
);
277 * Theoretically we do not have to handle this IRQ,
278 * but in Linux this does not cause problems and is
281 goto handle_real_irq
;
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
,
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.
297 static inline int sni_rm200_i8259_irq(void)
301 spin_lock(&sni_rm200_i8259A_lock
);
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
) {
308 * Interrupt is cascaded so perform interrupt
309 * acknowledge on controller 2.
311 writeb(0x0C, rm200_pic_slave
+ PIC_CMD
); /* prepare for poll */
312 irq
= (readb(rm200_pic_slave
+ PIC_CMD
) & 7) + 8;
315 if (unlikely(irq
== 7)) {
317 * This may be a spurious interrupt.
319 * Read the interrupt status register (ISR). If the most
320 * significant bit is not set then there is no valid
323 writeb(0x0B, rm200_pic_master
+ PIC_ISR
); /* ISR register */
324 if (~readb(rm200_pic_master
+ PIC_ISR
) & 0x80)
328 spin_unlock(&sni_rm200_i8259A_lock
);
330 return likely(irq
>= 0) ? irq
+ RM200_I8259A_IRQ_BASE
: irq
;
333 void sni_rm200_init_8259A(void)
337 spin_lock_irqsave(&sni_rm200_i8259A_lock
, flags
);
339 writeb(0xff, rm200_pic_master
+ PIC_IMR
);
340 writeb(0xff, rm200_pic_slave
+ PIC_IMR
);
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 */
352 writeb(cached_master_mask
, rm200_pic_master
+ PIC_IMR
);
353 writeb(cached_slave_mask
, rm200_pic_slave
+ PIC_IMR
);
355 spin_unlock_irqrestore(&sni_rm200_i8259A_lock
, flags
);
359 * IRQ2 is cascade interrupt to second interrupt controller
361 static struct irqaction sni_rm200_irq2
= {
362 no_action
, 0, CPU_MASK_NONE
, "cascade", NULL
, NULL
365 static struct resource sni_rm200_pic1_resource
= {
366 .name
= "onboard ISA pic1",
369 .flags
= IORESOURCE_BUSY
372 static struct resource sni_rm200_pic2_resource
= {
373 .name
= "onboard ISA pic2",
376 .flags
= IORESOURCE_BUSY
379 /* ISA irq handler */
380 static irqreturn_t
sni_rm200_i8259A_irq_handler(int dummy
, void *p
)
384 irq
= sni_rm200_i8259_irq();
385 if (unlikely(irq
< 0))
392 struct irqaction sni_rm200_i8259A_irq
= {
393 .handler
= sni_rm200_i8259A_irq_handler
,
394 .name
= "onboard ISA",
398 void __init
sni_rm200_i8259_irqs(void)
402 rm200_pic_master
= ioremap_nocache(0x16000020, 4);
403 if (!rm200_pic_master
)
405 rm200_pic_slave
= ioremap_nocache(0x160000a0, 4);
406 if (!rm200_pic_master
) {
407 iounmap(rm200_pic_master
);
411 insert_resource(&iomem_resource
, &sni_rm200_pic1_resource
);
412 insert_resource(&iomem_resource
, &sni_rm200_pic2_resource
);
414 sni_rm200_init_8259A();
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
,
420 setup_irq(RM200_I8259A_IRQ_BASE
+ PIC_CASCADE_IR
, &sni_rm200_irq2
);
424 #define SNI_RM200_INT_STAT_REG CKSEG1ADDR(0xbc000000)
425 #define SNI_RM200_INT_ENA_REG CKSEG1ADDR(0xbc080000)
427 #define SNI_RM200_INT_START 24
428 #define SNI_RM200_INT_END 28
430 static void enable_rm200_irq(unsigned int irq
)
432 unsigned int mask
= 1 << (irq
- SNI_RM200_INT_START
);
434 *(volatile u8
*)SNI_RM200_INT_ENA_REG
&= ~mask
;
437 void disable_rm200_irq(unsigned int irq
)
439 unsigned int mask
= 1 << (irq
- SNI_RM200_INT_START
);
441 *(volatile u8
*)SNI_RM200_INT_ENA_REG
|= mask
;
444 void end_rm200_irq(unsigned int irq
)
446 if (!(irq_desc
[irq
].status
& (IRQ_DISABLED
|IRQ_INPROGRESS
)))
447 enable_rm200_irq(irq
);
450 static struct irq_chip rm200_irq_type
= {
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
,
459 static void sni_rm200_hwint(void)
461 u32 pending
= read_c0_cause() & read_c0_status();
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);
475 do_IRQ(irq
+ SNI_RM200_INT_START
- 1);
476 set_c0_status(IE_IRQ0
);
480 void __init
sni_rm200_irq_init(void)
484 * (volatile u8
*)SNI_RM200_INT_ENA_REG
= 0x1f;
486 sni_rm200_i8259_irqs();
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
);
497 void __init
sni_rm200_init(void)