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1 /*
2  *
3  * Programmable Interrupt Controller functions for the Freescale MPC52xx.
4  *
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  * Copyright (C) 2006 bplan GmbH
7  * Copyright (C) 2004 Sylvain Munaut <tnt@246tNt.com>
8  * Copyright (C) 2003 Montavista Software, Inc
9  *
10  * Based on the code from the 2.4 kernel by
11  * Dale Farnsworth <dfarnsworth@mvista.com> and Kent Borg.
12  *
13  * This file is licensed under the terms of the GNU General Public License
14  * version 2. This program is licensed "as is" without any warranty of any
15  * kind, whether express or implied.
16  *
17  */
18 
19 /*
20  * This is the device driver for the MPC5200 interrupt controller.
21  *
22  * hardware overview
23  * -----------------
24  * The MPC5200 interrupt controller groups the all interrupt sources into
25  * three groups called 'critical', 'main', and 'peripheral'.  The critical
26  * group has 3 irqs, External IRQ0, slice timer 0 irq, and wake from deep
27  * sleep.  Main group include the other 3 external IRQs, slice timer 1, RTC,
28  * gpios, and the general purpose timers.  Peripheral group contains the
29  * remaining irq sources from all of the on-chip peripherals (PSCs, Ethernet,
30  * USB, DMA, etc).
31  *
32  * virqs
33  * -----
34  * The Linux IRQ subsystem requires that each irq source be assigned a
35  * system wide unique IRQ number starting at 1 (0 means no irq).  Since
36  * systems can have multiple interrupt controllers, the virtual IRQ (virq)
37  * infrastructure lets each interrupt controller to define a local set
38  * of IRQ numbers and the virq infrastructure maps those numbers into
39  * a unique range of the global IRQ# space.
40  *
41  * To define a range of virq numbers for this controller, this driver first
42  * assigns a number to each of the irq groups (called the level 1 or L1
43  * value).  Within each group individual irq sources are also assigned a
44  * number, as defined by the MPC5200 user guide, and refers to it as the
45  * level 2 or L2 value.  The virq number is determined by shifting up the
46  * L1 value by MPC52xx_IRQ_L1_OFFSET and ORing it with the L2 value.
47  *
48  * For example, the TMR0 interrupt is irq 9 in the main group.  The
49  * virq for TMR0 is calculated by ((1 << MPC52xx_IRQ_L1_OFFSET) | 9).
50  *
51  * The observant reader will also notice that this driver defines a 4th
52  * interrupt group called 'bestcomm'.  The bestcomm group isn't physically
53  * part of the MPC5200 interrupt controller, but it is used here to assign
54  * a separate virq number for each bestcomm task (since any of the 16
55  * bestcomm tasks can cause the bestcomm interrupt to be raised).  When a
56  * bestcomm interrupt occurs (peripheral group, irq 0) this driver determines
57  * which task needs servicing and returns the irq number for that task.  This
58  * allows drivers which use bestcomm to define their own interrupt handlers.
59  *
60  * irq_chip structures
61  * -------------------
62  * For actually manipulating IRQs (masking, enabling, clearing, etc) this
63  * driver defines four separate 'irq_chip' structures, one for the main
64  * group, one for the peripherals group, one for the bestcomm group and one
65  * for external interrupts.  The irq_chip structures provide the hooks needed
66  * to manipulate each IRQ source, and since each group is has a separate set
67  * of registers for controlling the irq, it makes sense to divide up the
68  * hooks along those lines.
69  *
70  * You'll notice that there is not an irq_chip for the critical group and
71  * you'll also notice that there is an irq_chip defined for external
72  * interrupts even though there is no external interrupt group.  The reason
73  * for this is that the four external interrupts are all managed with the same
74  * register even though one of the external IRQs is in the critical group and
75  * the other three are in the main group.  For this reason it makes sense for
76  * the 4 external irqs to be managed using a separate set of hooks.  The
77  * reason there is no crit irq_chip is that of the 3 irqs in the critical
78  * group, only external interrupt is actually support at this time by this
79  * driver and since external interrupt is the only one used, it can just
80  * be directed to make use of the external irq irq_chip.
81  *
82  * device tree bindings
83  * --------------------
84  * The device tree bindings for this controller reflect the two level
85  * organization of irqs in the device.  #interrupt-cells = <3> where the
86  * first cell is the group number [0..3], the second cell is the irq
87  * number in the group, and the third cell is the sense type (level/edge).
88  * For reference, the following is a list of the interrupt property values
89  * associated with external interrupt sources on the MPC5200 (just because
90  * it is non-obvious to determine what the interrupts property should be
91  * when reading the mpc5200 manual and it is a frequently asked question).
92  *
93  * External interrupts:
94  * <0 0 n>	external irq0, n is sense	(n=0: level high,
95  * <1 1 n>	external irq1, n is sense	 n=1: edge rising,
96  * <1 2 n>	external irq2, n is sense	 n=2: edge falling,
97  * <1 3 n>	external irq3, n is sense	 n=3: level low)
98  */
99 #undef DEBUG
100 
101 #include <linux/interrupt.h>
102 #include <linux/irq.h>
103 #include <linux/of.h>
104 #include <asm/io.h>
105 #include <asm/prom.h>
106 #include <asm/mpc52xx.h>
107 
108 /* HW IRQ mapping */
109 #define MPC52xx_IRQ_L1_CRIT	(0)
110 #define MPC52xx_IRQ_L1_MAIN	(1)
111 #define MPC52xx_IRQ_L1_PERP	(2)
112 #define MPC52xx_IRQ_L1_SDMA	(3)
113 
114 #define MPC52xx_IRQ_L1_OFFSET	(6)
115 #define MPC52xx_IRQ_L1_MASK	(0x00c0)
116 #define MPC52xx_IRQ_L2_MASK	(0x003f)
117 
118 #define MPC52xx_IRQ_HIGHTESTHWIRQ (0xd0)
119 
120 
121 /* MPC5200 device tree match tables */
122 static struct of_device_id mpc52xx_pic_ids[] __initdata = {
123 	{ .compatible = "fsl,mpc5200-pic", },
124 	{ .compatible = "mpc5200-pic", },
125 	{}
126 };
127 static struct of_device_id mpc52xx_sdma_ids[] __initdata = {
128 	{ .compatible = "fsl,mpc5200-bestcomm", },
129 	{ .compatible = "mpc5200-bestcomm", },
130 	{}
131 };
132 
133 static struct mpc52xx_intr __iomem *intr;
134 static struct mpc52xx_sdma __iomem *sdma;
135 static struct irq_host *mpc52xx_irqhost = NULL;
136 
137 static unsigned char mpc52xx_map_senses[4] = {
138 	IRQ_TYPE_LEVEL_HIGH,
139 	IRQ_TYPE_EDGE_RISING,
140 	IRQ_TYPE_EDGE_FALLING,
141 	IRQ_TYPE_LEVEL_LOW,
142 };
143 
144 /* Utility functions */
io_be_setbit(u32 __iomem * addr,int bitno)145 static inline void io_be_setbit(u32 __iomem *addr, int bitno)
146 {
147 	out_be32(addr, in_be32(addr) | (1 << bitno));
148 }
149 
io_be_clrbit(u32 __iomem * addr,int bitno)150 static inline void io_be_clrbit(u32 __iomem *addr, int bitno)
151 {
152 	out_be32(addr, in_be32(addr) & ~(1 << bitno));
153 }
154 
155 /*
156  * IRQ[0-3] interrupt irq_chip
157  */
mpc52xx_extirq_mask(unsigned int virq)158 static void mpc52xx_extirq_mask(unsigned int virq)
159 {
160 	int irq;
161 	int l2irq;
162 
163 	irq = irq_map[virq].hwirq;
164 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
165 
166 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
167 
168 	io_be_clrbit(&intr->ctrl, 11 - l2irq);
169 }
170 
mpc52xx_extirq_unmask(unsigned int virq)171 static void mpc52xx_extirq_unmask(unsigned int virq)
172 {
173 	int irq;
174 	int l2irq;
175 
176 	irq = irq_map[virq].hwirq;
177 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
178 
179 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
180 
181 	io_be_setbit(&intr->ctrl, 11 - l2irq);
182 }
183 
mpc52xx_extirq_ack(unsigned int virq)184 static void mpc52xx_extirq_ack(unsigned int virq)
185 {
186 	int irq;
187 	int l2irq;
188 
189 	irq = irq_map[virq].hwirq;
190 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
191 
192 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
193 
194 	io_be_setbit(&intr->ctrl, 27-l2irq);
195 }
196 
mpc52xx_extirq_set_type(unsigned int virq,unsigned int flow_type)197 static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
198 {
199 	struct irq_desc *desc = get_irq_desc(virq);
200 	u32 ctrl_reg, type;
201 	int irq;
202 	int l2irq;
203 
204 	irq = irq_map[virq].hwirq;
205 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
206 
207 	pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
208 
209 	switch (flow_type) {
210 	case IRQF_TRIGGER_HIGH:
211 		type = 0;
212 		break;
213 	case IRQF_TRIGGER_RISING:
214 		type = 1;
215 		break;
216 	case IRQF_TRIGGER_FALLING:
217 		type = 2;
218 		break;
219 	case IRQF_TRIGGER_LOW:
220 		type = 3;
221 		break;
222 	default:
223 		type = 0;
224 	}
225 
226 	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
227 	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
228 	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
229 		desc->status |= IRQ_LEVEL;
230 
231 	ctrl_reg = in_be32(&intr->ctrl);
232 	ctrl_reg &= ~(0x3 << (22 - (l2irq * 2)));
233 	ctrl_reg |= (type << (22 - (l2irq * 2)));
234 	out_be32(&intr->ctrl, ctrl_reg);
235 
236 	return 0;
237 }
238 
239 static struct irq_chip mpc52xx_extirq_irqchip = {
240 	.typename = "MPC52xx External",
241 	.mask = mpc52xx_extirq_mask,
242 	.unmask = mpc52xx_extirq_unmask,
243 	.ack = mpc52xx_extirq_ack,
244 	.set_type = mpc52xx_extirq_set_type,
245 };
246 
247 /*
248  * Main interrupt irq_chip
249  */
mpc52xx_main_mask(unsigned int virq)250 static void mpc52xx_main_mask(unsigned int virq)
251 {
252 	int irq;
253 	int l2irq;
254 
255 	irq = irq_map[virq].hwirq;
256 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
257 
258 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
259 
260 	io_be_setbit(&intr->main_mask, 16 - l2irq);
261 }
262 
mpc52xx_main_unmask(unsigned int virq)263 static void mpc52xx_main_unmask(unsigned int virq)
264 {
265 	int irq;
266 	int l2irq;
267 
268 	irq = irq_map[virq].hwirq;
269 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
270 
271 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
272 
273 	io_be_clrbit(&intr->main_mask, 16 - l2irq);
274 }
275 
276 static struct irq_chip mpc52xx_main_irqchip = {
277 	.typename = "MPC52xx Main",
278 	.mask = mpc52xx_main_mask,
279 	.mask_ack = mpc52xx_main_mask,
280 	.unmask = mpc52xx_main_unmask,
281 };
282 
283 /*
284  * Peripherals interrupt irq_chip
285  */
mpc52xx_periph_mask(unsigned int virq)286 static void mpc52xx_periph_mask(unsigned int virq)
287 {
288 	int irq;
289 	int l2irq;
290 
291 	irq = irq_map[virq].hwirq;
292 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
293 
294 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
295 
296 	io_be_setbit(&intr->per_mask, 31 - l2irq);
297 }
298 
mpc52xx_periph_unmask(unsigned int virq)299 static void mpc52xx_periph_unmask(unsigned int virq)
300 {
301 	int irq;
302 	int l2irq;
303 
304 	irq = irq_map[virq].hwirq;
305 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
306 
307 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
308 
309 	io_be_clrbit(&intr->per_mask, 31 - l2irq);
310 }
311 
312 static struct irq_chip mpc52xx_periph_irqchip = {
313 	.typename = "MPC52xx Peripherals",
314 	.mask = mpc52xx_periph_mask,
315 	.mask_ack = mpc52xx_periph_mask,
316 	.unmask = mpc52xx_periph_unmask,
317 };
318 
319 /*
320  * SDMA interrupt irq_chip
321  */
mpc52xx_sdma_mask(unsigned int virq)322 static void mpc52xx_sdma_mask(unsigned int virq)
323 {
324 	int irq;
325 	int l2irq;
326 
327 	irq = irq_map[virq].hwirq;
328 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
329 
330 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
331 
332 	io_be_setbit(&sdma->IntMask, l2irq);
333 }
334 
mpc52xx_sdma_unmask(unsigned int virq)335 static void mpc52xx_sdma_unmask(unsigned int virq)
336 {
337 	int irq;
338 	int l2irq;
339 
340 	irq = irq_map[virq].hwirq;
341 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
342 
343 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
344 
345 	io_be_clrbit(&sdma->IntMask, l2irq);
346 }
347 
mpc52xx_sdma_ack(unsigned int virq)348 static void mpc52xx_sdma_ack(unsigned int virq)
349 {
350 	int irq;
351 	int l2irq;
352 
353 	irq = irq_map[virq].hwirq;
354 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
355 
356 	pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq);
357 
358 	out_be32(&sdma->IntPend, 1 << l2irq);
359 }
360 
361 static struct irq_chip mpc52xx_sdma_irqchip = {
362 	.typename = "MPC52xx SDMA",
363 	.mask = mpc52xx_sdma_mask,
364 	.unmask = mpc52xx_sdma_unmask,
365 	.ack = mpc52xx_sdma_ack,
366 };
367 
368 /**
369  * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
370  */
mpc52xx_irqhost_xlate(struct irq_host * h,struct device_node * ct,u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_flags)371 static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
372 				 u32 *intspec, unsigned int intsize,
373 				 irq_hw_number_t *out_hwirq,
374 				 unsigned int *out_flags)
375 {
376 	int intrvect_l1;
377 	int intrvect_l2;
378 	int intrvect_type;
379 	int intrvect_linux;
380 
381 	if (intsize != 3)
382 		return -1;
383 
384 	intrvect_l1 = (int)intspec[0];
385 	intrvect_l2 = (int)intspec[1];
386 	intrvect_type = (int)intspec[2];
387 
388 	intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) &
389 			 MPC52xx_IRQ_L1_MASK;
390 	intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK;
391 
392 	pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
393 		 intrvect_l2);
394 
395 	*out_hwirq = intrvect_linux;
396 	*out_flags = mpc52xx_map_senses[intrvect_type];
397 
398 	return 0;
399 }
400 
401 /**
402  * mpc52xx_irqx_gettype - determine the IRQ sense type (level/edge)
403  *
404  * Only external IRQs need this.
405  */
mpc52xx_irqx_gettype(int irq)406 static int mpc52xx_irqx_gettype(int irq)
407 {
408 	int type;
409 	u32 ctrl_reg;
410 
411 	ctrl_reg = in_be32(&intr->ctrl);
412 	type = (ctrl_reg >> (22 - irq * 2)) & 0x3;
413 
414 	return mpc52xx_map_senses[type];
415 }
416 
417 /**
418  * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
419  */
mpc52xx_irqhost_map(struct irq_host * h,unsigned int virq,irq_hw_number_t irq)420 static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
421 			       irq_hw_number_t irq)
422 {
423 	int l1irq;
424 	int l2irq;
425 	struct irq_chip *good_irqchip;
426 	void *good_handle;
427 	int type;
428 
429 	l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET;
430 	l2irq = irq & MPC52xx_IRQ_L2_MASK;
431 
432 	/*
433 	 * Most of ours IRQs will be level low
434 	 * Only external IRQs on some platform may be others
435 	 */
436 	type = IRQ_TYPE_LEVEL_LOW;
437 
438 	switch (l1irq) {
439 	case MPC52xx_IRQ_L1_CRIT:
440 		pr_debug("%s: Critical. l2=%x\n", __func__, l2irq);
441 
442 		BUG_ON(l2irq != 0);
443 
444 		type = mpc52xx_irqx_gettype(l2irq);
445 		good_irqchip = &mpc52xx_extirq_irqchip;
446 		break;
447 
448 	case MPC52xx_IRQ_L1_MAIN:
449 		pr_debug("%s: Main IRQ[1-3] l2=%x\n", __func__, l2irq);
450 
451 		if ((l2irq >= 1) && (l2irq <= 3)) {
452 			type = mpc52xx_irqx_gettype(l2irq);
453 			good_irqchip = &mpc52xx_extirq_irqchip;
454 		} else {
455 			good_irqchip = &mpc52xx_main_irqchip;
456 		}
457 		break;
458 
459 	case MPC52xx_IRQ_L1_PERP:
460 		pr_debug("%s: Peripherals. l2=%x\n", __func__, l2irq);
461 		good_irqchip = &mpc52xx_periph_irqchip;
462 		break;
463 
464 	case MPC52xx_IRQ_L1_SDMA:
465 		pr_debug("%s: SDMA. l2=%x\n", __func__, l2irq);
466 		good_irqchip = &mpc52xx_sdma_irqchip;
467 		break;
468 
469 	default:
470 		pr_err("%s: invalid virq requested (0x%x)\n", __func__, virq);
471 		return -EINVAL;
472 	}
473 
474 	switch (type) {
475 	case IRQ_TYPE_EDGE_FALLING:
476 	case IRQ_TYPE_EDGE_RISING:
477 		good_handle = handle_edge_irq;
478 		break;
479 	default:
480 		good_handle = handle_level_irq;
481 	}
482 
483 	set_irq_chip_and_handler(virq, good_irqchip, good_handle);
484 
485 	pr_debug("%s: virq=%x, hw=%x. type=%x\n", __func__, virq,
486 		 (int)irq, type);
487 
488 	return 0;
489 }
490 
491 static struct irq_host_ops mpc52xx_irqhost_ops = {
492 	.xlate = mpc52xx_irqhost_xlate,
493 	.map = mpc52xx_irqhost_map,
494 };
495 
496 /**
497  * mpc52xx_init_irq - Initialize and register with the virq subsystem
498  *
499  * Hook for setting up IRQs on an mpc5200 system.  A pointer to this function
500  * is to be put into the machine definition structure.
501  *
502  * This function searches the device tree for an MPC5200 interrupt controller,
503  * initializes it, and registers it with the virq subsystem.
504  */
mpc52xx_init_irq(void)505 void __init mpc52xx_init_irq(void)
506 {
507 	u32 intr_ctrl;
508 	struct device_node *picnode;
509 	struct device_node *np;
510 
511 	/* Remap the necessary zones */
512 	picnode = of_find_matching_node(NULL, mpc52xx_pic_ids);
513 	intr = of_iomap(picnode, 0);
514 	if (!intr)
515 		panic(__FILE__	": find_and_map failed on 'mpc5200-pic'. "
516 				"Check node !");
517 
518 	np = of_find_matching_node(NULL, mpc52xx_sdma_ids);
519 	sdma = of_iomap(np, 0);
520 	of_node_put(np);
521 	if (!sdma)
522 		panic(__FILE__	": find_and_map failed on 'mpc5200-bestcomm'. "
523 				"Check node !");
524 
525 	/* Disable all interrupt sources. */
526 	out_be32(&sdma->IntPend, 0xffffffff);	/* 1 means clear pending */
527 	out_be32(&sdma->IntMask, 0xffffffff);	/* 1 means disabled */
528 	out_be32(&intr->per_mask, 0x7ffffc00);	/* 1 means disabled */
529 	out_be32(&intr->main_mask, 0x00010fff);	/* 1 means disabled */
530 	intr_ctrl = in_be32(&intr->ctrl);
531 	intr_ctrl &= 0x00ff0000;	/* Keeps IRQ[0-3] config */
532 	intr_ctrl |=	0x0f000000 |	/* clear IRQ 0-3 */
533 			0x00001000 |	/* MEE master external enable */
534 			0x00000000 |	/* 0 means disable IRQ 0-3 */
535 			0x00000001;	/* CEb route critical normally */
536 	out_be32(&intr->ctrl, intr_ctrl);
537 
538 	/* Zero a bunch of the priority settings. */
539 	out_be32(&intr->per_pri1, 0);
540 	out_be32(&intr->per_pri2, 0);
541 	out_be32(&intr->per_pri3, 0);
542 	out_be32(&intr->main_pri1, 0);
543 	out_be32(&intr->main_pri2, 0);
544 
545 	/*
546 	 * As last step, add an irq host to translate the real
547 	 * hw irq information provided by the ofw to linux virq
548 	 */
549 	mpc52xx_irqhost = irq_alloc_host(picnode, IRQ_HOST_MAP_LINEAR,
550 	                                 MPC52xx_IRQ_HIGHTESTHWIRQ,
551 	                                 &mpc52xx_irqhost_ops, -1);
552 
553 	if (!mpc52xx_irqhost)
554 		panic(__FILE__ ": Cannot allocate the IRQ host\n");
555 
556 	irq_set_default_host(mpc52xx_irqhost);
557 
558 	pr_info("MPC52xx PIC is up and running!\n");
559 }
560 
561 /**
562  * mpc52xx_get_irq - Get pending interrupt number hook function
563  *
564  * Called by the interupt handler to determine what IRQ handler needs to be
565  * executed.
566  *
567  * Status of pending interrupts is determined by reading the encoded status
568  * register.  The encoded status register has three fields; one for each of the
569  * types of interrupts defined by the controller - 'critical', 'main' and
570  * 'peripheral'.  This function reads the status register and returns the IRQ
571  * number associated with the highest priority pending interrupt.  'Critical'
572  * interrupts have the highest priority, followed by 'main' interrupts, and
573  * then 'peripheral'.
574  *
575  * The mpc5200 interrupt controller can be configured to boost the priority
576  * of individual 'peripheral' interrupts.  If this is the case then a special
577  * value will appear in either the crit or main fields indicating a high
578  * or medium priority peripheral irq has occurred.
579  *
580  * This function checks each of the 3 irq request fields and returns the
581  * first pending interrupt that it finds.
582  *
583  * This function also identifies a 4th type of interrupt; 'bestcomm'.  Each
584  * bestcomm DMA task can raise the bestcomm peripheral interrupt.  When this
585  * occurs at task-specific IRQ# is decoded so that each task can have its
586  * own IRQ handler.
587  */
mpc52xx_get_irq(void)588 unsigned int mpc52xx_get_irq(void)
589 {
590 	u32 status;
591 	int irq = NO_IRQ_IGNORE;
592 
593 	status = in_be32(&intr->enc_status);
594 	if (status & 0x00000400) {	/* critical */
595 		irq = (status >> 8) & 0x3;
596 		if (irq == 2)	/* high priority peripheral */
597 			goto peripheral;
598 		irq |= (MPC52xx_IRQ_L1_CRIT << MPC52xx_IRQ_L1_OFFSET);
599 	} else if (status & 0x00200000) {	/* main */
600 		irq = (status >> 16) & 0x1f;
601 		if (irq == 4)	/* low priority peripheral */
602 			goto peripheral;
603 		irq |= (MPC52xx_IRQ_L1_MAIN << MPC52xx_IRQ_L1_OFFSET);
604 	} else if (status & 0x20000000) {	/* peripheral */
605 	      peripheral:
606 		irq = (status >> 24) & 0x1f;
607 		if (irq == 0) {	/* bestcomm */
608 			status = in_be32(&sdma->IntPend);
609 			irq = ffs(status) - 1;
610 			irq |= (MPC52xx_IRQ_L1_SDMA << MPC52xx_IRQ_L1_OFFSET);
611 		} else {
612 			irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET);
613 		}
614 	}
615 
616 	pr_debug("%s: irq=%x. virq=%d\n", __func__, irq,
617 		 irq_linear_revmap(mpc52xx_irqhost, irq));
618 
619 	return irq_linear_revmap(mpc52xx_irqhost, irq);
620 }
621