1 /*
2  * arch/powerpc/sysdev/qe_lib/qe_ic.c
3  *
4  * Copyright (C) 2006 Freescale Semicondutor, Inc.  All rights reserved.
5  *
6  * Author: Li Yang <leoli@freescale.com>
7  * Based on code from Shlomi Gridish <gridish@freescale.com>
8  *
9  * QUICC ENGINE Interrupt Controller
10  *
11  * This program is free software; you can redistribute  it and/or modify it
12  * under  the terms of  the GNU General  Public License as published by the
13  * Free Software Foundation;  either version 2 of the  License, or (at your
14  * option) any later version.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/errno.h>
20 #include <linux/reboot.h>
21 #include <linux/slab.h>
22 #include <linux/stddef.h>
23 #include <linux/sched.h>
24 #include <linux/signal.h>
25 #include <linux/device.h>
26 #include <linux/bootmem.h>
27 #include <linux/spinlock.h>
28 #include <asm/irq.h>
29 #include <asm/io.h>
30 #include <asm/prom.h>
31 #include <asm/qe_ic.h>
32 
33 #include "qe_ic.h"
34 
35 static DEFINE_RAW_SPINLOCK(qe_ic_lock);
36 
37 static struct qe_ic_info qe_ic_info[] = {
38 	[1] = {
39 	       .mask = 0x00008000,
40 	       .mask_reg = QEIC_CIMR,
41 	       .pri_code = 0,
42 	       .pri_reg = QEIC_CIPWCC,
43 	       },
44 	[2] = {
45 	       .mask = 0x00004000,
46 	       .mask_reg = QEIC_CIMR,
47 	       .pri_code = 1,
48 	       .pri_reg = QEIC_CIPWCC,
49 	       },
50 	[3] = {
51 	       .mask = 0x00002000,
52 	       .mask_reg = QEIC_CIMR,
53 	       .pri_code = 2,
54 	       .pri_reg = QEIC_CIPWCC,
55 	       },
56 	[10] = {
57 		.mask = 0x00000040,
58 		.mask_reg = QEIC_CIMR,
59 		.pri_code = 1,
60 		.pri_reg = QEIC_CIPZCC,
61 		},
62 	[11] = {
63 		.mask = 0x00000020,
64 		.mask_reg = QEIC_CIMR,
65 		.pri_code = 2,
66 		.pri_reg = QEIC_CIPZCC,
67 		},
68 	[12] = {
69 		.mask = 0x00000010,
70 		.mask_reg = QEIC_CIMR,
71 		.pri_code = 3,
72 		.pri_reg = QEIC_CIPZCC,
73 		},
74 	[13] = {
75 		.mask = 0x00000008,
76 		.mask_reg = QEIC_CIMR,
77 		.pri_code = 4,
78 		.pri_reg = QEIC_CIPZCC,
79 		},
80 	[14] = {
81 		.mask = 0x00000004,
82 		.mask_reg = QEIC_CIMR,
83 		.pri_code = 5,
84 		.pri_reg = QEIC_CIPZCC,
85 		},
86 	[15] = {
87 		.mask = 0x00000002,
88 		.mask_reg = QEIC_CIMR,
89 		.pri_code = 6,
90 		.pri_reg = QEIC_CIPZCC,
91 		},
92 	[20] = {
93 		.mask = 0x10000000,
94 		.mask_reg = QEIC_CRIMR,
95 		.pri_code = 3,
96 		.pri_reg = QEIC_CIPRTA,
97 		},
98 	[25] = {
99 		.mask = 0x00800000,
100 		.mask_reg = QEIC_CRIMR,
101 		.pri_code = 0,
102 		.pri_reg = QEIC_CIPRTB,
103 		},
104 	[26] = {
105 		.mask = 0x00400000,
106 		.mask_reg = QEIC_CRIMR,
107 		.pri_code = 1,
108 		.pri_reg = QEIC_CIPRTB,
109 		},
110 	[27] = {
111 		.mask = 0x00200000,
112 		.mask_reg = QEIC_CRIMR,
113 		.pri_code = 2,
114 		.pri_reg = QEIC_CIPRTB,
115 		},
116 	[28] = {
117 		.mask = 0x00100000,
118 		.mask_reg = QEIC_CRIMR,
119 		.pri_code = 3,
120 		.pri_reg = QEIC_CIPRTB,
121 		},
122 	[32] = {
123 		.mask = 0x80000000,
124 		.mask_reg = QEIC_CIMR,
125 		.pri_code = 0,
126 		.pri_reg = QEIC_CIPXCC,
127 		},
128 	[33] = {
129 		.mask = 0x40000000,
130 		.mask_reg = QEIC_CIMR,
131 		.pri_code = 1,
132 		.pri_reg = QEIC_CIPXCC,
133 		},
134 	[34] = {
135 		.mask = 0x20000000,
136 		.mask_reg = QEIC_CIMR,
137 		.pri_code = 2,
138 		.pri_reg = QEIC_CIPXCC,
139 		},
140 	[35] = {
141 		.mask = 0x10000000,
142 		.mask_reg = QEIC_CIMR,
143 		.pri_code = 3,
144 		.pri_reg = QEIC_CIPXCC,
145 		},
146 	[36] = {
147 		.mask = 0x08000000,
148 		.mask_reg = QEIC_CIMR,
149 		.pri_code = 4,
150 		.pri_reg = QEIC_CIPXCC,
151 		},
152 	[40] = {
153 		.mask = 0x00800000,
154 		.mask_reg = QEIC_CIMR,
155 		.pri_code = 0,
156 		.pri_reg = QEIC_CIPYCC,
157 		},
158 	[41] = {
159 		.mask = 0x00400000,
160 		.mask_reg = QEIC_CIMR,
161 		.pri_code = 1,
162 		.pri_reg = QEIC_CIPYCC,
163 		},
164 	[42] = {
165 		.mask = 0x00200000,
166 		.mask_reg = QEIC_CIMR,
167 		.pri_code = 2,
168 		.pri_reg = QEIC_CIPYCC,
169 		},
170 	[43] = {
171 		.mask = 0x00100000,
172 		.mask_reg = QEIC_CIMR,
173 		.pri_code = 3,
174 		.pri_reg = QEIC_CIPYCC,
175 		},
176 };
177 
qe_ic_read(volatile __be32 __iomem * base,unsigned int reg)178 static inline u32 qe_ic_read(volatile __be32  __iomem * base, unsigned int reg)
179 {
180 	return in_be32(base + (reg >> 2));
181 }
182 
qe_ic_write(volatile __be32 __iomem * base,unsigned int reg,u32 value)183 static inline void qe_ic_write(volatile __be32  __iomem * base, unsigned int reg,
184 			       u32 value)
185 {
186 	out_be32(base + (reg >> 2), value);
187 }
188 
qe_ic_from_irq(unsigned int virq)189 static inline struct qe_ic *qe_ic_from_irq(unsigned int virq)
190 {
191 	return irq_get_chip_data(virq);
192 }
193 
qe_ic_from_irq_data(struct irq_data * d)194 static inline struct qe_ic *qe_ic_from_irq_data(struct irq_data *d)
195 {
196 	return irq_data_get_irq_chip_data(d);
197 }
198 
qe_ic_unmask_irq(struct irq_data * d)199 static void qe_ic_unmask_irq(struct irq_data *d)
200 {
201 	struct qe_ic *qe_ic = qe_ic_from_irq_data(d);
202 	unsigned int src = irqd_to_hwirq(d);
203 	unsigned long flags;
204 	u32 temp;
205 
206 	raw_spin_lock_irqsave(&qe_ic_lock, flags);
207 
208 	temp = qe_ic_read(qe_ic->regs, qe_ic_info[src].mask_reg);
209 	qe_ic_write(qe_ic->regs, qe_ic_info[src].mask_reg,
210 		    temp | qe_ic_info[src].mask);
211 
212 	raw_spin_unlock_irqrestore(&qe_ic_lock, flags);
213 }
214 
qe_ic_mask_irq(struct irq_data * d)215 static void qe_ic_mask_irq(struct irq_data *d)
216 {
217 	struct qe_ic *qe_ic = qe_ic_from_irq_data(d);
218 	unsigned int src = irqd_to_hwirq(d);
219 	unsigned long flags;
220 	u32 temp;
221 
222 	raw_spin_lock_irqsave(&qe_ic_lock, flags);
223 
224 	temp = qe_ic_read(qe_ic->regs, qe_ic_info[src].mask_reg);
225 	qe_ic_write(qe_ic->regs, qe_ic_info[src].mask_reg,
226 		    temp & ~qe_ic_info[src].mask);
227 
228 	/* Flush the above write before enabling interrupts; otherwise,
229 	 * spurious interrupts will sometimes happen.  To be 100% sure
230 	 * that the write has reached the device before interrupts are
231 	 * enabled, the mask register would have to be read back; however,
232 	 * this is not required for correctness, only to avoid wasting
233 	 * time on a large number of spurious interrupts.  In testing,
234 	 * a sync reduced the observed spurious interrupts to zero.
235 	 */
236 	mb();
237 
238 	raw_spin_unlock_irqrestore(&qe_ic_lock, flags);
239 }
240 
241 static struct irq_chip qe_ic_irq_chip = {
242 	.name = "QEIC",
243 	.irq_unmask = qe_ic_unmask_irq,
244 	.irq_mask = qe_ic_mask_irq,
245 	.irq_mask_ack = qe_ic_mask_irq,
246 };
247 
qe_ic_host_match(struct irq_domain * h,struct device_node * node)248 static int qe_ic_host_match(struct irq_domain *h, struct device_node *node)
249 {
250 	/* Exact match, unless qe_ic node is NULL */
251 	return h->of_node == NULL || h->of_node == node;
252 }
253 
qe_ic_host_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)254 static int qe_ic_host_map(struct irq_domain *h, unsigned int virq,
255 			  irq_hw_number_t hw)
256 {
257 	struct qe_ic *qe_ic = h->host_data;
258 	struct irq_chip *chip;
259 
260 	if (qe_ic_info[hw].mask == 0) {
261 		printk(KERN_ERR "Can't map reserved IRQ\n");
262 		return -EINVAL;
263 	}
264 	/* Default chip */
265 	chip = &qe_ic->hc_irq;
266 
267 	irq_set_chip_data(virq, qe_ic);
268 	irq_set_status_flags(virq, IRQ_LEVEL);
269 
270 	irq_set_chip_and_handler(virq, chip, handle_level_irq);
271 
272 	return 0;
273 }
274 
275 static struct irq_domain_ops qe_ic_host_ops = {
276 	.match = qe_ic_host_match,
277 	.map = qe_ic_host_map,
278 	.xlate = irq_domain_xlate_onetwocell,
279 };
280 
281 /* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
qe_ic_get_low_irq(struct qe_ic * qe_ic)282 unsigned int qe_ic_get_low_irq(struct qe_ic *qe_ic)
283 {
284 	int irq;
285 
286 	BUG_ON(qe_ic == NULL);
287 
288 	/* get the interrupt source vector. */
289 	irq = qe_ic_read(qe_ic->regs, QEIC_CIVEC) >> 26;
290 
291 	if (irq == 0)
292 		return NO_IRQ;
293 
294 	return irq_linear_revmap(qe_ic->irqhost, irq);
295 }
296 
297 /* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
qe_ic_get_high_irq(struct qe_ic * qe_ic)298 unsigned int qe_ic_get_high_irq(struct qe_ic *qe_ic)
299 {
300 	int irq;
301 
302 	BUG_ON(qe_ic == NULL);
303 
304 	/* get the interrupt source vector. */
305 	irq = qe_ic_read(qe_ic->regs, QEIC_CHIVEC) >> 26;
306 
307 	if (irq == 0)
308 		return NO_IRQ;
309 
310 	return irq_linear_revmap(qe_ic->irqhost, irq);
311 }
312 
qe_ic_init(struct device_node * node,unsigned int flags,void (* low_handler)(unsigned int irq,struct irq_desc * desc),void (* high_handler)(unsigned int irq,struct irq_desc * desc))313 void __init qe_ic_init(struct device_node *node, unsigned int flags,
314 		void (*low_handler)(unsigned int irq, struct irq_desc *desc),
315 		void (*high_handler)(unsigned int irq, struct irq_desc *desc))
316 {
317 	struct qe_ic *qe_ic;
318 	struct resource res;
319 	u32 temp = 0, ret, high_active = 0;
320 
321 	ret = of_address_to_resource(node, 0, &res);
322 	if (ret)
323 		return;
324 
325 	qe_ic = kzalloc(sizeof(*qe_ic), GFP_KERNEL);
326 	if (qe_ic == NULL)
327 		return;
328 
329 	qe_ic->irqhost = irq_domain_add_linear(node, NR_QE_IC_INTS,
330 					       &qe_ic_host_ops, qe_ic);
331 	if (qe_ic->irqhost == NULL) {
332 		kfree(qe_ic);
333 		return;
334 	}
335 
336 	qe_ic->regs = ioremap(res.start, resource_size(&res));
337 
338 	qe_ic->hc_irq = qe_ic_irq_chip;
339 
340 	qe_ic->virq_high = irq_of_parse_and_map(node, 0);
341 	qe_ic->virq_low = irq_of_parse_and_map(node, 1);
342 
343 	if (qe_ic->virq_low == NO_IRQ) {
344 		printk(KERN_ERR "Failed to map QE_IC low IRQ\n");
345 		kfree(qe_ic);
346 		return;
347 	}
348 
349 	/* default priority scheme is grouped. If spread mode is    */
350 	/* required, configure cicr accordingly.                    */
351 	if (flags & QE_IC_SPREADMODE_GRP_W)
352 		temp |= CICR_GWCC;
353 	if (flags & QE_IC_SPREADMODE_GRP_X)
354 		temp |= CICR_GXCC;
355 	if (flags & QE_IC_SPREADMODE_GRP_Y)
356 		temp |= CICR_GYCC;
357 	if (flags & QE_IC_SPREADMODE_GRP_Z)
358 		temp |= CICR_GZCC;
359 	if (flags & QE_IC_SPREADMODE_GRP_RISCA)
360 		temp |= CICR_GRTA;
361 	if (flags & QE_IC_SPREADMODE_GRP_RISCB)
362 		temp |= CICR_GRTB;
363 
364 	/* choose destination signal for highest priority interrupt */
365 	if (flags & QE_IC_HIGH_SIGNAL) {
366 		temp |= (SIGNAL_HIGH << CICR_HPIT_SHIFT);
367 		high_active = 1;
368 	}
369 
370 	qe_ic_write(qe_ic->regs, QEIC_CICR, temp);
371 
372 	irq_set_handler_data(qe_ic->virq_low, qe_ic);
373 	irq_set_chained_handler(qe_ic->virq_low, low_handler);
374 
375 	if (qe_ic->virq_high != NO_IRQ &&
376 			qe_ic->virq_high != qe_ic->virq_low) {
377 		irq_set_handler_data(qe_ic->virq_high, qe_ic);
378 		irq_set_chained_handler(qe_ic->virq_high, high_handler);
379 	}
380 }
381 
qe_ic_set_highest_priority(unsigned int virq,int high)382 void qe_ic_set_highest_priority(unsigned int virq, int high)
383 {
384 	struct qe_ic *qe_ic = qe_ic_from_irq(virq);
385 	unsigned int src = virq_to_hw(virq);
386 	u32 temp = 0;
387 
388 	temp = qe_ic_read(qe_ic->regs, QEIC_CICR);
389 
390 	temp &= ~CICR_HP_MASK;
391 	temp |= src << CICR_HP_SHIFT;
392 
393 	temp &= ~CICR_HPIT_MASK;
394 	temp |= (high ? SIGNAL_HIGH : SIGNAL_LOW) << CICR_HPIT_SHIFT;
395 
396 	qe_ic_write(qe_ic->regs, QEIC_CICR, temp);
397 }
398 
399 /* Set Priority level within its group, from 1 to 8 */
qe_ic_set_priority(unsigned int virq,unsigned int priority)400 int qe_ic_set_priority(unsigned int virq, unsigned int priority)
401 {
402 	struct qe_ic *qe_ic = qe_ic_from_irq(virq);
403 	unsigned int src = virq_to_hw(virq);
404 	u32 temp;
405 
406 	if (priority > 8 || priority == 0)
407 		return -EINVAL;
408 	if (src > 127)
409 		return -EINVAL;
410 	if (qe_ic_info[src].pri_reg == 0)
411 		return -EINVAL;
412 
413 	temp = qe_ic_read(qe_ic->regs, qe_ic_info[src].pri_reg);
414 
415 	if (priority < 4) {
416 		temp &= ~(0x7 << (32 - priority * 3));
417 		temp |= qe_ic_info[src].pri_code << (32 - priority * 3);
418 	} else {
419 		temp &= ~(0x7 << (24 - priority * 3));
420 		temp |= qe_ic_info[src].pri_code << (24 - priority * 3);
421 	}
422 
423 	qe_ic_write(qe_ic->regs, qe_ic_info[src].pri_reg, temp);
424 
425 	return 0;
426 }
427 
428 /* Set a QE priority to use high irq, only priority 1~2 can use high irq */
qe_ic_set_high_priority(unsigned int virq,unsigned int priority,int high)429 int qe_ic_set_high_priority(unsigned int virq, unsigned int priority, int high)
430 {
431 	struct qe_ic *qe_ic = qe_ic_from_irq(virq);
432 	unsigned int src = virq_to_hw(virq);
433 	u32 temp, control_reg = QEIC_CICNR, shift = 0;
434 
435 	if (priority > 2 || priority == 0)
436 		return -EINVAL;
437 
438 	switch (qe_ic_info[src].pri_reg) {
439 	case QEIC_CIPZCC:
440 		shift = CICNR_ZCC1T_SHIFT;
441 		break;
442 	case QEIC_CIPWCC:
443 		shift = CICNR_WCC1T_SHIFT;
444 		break;
445 	case QEIC_CIPYCC:
446 		shift = CICNR_YCC1T_SHIFT;
447 		break;
448 	case QEIC_CIPXCC:
449 		shift = CICNR_XCC1T_SHIFT;
450 		break;
451 	case QEIC_CIPRTA:
452 		shift = CRICR_RTA1T_SHIFT;
453 		control_reg = QEIC_CRICR;
454 		break;
455 	case QEIC_CIPRTB:
456 		shift = CRICR_RTB1T_SHIFT;
457 		control_reg = QEIC_CRICR;
458 		break;
459 	default:
460 		return -EINVAL;
461 	}
462 
463 	shift += (2 - priority) * 2;
464 	temp = qe_ic_read(qe_ic->regs, control_reg);
465 	temp &= ~(SIGNAL_MASK << shift);
466 	temp |= (high ? SIGNAL_HIGH : SIGNAL_LOW) << shift;
467 	qe_ic_write(qe_ic->regs, control_reg, temp);
468 
469 	return 0;
470 }
471 
472 static struct bus_type qe_ic_subsys = {
473 	.name = "qe_ic",
474 	.dev_name = "qe_ic",
475 };
476 
477 static struct device device_qe_ic = {
478 	.id = 0,
479 	.bus = &qe_ic_subsys,
480 };
481 
init_qe_ic_sysfs(void)482 static int __init init_qe_ic_sysfs(void)
483 {
484 	int rc;
485 
486 	printk(KERN_DEBUG "Registering qe_ic with sysfs...\n");
487 
488 	rc = subsys_system_register(&qe_ic_subsys, NULL);
489 	if (rc) {
490 		printk(KERN_ERR "Failed registering qe_ic sys class\n");
491 		return -ENODEV;
492 	}
493 	rc = device_register(&device_qe_ic);
494 	if (rc) {
495 		printk(KERN_ERR "Failed registering qe_ic sys device\n");
496 		return -ENODEV;
497 	}
498 	return 0;
499 }
500 
501 subsys_initcall(init_qe_ic_sysfs);
502