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