xref: /openbmc/linux/kernel/irq/generic-chip.c (revision 54525552)
1 /*
2  * Library implementing the most common irq chip callback functions
3  *
4  * Copyright (C) 2011, Thomas Gleixner
5  */
6 #include <linux/io.h>
7 #include <linux/irq.h>
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel_stat.h>
11 #include <linux/syscore_ops.h>
12 
13 #include "internals.h"
14 
15 static LIST_HEAD(gc_list);
16 static DEFINE_RAW_SPINLOCK(gc_lock);
17 
18 static inline struct irq_chip_regs *cur_regs(struct irq_data *d)
19 {
20 	return &container_of(d->chip, struct irq_chip_type, chip)->regs;
21 }
22 
23 /**
24  * irq_gc_noop - NOOP function
25  * @d: irq_data
26  */
27 void irq_gc_noop(struct irq_data *d)
28 {
29 }
30 
31 /**
32  * irq_gc_mask_disable_reg - Mask chip via disable register
33  * @d: irq_data
34  *
35  * Chip has separate enable/disable registers instead of a single mask
36  * register.
37  */
38 void irq_gc_mask_disable_reg(struct irq_data *d)
39 {
40 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
41 	u32 mask = 1 << (d->irq - gc->irq_base);
42 
43 	irq_gc_lock(gc);
44 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->disable);
45 	gc->mask_cache &= ~mask;
46 	irq_gc_unlock(gc);
47 }
48 
49 /**
50  * irq_gc_mask_set_mask_bit - Mask chip via setting bit in mask register
51  * @d: irq_data
52  *
53  * Chip has a single mask register. Values of this register are cached
54  * and protected by gc->lock
55  */
56 void irq_gc_mask_set_bit(struct irq_data *d)
57 {
58 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
59 	u32 mask = 1 << (d->irq - gc->irq_base);
60 
61 	irq_gc_lock(gc);
62 	gc->mask_cache |= mask;
63 	irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
64 	irq_gc_unlock(gc);
65 }
66 
67 /**
68  * irq_gc_mask_set_mask_bit - Mask chip via clearing bit in mask register
69  * @d: irq_data
70  *
71  * Chip has a single mask register. Values of this register are cached
72  * and protected by gc->lock
73  */
74 void irq_gc_mask_clr_bit(struct irq_data *d)
75 {
76 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
77 	u32 mask = 1 << (d->irq - gc->irq_base);
78 
79 	irq_gc_lock(gc);
80 	gc->mask_cache &= ~mask;
81 	irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
82 	irq_gc_unlock(gc);
83 }
84 
85 /**
86  * irq_gc_unmask_enable_reg - Unmask chip via enable register
87  * @d: irq_data
88  *
89  * Chip has separate enable/disable registers instead of a single mask
90  * register.
91  */
92 void irq_gc_unmask_enable_reg(struct irq_data *d)
93 {
94 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
95 	u32 mask = 1 << (d->irq - gc->irq_base);
96 
97 	irq_gc_lock(gc);
98 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->enable);
99 	gc->mask_cache |= mask;
100 	irq_gc_unlock(gc);
101 }
102 
103 /**
104  * irq_gc_ack - Ack pending interrupt
105  * @d: irq_data
106  */
107 void irq_gc_ack(struct irq_data *d)
108 {
109 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
110 	u32 mask = 1 << (d->irq - gc->irq_base);
111 
112 	irq_gc_lock(gc);
113 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
114 	irq_gc_unlock(gc);
115 }
116 
117 /**
118  * irq_gc_mask_disable_reg_and_ack- Mask and ack pending interrupt
119  * @d: irq_data
120  */
121 void irq_gc_mask_disable_reg_and_ack(struct irq_data *d)
122 {
123 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
124 	u32 mask = 1 << (d->irq - gc->irq_base);
125 
126 	irq_gc_lock(gc);
127 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->mask);
128 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
129 	irq_gc_unlock(gc);
130 }
131 
132 /**
133  * irq_gc_eoi - EOI interrupt
134  * @d: irq_data
135  */
136 void irq_gc_eoi(struct irq_data *d)
137 {
138 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
139 	u32 mask = 1 << (d->irq - gc->irq_base);
140 
141 	irq_gc_lock(gc);
142 	irq_reg_writel(mask, gc->reg_base + cur_regs(d)->eoi);
143 	irq_gc_unlock(gc);
144 }
145 
146 /**
147  * irq_gc_set_wake - Set/clr wake bit for an interrupt
148  * @d: irq_data
149  *
150  * For chips where the wake from suspend functionality is not
151  * configured in a separate register and the wakeup active state is
152  * just stored in a bitmask.
153  */
154 int irq_gc_set_wake(struct irq_data *d, unsigned int on)
155 {
156 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
157 	u32 mask = 1 << (d->irq - gc->irq_base);
158 
159 	if (!(mask & gc->wake_enabled))
160 		return -EINVAL;
161 
162 	irq_gc_lock(gc);
163 	if (on)
164 		gc->wake_active |= mask;
165 	else
166 		gc->wake_active &= ~mask;
167 	irq_gc_unlock(gc);
168 	return 0;
169 }
170 
171 /**
172  * irq_alloc_generic_chip - Allocate a generic chip and initialize it
173  * @name:	Name of the irq chip
174  * @num_ct:	Number of irq_chip_type instances associated with this
175  * @irq_base:	Interrupt base nr for this chip
176  * @reg_base:	Register base address (virtual)
177  * @handler:	Default flow handler associated with this chip
178  *
179  * Returns an initialized irq_chip_generic structure. The chip defaults
180  * to the primary (index 0) irq_chip_type and @handler
181  */
182 struct irq_chip_generic *
183 irq_alloc_generic_chip(const char *name, int num_ct, unsigned int irq_base,
184 		       void __iomem *reg_base, irq_flow_handler_t handler)
185 {
186 	struct irq_chip_generic *gc;
187 	unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
188 
189 	gc = kzalloc(sz, GFP_KERNEL);
190 	if (gc) {
191 		raw_spin_lock_init(&gc->lock);
192 		gc->num_ct = num_ct;
193 		gc->irq_base = irq_base;
194 		gc->reg_base = reg_base;
195 		gc->chip_types->chip.name = name;
196 		gc->chip_types->handler = handler;
197 	}
198 	return gc;
199 }
200 
201 /*
202  * Separate lockdep class for interrupt chip which can nest irq_desc
203  * lock.
204  */
205 static struct lock_class_key irq_nested_lock_class;
206 
207 /**
208  * irq_setup_generic_chip - Setup a range of interrupts with a generic chip
209  * @gc:		Generic irq chip holding all data
210  * @msk:	Bitmask holding the irqs to initialize relative to gc->irq_base
211  * @flags:	Flags for initialization
212  * @clr:	IRQ_* bits to clear
213  * @set:	IRQ_* bits to set
214  *
215  * Set up max. 32 interrupts starting from gc->irq_base. Note, this
216  * initializes all interrupts to the primary irq_chip_type and its
217  * associated handler.
218  */
219 void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
220 			    enum irq_gc_flags flags, unsigned int clr,
221 			    unsigned int set)
222 {
223 	struct irq_chip_type *ct = gc->chip_types;
224 	unsigned int i;
225 
226 	raw_spin_lock(&gc_lock);
227 	list_add_tail(&gc->list, &gc_list);
228 	raw_spin_unlock(&gc_lock);
229 
230 	/* Init mask cache ? */
231 	if (flags & IRQ_GC_INIT_MASK_CACHE)
232 		gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask);
233 
234 	for (i = gc->irq_base; msk; msk >>= 1, i++) {
235 		if (!msk & 0x01)
236 			continue;
237 
238 		if (flags & IRQ_GC_INIT_NESTED_LOCK)
239 			irq_set_lockdep_class(i, &irq_nested_lock_class);
240 
241 		irq_set_chip_and_handler(i, &ct->chip, ct->handler);
242 		irq_set_chip_data(i, gc);
243 		irq_modify_status(i, clr, set);
244 	}
245 	gc->irq_cnt = i - gc->irq_base;
246 }
247 
248 /**
249  * irq_setup_alt_chip - Switch to alternative chip
250  * @d:		irq_data for this interrupt
251  * @type	Flow type to be initialized
252  *
253  * Only to be called from chip->irq_set_type() callbacks.
254  */
255 int irq_setup_alt_chip(struct irq_data *d, unsigned int type)
256 {
257 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
258 	struct irq_chip_type *ct = gc->chip_types;
259 	unsigned int i;
260 
261 	for (i = 0; i < gc->num_ct; i++, ct++) {
262 		if (ct->type & type) {
263 			d->chip = &ct->chip;
264 			irq_data_to_desc(d)->handle_irq = ct->handler;
265 			return 0;
266 		}
267 	}
268 	return -EINVAL;
269 }
270 
271 /**
272  * irq_remove_generic_chip - Remove a chip
273  * @gc:		Generic irq chip holding all data
274  * @msk:	Bitmask holding the irqs to initialize relative to gc->irq_base
275  * @clr:	IRQ_* bits to clear
276  * @set:	IRQ_* bits to set
277  *
278  * Remove up to 32 interrupts starting from gc->irq_base.
279  */
280 void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
281 			     unsigned int clr, unsigned int set)
282 {
283 	unsigned int i = gc->irq_base;
284 
285 	raw_spin_lock(&gc_lock);
286 	list_del(&gc->list);
287 	raw_spin_unlock(&gc_lock);
288 
289 	for (; msk; msk >>= 1, i++) {
290 		if (!msk & 0x01)
291 			continue;
292 
293 		/* Remove handler first. That will mask the irq line */
294 		irq_set_handler(i, NULL);
295 		irq_set_chip(i, &no_irq_chip);
296 		irq_set_chip_data(i, NULL);
297 		irq_modify_status(i, clr, set);
298 	}
299 }
300 
301 #ifdef CONFIG_PM
302 static int irq_gc_suspend(void)
303 {
304 	struct irq_chip_generic *gc;
305 
306 	list_for_each_entry(gc, &gc_list, list) {
307 		struct irq_chip_type *ct = gc->chip_types;
308 
309 		if (ct->chip.irq_suspend)
310 			ct->chip.irq_suspend(irq_get_irq_data(gc->irq_base));
311 	}
312 	return 0;
313 }
314 
315 static void irq_gc_resume(void)
316 {
317 	struct irq_chip_generic *gc;
318 
319 	list_for_each_entry(gc, &gc_list, list) {
320 		struct irq_chip_type *ct = gc->chip_types;
321 
322 		if (ct->chip.irq_resume)
323 			ct->chip.irq_resume(irq_get_irq_data(gc->irq_base));
324 	}
325 }
326 #else
327 #define irq_gc_suspend NULL
328 #define irq_gc_resume NULL
329 #endif
330 
331 static void irq_gc_shutdown(void)
332 {
333 	struct irq_chip_generic *gc;
334 
335 	list_for_each_entry(gc, &gc_list, list) {
336 		struct irq_chip_type *ct = gc->chip_types;
337 
338 		if (ct->chip.irq_pm_shutdown)
339 			ct->chip.irq_pm_shutdown(irq_get_irq_data(gc->irq_base));
340 	}
341 }
342 
343 static struct syscore_ops irq_gc_syscore_ops = {
344 	.suspend = irq_gc_suspend,
345 	.resume = irq_gc_resume,
346 	.shutdown = irq_gc_shutdown,
347 };
348 
349 static int __init irq_gc_init_ops(void)
350 {
351 	register_syscore_ops(&irq_gc_syscore_ops);
352 	return 0;
353 }
354 device_initcall(irq_gc_init_ops);
355