Commit | Line | Data |
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0a84a91c TK |
1 | /* |
2 | * OMAP2+ common Power & Reset Management (PRM) IP block functions | |
3 | * | |
4 | * Copyright (C) 2011 Texas Instruments, Inc. | |
5 | * Tero Kristo <t-kristo@ti.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * | |
12 | * For historical purposes, the API used to configure the PRM | |
13 | * interrupt handler refers to it as the "PRCM interrupt." The | |
14 | * underlying registers are located in the PRM on OMAP3/4. | |
15 | * | |
16 | * XXX This code should eventually be moved to a PRM driver. | |
17 | */ | |
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/io.h> | |
23 | #include <linux/irq.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #include <mach/system.h> | |
28 | #include <plat/common.h> | |
29 | #include <plat/prcm.h> | |
30 | #include <plat/irqs.h> | |
31 | ||
32 | #include "prm2xxx_3xxx.h" | |
33 | #include "prm44xx.h" | |
34 | ||
35 | /* | |
36 | * OMAP_PRCM_MAX_NR_PENDING_REG: maximum number of PRM_IRQ*_MPU regs | |
37 | * XXX this is technically not needed, since | |
38 | * omap_prcm_register_chain_handler() could allocate this based on the | |
39 | * actual amount of memory needed for the SoC | |
40 | */ | |
41 | #define OMAP_PRCM_MAX_NR_PENDING_REG 2 | |
42 | ||
43 | /* | |
44 | * prcm_irq_chips: an array of all of the "generic IRQ chips" in use | |
45 | * by the PRCM interrupt handler code. There will be one 'chip' per | |
46 | * PRM_{IRQSTATUS,IRQENABLE}_MPU register pair. (So OMAP3 will have | |
47 | * one "chip" and OMAP4 will have two.) | |
48 | */ | |
49 | static struct irq_chip_generic **prcm_irq_chips; | |
50 | ||
51 | /* | |
52 | * prcm_irq_setup: the PRCM IRQ parameters for the hardware the code | |
53 | * is currently running on. Defined and passed by initialization code | |
54 | * that calls omap_prcm_register_chain_handler(). | |
55 | */ | |
56 | static struct omap_prcm_irq_setup *prcm_irq_setup; | |
57 | ||
58 | /* Private functions */ | |
59 | ||
60 | /* | |
61 | * Move priority events from events to priority_events array | |
62 | */ | |
63 | static void omap_prcm_events_filter_priority(unsigned long *events, | |
64 | unsigned long *priority_events) | |
65 | { | |
66 | int i; | |
67 | ||
68 | for (i = 0; i < prcm_irq_setup->nr_regs; i++) { | |
69 | priority_events[i] = | |
70 | events[i] & prcm_irq_setup->priority_mask[i]; | |
71 | events[i] ^= priority_events[i]; | |
72 | } | |
73 | } | |
74 | ||
75 | /* | |
76 | * PRCM Interrupt Handler | |
77 | * | |
78 | * This is a common handler for the OMAP PRCM interrupts. Pending | |
79 | * interrupts are detected by a call to prcm_pending_events and | |
80 | * dispatched accordingly. Clearing of the wakeup events should be | |
81 | * done by the SoC specific individual handlers. | |
82 | */ | |
83 | static void omap_prcm_irq_handler(unsigned int irq, struct irq_desc *desc) | |
84 | { | |
85 | unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG]; | |
86 | unsigned long priority_pending[OMAP_PRCM_MAX_NR_PENDING_REG]; | |
87 | struct irq_chip *chip = irq_desc_get_chip(desc); | |
88 | unsigned int virtirq; | |
89 | int nr_irqs = prcm_irq_setup->nr_regs * 32; | |
90 | ||
91285b6f TK |
91 | /* |
92 | * If we are suspended, mask all interrupts from PRCM level, | |
93 | * this does not ack them, and they will be pending until we | |
94 | * re-enable the interrupts, at which point the | |
95 | * omap_prcm_irq_handler will be executed again. The | |
96 | * _save_and_clear_irqen() function must ensure that the PRM | |
97 | * write to disable all IRQs has reached the PRM before | |
98 | * returning, or spurious PRCM interrupts may occur during | |
99 | * suspend. | |
100 | */ | |
101 | if (prcm_irq_setup->suspended) { | |
102 | prcm_irq_setup->save_and_clear_irqen(prcm_irq_setup->saved_mask); | |
103 | prcm_irq_setup->suspend_save_flag = true; | |
104 | } | |
105 | ||
0a84a91c TK |
106 | /* |
107 | * Loop until all pending irqs are handled, since | |
108 | * generic_handle_irq() can cause new irqs to come | |
109 | */ | |
91285b6f | 110 | while (!prcm_irq_setup->suspended) { |
0a84a91c TK |
111 | prcm_irq_setup->read_pending_irqs(pending); |
112 | ||
113 | /* No bit set, then all IRQs are handled */ | |
114 | if (find_first_bit(pending, nr_irqs) >= nr_irqs) | |
115 | break; | |
116 | ||
117 | omap_prcm_events_filter_priority(pending, priority_pending); | |
118 | ||
119 | /* | |
120 | * Loop on all currently pending irqs so that new irqs | |
121 | * cannot starve previously pending irqs | |
122 | */ | |
123 | ||
124 | /* Serve priority events first */ | |
125 | for_each_set_bit(virtirq, priority_pending, nr_irqs) | |
126 | generic_handle_irq(prcm_irq_setup->base_irq + virtirq); | |
127 | ||
128 | /* Serve normal events next */ | |
129 | for_each_set_bit(virtirq, pending, nr_irqs) | |
130 | generic_handle_irq(prcm_irq_setup->base_irq + virtirq); | |
131 | } | |
132 | if (chip->irq_ack) | |
133 | chip->irq_ack(&desc->irq_data); | |
134 | if (chip->irq_eoi) | |
135 | chip->irq_eoi(&desc->irq_data); | |
136 | chip->irq_unmask(&desc->irq_data); | |
137 | ||
138 | prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */ | |
139 | } | |
140 | ||
141 | /* Public functions */ | |
142 | ||
143 | /** | |
144 | * omap_prcm_event_to_irq - given a PRCM event name, returns the | |
145 | * corresponding IRQ on which the handler should be registered | |
146 | * @name: name of the PRCM interrupt bit to look up - see struct omap_prcm_irq | |
147 | * | |
148 | * Returns the Linux internal IRQ ID corresponding to @name upon success, | |
149 | * or -ENOENT upon failure. | |
150 | */ | |
151 | int omap_prcm_event_to_irq(const char *name) | |
152 | { | |
153 | int i; | |
154 | ||
155 | if (!prcm_irq_setup || !name) | |
156 | return -ENOENT; | |
157 | ||
158 | for (i = 0; i < prcm_irq_setup->nr_irqs; i++) | |
159 | if (!strcmp(prcm_irq_setup->irqs[i].name, name)) | |
160 | return prcm_irq_setup->base_irq + | |
161 | prcm_irq_setup->irqs[i].offset; | |
162 | ||
163 | return -ENOENT; | |
164 | } | |
165 | ||
166 | /** | |
167 | * omap_prcm_irq_cleanup - reverses memory allocated and other steps | |
168 | * done by omap_prcm_register_chain_handler() | |
169 | * | |
170 | * No return value. | |
171 | */ | |
172 | void omap_prcm_irq_cleanup(void) | |
173 | { | |
174 | int i; | |
175 | ||
176 | if (!prcm_irq_setup) { | |
177 | pr_err("PRCM: IRQ handler not initialized; cannot cleanup\n"); | |
178 | return; | |
179 | } | |
180 | ||
181 | if (prcm_irq_chips) { | |
182 | for (i = 0; i < prcm_irq_setup->nr_regs; i++) { | |
183 | if (prcm_irq_chips[i]) | |
184 | irq_remove_generic_chip(prcm_irq_chips[i], | |
185 | 0xffffffff, 0, 0); | |
186 | prcm_irq_chips[i] = NULL; | |
187 | } | |
188 | kfree(prcm_irq_chips); | |
189 | prcm_irq_chips = NULL; | |
190 | } | |
191 | ||
91285b6f TK |
192 | kfree(prcm_irq_setup->saved_mask); |
193 | prcm_irq_setup->saved_mask = NULL; | |
194 | ||
0a84a91c TK |
195 | kfree(prcm_irq_setup->priority_mask); |
196 | prcm_irq_setup->priority_mask = NULL; | |
197 | ||
198 | irq_set_chained_handler(prcm_irq_setup->irq, NULL); | |
199 | ||
200 | if (prcm_irq_setup->base_irq > 0) | |
201 | irq_free_descs(prcm_irq_setup->base_irq, | |
202 | prcm_irq_setup->nr_regs * 32); | |
203 | prcm_irq_setup->base_irq = 0; | |
204 | } | |
205 | ||
91285b6f TK |
206 | void omap_prcm_irq_prepare(void) |
207 | { | |
208 | prcm_irq_setup->suspended = true; | |
209 | } | |
210 | ||
211 | void omap_prcm_irq_complete(void) | |
212 | { | |
213 | prcm_irq_setup->suspended = false; | |
214 | ||
215 | /* If we have not saved the masks, do not attempt to restore */ | |
216 | if (!prcm_irq_setup->suspend_save_flag) | |
217 | return; | |
218 | ||
219 | prcm_irq_setup->suspend_save_flag = false; | |
220 | ||
221 | /* | |
222 | * Re-enable all masked PRCM irq sources, this causes the PRCM | |
223 | * interrupt to fire immediately if the events were masked | |
224 | * previously in the chain handler | |
225 | */ | |
226 | prcm_irq_setup->restore_irqen(prcm_irq_setup->saved_mask); | |
227 | } | |
228 | ||
0a84a91c TK |
229 | /** |
230 | * omap_prcm_register_chain_handler - initializes the prcm chained interrupt | |
231 | * handler based on provided parameters | |
232 | * @irq_setup: hardware data about the underlying PRM/PRCM | |
233 | * | |
234 | * Set up the PRCM chained interrupt handler on the PRCM IRQ. Sets up | |
235 | * one generic IRQ chip per PRM interrupt status/enable register pair. | |
236 | * Returns 0 upon success, -EINVAL if called twice or if invalid | |
237 | * arguments are passed, or -ENOMEM on any other error. | |
238 | */ | |
239 | int omap_prcm_register_chain_handler(struct omap_prcm_irq_setup *irq_setup) | |
240 | { | |
241 | int nr_regs = irq_setup->nr_regs; | |
242 | u32 mask[OMAP_PRCM_MAX_NR_PENDING_REG]; | |
243 | int offset, i; | |
244 | struct irq_chip_generic *gc; | |
245 | struct irq_chip_type *ct; | |
246 | ||
247 | if (!irq_setup) | |
248 | return -EINVAL; | |
249 | ||
250 | if (prcm_irq_setup) { | |
251 | pr_err("PRCM: already initialized; won't reinitialize\n"); | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | if (nr_regs > OMAP_PRCM_MAX_NR_PENDING_REG) { | |
256 | pr_err("PRCM: nr_regs too large\n"); | |
257 | return -EINVAL; | |
258 | } | |
259 | ||
260 | prcm_irq_setup = irq_setup; | |
261 | ||
262 | prcm_irq_chips = kzalloc(sizeof(void *) * nr_regs, GFP_KERNEL); | |
91285b6f | 263 | prcm_irq_setup->saved_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL); |
0a84a91c TK |
264 | prcm_irq_setup->priority_mask = kzalloc(sizeof(u32) * nr_regs, |
265 | GFP_KERNEL); | |
266 | ||
91285b6f TK |
267 | if (!prcm_irq_chips || !prcm_irq_setup->saved_mask || |
268 | !prcm_irq_setup->priority_mask) { | |
0a84a91c TK |
269 | pr_err("PRCM: kzalloc failed\n"); |
270 | goto err; | |
271 | } | |
272 | ||
273 | memset(mask, 0, sizeof(mask)); | |
274 | ||
275 | for (i = 0; i < irq_setup->nr_irqs; i++) { | |
276 | offset = irq_setup->irqs[i].offset; | |
277 | mask[offset >> 5] |= 1 << (offset & 0x1f); | |
278 | if (irq_setup->irqs[i].priority) | |
279 | irq_setup->priority_mask[offset >> 5] |= | |
280 | 1 << (offset & 0x1f); | |
281 | } | |
282 | ||
283 | irq_set_chained_handler(irq_setup->irq, omap_prcm_irq_handler); | |
284 | ||
285 | irq_setup->base_irq = irq_alloc_descs(-1, 0, irq_setup->nr_regs * 32, | |
286 | 0); | |
287 | ||
288 | if (irq_setup->base_irq < 0) { | |
289 | pr_err("PRCM: failed to allocate irq descs: %d\n", | |
290 | irq_setup->base_irq); | |
291 | goto err; | |
292 | } | |
293 | ||
294 | for (i = 0; i <= irq_setup->nr_regs; i++) { | |
295 | gc = irq_alloc_generic_chip("PRCM", 1, | |
296 | irq_setup->base_irq + i * 32, prm_base, | |
297 | handle_level_irq); | |
298 | ||
299 | if (!gc) { | |
300 | pr_err("PRCM: failed to allocate generic chip\n"); | |
301 | goto err; | |
302 | } | |
303 | ct = gc->chip_types; | |
304 | ct->chip.irq_ack = irq_gc_ack_set_bit; | |
305 | ct->chip.irq_mask = irq_gc_mask_clr_bit; | |
306 | ct->chip.irq_unmask = irq_gc_mask_set_bit; | |
307 | ||
308 | ct->regs.ack = irq_setup->ack + i * 4; | |
309 | ct->regs.mask = irq_setup->mask + i * 4; | |
310 | ||
311 | irq_setup_generic_chip(gc, mask[i], 0, IRQ_NOREQUEST, 0); | |
312 | prcm_irq_chips[i] = gc; | |
313 | } | |
314 | ||
315 | return 0; | |
316 | ||
317 | err: | |
318 | omap_prcm_irq_cleanup(); | |
319 | return -ENOMEM; | |
320 | } |