2 * OMAP2+ common Power & Reset Management (PRM) IP block functions
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Tero Kristo <t-kristo@ti.com>
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.
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.
16 * XXX This code should eventually be moved to a PRM driver.
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
23 #include <linux/irq.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
27 #include <plat/prcm.h>
29 #include "prm2xxx_3xxx.h"
35 * OMAP_PRCM_MAX_NR_PENDING_REG: maximum number of PRM_IRQ*_MPU regs
36 * XXX this is technically not needed, since
37 * omap_prcm_register_chain_handler() could allocate this based on the
38 * actual amount of memory needed for the SoC
40 #define OMAP_PRCM_MAX_NR_PENDING_REG 2
43 * prcm_irq_chips: an array of all of the "generic IRQ chips" in use
44 * by the PRCM interrupt handler code. There will be one 'chip' per
45 * PRM_{IRQSTATUS,IRQENABLE}_MPU register pair. (So OMAP3 will have
46 * one "chip" and OMAP4 will have two.)
48 static struct irq_chip_generic **prcm_irq_chips;
51 * prcm_irq_setup: the PRCM IRQ parameters for the hardware the code
52 * is currently running on. Defined and passed by initialization code
53 * that calls omap_prcm_register_chain_handler().
55 static struct omap_prcm_irq_setup *prcm_irq_setup;
58 * prm_ll_data: function pointers to SoC-specific implementations of
59 * common PRM functions
61 static struct prm_ll_data null_prm_ll_data;
62 static struct prm_ll_data *prm_ll_data = &null_prm_ll_data;
64 /* Private functions */
67 * Move priority events from events to priority_events array
69 static void omap_prcm_events_filter_priority(unsigned long *events,
70 unsigned long *priority_events)
74 for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
76 events[i] & prcm_irq_setup->priority_mask[i];
77 events[i] ^= priority_events[i];
82 * PRCM Interrupt Handler
84 * This is a common handler for the OMAP PRCM interrupts. Pending
85 * interrupts are detected by a call to prcm_pending_events and
86 * dispatched accordingly. Clearing of the wakeup events should be
87 * done by the SoC specific individual handlers.
89 static void omap_prcm_irq_handler(unsigned int irq, struct irq_desc *desc)
91 unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG];
92 unsigned long priority_pending[OMAP_PRCM_MAX_NR_PENDING_REG];
93 struct irq_chip *chip = irq_desc_get_chip(desc);
95 int nr_irq = prcm_irq_setup->nr_regs * 32;
98 * If we are suspended, mask all interrupts from PRCM level,
99 * this does not ack them, and they will be pending until we
100 * re-enable the interrupts, at which point the
101 * omap_prcm_irq_handler will be executed again. The
102 * _save_and_clear_irqen() function must ensure that the PRM
103 * write to disable all IRQs has reached the PRM before
104 * returning, or spurious PRCM interrupts may occur during
107 if (prcm_irq_setup->suspended) {
108 prcm_irq_setup->save_and_clear_irqen(prcm_irq_setup->saved_mask);
109 prcm_irq_setup->suspend_save_flag = true;
113 * Loop until all pending irqs are handled, since
114 * generic_handle_irq() can cause new irqs to come
116 while (!prcm_irq_setup->suspended) {
117 prcm_irq_setup->read_pending_irqs(pending);
119 /* No bit set, then all IRQs are handled */
120 if (find_first_bit(pending, nr_irq) >= nr_irq)
123 omap_prcm_events_filter_priority(pending, priority_pending);
126 * Loop on all currently pending irqs so that new irqs
127 * cannot starve previously pending irqs
130 /* Serve priority events first */
131 for_each_set_bit(virtirq, priority_pending, nr_irq)
132 generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
134 /* Serve normal events next */
135 for_each_set_bit(virtirq, pending, nr_irq)
136 generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
139 chip->irq_ack(&desc->irq_data);
141 chip->irq_eoi(&desc->irq_data);
142 chip->irq_unmask(&desc->irq_data);
144 prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */
147 /* Public functions */
150 * omap_prcm_event_to_irq - given a PRCM event name, returns the
151 * corresponding IRQ on which the handler should be registered
152 * @name: name of the PRCM interrupt bit to look up - see struct omap_prcm_irq
154 * Returns the Linux internal IRQ ID corresponding to @name upon success,
155 * or -ENOENT upon failure.
157 int omap_prcm_event_to_irq(const char *name)
161 if (!prcm_irq_setup || !name)
164 for (i = 0; i < prcm_irq_setup->nr_irqs; i++)
165 if (!strcmp(prcm_irq_setup->irqs[i].name, name))
166 return prcm_irq_setup->base_irq +
167 prcm_irq_setup->irqs[i].offset;
173 * omap_prcm_irq_cleanup - reverses memory allocated and other steps
174 * done by omap_prcm_register_chain_handler()
178 void omap_prcm_irq_cleanup(void)
182 if (!prcm_irq_setup) {
183 pr_err("PRCM: IRQ handler not initialized; cannot cleanup\n");
187 if (prcm_irq_chips) {
188 for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
189 if (prcm_irq_chips[i])
190 irq_remove_generic_chip(prcm_irq_chips[i],
192 prcm_irq_chips[i] = NULL;
194 kfree(prcm_irq_chips);
195 prcm_irq_chips = NULL;
198 kfree(prcm_irq_setup->saved_mask);
199 prcm_irq_setup->saved_mask = NULL;
201 kfree(prcm_irq_setup->priority_mask);
202 prcm_irq_setup->priority_mask = NULL;
204 irq_set_chained_handler(prcm_irq_setup->irq, NULL);
206 if (prcm_irq_setup->base_irq > 0)
207 irq_free_descs(prcm_irq_setup->base_irq,
208 prcm_irq_setup->nr_regs * 32);
209 prcm_irq_setup->base_irq = 0;
212 void omap_prcm_irq_prepare(void)
214 prcm_irq_setup->suspended = true;
217 void omap_prcm_irq_complete(void)
219 prcm_irq_setup->suspended = false;
221 /* If we have not saved the masks, do not attempt to restore */
222 if (!prcm_irq_setup->suspend_save_flag)
225 prcm_irq_setup->suspend_save_flag = false;
228 * Re-enable all masked PRCM irq sources, this causes the PRCM
229 * interrupt to fire immediately if the events were masked
230 * previously in the chain handler
232 prcm_irq_setup->restore_irqen(prcm_irq_setup->saved_mask);
236 * omap_prcm_register_chain_handler - initializes the prcm chained interrupt
237 * handler based on provided parameters
238 * @irq_setup: hardware data about the underlying PRM/PRCM
240 * Set up the PRCM chained interrupt handler on the PRCM IRQ. Sets up
241 * one generic IRQ chip per PRM interrupt status/enable register pair.
242 * Returns 0 upon success, -EINVAL if called twice or if invalid
243 * arguments are passed, or -ENOMEM on any other error.
245 int omap_prcm_register_chain_handler(struct omap_prcm_irq_setup *irq_setup)
248 u32 mask[OMAP_PRCM_MAX_NR_PENDING_REG];
250 struct irq_chip_generic *gc;
251 struct irq_chip_type *ct;
256 nr_regs = irq_setup->nr_regs;
258 if (prcm_irq_setup) {
259 pr_err("PRCM: already initialized; won't reinitialize\n");
263 if (nr_regs > OMAP_PRCM_MAX_NR_PENDING_REG) {
264 pr_err("PRCM: nr_regs too large\n");
268 prcm_irq_setup = irq_setup;
270 prcm_irq_chips = kzalloc(sizeof(void *) * nr_regs, GFP_KERNEL);
271 prcm_irq_setup->saved_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL);
272 prcm_irq_setup->priority_mask = kzalloc(sizeof(u32) * nr_regs,
275 if (!prcm_irq_chips || !prcm_irq_setup->saved_mask ||
276 !prcm_irq_setup->priority_mask) {
277 pr_err("PRCM: kzalloc failed\n");
281 memset(mask, 0, sizeof(mask));
283 for (i = 0; i < irq_setup->nr_irqs; i++) {
284 offset = irq_setup->irqs[i].offset;
285 mask[offset >> 5] |= 1 << (offset & 0x1f);
286 if (irq_setup->irqs[i].priority)
287 irq_setup->priority_mask[offset >> 5] |=
288 1 << (offset & 0x1f);
291 irq_set_chained_handler(irq_setup->irq, omap_prcm_irq_handler);
293 irq_setup->base_irq = irq_alloc_descs(-1, 0, irq_setup->nr_regs * 32,
296 if (irq_setup->base_irq < 0) {
297 pr_err("PRCM: failed to allocate irq descs: %d\n",
298 irq_setup->base_irq);
302 for (i = 0; i < irq_setup->nr_regs; i++) {
303 gc = irq_alloc_generic_chip("PRCM", 1,
304 irq_setup->base_irq + i * 32, prm_base,
308 pr_err("PRCM: failed to allocate generic chip\n");
312 ct->chip.irq_ack = irq_gc_ack_set_bit;
313 ct->chip.irq_mask = irq_gc_mask_clr_bit;
314 ct->chip.irq_unmask = irq_gc_mask_set_bit;
316 ct->regs.ack = irq_setup->ack + i * 4;
317 ct->regs.mask = irq_setup->mask + i * 4;
319 irq_setup_generic_chip(gc, mask[i], 0, IRQ_NOREQUEST, 0);
320 prcm_irq_chips[i] = gc;
326 omap_prcm_irq_cleanup();
331 * prm_read_reset_sources - return the sources of the SoC's last reset
333 * Return a u32 bitmask representing the reset sources that caused the
334 * SoC to reset. The low-level per-SoC functions called by this
335 * function remap the SoC-specific reset source bits into an
336 * OMAP-common set of reset source bits, defined in
337 * arch/arm/mach-omap2/prm.h. Returns the standardized reset source
338 * u32 bitmask from the hardware upon success, or returns (1 <<
339 * OMAP_UNKNOWN_RST_SRC_ID_SHIFT) if no low-level read_reset_sources()
340 * function was registered.
342 u32 prm_read_reset_sources(void)
344 u32 ret = 1 << OMAP_UNKNOWN_RST_SRC_ID_SHIFT;
346 if (prm_ll_data->read_reset_sources)
347 ret = prm_ll_data->read_reset_sources();
349 WARN_ONCE(1, "prm: %s: no mapping function defined for reset sources\n", __func__);
355 * prm_register - register per-SoC low-level data with the PRM
356 * @pld: low-level per-SoC OMAP PRM data & function pointers to register
358 * Register per-SoC low-level OMAP PRM data and function pointers with
359 * the OMAP PRM common interface. The caller must keep the data
360 * pointed to by @pld valid until it calls prm_unregister() and
361 * it returns successfully. Returns 0 upon success, -EINVAL if @pld
362 * is NULL, or -EEXIST if prm_register() has already been called
363 * without an intervening prm_unregister().
365 int prm_register(struct prm_ll_data *pld)
370 if (prm_ll_data != &null_prm_ll_data)
379 * prm_unregister - unregister per-SoC low-level data & function pointers
380 * @pld: low-level per-SoC OMAP PRM data & function pointers to unregister
382 * Unregister per-SoC low-level OMAP PRM data and function pointers
383 * that were previously registered with prm_register(). The
384 * caller may not destroy any of the data pointed to by @pld until
385 * this function returns successfully. Returns 0 upon success, or
386 * -EINVAL if @pld is NULL or if @pld does not match the struct
387 * prm_ll_data * previously registered by prm_register().
389 int prm_unregister(struct prm_ll_data *pld)
391 if (!pld || prm_ll_data != pld)
394 prm_ll_data = &null_prm_ll_data;