/*
* OMAP2+ common Power & Reset Management (PRM) IP block functions
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Tero Kristo <t-kristo@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*
* For historical purposes, the API used to configure the PRM
* interrupt handler refers to it as the "PRCM interrupt." The
* underlying registers are located in the PRM on OMAP3/4.
*
* XXX This code should eventually be moved to a PRM driver.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <mach/system.h>
#include <plat/common.h>
#include <plat/prcm.h>
#include <plat/irqs.h>
#include "prm2xxx_3xxx.h"
#include "prm44xx.h"
/*
* OMAP_PRCM_MAX_NR_PENDING_REG: maximum number of PRM_IRQ*_MPU regs
* XXX this is technically not needed, since
* omap_prcm_register_chain_handler() could allocate this based on the
* actual amount of memory needed for the SoC
*/
#define OMAP_PRCM_MAX_NR_PENDING_REG 2
/*
* prcm_irq_chips: an array of all of the "generic IRQ chips" in use
* by the PRCM interrupt handler code. There will be one 'chip' per
* PRM_{IRQSTATUS,IRQENABLE}_MPU register pair. (So OMAP3 will have
* one "chip" and OMAP4 will have two.)
*/
static struct irq_chip_generic **prcm_irq_chips;
/*
* prcm_irq_setup: the PRCM IRQ parameters for the hardware the code
* is currently running on. Defined and passed by initialization code
* that calls omap_prcm_register_chain_handler().
*/
static struct omap_prcm_irq_setup *prcm_irq_setup;
/* Private functions */
/*
* Move priority events from events to priority_events array
*/
static void omap_prcm_events_filter_priority(unsigned long *events,
unsigned long *priority_events)
{
int i;
for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
priority_events[i] =
events[i] & prcm_irq_setup->priority_mask[i];
events[i] ^= priority_events[i];
}
}
/*
* PRCM Interrupt Handler
*
* This is a common handler for the OMAP PRCM interrupts. Pending
* interrupts are detected by a call to prcm_pending_events and
* dispatched accordingly. Clearing of the wakeup events should be
* done by the SoC specific individual handlers.
*/
static void omap_prcm_irq_handler(unsigned int irq, struct irq_desc *desc)
{
unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG];
unsigned long priority_pending[OMAP_PRCM_MAX_NR_PENDING_REG];
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int virtirq;
int nr_irqs = prcm_irq_setup->nr_regs * 32;
/*
* If we are suspended, mask all interrupts from PRCM level,
* this does not ack them, and they will be pending until we
* re-enable the interrupts, at which point the
* omap_prcm_irq_handler will be executed again. The
* _save_and_clear_irqen() function must ensure that the PRM
* write to disable all IRQs has reached the PRM before
* returning, or spurious PRCM interrupts may occur during
* suspend.
*/
if (prcm_irq_setup->suspended) {
prcm_irq_setup->save_and_clear_irqen(prcm_irq_setup->saved_mask);
prcm_irq_setup->suspend_save_flag = true;
}
/*
* Loop until all pending irqs are handled, since
* generic_handle_irq() can cause new irqs to come
*/
while (!prcm_irq_setup->suspended) {
prcm_irq_setup->read_pending_irqs(pending);
/* No bit set, then all IRQs are handled */
if (find_first_bit(pending, nr_irqs) >= nr_irqs)
break;
omap_prcm_events_filter_priority(pending, priority_pending);
/*
* Loop on all currently pending irqs so that new irqs
* cannot starve previously pending irqs
*/
/* Serve priority events first */
for_each_set_bit(virtirq, priority_pending, nr_irqs)
generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
/* Serve normal events next */
for_each_set_bit(virtirq, pending, nr_irqs)
generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
}
if (chip->irq_ack)
chip->irq_ack(&desc->irq_data);
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
chip->irq_unmask(&desc->irq_data);
prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */
}
/* Public functions */
/**
* omap_prcm_event_to_irq - given a PRCM event name, returns the
* corresponding IRQ on which the handler should be registered
* @name: name of the PRCM interrupt bit to look up - see struct omap_prcm_irq
*
* Returns the Linux internal IRQ ID corresponding to @name upon success,
* or -ENOENT upon failure.
*/
int omap_prcm_event_to_irq(const char *name)
{
int i;
if (!prcm_irq_setup || !name)
return -ENOENT;
for (i = 0; i < prcm_irq_setup->nr_irqs; i++)
if (!strcmp(prcm_irq_setup->irqs[i].name, name))
return prcm_irq_setup->base_irq +
prcm_irq_setup->irqs[i].offset;
return -ENOENT;
}
/**
* omap_prcm_irq_cleanup - reverses memory allocated and other steps
* done by omap_prcm_register_chain_handler()
*
* No return value.
*/
void omap_prcm_irq_cleanup(void)
{
int i;
if (!prcm_irq_setup) {
pr_err("PRCM: IRQ handler not initialized; cannot cleanup\n");
return;
}
if (prcm_irq_chips) {
for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
if (prcm_irq_chips[i])
irq_remove_generic_chip(prcm_irq_chips[i],
0xffffffff, 0, 0);
prcm_irq_chips[i] = NULL;
}
kfree(prcm_irq_chips);
prcm_irq_chips = NULL;
}
kfree(prcm_irq_setup->saved_mask);
prcm_irq_setup->saved_mask = NULL;
kfree(prcm_irq_setup->priority_mask);
prcm_irq_setup->priority_mask = NULL;
irq_set_chained_handler(prcm_irq_setup->irq, NULL);
if (prcm_irq_setup->base_irq > 0)
irq_free_descs(prcm_irq_setup->base_irq,
prcm_irq_setup->nr_regs * 32);
prcm_irq_setup->base_irq = 0;
}
void omap_prcm_irq_prepare(void)
{
prcm_irq_setup->suspended = true;
}
void omap_prcm_irq_complete(void)
{
prcm_irq_setup->suspended = false;
/* If we have not saved the masks, do not attempt to restore */
if (!prcm_irq_setup->suspend_save_flag)
return;
prcm_irq_setup->suspend_save_flag = false;
/*
* Re-enable all masked PRCM irq sources, this causes the PRCM
* interrupt to fire immediately if the events were masked
* previously in the chain handler
*/
prcm_irq_setup->restore_irqen(prcm_irq_setup->saved_mask);
}
/**
* omap_prcm_register_chain_handler - initializes the prcm chained interrupt
* handler based on provided parameters
* @irq_setup: hardware data about the underlying PRM/PRCM
*
* Set up the PRCM chained interrupt handler on the PRCM IRQ. Sets up
* one generic IRQ chip per PRM interrupt status/enable register pair.
* Returns 0 upon success, -EINVAL if called twice or if invalid
* arguments are passed, or -ENOMEM on any other error.
*/
int omap_prcm_register_chain_handler(struct omap_prcm_irq_setup *irq_setup)
{
int nr_regs = irq_setup->nr_regs;
u32 mask[OMAP_PRCM_MAX_NR_PENDING_REG];
int offset, i;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
if (!irq_setup)
return -EINVAL;
if (prcm_irq_setup) {
pr_err("PRCM: already initialized; won't reinitialize\n");
return -EINVAL;
}
if (nr_regs > OMAP_PRCM_MAX_NR_PENDING_REG) {
pr_err("PRCM: nr_regs too large\n");
return -EINVAL;
}
prcm_irq_setup = irq_setup;
prcm_irq_chips = kzalloc(sizeof(void *) * nr_regs, GFP_KERNEL);
prcm_irq_setup->saved_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL);
prcm_irq_setup->priority_mask = kzalloc(sizeof(u32) * nr_regs,
GFP_KERNEL);
if (!prcm_irq_chips || !prcm_irq_setup->saved_mask ||
!prcm_irq_setup->priority_mask) {
pr_err("PRCM: kzalloc failed\n");
goto err;
}
memset(mask, 0, sizeof(mask));
for (i = 0; i < irq_setup->nr_irqs; i++) {
offset = irq_setup->irqs[i].offset;
mask[offset >> 5] |= 1 << (offset & 0x1f);
if (irq_setup->irqs[i].priority)
irq_setup->priority_mask[offset >> 5] |=
1 << (offset & 0x1f);
}
irq_set_chained_handler(irq_setup->irq, omap_prcm_irq_handler);
irq_setup->base_irq = irq_alloc_descs(-1, 0, irq_setup->nr_regs * 32,
0);
if (irq_setup->base_irq < 0) {
pr_err("PRCM: failed to allocate irq descs: %d\n",
irq_setup->base_irq);
goto err;
}
for (i = 0; i <= irq_setup->nr_regs; i++) {
gc = irq_alloc_generic_chip("PRCM", 1,
irq_setup->base_irq + i * 32, prm_base,
handle_level_irq);
if (!gc) {
pr_err("PRCM: failed to allocate generic chip\n");
goto err;
}
ct = gc->chip_types;
ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->regs.ack = irq_setup->ack + i * 4;
ct->regs.mask = irq_setup->mask + i * 4;
irq_setup_generic_chip(gc, mask[i], 0, IRQ_NOREQUEST, 0);
prcm_irq_chips[i] = gc;
}
return 0;
err:
omap_prcm_irq_cleanup();
return -ENOMEM;
}
