/*
* System Manager driver for AT32AP CPUs
*
* Copyright (C) 2006 Atmel Corporation
*
* 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.
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <asm/intc.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/arch/sm.h>
#include "sm.h"
#define SM_EIM_IRQ_RESOURCE 1
#define SM_PM_IRQ_RESOURCE 2
#define SM_RTC_IRQ_RESOURCE 3
#define to_eim(irqc) container_of(irqc, struct at32_sm, irqc)
struct at32_sm system_manager;
int __init at32_sm_init(void)
{
struct resource *regs;
struct at32_sm *sm = &system_manager;
int ret = -ENXIO;
regs = platform_get_resource(&at32_sm_device, IORESOURCE_MEM, 0);
if (!regs)
goto fail;
spin_lock_init(&sm->lock);
sm->pdev = &at32_sm_device;
ret = -ENOMEM;
sm->regs = ioremap(regs->start, regs->end - regs->start + 1);
if (!sm->regs)
goto fail;
return 0;
fail:
printk(KERN_ERR "Failed to initialize System Manager: %d\n", ret);
return ret;
}
/*
* External Interrupt Module (EIM).
*
* EIM gets level- or edge-triggered interrupts of either polarity
* from the outside and converts it to active-high level-triggered
* interrupts that the internal interrupt controller can handle. EIM
* also provides masking/unmasking of interrupts, as well as
* acknowledging of edge-triggered interrupts.
*/
static irqreturn_t spurious_eim_interrupt(int irq, void *dev_id,
struct pt_regs *regs)
{
printk(KERN_WARNING "Spurious EIM interrupt %d\n", irq);
disable_irq(irq);
return IRQ_NONE;
}
static struct irqaction eim_spurious_action = {
.handler = spurious_eim_interrupt,
};
static irqreturn_t eim_handle_irq(int irq, void *dev_id, struct pt_regs *regs)
{
struct irq_controller * irqc = dev_id;
struct at32_sm *sm = to_eim(irqc);
unsigned long pending;
/*
* No need to disable interrupts globally. The interrupt
* level relevant to this group must be masked all the time,
* so we know that this particular EIM instance will not be
* re-entered.
*/
spin_lock(&sm->lock);
pending = intc_get_pending(sm->irqc.irq_group);
if (unlikely(!pending)) {
printk(KERN_ERR "EIM (group %u): No interrupts pending!\n",
sm->irqc.irq_group);
goto unlock;
}
do {
struct irqaction *action;
unsigned int i;
i = fls(pending) - 1;
pending &= ~(1 << i);
action = sm->action[i];
/* Acknowledge the interrupt */
sm_writel(sm, EIM_ICR, 1 << i);
spin_unlock(&sm->lock);
if (action->flags & SA_INTERRUPT)
local_irq_disable();
action->handler(sm->irqc.first_irq + i, action->dev_id, regs);
local_irq_enable();
spin_lock(&sm->lock);
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(sm->irqc.first_irq + i);
} while (pending);
unlock:
spin_unlock(&sm->lock);
return IRQ_HANDLED;
}
static void eim_mask(struct irq_controller *irqc, unsigned int irq)
{
struct at32_sm *sm = to_eim(irqc);
unsigned int i;
i = irq - sm->irqc.first_irq;
sm_writel(sm, EIM_IDR, 1 << i);
}
static void eim_unmask(struct irq_controller *irqc, unsigned int irq)
{
struct at32_sm *sm = to_eim(irqc);
unsigned int i;
i = irq - sm->irqc.first_irq;
sm_writel(sm, EIM_IER, 1 << i);
}
static int eim_setup(struct irq_controller *irqc, unsigned int irq,
struct irqaction *action)
{
struct at32_sm *sm = to_eim(irqc);
sm->action[irq - sm->irqc.first_irq] = action;
/* Acknowledge earlier interrupts */
sm_writel(sm, EIM_ICR, (1<<(irq - sm->irqc.first_irq)));
eim_unmask(irqc, irq);
return 0;
}
static void eim_free(struct irq_controller *irqc, unsigned int irq,
void *dev)
{
struct at32_sm *sm = to_eim(irqc);
eim_mask(irqc, irq);
sm->action[irq - sm->irqc.first_irq] = &eim_spurious_action;
}
static int eim_set_type(struct irq_controller *irqc, unsigned int irq,
unsigned int type)
{
struct at32_sm *sm = to_eim(irqc);
unsigned long flags;
u32 value, pattern;
spin_lock_irqsave(&sm->lock, flags);
pattern = 1 << (irq - sm->irqc.first_irq);
value = sm_readl(sm, EIM_MODE);
if (type & IRQ_TYPE_LEVEL)
value |= pattern;
else
value &= ~pattern;
sm_writel(sm, EIM_MODE, value);
value = sm_readl(sm, EIM_EDGE);
if (type & IRQ_EDGE_RISING)
value |= pattern;
else
value &= ~pattern;
sm_writel(sm, EIM_EDGE, value);
value = sm_readl(sm, EIM_LEVEL);
if (type & IRQ_LEVEL_HIGH)
value |= pattern;
else
value &= ~pattern;
sm_writel(sm, EIM_LEVEL, value);
spin_unlock_irqrestore(&sm->lock, flags);
return 0;
}
static unsigned int eim_get_type(struct irq_controller *irqc,
unsigned int irq)
{
struct at32_sm *sm = to_eim(irqc);
unsigned long flags;
unsigned int type = 0;
u32 mode, edge, level, pattern;
pattern = 1 << (irq - sm->irqc.first_irq);
spin_lock_irqsave(&sm->lock, flags);
mode = sm_readl(sm, EIM_MODE);
edge = sm_readl(sm, EIM_EDGE);
level = sm_readl(sm, EIM_LEVEL);
spin_unlock_irqrestore(&sm->lock, flags);
if (mode & pattern)
type |= IRQ_TYPE_LEVEL;
if (edge & pattern)
type |= IRQ_EDGE_RISING;
if (level & pattern)
type |= IRQ_LEVEL_HIGH;
return type;
}
static struct irq_controller_class eim_irq_class = {
.typename = "EIM",
.handle = eim_handle_irq,
.setup = eim_setup,
.free = eim_free,
.mask = eim_mask,
.unmask = eim_unmask,
.set_type = eim_set_type,
.get_type = eim_get_type,
};
static int __init eim_init(void)
{
struct at32_sm *sm = &system_manager;
unsigned int i;
u32 pattern;
int ret;
/*
* The EIM is really the same module as SM, so register
* mapping, etc. has been taken care of already.
*/
/*
* Find out how many interrupt lines that are actually
* implemented in hardware.
*/
sm_writel(sm, EIM_IDR, ~0UL);
sm_writel(sm, EIM_MODE, ~0UL);
pattern = sm_readl(sm, EIM_MODE);
sm->irqc.nr_irqs = fls(pattern);
ret = -ENOMEM;
sm->action = kmalloc(sizeof(*sm->action) * sm->irqc.nr_irqs,
GFP_KERNEL);
if (!sm->action)
goto out;
for (i = 0; i < sm->irqc.nr_irqs; i++)
sm->action[i] = &eim_spurious_action;
spin_lock_init(&sm->lock);
sm->irqc.irq_group = sm->pdev->resource[SM_EIM_IRQ_RESOURCE].start;
sm->irqc.class = &eim_irq_class;
ret = intc_register_controller(&sm->irqc);
if (ret < 0)
goto out_free_actions;
printk("EIM: External Interrupt Module at 0x%p, IRQ group %u\n",
sm->regs, sm->irqc.irq_group);
printk("EIM: Handling %u external IRQs, starting with IRQ%u\n",
sm->irqc.nr_irqs, sm->irqc.first_irq);
return 0;
out_free_actions:
kfree(sm->action);
out:
return ret;
}
arch_initcall(eim_init);
