/*
* OMAP WakeupGen Source file
*
* OMAP WakeupGen is the interrupt controller extension used along
* with ARM GIC to wake the CPU out from low power states on
* external interrupts. It is responsible for generating wakeup
* event from the incoming interrupts and enable bits. It is
* implemented in MPU always ON power domain. During normal operation,
* WakeupGen delivers external interrupts directly to the GIC.
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Santosh Shilimkar <santosh.shilimkar@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.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/cpu.h>
#include <asm/hardware/gic.h>
#include <mach/omap-wakeupgen.h>
#define NR_REG_BANKS 4
#define MAX_IRQS 128
#define WKG_MASK_ALL 0x00000000
#define WKG_UNMASK_ALL 0xffffffff
#define CPU_ENA_OFFSET 0x400
#define CPU0_ID 0x0
#define CPU1_ID 0x1
static void __iomem *wakeupgen_base;
static DEFINE_PER_CPU(u32 [NR_REG_BANKS], irqmasks);
static DEFINE_SPINLOCK(wakeupgen_lock);
static unsigned int irq_target_cpu[NR_IRQS];
/*
* Static helper functions.
*/
static inline u32 wakeupgen_readl(u8 idx, u32 cpu)
{
return __raw_readl(wakeupgen_base + OMAP_WKG_ENB_A_0 +
(cpu * CPU_ENA_OFFSET) + (idx * 4));
}
static inline void wakeupgen_writel(u32 val, u8 idx, u32 cpu)
{
__raw_writel(val, wakeupgen_base + OMAP_WKG_ENB_A_0 +
(cpu * CPU_ENA_OFFSET) + (idx * 4));
}
static void _wakeupgen_set_all(unsigned int cpu, unsigned int reg)
{
u8 i;
for (i = 0; i < NR_REG_BANKS; i++)
wakeupgen_writel(reg, i, cpu);
}
static inline int _wakeupgen_get_irq_info(u32 irq, u32 *bit_posn, u8 *reg_index)
{
unsigned int spi_irq;
/*
* PPIs and SGIs are not supported.
*/
if (irq < OMAP44XX_IRQ_GIC_START)
return -EINVAL;
/*
* Subtract the GIC offset.
*/
spi_irq = irq - OMAP44XX_IRQ_GIC_START;
if (spi_irq > MAX_IRQS) {
pr_err("omap wakeupGen: Invalid IRQ%d\n", irq);
return -EINVAL;
}
/*
* Each WakeupGen register controls 32 interrupt.
* i.e. 1 bit per SPI IRQ
*/
*reg_index = spi_irq >> 5;
*bit_posn = spi_irq %= 32;
return 0;
}
static void _wakeupgen_clear(unsigned int irq, unsigned int cpu)
{
u32 val, bit_number;
u8 i;
if (_wakeupgen_get_irq_info(irq, &bit_number, &i))
return;
val = wakeupgen_readl(i, cpu);
val &= ~BIT(bit_number);
wakeupgen_writel(val, i, cpu);
}
static void _wakeupgen_set(unsigned int irq, unsigned int cpu)
{
u32 val, bit_number;
u8 i;
if (_wakeupgen_get_irq_info(irq, &bit_number, &i))
return;
val = wakeupgen_readl(i, cpu);
val |= BIT(bit_number);
wakeupgen_writel(val, i, cpu);
}
static void _wakeupgen_save_masks(unsigned int cpu)
{
u8 i;
for (i = 0; i < NR_REG_BANKS; i++)
per_cpu(irqmasks, cpu)[i] = wakeupgen_readl(i, cpu);
}
static void _wakeupgen_restore_masks(unsigned int cpu)
{
u8 i;
for (i = 0; i < NR_REG_BANKS; i++)
wakeupgen_writel(per_cpu(irqmasks, cpu)[i], i, cpu);
}
/*
* Architecture specific Mask extension
*/
static void wakeupgen_mask(struct irq_data *d)
{
unsigned long flags;
spin_lock_irqsave(&wakeupgen_lock, flags);
_wakeupgen_clear(d->irq, irq_target_cpu[d->irq]);
spin_unlock_irqrestore(&wakeupgen_lock, flags);
}
/*
* Architecture specific Unmask extension
*/
static void wakeupgen_unmask(struct irq_data *d)
{
unsigned long flags;
spin_lock_irqsave(&wakeupgen_lock, flags);
_wakeupgen_set(d->irq, irq_target_cpu[d->irq]);
spin_unlock_irqrestore(&wakeupgen_lock, flags);
}
/*
* Mask or unmask all interrupts on given CPU.
* 0 = Mask all interrupts on the 'cpu'
* 1 = Unmask all interrupts on the 'cpu'
* Ensure that the initial mask is maintained. This is faster than
* iterating through GIC registers to arrive at the correct masks.
*/
static void wakeupgen_irqmask_all(unsigned int cpu, unsigned int set)
{
unsigned long flags;
spin_lock_irqsave(&wakeupgen_lock, flags);
if (set) {
_wakeupgen_save_masks(cpu);
_wakeupgen_set_all(cpu, WKG_MASK_ALL);
} else {
_wakeupgen_set_all(cpu, WKG_UNMASK_ALL);
_wakeupgen_restore_masks(cpu);
}
spin_unlock_irqrestore(&wakeupgen_lock, flags);
}
#ifdef CONFIG_HOTPLUG_CPU
static int __cpuinit irq_cpu_hotplug_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned int)hcpu;
switch (action) {
case CPU_ONLINE:
wakeupgen_irqmask_all(cpu, 0);
break;
case CPU_DEAD:
wakeupgen_irqmask_all(cpu, 1);
break;
}
return NOTIFY_OK;
}
static struct notifier_block __refdata irq_hotplug_notifier = {
.notifier_call = irq_cpu_hotplug_notify,
};
static void __init irq_hotplug_init(void)
{
register_hotcpu_notifier(&irq_hotplug_notifier);
}
#else
static void __init irq_hotplug_init(void)
{}
#endif
/*
* Initialise the wakeupgen module.
*/
int __init omap_wakeupgen_init(void)
{
int i;
unsigned int boot_cpu = smp_processor_id();
/* Not supported on OMAP4 ES1.0 silicon */
if (omap_rev() == OMAP4430_REV_ES1_0) {
WARN(1, "WakeupGen: Not supported on OMAP4430 ES1.0\n");
return -EPERM;
}
/* Static mapping, never released */
wakeupgen_base = ioremap(OMAP44XX_WKUPGEN_BASE, SZ_4K);
if (WARN_ON(!wakeupgen_base))
return -ENOMEM;
/* Clear all IRQ bitmasks at wakeupGen level */
for (i = 0; i < NR_REG_BANKS; i++) {
wakeupgen_writel(0, i, CPU0_ID);
wakeupgen_writel(0, i, CPU1_ID);
}
/*
* Override GIC architecture specific functions to add
* OMAP WakeupGen interrupt controller along with GIC
*/
gic_arch_extn.irq_mask = wakeupgen_mask;
gic_arch_extn.irq_unmask = wakeupgen_unmask;
gic_arch_extn.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
/*
* FIXME: Add support to set_smp_affinity() once the core
* GIC code has necessary hooks in place.
*/
/* Associate all the IRQs to boot CPU like GIC init does. */
for (i = 0; i < NR_IRQS; i++)
irq_target_cpu[i] = boot_cpu;
irq_hotplug_init();
return 0;
}
