/*
* arch/arm/mach-vt8500/irq.c
*
* Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
* Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* This file is copied and modified from the original irq.c provided by
* Alexey Charkov. Minor changes have been made for Device Tree Support.
*/
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <asm/irq.h>
#include <asm/exception.h>
#define VT8500_ICPC_IRQ 0x20
#define VT8500_ICPC_FIQ 0x24
#define VT8500_ICDC 0x40 /* Destination Control 64*u32 */
#define VT8500_ICIS 0x80 /* Interrupt status, 16*u32 */
/* ICPC */
#define ICPC_MASK 0x3F
#define ICPC_ROTATE BIT(6)
/* IC_DCTR */
#define ICDC_IRQ 0x00
#define ICDC_FIQ 0x01
#define ICDC_DSS0 0x02
#define ICDC_DSS1 0x03
#define ICDC_DSS2 0x04
#define ICDC_DSS3 0x05
#define ICDC_DSS4 0x06
#define ICDC_DSS5 0x07
#define VT8500_INT_DISABLE 0
#define VT8500_INT_ENABLE BIT(3)
#define VT8500_TRIGGER_HIGH 0
#define VT8500_TRIGGER_RISING BIT(5)
#define VT8500_TRIGGER_FALLING BIT(6)
#define VT8500_EDGE ( VT8500_TRIGGER_RISING \
| VT8500_TRIGGER_FALLING)
/* vt8500 has 1 intc, wm8505 and wm8650 have 2 */
#define VT8500_INTC_MAX 2
struct vt8500_irq_data {
void __iomem *base; /* IO Memory base address */
struct irq_domain *domain; /* Domain for this controller */
};
/* Global variable for accessing io-mem addresses */
static struct vt8500_irq_data intc[VT8500_INTC_MAX];
static u32 active_cnt = 0;
static void vt8500_irq_mask(struct irq_data *d)
{
struct vt8500_irq_data *priv = d->domain->host_data;
void __iomem *base = priv->base;
void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
u8 edge, dctr;
u32 status;
edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
if (edge) {
status = readl(stat_reg);
status |= (1 << (d->hwirq & 0x1f));
writel(status, stat_reg);
} else {
dctr = readb(base + VT8500_ICDC + d->hwirq);
dctr &= ~VT8500_INT_ENABLE;
writeb(dctr, base + VT8500_ICDC + d->hwirq);
}
}
static void vt8500_irq_unmask(struct irq_data *d)
{
struct vt8500_irq_data *priv = d->domain->host_data;
void __iomem *base = priv->base;
u8 dctr;
dctr = readb(base + VT8500_ICDC + d->hwirq);
dctr |= VT8500_INT_ENABLE;
writeb(dctr, base + VT8500_ICDC + d->hwirq);
}
static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)
{
struct vt8500_irq_data *priv = d->domain->host_data;
void __iomem *base = priv->base;
u8 dctr;
dctr = readb(base + VT8500_ICDC + d->hwirq);
dctr &= ~VT8500_EDGE;
switch (flow_type) {
case IRQF_TRIGGER_LOW:
return -EINVAL;
case IRQF_TRIGGER_HIGH:
dctr |= VT8500_TRIGGER_HIGH;
__irq_set_handler_locked(d->irq, handle_level_irq);
break;
case IRQF_TRIGGER_FALLING:
dctr |= VT8500_TRIGGER_FALLING;
__irq_set_handler_locked(d->irq, handle_edge_irq);
break;
case IRQF_TRIGGER_RISING:
dctr |= VT8500_TRIGGER_RISING;
__irq_set_handler_locked(d->irq, handle_edge_irq);
break;
}
writeb(dctr, base + VT8500_ICDC + d->hwirq);
return 0;
}
static struct irq_chip vt8500_irq_chip = {
.name = "vt8500",
.irq_ack = vt8500_irq_mask,
.irq_mask = vt8500_irq_mask,
.irq_unmask = vt8500_irq_unmask,
.irq_set_type = vt8500_irq_set_type,
};
static void __init vt8500_init_irq_hw(void __iomem *base)
{
u32 i;
/* Enable rotating priority for IRQ */
writel(ICPC_ROTATE, base + VT8500_ICPC_IRQ);
writel(0x00, base + VT8500_ICPC_FIQ);
/* Disable all interrupts and route them to IRQ */
for (i = 0; i < 64; i++)
writeb(VT8500_INT_DISABLE | ICDC_IRQ, base + VT8500_ICDC + i);
}
static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_chip_and_handler(virq, &vt8500_irq_chip, handle_level_irq);
set_irq_flags(virq, IRQF_VALID);
return 0;
}
static struct irq_domain_ops vt8500_irq_domain_ops = {
.map = vt8500_irq_map,
.xlate = irq_domain_xlate_onecell,
};
asmlinkage void __exception_irq_entry vt8500_handle_irq(struct pt_regs *regs)
{
u32 stat, i;
int irqnr, virq;
void __iomem *base;
/* Loop through each active controller */
for (i=0; i<active_cnt; i++) {
base = intc[i].base;
irqnr = readl_relaxed(base) & 0x3F;
/*
Highest Priority register default = 63, so check that this
is a real interrupt by checking the status register
*/
if (irqnr == 63) {
stat = readl_relaxed(base + VT8500_ICIS + 4);
if (!(stat & BIT(31)))
continue;
}
virq = irq_find_mapping(intc[i].domain, irqnr);
handle_IRQ(virq, regs);
}
}
int __init vt8500_irq_init(struct device_node *node, struct device_node *parent)
{
int irq, i;
struct device_node *np = node;
if (active_cnt == VT8500_INTC_MAX) {
pr_err("%s: Interrupt controllers > VT8500_INTC_MAX\n",
__func__);
goto out;
}
intc[active_cnt].base = of_iomap(np, 0);
intc[active_cnt].domain = irq_domain_add_linear(node, 64,
&vt8500_irq_domain_ops, &intc[active_cnt]);
if (!intc[active_cnt].base) {
pr_err("%s: Unable to map IO memory\n", __func__);
goto out;
}
if (!intc[active_cnt].domain) {
pr_err("%s: Unable to add irq domain!\n", __func__);
goto out;
}
vt8500_init_irq_hw(intc[active_cnt].base);
pr_info("vt8500-irq: Added interrupt controller\n");
active_cnt++;
/* check if this is a slaved controller */
if (of_irq_count(np) != 0) {
/* check that we have the correct number of interrupts */
if (of_irq_count(np) != 8) {
pr_err("%s: Incorrect IRQ map for slaved controller\n",
__func__);
return -EINVAL;
}
for (i = 0; i < 8; i++) {
irq = irq_of_parse_and_map(np, i);
enable_irq(irq);
}
pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
}
out:
return 0;
}
