/*
* MOXA ART SoCs IRQ chip driver.
*
* Copyright (C) 2013 Jonas Jensen
*
* Jonas Jensen <jonas.jensen@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqdomain.h>
#include <asm/exception.h>
#define IRQ_SOURCE_REG 0
#define IRQ_MASK_REG 0x04
#define IRQ_CLEAR_REG 0x08
#define IRQ_MODE_REG 0x0c
#define IRQ_LEVEL_REG 0x10
#define IRQ_STATUS_REG 0x14
#define FIQ_SOURCE_REG 0x20
#define FIQ_MASK_REG 0x24
#define FIQ_CLEAR_REG 0x28
#define FIQ_MODE_REG 0x2c
#define FIQ_LEVEL_REG 0x30
#define FIQ_STATUS_REG 0x34
struct moxart_irq_data {
void __iomem *base;
struct irq_domain *domain;
unsigned int interrupt_mask;
};
static struct moxart_irq_data intc;
static void __exception_irq_entry handle_irq(struct pt_regs *regs)
{
u32 irqstat;
int hwirq;
irqstat = readl(intc.base + IRQ_STATUS_REG);
while (irqstat) {
hwirq = ffs(irqstat) - 1;
handle_IRQ(irq_linear_revmap(intc.domain, hwirq), regs);
irqstat &= ~(1 << hwirq);
}
}
static int __init moxart_of_intc_init(struct device_node *node,
struct device_node *parent)
{
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
int ret;
struct irq_chip_generic *gc;
intc.base = of_iomap(node, 0);
if (!intc.base) {
pr_err("%s: unable to map IC registers\n",
node->full_name);
return -EINVAL;
}
intc.domain = irq_domain_add_linear(node, 32, &irq_generic_chip_ops,
intc.base);
if (!intc.domain) {
pr_err("%s: unable to create IRQ domain\n", node->full_name);
return -EINVAL;
}
ret = irq_alloc_domain_generic_chips(intc.domain, 32, 1,
"MOXARTINTC", handle_edge_irq,
clr, 0, IRQ_GC_INIT_MASK_CACHE);
if (ret) {
pr_err("%s: could not allocate generic chip\n",
node->full_name);
irq_domain_remove(intc.domain);
return -EINVAL;
}
ret = of_property_read_u32(node, "interrupt-mask",
&intc.interrupt_mask);
if (ret)
pr_err("%s: could not read interrupt-mask DT property\n",
node->full_name);
gc = irq_get_domain_generic_chip(intc.domain, 0);
gc->reg_base = intc.base;
gc->chip_types[0].regs.mask = IRQ_MASK_REG;
gc->chip_types[0].regs.ack = IRQ_CLEAR_REG;
gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
writel(0, intc.base + IRQ_MASK_REG);
writel(0xffffffff, intc.base + IRQ_CLEAR_REG);
writel(intc.interrupt_mask, intc.base + IRQ_MODE_REG);
writel(intc.interrupt_mask, intc.base + IRQ_LEVEL_REG);
set_handle_irq(handle_irq);
return 0;
}
IRQCHIP_DECLARE(moxa_moxart_ic, "moxa,moxart-ic", moxart_of_intc_init);
