/*
* Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com>
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <asm/exception.h>
#define LPC32XX_INTC_MASK 0x00
#define LPC32XX_INTC_RAW 0x04
#define LPC32XX_INTC_STAT 0x08
#define LPC32XX_INTC_POL 0x0C
#define LPC32XX_INTC_TYPE 0x10
#define LPC32XX_INTC_FIQ 0x14
#define NR_LPC32XX_IC_IRQS 32
struct lpc32xx_irq_chip {
void __iomem *base;
struct irq_domain *domain;
struct irq_chip chip;
};
static struct lpc32xx_irq_chip *lpc32xx_mic_irqc;
static inline u32 lpc32xx_ic_read(struct lpc32xx_irq_chip *ic, u32 reg)
{
return readl_relaxed(ic->base + reg);
}
static inline void lpc32xx_ic_write(struct lpc32xx_irq_chip *ic,
u32 reg, u32 val)
{
writel_relaxed(val, ic->base + reg);
}
static void lpc32xx_irq_mask(struct irq_data *d)
{
struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
u32 val, mask = BIT(d->hwirq);
val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) & ~mask;
lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
}
static void lpc32xx_irq_unmask(struct irq_data *d)
{
struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
u32 val, mask = BIT(d->hwirq);
val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) | mask;
lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
}
static void lpc32xx_irq_ack(struct irq_data *d)
{
struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
u32 mask = BIT(d->hwirq);
lpc32xx_ic_write(ic, LPC32XX_INTC_RAW, mask);
}
static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)
{
struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
u32 val, mask = BIT(d->hwirq);
bool high, edge;
switch (type) {
case IRQ_TYPE_EDGE_RISING:
edge = true;
high = true;
break;
case IRQ_TYPE_EDGE_FALLING:
edge = true;
high = false;
break;
case IRQ_TYPE_LEVEL_HIGH:
edge = false;
high = true;
break;
case IRQ_TYPE_LEVEL_LOW:
edge = false;
high = false;
break;
default:
pr_info("unsupported irq type %d\n", type);
return -EINVAL;
}
irqd_set_trigger_type(d, type);
val = lpc32xx_ic_read(ic, LPC32XX_INTC_POL);
if (high)
val |= mask;
else
val &= ~mask;
lpc32xx_ic_write(ic, LPC32XX_INTC_POL, val);
val = lpc32xx_ic_read(ic, LPC32XX_INTC_TYPE);
if (edge) {
val |= mask;
irq_set_handler_locked(d, handle_edge_irq);
} else {
val &= ~mask;
irq_set_handler_locked(d, handle_level_irq);
}
lpc32xx_ic_write(ic, LPC32XX_INTC_TYPE, val);
return 0;
}
static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)
{
struct lpc32xx_irq_chip *ic = lpc32xx_mic_irqc;
u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
while (hwirq) {
irq = __ffs(hwirq);
hwirq &= ~BIT(irq);
handle_domain_irq(lpc32xx_mic_irqc->domain, irq, regs);
}
}
static void lpc32xx_sic_handler(struct irq_desc *desc)
{
struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);
struct irq_chip *chip = irq_desc_get_chip(desc);
u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
chained_irq_enter(chip, desc);
while (hwirq) {
irq = __ffs(hwirq);
hwirq &= ~BIT(irq);
generic_handle_irq(irq_find_mapping(ic->domain, irq));
}
chained_irq_exit(chip, desc);
}
static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,
irq_hw_number_t hw)
{
struct lpc32xx_irq_chip *ic = id->host_data;
irq_set_chip_data(virq, ic);
irq_set_chip_and_handler(virq, &ic->chip, handle_level_irq);
irq_set_status_flags(virq, IRQ_LEVEL);
irq_set_noprobe(virq);
return 0;
}
static void lpc32xx_irq_domain_unmap(struct irq_domain *id, unsigned int virq)
{
irq_set_chip_and_handler(virq, NULL, NULL);
}
static const struct irq_domain_ops lpc32xx_irq_domain_ops = {
.map = lpc32xx_irq_domain_map,
.unmap = lpc32xx_irq_domain_unmap,
.xlate = irq_domain_xlate_twocell,
};
static int __init lpc32xx_of_ic_init(struct device_node *node,
struct device_node *parent)
{
struct lpc32xx_irq_chip *irqc;
bool is_mic = of_device_is_compatible(node, "nxp,lpc3220-mic");
const __be32 *reg = of_get_property(node, "reg", NULL);
u32 parent_irq, i, addr = reg ? be32_to_cpu(*reg) : 0;
irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
if (!irqc)
return -ENOMEM;
irqc->base = of_iomap(node, 0);
if (!irqc->base) {
pr_err("%s: unable to map registers\n", node->full_name);
kfree(irqc);
return -EINVAL;
}
irqc->chip.irq_ack = lpc32xx_irq_ack;
irqc->chip.irq_mask = lpc32xx_irq_mask;
irqc->chip.irq_unmask = lpc32xx_irq_unmask;
irqc->chip.irq_set_type = lpc32xx_irq_set_type;
if (is_mic)
irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.mic", addr);
else
irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.sic", addr);
irqc->domain = irq_domain_add_linear(node, NR_LPC32XX_IC_IRQS,
&lpc32xx_irq_domain_ops, irqc);
if (!irqc->domain) {
pr_err("unable to add irq domain\n");
iounmap(irqc->base);
kfree(irqc->chip.name);
kfree(irqc);
return -ENODEV;
}
if (is_mic) {
lpc32xx_mic_irqc = irqc;
set_handle_irq(lpc32xx_handle_irq);
} else {
for (i = 0; i < of_irq_count(node); i++) {
parent_irq = irq_of_parse_and_map(node, i);
if (parent_irq)
irq_set_chained_handler_and_data(parent_irq,
lpc32xx_sic_handler, irqc);
}
}
lpc32xx_ic_write(irqc, LPC32XX_INTC_MASK, 0x00);
lpc32xx_ic_write(irqc, LPC32XX_INTC_POL, 0x00);
lpc32xx_ic_write(irqc, LPC32XX_INTC_TYPE, 0x00);
return 0;
}
IRQCHIP_DECLARE(nxp_lpc32xx_mic, "nxp,lpc3220-mic", lpc32xx_of_ic_init);
IRQCHIP_DECLARE(nxp_lpc32xx_sic, "nxp,lpc3220-sic", lpc32xx_of_ic_init);
