linux/drivers/irqchip/irq-ls1x.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019, Jiaxun Yang <jiaxun.yang@flygoat.com>
* Loongson-1 platform IRQ support
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/irqchip.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/irqchip/chained_irq.h>
#define LS_REG_INTC_STATUS 0x00
#define LS_REG_INTC_EN 0x04
#define LS_REG_INTC_SET 0x08
#define LS_REG_INTC_CLR 0x0c
#define LS_REG_INTC_POL 0x10
#define LS_REG_INTC_EDGE 0x14
/**
* struct ls1x_intc_priv - private ls1x-intc data.
* @domain: IRQ domain.
* @intc_base: IO Base of intc registers.
*/
struct ls1x_intc_priv {
struct irq_domain *domain;
void __iomem *intc_base;
};
static void ls1x_chained_handle_irq(struct irq_desc *desc)
{
struct ls1x_intc_priv *priv = irq_desc_get_handler_data(desc);
struct irq_chip *chip = irq_desc_get_chip(desc);
u32 pending;
chained_irq_enter(chip, desc);
pending = readl(priv->intc_base + LS_REG_INTC_STATUS) &
readl(priv->intc_base + LS_REG_INTC_EN);
if (!pending)
spurious_interrupt();
while (pending) {
int bit = __ffs(pending);
generic_handle_irq(irq_find_mapping(priv->domain, bit));
pending &= ~BIT(bit);
}
chained_irq_exit(chip, desc);
}
static void ls_intc_set_bit(struct irq_chip_generic *gc,
unsigned int offset,
u32 mask, bool set)
{
if (set)
writel(readl(gc->reg_base + offset) | mask,
gc->reg_base + offset);
else
writel(readl(gc->reg_base + offset) & ~mask,
gc->reg_base + offset);
}
static int ls_intc_set_type(struct irq_data *data, unsigned int type)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
u32 mask = data->mask;
switch (type) {
case IRQ_TYPE_LEVEL_HIGH:
ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
break;
case IRQ_TYPE_LEVEL_LOW:
ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
break;
case IRQ_TYPE_EDGE_RISING:
ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
break;
case IRQ_TYPE_EDGE_FALLING:
ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
break;
default:
return -EINVAL;
}
irqd_set_trigger_type(data, type);
return irq_setup_alt_chip(data, type);
}
static int __init ls1x_intc_of_init(struct device_node *node,
struct device_node *parent)
{
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
struct ls1x_intc_priv *priv;
int parent_irq, err = 0;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->intc_base = of_iomap(node, 0);
if (!priv->intc_base) {
err = -ENODEV;
goto out_free_priv;
}
parent_irq = irq_of_parse_and_map(node, 0);
if (!parent_irq) {
pr_err("ls1x-irq: unable to get parent irq\n");
err = -ENODEV;
goto out_iounmap;
}
/* Set up an IRQ domain */
priv->domain = irq_domain_add_linear(node, 32, &irq_generic_chip_ops,
NULL);
if (!priv->domain) {
pr_err("ls1x-irq: cannot add IRQ domain\n");
goto out_iounmap;
}
err = irq_alloc_domain_generic_chips(priv->domain, 32, 2,
node->full_name, handle_level_irq,
IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN, 0,
IRQ_GC_INIT_MASK_CACHE);
if (err) {
pr_err("ls1x-irq: unable to register IRQ domain\n");
goto out_free_domain;
}
/* Mask all irqs */
writel(0x0, priv->intc_base + LS_REG_INTC_EN);
/* Ack all irqs */
writel(0xffffffff, priv->intc_base + LS_REG_INTC_CLR);
/* Set all irqs to high level triggered */
writel(0xffffffff, priv->intc_base + LS_REG_INTC_POL);
gc = irq_get_domain_generic_chip(priv->domain, 0);
gc->reg_base = priv->intc_base;
ct = gc->chip_types;
ct[0].type = IRQ_TYPE_LEVEL_MASK;
ct[0].regs.mask = LS_REG_INTC_EN;
ct[0].regs.ack = LS_REG_INTC_CLR;
ct[0].chip.irq_unmask = irq_gc_mask_set_bit;
ct[0].chip.irq_mask = irq_gc_mask_clr_bit;
ct[0].chip.irq_ack = irq_gc_ack_set_bit;
ct[0].chip.irq_set_type = ls_intc_set_type;
ct[0].handler = handle_level_irq;
ct[1].type = IRQ_TYPE_EDGE_BOTH;
ct[1].regs.mask = LS_REG_INTC_EN;
ct[1].regs.ack = LS_REG_INTC_CLR;
ct[1].chip.irq_unmask = irq_gc_mask_set_bit;
ct[1].chip.irq_mask = irq_gc_mask_clr_bit;
ct[1].chip.irq_ack = irq_gc_ack_set_bit;
ct[1].chip.irq_set_type = ls_intc_set_type;
ct[1].handler = handle_edge_irq;
irq_set_chained_handler_and_data(parent_irq,
ls1x_chained_handle_irq, priv);
return 0;
out_free_domain:
irq_domain_remove(priv->domain);
out_iounmap:
iounmap(priv->intc_base);
out_free_priv:
kfree(priv);
return err;
}
IRQCHIP_DECLARE(ls1x_intc, "loongson,ls1x-intc", ls1x_intc_of_init);