linuxdebug/drivers/irqchip/irq-sp7021-intc.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/*
* Copyright (C) Sunplus Technology Co., Ltd.
* All rights reserved.
*/
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#define SP_INTC_HWIRQ_MIN 0
#define SP_INTC_HWIRQ_MAX 223
#define SP_INTC_NR_IRQS (SP_INTC_HWIRQ_MAX - SP_INTC_HWIRQ_MIN + 1)
#define SP_INTC_NR_GROUPS DIV_ROUND_UP(SP_INTC_NR_IRQS, 32)
#define SP_INTC_REG_SIZE (SP_INTC_NR_GROUPS * 4)
/* REG_GROUP_0 regs */
#define REG_INTR_TYPE (sp_intc.g0)
#define REG_INTR_POLARITY (REG_INTR_TYPE + SP_INTC_REG_SIZE)
#define REG_INTR_PRIORITY (REG_INTR_POLARITY + SP_INTC_REG_SIZE)
#define REG_INTR_MASK (REG_INTR_PRIORITY + SP_INTC_REG_SIZE)
/* REG_GROUP_1 regs */
#define REG_INTR_CLEAR (sp_intc.g1)
#define REG_MASKED_EXT1 (REG_INTR_CLEAR + SP_INTC_REG_SIZE)
#define REG_MASKED_EXT0 (REG_MASKED_EXT1 + SP_INTC_REG_SIZE)
#define REG_INTR_GROUP (REG_INTR_CLEAR + 31 * 4)
#define GROUP_MASK (BIT(SP_INTC_NR_GROUPS) - 1)
#define GROUP_SHIFT_EXT1 (0)
#define GROUP_SHIFT_EXT0 (8)
/*
* When GPIO_INT0~7 set to edge trigger, doesn't work properly.
* WORKAROUND: change it to level trigger, and toggle the polarity
* at ACK/Handler to make the HW work.
*/
#define GPIO_INT0_HWIRQ 120
#define GPIO_INT7_HWIRQ 127
#define IS_GPIO_INT(irq) \
({ \
u32 i = irq; \
(i >= GPIO_INT0_HWIRQ) && (i <= GPIO_INT7_HWIRQ); \
})
/* index of states */
enum {
_IS_EDGE = 0,
_IS_LOW,
_IS_ACTIVE
};
#define STATE_BIT(irq, idx) (((irq) - GPIO_INT0_HWIRQ) * 3 + (idx))
#define ASSIGN_STATE(irq, idx, v) assign_bit(STATE_BIT(irq, idx), sp_intc.states, v)
#define TEST_STATE(irq, idx) test_bit(STATE_BIT(irq, idx), sp_intc.states)
static struct sp_intctl {
/*
* REG_GROUP_0: include type/polarity/priority/mask regs.
* REG_GROUP_1: include clear/masked_ext0/masked_ext1/group regs.
*/
void __iomem *g0; // REG_GROUP_0 base
void __iomem *g1; // REG_GROUP_1 base
struct irq_domain *domain;
raw_spinlock_t lock;
/*
* store GPIO_INT states
* each interrupt has 3 states: is_edge, is_low, is_active
*/
DECLARE_BITMAP(states, (GPIO_INT7_HWIRQ - GPIO_INT0_HWIRQ + 1) * 3);
} sp_intc;
static struct irq_chip sp_intc_chip;
static void sp_intc_assign_bit(u32 hwirq, void __iomem *base, bool value)
{
u32 offset, mask;
unsigned long flags;
void __iomem *reg;
offset = (hwirq / 32) * 4;
reg = base + offset;
raw_spin_lock_irqsave(&sp_intc.lock, flags);
mask = readl_relaxed(reg);
if (value)
mask |= BIT(hwirq % 32);
else
mask &= ~BIT(hwirq % 32);
writel_relaxed(mask, reg);
raw_spin_unlock_irqrestore(&sp_intc.lock, flags);
}
static void sp_intc_ack_irq(struct irq_data *d)
{
u32 hwirq = d->hwirq;
if (unlikely(IS_GPIO_INT(hwirq) && TEST_STATE(hwirq, _IS_EDGE))) { // WORKAROUND
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, !TEST_STATE(hwirq, _IS_LOW));
ASSIGN_STATE(hwirq, _IS_ACTIVE, true);
}
sp_intc_assign_bit(hwirq, REG_INTR_CLEAR, 1);
}
static void sp_intc_mask_irq(struct irq_data *d)
{
sp_intc_assign_bit(d->hwirq, REG_INTR_MASK, 0);
}
static void sp_intc_unmask_irq(struct irq_data *d)
{
sp_intc_assign_bit(d->hwirq, REG_INTR_MASK, 1);
}
static int sp_intc_set_type(struct irq_data *d, unsigned int type)
{
u32 hwirq = d->hwirq;
bool is_edge = !(type & IRQ_TYPE_LEVEL_MASK);
bool is_low = (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING);
irq_set_handler_locked(d, is_edge ? handle_edge_irq : handle_level_irq);
if (unlikely(IS_GPIO_INT(hwirq) && is_edge)) { // WORKAROUND
/* store states */
ASSIGN_STATE(hwirq, _IS_EDGE, is_edge);
ASSIGN_STATE(hwirq, _IS_LOW, is_low);
ASSIGN_STATE(hwirq, _IS_ACTIVE, false);
/* change to level */
is_edge = false;
}
sp_intc_assign_bit(hwirq, REG_INTR_TYPE, is_edge);
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, is_low);
return 0;
}
static int sp_intc_get_ext_irq(int ext_num)
{
void __iomem *base = ext_num ? REG_MASKED_EXT1 : REG_MASKED_EXT0;
u32 shift = ext_num ? GROUP_SHIFT_EXT1 : GROUP_SHIFT_EXT0;
u32 groups;
u32 pending_group;
u32 group;
u32 pending_irq;
groups = readl_relaxed(REG_INTR_GROUP);
pending_group = (groups >> shift) & GROUP_MASK;
if (!pending_group)
return -1;
group = fls(pending_group) - 1;
pending_irq = readl_relaxed(base + group * 4);
if (!pending_irq)
return -1;
return (group * 32) + fls(pending_irq) - 1;
}
static void sp_intc_handle_ext_cascaded(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
int ext_num = (uintptr_t)irq_desc_get_handler_data(desc);
int hwirq;
chained_irq_enter(chip, desc);
while ((hwirq = sp_intc_get_ext_irq(ext_num)) >= 0) {
if (unlikely(IS_GPIO_INT(hwirq) && TEST_STATE(hwirq, _IS_ACTIVE))) { // WORKAROUND
ASSIGN_STATE(hwirq, _IS_ACTIVE, false);
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, TEST_STATE(hwirq, _IS_LOW));
} else {
generic_handle_domain_irq(sp_intc.domain, hwirq);
}
}
chained_irq_exit(chip, desc);
}
static struct irq_chip sp_intc_chip = {
.name = "sp_intc",
.irq_ack = sp_intc_ack_irq,
.irq_mask = sp_intc_mask_irq,
.irq_unmask = sp_intc_unmask_irq,
.irq_set_type = sp_intc_set_type,
};
static int sp_intc_irq_domain_map(struct irq_domain *domain,
unsigned int irq, irq_hw_number_t hwirq)
{
irq_set_chip_and_handler(irq, &sp_intc_chip, handle_level_irq);
irq_set_chip_data(irq, &sp_intc_chip);
irq_set_noprobe(irq);
return 0;
}
static const struct irq_domain_ops sp_intc_dm_ops = {
.xlate = irq_domain_xlate_twocell,
.map = sp_intc_irq_domain_map,
};
static int sp_intc_irq_map(struct device_node *node, int i)
{
unsigned int irq;
irq = irq_of_parse_and_map(node, i);
if (!irq)
return -ENOENT;
irq_set_chained_handler_and_data(irq, sp_intc_handle_ext_cascaded, (void *)(uintptr_t)i);
return 0;
}
static int __init sp_intc_init_dt(struct device_node *node, struct device_node *parent)
{
int i, ret;
sp_intc.g0 = of_iomap(node, 0);
if (!sp_intc.g0)
return -ENXIO;
sp_intc.g1 = of_iomap(node, 1);
if (!sp_intc.g1) {
ret = -ENXIO;
goto out_unmap0;
}
ret = sp_intc_irq_map(node, 0); // EXT_INT0
if (ret)
goto out_unmap1;
ret = sp_intc_irq_map(node, 1); // EXT_INT1
if (ret)
goto out_unmap1;
/* initial regs */
for (i = 0; i < SP_INTC_NR_GROUPS; i++) {
/* all mask */
writel_relaxed(0, REG_INTR_MASK + i * 4);
/* all edge */
writel_relaxed(~0, REG_INTR_TYPE + i * 4);
/* all high-active */
writel_relaxed(0, REG_INTR_POLARITY + i * 4);
/* all EXT_INT0 */
writel_relaxed(~0, REG_INTR_PRIORITY + i * 4);
/* all clear */
writel_relaxed(~0, REG_INTR_CLEAR + i * 4);
}
sp_intc.domain = irq_domain_add_linear(node, SP_INTC_NR_IRQS,
&sp_intc_dm_ops, &sp_intc);
if (!sp_intc.domain) {
ret = -ENOMEM;
goto out_unmap1;
}
raw_spin_lock_init(&sp_intc.lock);
return 0;
out_unmap1:
iounmap(sp_intc.g1);
out_unmap0:
iounmap(sp_intc.g0);
return ret;
}
IRQCHIP_DECLARE(sp_intc, "sunplus,sp7021-intc", sp_intc_init_dt);