1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  Aspeed Interrupt Controller.
  4 *
  5 *  Copyright (C) 2023 ASPEED Technology Inc.
  6 */
  7
  8#include <linux/bitops.h>
  9#include <linux/irq.h>
 10#include <linux/irqchip.h>
 11#include <linux/irqchip/chained_irq.h>
 12#include <linux/irqdomain.h>
 13#include <linux/of_address.h>
 14#include <linux/of_irq.h>
 15#include <linux/io.h>
 16#include <linux/spinlock.h>
 17
 18#define INTC_INT_ENABLE_REG	0x00
 19#define INTC_INT_STATUS_REG	0x04
 20#define INTC_IRQS_PER_WORD	32
 21
 22struct aspeed_intc_ic {
 23	void __iomem		*base;
 24	raw_spinlock_t		gic_lock;
 25	raw_spinlock_t		intc_lock;
 26	struct irq_domain	*irq_domain;
 27};
 28
 29static void aspeed_intc_ic_irq_handler(struct irq_desc *desc)
 30{
 31	struct aspeed_intc_ic *intc_ic = irq_desc_get_handler_data(desc);
 32	struct irq_chip *chip = irq_desc_get_chip(desc);
 33
 34	chained_irq_enter(chip, desc);
 35
 36	scoped_guard(raw_spinlock, &intc_ic->gic_lock) {
 37		unsigned long bit, status;
 38
 39		status = readl(intc_ic->base + INTC_INT_STATUS_REG);
 40		for_each_set_bit(bit, &status, INTC_IRQS_PER_WORD) {
 41			generic_handle_domain_irq(intc_ic->irq_domain, bit);
 42			writel(BIT(bit), intc_ic->base + INTC_INT_STATUS_REG);
 43		}
 44	}
 45
 46	chained_irq_exit(chip, desc);
 47}
 48
 49static void aspeed_intc_irq_mask(struct irq_data *data)
 50{
 51	struct aspeed_intc_ic *intc_ic = irq_data_get_irq_chip_data(data);
 52	unsigned int mask = readl(intc_ic->base + INTC_INT_ENABLE_REG) & ~BIT(data->hwirq);
 53
 54	guard(raw_spinlock)(&intc_ic->intc_lock);
 55	writel(mask, intc_ic->base + INTC_INT_ENABLE_REG);
 56}
 57
 58static void aspeed_intc_irq_unmask(struct irq_data *data)
 59{
 60	struct aspeed_intc_ic *intc_ic = irq_data_get_irq_chip_data(data);
 61	unsigned int unmask = readl(intc_ic->base + INTC_INT_ENABLE_REG) | BIT(data->hwirq);
 62
 63	guard(raw_spinlock)(&intc_ic->intc_lock);
 64	writel(unmask, intc_ic->base + INTC_INT_ENABLE_REG);
 65}
 66
 67static struct irq_chip aspeed_intc_chip = {
 68	.name			= "ASPEED INTC",
 69	.irq_mask		= aspeed_intc_irq_mask,
 70	.irq_unmask		= aspeed_intc_irq_unmask,
 71};
 72
 73static int aspeed_intc_ic_map_irq_domain(struct irq_domain *domain, unsigned int irq,
 74					 irq_hw_number_t hwirq)
 75{
 76	irq_set_chip_and_handler(irq, &aspeed_intc_chip, handle_level_irq);
 77	irq_set_chip_data(irq, domain->host_data);
 78
 79	return 0;
 80}
 81
 82static const struct irq_domain_ops aspeed_intc_ic_irq_domain_ops = {
 83	.map = aspeed_intc_ic_map_irq_domain,
 84};
 85
 86static int __init aspeed_intc_ic_of_init(struct device_node *node,
 87					 struct device_node *parent)
 88{
 89	struct aspeed_intc_ic *intc_ic;
 90	int irq, i, ret = 0;
 91
 92	intc_ic = kzalloc(sizeof(*intc_ic), GFP_KERNEL);
 93	if (!intc_ic)
 94		return -ENOMEM;
 95
 96	intc_ic->base = of_iomap(node, 0);
 97	if (!intc_ic->base) {
 98		pr_err("Failed to iomap intc_ic base\n");
 99		ret = -ENOMEM;
100		goto err_free_ic;
101	}
102	writel(0xffffffff, intc_ic->base + INTC_INT_STATUS_REG);
103	writel(0x0, intc_ic->base + INTC_INT_ENABLE_REG);
104
105	intc_ic->irq_domain = irq_domain_add_linear(node, INTC_IRQS_PER_WORD,
106						    &aspeed_intc_ic_irq_domain_ops, intc_ic);
107	if (!intc_ic->irq_domain) {
108		ret = -ENOMEM;
109		goto err_iounmap;
110	}
111
112	raw_spin_lock_init(&intc_ic->gic_lock);
113	raw_spin_lock_init(&intc_ic->intc_lock);
114
115	/* Check all the irq numbers valid. If not, unmaps all the base and frees the data. */
116	for (i = 0; i < of_irq_count(node); i++) {
117		irq = irq_of_parse_and_map(node, i);
118		if (!irq) {
119			pr_err("Failed to get irq number\n");
120			ret = -EINVAL;
121			goto err_iounmap;
122		}
123	}
124
125	for (i = 0; i < of_irq_count(node); i++) {
126		irq = irq_of_parse_and_map(node, i);
127		irq_set_chained_handler_and_data(irq, aspeed_intc_ic_irq_handler, intc_ic);
128	}
129
130	return 0;
131
132err_iounmap:
133	iounmap(intc_ic->base);
134err_free_ic:
135	kfree(intc_ic);
136	return ret;
137}
138
139IRQCHIP_DECLARE(ast2700_intc_ic, "aspeed,ast2700-intc-ic", aspeed_intc_ic_of_init);