xref: /linux/drivers/irqchip/irq-starfive-jh8100-intc.c (revision f5c31bcf604db54470868f3118a60dc4a9ba8813)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * StarFive JH8100 External Interrupt Controller driver
4  *
5  * Copyright (C) 2023 StarFive Technology Co., Ltd.
6  *
7  * Author: Changhuang Liang <changhuang.liang@starfivetech.com>
8  */
9 
10 #define pr_fmt(fmt) "irq-starfive-jh8100: " fmt
11 
12 #include <linux/bitops.h>
13 #include <linux/clk.h>
14 #include <linux/irq.h>
15 #include <linux/irqchip.h>
16 #include <linux/irqchip/chained_irq.h>
17 #include <linux/irqdomain.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/reset.h>
21 #include <linux/spinlock.h>
22 
23 #define STARFIVE_INTC_SRC0_CLEAR	0x10
24 #define STARFIVE_INTC_SRC0_MASK		0x14
25 #define STARFIVE_INTC_SRC0_INT		0x1c
26 
27 #define STARFIVE_INTC_SRC_IRQ_NUM	32
28 
29 struct starfive_irq_chip {
30 	void __iomem		*base;
31 	struct irq_domain	*domain;
32 	raw_spinlock_t		lock;
33 };
34 
35 static void starfive_intc_bit_set(struct starfive_irq_chip *irqc,
36 				  u32 reg, u32 bit_mask)
37 {
38 	u32 value;
39 
40 	value = ioread32(irqc->base + reg);
41 	value |= bit_mask;
42 	iowrite32(value, irqc->base + reg);
43 }
44 
45 static void starfive_intc_bit_clear(struct starfive_irq_chip *irqc,
46 				    u32 reg, u32 bit_mask)
47 {
48 	u32 value;
49 
50 	value = ioread32(irqc->base + reg);
51 	value &= ~bit_mask;
52 	iowrite32(value, irqc->base + reg);
53 }
54 
55 static void starfive_intc_unmask(struct irq_data *d)
56 {
57 	struct starfive_irq_chip *irqc = irq_data_get_irq_chip_data(d);
58 
59 	raw_spin_lock(&irqc->lock);
60 	starfive_intc_bit_clear(irqc, STARFIVE_INTC_SRC0_MASK, BIT(d->hwirq));
61 	raw_spin_unlock(&irqc->lock);
62 }
63 
64 static void starfive_intc_mask(struct irq_data *d)
65 {
66 	struct starfive_irq_chip *irqc = irq_data_get_irq_chip_data(d);
67 
68 	raw_spin_lock(&irqc->lock);
69 	starfive_intc_bit_set(irqc, STARFIVE_INTC_SRC0_MASK, BIT(d->hwirq));
70 	raw_spin_unlock(&irqc->lock);
71 }
72 
73 static struct irq_chip intc_dev = {
74 	.name		= "StarFive JH8100 INTC",
75 	.irq_unmask	= starfive_intc_unmask,
76 	.irq_mask	= starfive_intc_mask,
77 };
78 
79 static int starfive_intc_map(struct irq_domain *d, unsigned int irq,
80 			     irq_hw_number_t hwirq)
81 {
82 	irq_domain_set_info(d, irq, hwirq, &intc_dev, d->host_data,
83 			    handle_level_irq, NULL, NULL);
84 
85 	return 0;
86 }
87 
88 static const struct irq_domain_ops starfive_intc_domain_ops = {
89 	.xlate	= irq_domain_xlate_onecell,
90 	.map	= starfive_intc_map,
91 };
92 
93 static void starfive_intc_irq_handler(struct irq_desc *desc)
94 {
95 	struct starfive_irq_chip *irqc = irq_data_get_irq_handler_data(&desc->irq_data);
96 	struct irq_chip *chip = irq_desc_get_chip(desc);
97 	unsigned long value;
98 	int hwirq;
99 
100 	chained_irq_enter(chip, desc);
101 
102 	value = ioread32(irqc->base + STARFIVE_INTC_SRC0_INT);
103 	while (value) {
104 		hwirq = ffs(value) - 1;
105 
106 		generic_handle_domain_irq(irqc->domain, hwirq);
107 
108 		starfive_intc_bit_set(irqc, STARFIVE_INTC_SRC0_CLEAR, BIT(hwirq));
109 		starfive_intc_bit_clear(irqc, STARFIVE_INTC_SRC0_CLEAR, BIT(hwirq));
110 
111 		__clear_bit(hwirq, &value);
112 	}
113 
114 	chained_irq_exit(chip, desc);
115 }
116 
117 static int __init starfive_intc_init(struct device_node *intc,
118 				     struct device_node *parent)
119 {
120 	struct starfive_irq_chip *irqc;
121 	struct reset_control *rst;
122 	struct clk *clk;
123 	int parent_irq;
124 	int ret;
125 
126 	irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
127 	if (!irqc)
128 		return -ENOMEM;
129 
130 	irqc->base = of_iomap(intc, 0);
131 	if (!irqc->base) {
132 		pr_err("Unable to map registers\n");
133 		ret = -ENXIO;
134 		goto err_free;
135 	}
136 
137 	rst = of_reset_control_get_exclusive(intc, NULL);
138 	if (IS_ERR(rst)) {
139 		pr_err("Unable to get reset control %pe\n", rst);
140 		ret = PTR_ERR(rst);
141 		goto err_unmap;
142 	}
143 
144 	clk = of_clk_get(intc, 0);
145 	if (IS_ERR(clk)) {
146 		pr_err("Unable to get clock %pe\n", clk);
147 		ret = PTR_ERR(clk);
148 		goto err_reset_put;
149 	}
150 
151 	ret = reset_control_deassert(rst);
152 	if (ret)
153 		goto err_clk_put;
154 
155 	ret = clk_prepare_enable(clk);
156 	if (ret)
157 		goto err_reset_assert;
158 
159 	raw_spin_lock_init(&irqc->lock);
160 
161 	irqc->domain = irq_domain_add_linear(intc, STARFIVE_INTC_SRC_IRQ_NUM,
162 					     &starfive_intc_domain_ops, irqc);
163 	if (!irqc->domain) {
164 		pr_err("Unable to create IRQ domain\n");
165 		ret = -EINVAL;
166 		goto err_clk_disable;
167 	}
168 
169 	parent_irq = of_irq_get(intc, 0);
170 	if (parent_irq < 0) {
171 		pr_err("Failed to get main IRQ: %d\n", parent_irq);
172 		ret = parent_irq;
173 		goto err_remove_domain;
174 	}
175 
176 	irq_set_chained_handler_and_data(parent_irq, starfive_intc_irq_handler,
177 					 irqc);
178 
179 	pr_info("Interrupt controller register, nr_irqs %d\n",
180 		STARFIVE_INTC_SRC_IRQ_NUM);
181 
182 	return 0;
183 
184 err_remove_domain:
185 	irq_domain_remove(irqc->domain);
186 err_clk_disable:
187 	clk_disable_unprepare(clk);
188 err_reset_assert:
189 	reset_control_assert(rst);
190 err_clk_put:
191 	clk_put(clk);
192 err_reset_put:
193 	reset_control_put(rst);
194 err_unmap:
195 	iounmap(irqc->base);
196 err_free:
197 	kfree(irqc);
198 	return ret;
199 }
200 
201 IRQCHIP_PLATFORM_DRIVER_BEGIN(starfive_intc)
202 IRQCHIP_MATCH("starfive,jh8100-intc", starfive_intc_init)
203 IRQCHIP_PLATFORM_DRIVER_END(starfive_intc)
204 
205 MODULE_DESCRIPTION("StarFive JH8100 External Interrupt Controller");
206 MODULE_LICENSE("GPL");
207 MODULE_AUTHOR("Changhuang Liang <changhuang.liang@starfivetech.com>");
208