1 /*
2  * Copyright (c) 2014 MediaTek Inc.
3  * Author: Joe.C <yingjoe.chen@mediatek.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/irq.h>
16 #include <linux/irqchip.h>
17 #include <linux/irqdomain.h>
18 #include <linux/of.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_address.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 
25 struct mtk_sysirq_chip_data {
26 	spinlock_t lock;
27 	void __iomem *intpol_base;
28 };
29 
30 static int mtk_sysirq_set_type(struct irq_data *data, unsigned int type)
31 {
32 	irq_hw_number_t hwirq = data->hwirq;
33 	struct mtk_sysirq_chip_data *chip_data = data->chip_data;
34 	u32 offset, reg_index, value;
35 	unsigned long flags;
36 	int ret;
37 
38 	offset = hwirq & 0x1f;
39 	reg_index = hwirq >> 5;
40 
41 	spin_lock_irqsave(&chip_data->lock, flags);
42 	value = readl_relaxed(chip_data->intpol_base + reg_index * 4);
43 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING) {
44 		if (type == IRQ_TYPE_LEVEL_LOW)
45 			type = IRQ_TYPE_LEVEL_HIGH;
46 		else
47 			type = IRQ_TYPE_EDGE_RISING;
48 		value |= (1 << offset);
49 	} else {
50 		value &= ~(1 << offset);
51 	}
52 	writel(value, chip_data->intpol_base + reg_index * 4);
53 
54 	data = data->parent_data;
55 	ret = data->chip->irq_set_type(data, type);
56 	spin_unlock_irqrestore(&chip_data->lock, flags);
57 	return ret;
58 }
59 
60 static struct irq_chip mtk_sysirq_chip = {
61 	.name			= "MT_SYSIRQ",
62 	.irq_mask		= irq_chip_mask_parent,
63 	.irq_unmask		= irq_chip_unmask_parent,
64 	.irq_eoi		= irq_chip_eoi_parent,
65 	.irq_set_type		= mtk_sysirq_set_type,
66 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
67 	.irq_set_affinity	= irq_chip_set_affinity_parent,
68 };
69 
70 static int mtk_sysirq_domain_xlate(struct irq_domain *d,
71 				   struct device_node *controller,
72 				   const u32 *intspec, unsigned int intsize,
73 				   unsigned long *out_hwirq,
74 				   unsigned int *out_type)
75 {
76 	if (intsize != 3)
77 		return -EINVAL;
78 
79 	/* sysirq doesn't support PPI */
80 	if (intspec[0])
81 		return -EINVAL;
82 
83 	*out_hwirq = intspec[1];
84 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
85 	return 0;
86 }
87 
88 static int mtk_sysirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
89 				   unsigned int nr_irqs, void *arg)
90 {
91 	int i;
92 	irq_hw_number_t hwirq;
93 	struct of_phandle_args *irq_data = arg;
94 	struct of_phandle_args gic_data = *irq_data;
95 
96 	if (irq_data->args_count != 3)
97 		return -EINVAL;
98 
99 	/* sysirq doesn't support PPI */
100 	if (irq_data->args[0])
101 		return -EINVAL;
102 
103 	hwirq = irq_data->args[1];
104 	for (i = 0; i < nr_irqs; i++)
105 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
106 					      &mtk_sysirq_chip,
107 					      domain->host_data);
108 
109 	gic_data.np = domain->parent->of_node;
110 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &gic_data);
111 }
112 
113 static const struct irq_domain_ops sysirq_domain_ops = {
114 	.xlate = mtk_sysirq_domain_xlate,
115 	.alloc = mtk_sysirq_domain_alloc,
116 	.free = irq_domain_free_irqs_common,
117 };
118 
119 static int __init mtk_sysirq_of_init(struct device_node *node,
120 				     struct device_node *parent)
121 {
122 	struct irq_domain *domain, *domain_parent;
123 	struct mtk_sysirq_chip_data *chip_data;
124 	int ret, size, intpol_num;
125 	struct resource res;
126 
127 	domain_parent = irq_find_host(parent);
128 	if (!domain_parent) {
129 		pr_err("mtk_sysirq: interrupt-parent not found\n");
130 		return -EINVAL;
131 	}
132 
133 	ret = of_address_to_resource(node, 0, &res);
134 	if (ret)
135 		return ret;
136 
137 	chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
138 	if (!chip_data)
139 		return -ENOMEM;
140 
141 	size = resource_size(&res);
142 	intpol_num = size * 8;
143 	chip_data->intpol_base = ioremap(res.start, size);
144 	if (!chip_data->intpol_base) {
145 		pr_err("mtk_sysirq: unable to map sysirq register\n");
146 		ret = -ENXIO;
147 		goto out_free;
148 	}
149 
150 	domain = irq_domain_add_hierarchy(domain_parent, 0, intpol_num, node,
151 					  &sysirq_domain_ops, chip_data);
152 	if (!domain) {
153 		ret = -ENOMEM;
154 		goto out_unmap;
155 	}
156 	spin_lock_init(&chip_data->lock);
157 
158 	return 0;
159 
160 out_unmap:
161 	iounmap(chip_data->intpol_base);
162 out_free:
163 	kfree(chip_data);
164 	return ret;
165 }
166 IRQCHIP_DECLARE(mtk_sysirq, "mediatek,mt6577-sysirq", mtk_sysirq_of_init);
167