1 /*
2  * Copyright (C) 2016 Marvell
3  *
4  * Yehuda Yitschak <yehuday@marvell.com>
5  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
6  *
7  * This file is licensed under the terms of the GNU General Public
8  * License version 2.  This program is licensed "as is" without any
9  * warranty of any kind, whether express or implied.
10  */
11 
12 #include <linux/interrupt.h>
13 #include <linux/io.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/module.h>
19 #include <linux/of_irq.h>
20 #include <linux/platform_device.h>
21 
22 #define PIC_CAUSE	       0x0
23 #define PIC_MASK	       0x4
24 
25 #define PIC_MAX_IRQS		32
26 #define PIC_MAX_IRQ_MASK	((1UL << PIC_MAX_IRQS) - 1)
27 
28 struct mvebu_pic {
29 	void __iomem *base;
30 	u32 parent_irq;
31 	struct irq_domain *domain;
32 	struct irq_chip irq_chip;
33 };
34 
35 static void mvebu_pic_reset(struct mvebu_pic *pic)
36 {
37 	/* ACK and mask all interrupts */
38 	writel(0, pic->base + PIC_MASK);
39 	writel(PIC_MAX_IRQ_MASK, pic->base + PIC_CAUSE);
40 }
41 
42 static void mvebu_pic_eoi_irq(struct irq_data *d)
43 {
44 	struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
45 
46 	writel(1 << d->hwirq, pic->base + PIC_CAUSE);
47 }
48 
49 static void mvebu_pic_mask_irq(struct irq_data *d)
50 {
51 	struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
52 	u32 reg;
53 
54 	reg =  readl(pic->base + PIC_MASK);
55 	reg |= (1 << d->hwirq);
56 	writel(reg, pic->base + PIC_MASK);
57 }
58 
59 static void mvebu_pic_unmask_irq(struct irq_data *d)
60 {
61 	struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
62 	u32 reg;
63 
64 	reg = readl(pic->base + PIC_MASK);
65 	reg &= ~(1 << d->hwirq);
66 	writel(reg, pic->base + PIC_MASK);
67 }
68 
69 static int mvebu_pic_irq_map(struct irq_domain *domain, unsigned int virq,
70 			     irq_hw_number_t hwirq)
71 {
72 	struct mvebu_pic *pic = domain->host_data;
73 
74 	irq_set_percpu_devid(virq);
75 	irq_set_chip_data(virq, pic);
76 	irq_set_chip_and_handler(virq, &pic->irq_chip,
77 				 handle_percpu_devid_irq);
78 	irq_set_status_flags(virq, IRQ_LEVEL);
79 	irq_set_probe(virq);
80 
81 	return 0;
82 }
83 
84 static const struct irq_domain_ops mvebu_pic_domain_ops = {
85 	.map = mvebu_pic_irq_map,
86 	.xlate = irq_domain_xlate_onecell,
87 };
88 
89 static void mvebu_pic_handle_cascade_irq(struct irq_desc *desc)
90 {
91 	struct mvebu_pic *pic = irq_desc_get_handler_data(desc);
92 	struct irq_chip *chip = irq_desc_get_chip(desc);
93 	unsigned long irqmap, irqn;
94 
95 	irqmap = readl_relaxed(pic->base + PIC_CAUSE);
96 	chained_irq_enter(chip, desc);
97 
98 	for_each_set_bit(irqn, &irqmap, BITS_PER_LONG)
99 		generic_handle_domain_irq(pic->domain, irqn);
100 
101 	chained_irq_exit(chip, desc);
102 }
103 
104 static void mvebu_pic_enable_percpu_irq(void *data)
105 {
106 	struct mvebu_pic *pic = data;
107 
108 	mvebu_pic_reset(pic);
109 	enable_percpu_irq(pic->parent_irq, IRQ_TYPE_NONE);
110 }
111 
112 static void mvebu_pic_disable_percpu_irq(void *data)
113 {
114 	struct mvebu_pic *pic = data;
115 
116 	disable_percpu_irq(pic->parent_irq);
117 }
118 
119 static int mvebu_pic_probe(struct platform_device *pdev)
120 {
121 	struct device_node *node = pdev->dev.of_node;
122 	struct mvebu_pic *pic;
123 	struct irq_chip *irq_chip;
124 
125 	pic = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pic), GFP_KERNEL);
126 	if (!pic)
127 		return -ENOMEM;
128 
129 	pic->base = devm_platform_ioremap_resource(pdev, 0);
130 	if (IS_ERR(pic->base))
131 		return PTR_ERR(pic->base);
132 
133 	irq_chip = &pic->irq_chip;
134 	irq_chip->name = dev_name(&pdev->dev);
135 	irq_chip->irq_mask = mvebu_pic_mask_irq;
136 	irq_chip->irq_unmask = mvebu_pic_unmask_irq;
137 	irq_chip->irq_eoi = mvebu_pic_eoi_irq;
138 
139 	pic->parent_irq = irq_of_parse_and_map(node, 0);
140 	if (pic->parent_irq <= 0) {
141 		dev_err(&pdev->dev, "Failed to parse parent interrupt\n");
142 		return -EINVAL;
143 	}
144 
145 	pic->domain = irq_domain_add_linear(node, PIC_MAX_IRQS,
146 					    &mvebu_pic_domain_ops, pic);
147 	if (!pic->domain) {
148 		dev_err(&pdev->dev, "Failed to allocate irq domain\n");
149 		return -ENOMEM;
150 	}
151 
152 	irq_set_chained_handler(pic->parent_irq, mvebu_pic_handle_cascade_irq);
153 	irq_set_handler_data(pic->parent_irq, pic);
154 
155 	on_each_cpu(mvebu_pic_enable_percpu_irq, pic, 1);
156 
157 	platform_set_drvdata(pdev, pic);
158 
159 	return 0;
160 }
161 
162 static int mvebu_pic_remove(struct platform_device *pdev)
163 {
164 	struct mvebu_pic *pic = platform_get_drvdata(pdev);
165 
166 	on_each_cpu(mvebu_pic_disable_percpu_irq, pic, 1);
167 	irq_domain_remove(pic->domain);
168 
169 	return 0;
170 }
171 
172 static const struct of_device_id mvebu_pic_of_match[] = {
173 	{ .compatible = "marvell,armada-8k-pic", },
174 	{},
175 };
176 MODULE_DEVICE_TABLE(of, mvebu_pic_of_match);
177 
178 static struct platform_driver mvebu_pic_driver = {
179 	.probe  = mvebu_pic_probe,
180 	.remove = mvebu_pic_remove,
181 	.driver = {
182 		.name = "mvebu-pic",
183 		.of_match_table = mvebu_pic_of_match,
184 	},
185 };
186 module_platform_driver(mvebu_pic_driver);
187 
188 MODULE_AUTHOR("Yehuda Yitschak <yehuday@marvell.com>");
189 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
190 MODULE_LICENSE("GPL v2");
191 MODULE_ALIAS("platform:mvebu_pic");
192 
193