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 	unsigned int cascade_irq;
95 
96 	irqmap = readl_relaxed(pic->base + PIC_CAUSE);
97 	chained_irq_enter(chip, desc);
98 
99 	for_each_set_bit(irqn, &irqmap, BITS_PER_LONG) {
100 		cascade_irq = irq_find_mapping(pic->domain, irqn);
101 		generic_handle_irq(cascade_irq);
102 	}
103 
104 	chained_irq_exit(chip, desc);
105 }
106 
107 static void mvebu_pic_enable_percpu_irq(void *data)
108 {
109 	struct mvebu_pic *pic = data;
110 
111 	mvebu_pic_reset(pic);
112 	enable_percpu_irq(pic->parent_irq, IRQ_TYPE_NONE);
113 }
114 
115 static void mvebu_pic_disable_percpu_irq(void *data)
116 {
117 	struct mvebu_pic *pic = data;
118 
119 	disable_percpu_irq(pic->parent_irq);
120 }
121 
122 static int mvebu_pic_probe(struct platform_device *pdev)
123 {
124 	struct device_node *node = pdev->dev.of_node;
125 	struct mvebu_pic *pic;
126 	struct irq_chip *irq_chip;
127 	struct resource *res;
128 
129 	pic = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pic), GFP_KERNEL);
130 	if (!pic)
131 		return -ENOMEM;
132 
133 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
134 	pic->base = devm_ioremap_resource(&pdev->dev, res);
135 	if (IS_ERR(pic->base))
136 		return PTR_ERR(pic->base);
137 
138 	irq_chip = &pic->irq_chip;
139 	irq_chip->name = dev_name(&pdev->dev);
140 	irq_chip->irq_mask = mvebu_pic_mask_irq;
141 	irq_chip->irq_unmask = mvebu_pic_unmask_irq;
142 	irq_chip->irq_eoi = mvebu_pic_eoi_irq;
143 
144 	pic->parent_irq = irq_of_parse_and_map(node, 0);
145 	if (pic->parent_irq <= 0) {
146 		dev_err(&pdev->dev, "Failed to parse parent interrupt\n");
147 		return -EINVAL;
148 	}
149 
150 	pic->domain = irq_domain_add_linear(node, PIC_MAX_IRQS,
151 					    &mvebu_pic_domain_ops, pic);
152 	if (!pic->domain) {
153 		dev_err(&pdev->dev, "Failed to allocate irq domain\n");
154 		return -ENOMEM;
155 	}
156 
157 	irq_set_chained_handler(pic->parent_irq, mvebu_pic_handle_cascade_irq);
158 	irq_set_handler_data(pic->parent_irq, pic);
159 
160 	on_each_cpu(mvebu_pic_enable_percpu_irq, pic, 1);
161 
162 	platform_set_drvdata(pdev, pic);
163 
164 	return 0;
165 }
166 
167 static int mvebu_pic_remove(struct platform_device *pdev)
168 {
169 	struct mvebu_pic *pic = platform_get_drvdata(pdev);
170 
171 	on_each_cpu(mvebu_pic_disable_percpu_irq, pic, 1);
172 	irq_domain_remove(pic->domain);
173 
174 	return 0;
175 }
176 
177 static const struct of_device_id mvebu_pic_of_match[] = {
178 	{ .compatible = "marvell,armada-8k-pic", },
179 	{},
180 };
181 MODULE_DEVICE_TABLE(of, mvebu_pic_of_match);
182 
183 static struct platform_driver mvebu_pic_driver = {
184 	.probe  = mvebu_pic_probe,
185 	.remove = mvebu_pic_remove,
186 	.driver = {
187 		.name = "mvebu-pic",
188 		.of_match_table = mvebu_pic_of_match,
189 	},
190 };
191 module_platform_driver(mvebu_pic_driver);
192 
193 MODULE_AUTHOR("Yehuda Yitschak <yehuday@marvell.com>");
194 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
195 MODULE_LICENSE("GPL v2");
196 MODULE_ALIAS("platform:mvebu_pic");
197 
198