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
mvebu_pic_reset(struct mvebu_pic * pic)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
mvebu_pic_eoi_irq(struct irq_data * d)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
mvebu_pic_mask_irq(struct irq_data * d)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
mvebu_pic_unmask_irq(struct irq_data * d)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
mvebu_pic_irq_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)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
mvebu_pic_handle_cascade_irq(struct irq_desc * desc)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
mvebu_pic_enable_percpu_irq(void * data)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
mvebu_pic_disable_percpu_irq(void * data)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
mvebu_pic_probe(struct platform_device * pdev)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
mvebu_pic_remove(struct platform_device * pdev)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