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 #include <linux/seq_file.h>
22
23 #define PIC_CAUSE 0x0
24 #define PIC_MASK 0x4
25
26 #define PIC_MAX_IRQS 32
27 #define PIC_MAX_IRQ_MASK ((1UL << PIC_MAX_IRQS) - 1)
28
29 struct mvebu_pic {
30 void __iomem *base;
31 u32 parent_irq;
32 struct irq_domain *domain;
33 struct platform_device *pdev;
34 };
35
mvebu_pic_reset(struct mvebu_pic * pic)36 static void mvebu_pic_reset(struct mvebu_pic *pic)
37 {
38 /* ACK and mask all interrupts */
39 writel(0, pic->base + PIC_MASK);
40 writel(PIC_MAX_IRQ_MASK, pic->base + PIC_CAUSE);
41 }
42
mvebu_pic_eoi_irq(struct irq_data * d)43 static void mvebu_pic_eoi_irq(struct irq_data *d)
44 {
45 struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
46
47 writel(1 << d->hwirq, pic->base + PIC_CAUSE);
48 }
49
mvebu_pic_mask_irq(struct irq_data * d)50 static void mvebu_pic_mask_irq(struct irq_data *d)
51 {
52 struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
53 u32 reg;
54
55 reg = readl(pic->base + PIC_MASK);
56 reg |= (1 << d->hwirq);
57 writel(reg, pic->base + PIC_MASK);
58 }
59
mvebu_pic_unmask_irq(struct irq_data * d)60 static void mvebu_pic_unmask_irq(struct irq_data *d)
61 {
62 struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
63 u32 reg;
64
65 reg = readl(pic->base + PIC_MASK);
66 reg &= ~(1 << d->hwirq);
67 writel(reg, pic->base + PIC_MASK);
68 }
69
mvebu_pic_print_chip(struct irq_data * d,struct seq_file * p)70 static void mvebu_pic_print_chip(struct irq_data *d, struct seq_file *p)
71 {
72 struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
73
74 seq_printf(p, dev_name(&pic->pdev->dev));
75 }
76
77 static const struct irq_chip mvebu_pic_chip = {
78 .irq_mask = mvebu_pic_mask_irq,
79 .irq_unmask = mvebu_pic_unmask_irq,
80 .irq_eoi = mvebu_pic_eoi_irq,
81 .irq_print_chip = mvebu_pic_print_chip,
82 };
83
mvebu_pic_irq_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)84 static int mvebu_pic_irq_map(struct irq_domain *domain, unsigned int virq,
85 irq_hw_number_t hwirq)
86 {
87 struct mvebu_pic *pic = domain->host_data;
88
89 irq_set_percpu_devid(virq);
90 irq_set_chip_data(virq, pic);
91 irq_set_chip_and_handler(virq, &mvebu_pic_chip, handle_percpu_devid_irq);
92 irq_set_status_flags(virq, IRQ_LEVEL);
93 irq_set_probe(virq);
94
95 return 0;
96 }
97
98 static const struct irq_domain_ops mvebu_pic_domain_ops = {
99 .map = mvebu_pic_irq_map,
100 .xlate = irq_domain_xlate_onecell,
101 };
102
mvebu_pic_handle_cascade_irq(struct irq_desc * desc)103 static void mvebu_pic_handle_cascade_irq(struct irq_desc *desc)
104 {
105 struct mvebu_pic *pic = irq_desc_get_handler_data(desc);
106 struct irq_chip *chip = irq_desc_get_chip(desc);
107 unsigned long irqmap, irqn;
108
109 irqmap = readl_relaxed(pic->base + PIC_CAUSE);
110 chained_irq_enter(chip, desc);
111
112 for_each_set_bit(irqn, &irqmap, BITS_PER_LONG)
113 generic_handle_domain_irq(pic->domain, irqn);
114
115 chained_irq_exit(chip, desc);
116 }
117
mvebu_pic_enable_percpu_irq(void * data)118 static void mvebu_pic_enable_percpu_irq(void *data)
119 {
120 struct mvebu_pic *pic = data;
121
122 mvebu_pic_reset(pic);
123 enable_percpu_irq(pic->parent_irq, IRQ_TYPE_NONE);
124 }
125
mvebu_pic_disable_percpu_irq(void * data)126 static void mvebu_pic_disable_percpu_irq(void *data)
127 {
128 struct mvebu_pic *pic = data;
129
130 disable_percpu_irq(pic->parent_irq);
131 }
132
mvebu_pic_probe(struct platform_device * pdev)133 static int mvebu_pic_probe(struct platform_device *pdev)
134 {
135 struct device_node *node = pdev->dev.of_node;
136 struct mvebu_pic *pic;
137
138 pic = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pic), GFP_KERNEL);
139 if (!pic)
140 return -ENOMEM;
141
142 pic->pdev = pdev;
143 pic->base = devm_platform_ioremap_resource(pdev, 0);
144 if (IS_ERR(pic->base))
145 return PTR_ERR(pic->base);
146
147 pic->parent_irq = irq_of_parse_and_map(node, 0);
148 if (pic->parent_irq <= 0) {
149 dev_err(&pdev->dev, "Failed to parse parent interrupt\n");
150 return -EINVAL;
151 }
152
153 pic->domain = irq_domain_add_linear(node, PIC_MAX_IRQS,
154 &mvebu_pic_domain_ops, pic);
155 if (!pic->domain) {
156 dev_err(&pdev->dev, "Failed to allocate irq domain\n");
157 return -ENOMEM;
158 }
159
160 irq_set_chained_handler(pic->parent_irq, mvebu_pic_handle_cascade_irq);
161 irq_set_handler_data(pic->parent_irq, pic);
162
163 on_each_cpu(mvebu_pic_enable_percpu_irq, pic, 1);
164
165 platform_set_drvdata(pdev, pic);
166
167 return 0;
168 }
169
mvebu_pic_remove(struct platform_device * pdev)170 static int mvebu_pic_remove(struct platform_device *pdev)
171 {
172 struct mvebu_pic *pic = platform_get_drvdata(pdev);
173
174 on_each_cpu(mvebu_pic_disable_percpu_irq, pic, 1);
175 irq_domain_remove(pic->domain);
176
177 return 0;
178 }
179
180 static const struct of_device_id mvebu_pic_of_match[] = {
181 { .compatible = "marvell,armada-8k-pic", },
182 {},
183 };
184 MODULE_DEVICE_TABLE(of, mvebu_pic_of_match);
185
186 static struct platform_driver mvebu_pic_driver = {
187 .probe = mvebu_pic_probe,
188 .remove = mvebu_pic_remove,
189 .driver = {
190 .name = "mvebu-pic",
191 .of_match_table = mvebu_pic_of_match,
192 },
193 };
194 module_platform_driver(mvebu_pic_driver);
195
196 MODULE_AUTHOR("Yehuda Yitschak <yehuday@marvell.com>");
197 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
198 MODULE_LICENSE("GPL v2");
199 MODULE_ALIAS("platform:mvebu_pic");
200
201