bus: ti-sysc: Fix watchdog quirk handling
[linux-2.6-microblaze.git] / drivers / irqchip / irq-ts4800.c
1 /*
2  * Multiplexed-IRQs driver for TS-4800's FPGA
3  *
4  * Copyright (c) 2015 - Savoir-faire Linux
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2. This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/platform_device.h>
22
23 #define IRQ_MASK        0x4
24 #define IRQ_STATUS      0x8
25
26 struct ts4800_irq_data {
27         void __iomem            *base;
28         struct irq_domain       *domain;
29         struct irq_chip         irq_chip;
30 };
31
32 static void ts4800_irq_mask(struct irq_data *d)
33 {
34         struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
35         u16 reg = readw(data->base + IRQ_MASK);
36         u16 mask = 1 << d->hwirq;
37
38         writew(reg | mask, data->base + IRQ_MASK);
39 }
40
41 static void ts4800_irq_unmask(struct irq_data *d)
42 {
43         struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
44         u16 reg = readw(data->base + IRQ_MASK);
45         u16 mask = 1 << d->hwirq;
46
47         writew(reg & ~mask, data->base + IRQ_MASK);
48 }
49
50 static int ts4800_irqdomain_map(struct irq_domain *d, unsigned int irq,
51                                 irq_hw_number_t hwirq)
52 {
53         struct ts4800_irq_data *data = d->host_data;
54
55         irq_set_chip_and_handler(irq, &data->irq_chip, handle_simple_irq);
56         irq_set_chip_data(irq, data);
57         irq_set_noprobe(irq);
58
59         return 0;
60 }
61
62 static const struct irq_domain_ops ts4800_ic_ops = {
63         .map = ts4800_irqdomain_map,
64         .xlate = irq_domain_xlate_onecell,
65 };
66
67 static void ts4800_ic_chained_handle_irq(struct irq_desc *desc)
68 {
69         struct ts4800_irq_data *data = irq_desc_get_handler_data(desc);
70         struct irq_chip *chip = irq_desc_get_chip(desc);
71         u16 status = readw(data->base + IRQ_STATUS);
72
73         chained_irq_enter(chip, desc);
74
75         if (unlikely(status == 0)) {
76                 handle_bad_irq(desc);
77                 goto out;
78         }
79
80         do {
81                 unsigned int bit = __ffs(status);
82                 int irq = irq_find_mapping(data->domain, bit);
83
84                 status &= ~(1 << bit);
85                 generic_handle_irq(irq);
86         } while (status);
87
88 out:
89         chained_irq_exit(chip, desc);
90 }
91
92 static int ts4800_ic_probe(struct platform_device *pdev)
93 {
94         struct device_node *node = pdev->dev.of_node;
95         struct ts4800_irq_data *data;
96         struct irq_chip *irq_chip;
97         struct resource *res;
98         int parent_irq;
99
100         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
101         if (!data)
102                 return -ENOMEM;
103
104         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
105         data->base = devm_ioremap_resource(&pdev->dev, res);
106         if (IS_ERR(data->base))
107                 return PTR_ERR(data->base);
108
109         writew(0xFFFF, data->base + IRQ_MASK);
110
111         parent_irq = irq_of_parse_and_map(node, 0);
112         if (!parent_irq) {
113                 dev_err(&pdev->dev, "failed to get parent IRQ\n");
114                 return -EINVAL;
115         }
116
117         irq_chip = &data->irq_chip;
118         irq_chip->name = dev_name(&pdev->dev);
119         irq_chip->irq_mask = ts4800_irq_mask;
120         irq_chip->irq_unmask = ts4800_irq_unmask;
121
122         data->domain = irq_domain_add_linear(node, 8, &ts4800_ic_ops, data);
123         if (!data->domain) {
124                 dev_err(&pdev->dev, "cannot add IRQ domain\n");
125                 return -ENOMEM;
126         }
127
128         irq_set_chained_handler_and_data(parent_irq,
129                                          ts4800_ic_chained_handle_irq, data);
130
131         platform_set_drvdata(pdev, data);
132
133         return 0;
134 }
135
136 static int ts4800_ic_remove(struct platform_device *pdev)
137 {
138         struct ts4800_irq_data *data = platform_get_drvdata(pdev);
139
140         irq_domain_remove(data->domain);
141
142         return 0;
143 }
144
145 static const struct of_device_id ts4800_ic_of_match[] = {
146         { .compatible = "technologic,ts4800-irqc", },
147         {},
148 };
149 MODULE_DEVICE_TABLE(of, ts4800_ic_of_match);
150
151 static struct platform_driver ts4800_ic_driver = {
152         .probe  = ts4800_ic_probe,
153         .remove = ts4800_ic_remove,
154         .driver = {
155                 .name = "ts4800-irqc",
156                 .of_match_table = ts4800_ic_of_match,
157         },
158 };
159 module_platform_driver(ts4800_ic_driver);
160
161 MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
162 MODULE_LICENSE("GPL v2");
163 MODULE_ALIAS("platform:ts4800_irqc");