Commit | Line | Data |
---|---|---|
f48e699d BH |
1 | /* |
2 | * Aspeed 24XX/25XX I2C Interrupt Controller. | |
3 | * | |
4 | * Copyright (C) 2012-2017 ASPEED Technology Inc. | |
5 | * Copyright 2017 IBM Corporation | |
6 | * Copyright 2017 Google, Inc. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
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/of_address.h> | |
18 | #include <linux/of_irq.h> | |
19 | #include <linux/io.h> | |
20 | ||
21 | ||
22 | #define ASPEED_I2C_IC_NUM_BUS 14 | |
23 | ||
24 | struct aspeed_i2c_ic { | |
25 | void __iomem *base; | |
26 | int parent_irq; | |
27 | struct irq_domain *irq_domain; | |
28 | }; | |
29 | ||
30 | /* | |
31 | * The aspeed chip provides a single hardware interrupt for all of the I2C | |
32 | * busses, so we use a dummy interrupt chip to translate this single interrupt | |
33 | * into multiple interrupts, each associated with a single I2C bus. | |
34 | */ | |
35 | static void aspeed_i2c_ic_irq_handler(struct irq_desc *desc) | |
36 | { | |
37 | struct aspeed_i2c_ic *i2c_ic = irq_desc_get_handler_data(desc); | |
38 | struct irq_chip *chip = irq_desc_get_chip(desc); | |
39 | unsigned long bit, status; | |
40 | unsigned int bus_irq; | |
41 | ||
42 | chained_irq_enter(chip, desc); | |
43 | status = readl(i2c_ic->base); | |
44 | for_each_set_bit(bit, &status, ASPEED_I2C_IC_NUM_BUS) { | |
45 | bus_irq = irq_find_mapping(i2c_ic->irq_domain, bit); | |
46 | generic_handle_irq(bus_irq); | |
47 | } | |
48 | chained_irq_exit(chip, desc); | |
49 | } | |
50 | ||
51 | /* | |
52 | * Set simple handler and mark IRQ as valid. Nothing interesting to do here | |
53 | * since we are using a dummy interrupt chip. | |
54 | */ | |
55 | static int aspeed_i2c_ic_map_irq_domain(struct irq_domain *domain, | |
56 | unsigned int irq, irq_hw_number_t hwirq) | |
57 | { | |
58 | irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq); | |
59 | irq_set_chip_data(irq, domain->host_data); | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | static const struct irq_domain_ops aspeed_i2c_ic_irq_domain_ops = { | |
65 | .map = aspeed_i2c_ic_map_irq_domain, | |
66 | }; | |
67 | ||
68 | static int __init aspeed_i2c_ic_of_init(struct device_node *node, | |
69 | struct device_node *parent) | |
70 | { | |
71 | struct aspeed_i2c_ic *i2c_ic; | |
72 | int ret = 0; | |
73 | ||
74 | i2c_ic = kzalloc(sizeof(*i2c_ic), GFP_KERNEL); | |
75 | if (!i2c_ic) | |
76 | return -ENOMEM; | |
77 | ||
78 | i2c_ic->base = of_iomap(node, 0); | |
79 | if (IS_ERR(i2c_ic->base)) { | |
80 | ret = PTR_ERR(i2c_ic->base); | |
81 | goto err_free_ic; | |
82 | } | |
83 | ||
84 | i2c_ic->parent_irq = irq_of_parse_and_map(node, 0); | |
85 | if (i2c_ic->parent_irq < 0) { | |
86 | ret = i2c_ic->parent_irq; | |
87 | goto err_iounmap; | |
88 | } | |
89 | ||
90 | i2c_ic->irq_domain = irq_domain_add_linear(node, ASPEED_I2C_IC_NUM_BUS, | |
91 | &aspeed_i2c_ic_irq_domain_ops, | |
92 | NULL); | |
93 | if (!i2c_ic->irq_domain) { | |
94 | ret = -ENOMEM; | |
95 | goto err_iounmap; | |
96 | } | |
97 | ||
98 | i2c_ic->irq_domain->name = "aspeed-i2c-domain"; | |
99 | ||
100 | irq_set_chained_handler_and_data(i2c_ic->parent_irq, | |
101 | aspeed_i2c_ic_irq_handler, i2c_ic); | |
102 | ||
103 | pr_info("i2c controller registered, irq %d\n", i2c_ic->parent_irq); | |
104 | ||
105 | return 0; | |
106 | ||
107 | err_iounmap: | |
108 | iounmap(i2c_ic->base); | |
109 | err_free_ic: | |
110 | kfree(i2c_ic); | |
111 | return ret; | |
112 | } | |
113 | ||
114 | IRQCHIP_DECLARE(ast2400_i2c_ic, "aspeed,ast2400-i2c-ic", aspeed_i2c_ic_of_init); | |
115 | IRQCHIP_DECLARE(ast2500_i2c_ic, "aspeed,ast2500-i2c-ic", aspeed_i2c_ic_of_init); |