xref: /openbmc/linux/drivers/irqchip/irq-sun4i.c (revision ee89bd6b)
1 /*
2  * Allwinner A1X SoCs IRQ chip driver.
3  *
4  * Copyright (C) 2012 Maxime Ripard
5  *
6  * Maxime Ripard <maxime.ripard@free-electrons.com>
7  *
8  * Based on code from
9  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
10  * Benn Huang <benn@allwinnertech.com>
11  *
12  * This file is licensed under the terms of the GNU General Public
13  * License version 2.  This program is licensed "as is" without any
14  * warranty of any kind, whether express or implied.
15  */
16 
17 #include <linux/io.h>
18 #include <linux/irq.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 
23 #include <asm/exception.h>
24 #include <asm/mach/irq.h>
25 
26 #include "irqchip.h"
27 
28 #define SUN4I_IRQ_VECTOR_REG		0x00
29 #define SUN4I_IRQ_PROTECTION_REG	0x08
30 #define SUN4I_IRQ_NMI_CTRL_REG		0x0c
31 #define SUN4I_IRQ_PENDING_REG(x)	(0x10 + 0x4 * x)
32 #define SUN4I_IRQ_FIQ_PENDING_REG(x)	(0x20 + 0x4 * x)
33 #define SUN4I_IRQ_ENABLE_REG(x)		(0x40 + 0x4 * x)
34 #define SUN4I_IRQ_MASK_REG(x)		(0x50 + 0x4 * x)
35 
36 static void __iomem *sun4i_irq_base;
37 static struct irq_domain *sun4i_irq_domain;
38 
39 static asmlinkage void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs);
40 
41 void sun4i_irq_ack(struct irq_data *irqd)
42 {
43 	unsigned int irq = irqd_to_hwirq(irqd);
44 	unsigned int irq_off = irq % 32;
45 	int reg = irq / 32;
46 	u32 val;
47 
48 	val = readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg));
49 	writel(val | (1 << irq_off),
50 	       sun4i_irq_base + SUN4I_IRQ_PENDING_REG(reg));
51 }
52 
53 static void sun4i_irq_mask(struct irq_data *irqd)
54 {
55 	unsigned int irq = irqd_to_hwirq(irqd);
56 	unsigned int irq_off = irq % 32;
57 	int reg = irq / 32;
58 	u32 val;
59 
60 	val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
61 	writel(val & ~(1 << irq_off),
62 	       sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
63 }
64 
65 static void sun4i_irq_unmask(struct irq_data *irqd)
66 {
67 	unsigned int irq = irqd_to_hwirq(irqd);
68 	unsigned int irq_off = irq % 32;
69 	int reg = irq / 32;
70 	u32 val;
71 
72 	val = readl(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
73 	writel(val | (1 << irq_off),
74 	       sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
75 }
76 
77 static struct irq_chip sun4i_irq_chip = {
78 	.name		= "sun4i_irq",
79 	.irq_ack	= sun4i_irq_ack,
80 	.irq_mask	= sun4i_irq_mask,
81 	.irq_unmask	= sun4i_irq_unmask,
82 };
83 
84 static int sun4i_irq_map(struct irq_domain *d, unsigned int virq,
85 			 irq_hw_number_t hw)
86 {
87 	irq_set_chip_and_handler(virq, &sun4i_irq_chip,
88 				 handle_level_irq);
89 	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
90 
91 	return 0;
92 }
93 
94 static struct irq_domain_ops sun4i_irq_ops = {
95 	.map = sun4i_irq_map,
96 	.xlate = irq_domain_xlate_onecell,
97 };
98 
99 static int __init sun4i_of_init(struct device_node *node,
100 				struct device_node *parent)
101 {
102 	sun4i_irq_base = of_iomap(node, 0);
103 	if (!sun4i_irq_base)
104 		panic("%s: unable to map IC registers\n",
105 			node->full_name);
106 
107 	/* Disable all interrupts */
108 	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(0));
109 	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(1));
110 	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(2));
111 
112 	/* Mask all the interrupts */
113 	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(0));
114 	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1));
115 	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2));
116 
117 	/* Clear all the pending interrupts */
118 	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
119 	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
120 	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
121 
122 	/* Enable protection mode */
123 	writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
124 
125 	/* Configure the external interrupt source type */
126 	writel(0x00, sun4i_irq_base + SUN4I_IRQ_NMI_CTRL_REG);
127 
128 	sun4i_irq_domain = irq_domain_add_linear(node, 3 * 32,
129 						 &sun4i_irq_ops, NULL);
130 	if (!sun4i_irq_domain)
131 		panic("%s: unable to create IRQ domain\n", node->full_name);
132 
133 	set_handle_irq(sun4i_handle_irq);
134 
135 	return 0;
136 }
137 IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-ic", sun4i_of_init);
138 
139 static asmlinkage void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs)
140 {
141 	u32 irq, hwirq;
142 
143 	hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
144 	while (hwirq != 0) {
145 		irq = irq_find_mapping(sun4i_irq_domain, hwirq);
146 		handle_IRQ(irq, regs);
147 		hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
148 	}
149 }
150