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/irqchip.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23
24 #include <asm/exception.h>
25
26 #define SUN4I_IRQ_VECTOR_REG 0x00
27 #define SUN4I_IRQ_PROTECTION_REG 0x08
28 #define SUN4I_IRQ_NMI_CTRL_REG 0x0c
29 #define SUN4I_IRQ_PENDING_REG(x) (0x10 + 0x4 * x)
30 #define SUN4I_IRQ_FIQ_PENDING_REG(x) (0x20 + 0x4 * x)
31 #define SUN4I_IRQ_ENABLE_REG(data, x) ((data)->enable_reg_offset + 0x4 * x)
32 #define SUN4I_IRQ_MASK_REG(data, x) ((data)->mask_reg_offset + 0x4 * x)
33 #define SUN4I_IRQ_ENABLE_REG_OFFSET 0x40
34 #define SUN4I_IRQ_MASK_REG_OFFSET 0x50
35 #define SUNIV_IRQ_ENABLE_REG_OFFSET 0x20
36 #define SUNIV_IRQ_MASK_REG_OFFSET 0x30
37
38 struct sun4i_irq_chip_data {
39 void __iomem *irq_base;
40 struct irq_domain *irq_domain;
41 u32 enable_reg_offset;
42 u32 mask_reg_offset;
43 };
44
45 static struct sun4i_irq_chip_data *irq_ic_data;
46
47 static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs);
48
sun4i_irq_ack(struct irq_data * irqd)49 static void sun4i_irq_ack(struct irq_data *irqd)
50 {
51 unsigned int irq = irqd_to_hwirq(irqd);
52
53 if (irq != 0)
54 return; /* Only IRQ 0 / the ENMI needs to be acked */
55
56 writel(BIT(0), irq_ic_data->irq_base + SUN4I_IRQ_PENDING_REG(0));
57 }
58
sun4i_irq_mask(struct irq_data * irqd)59 static void sun4i_irq_mask(struct irq_data *irqd)
60 {
61 unsigned int irq = irqd_to_hwirq(irqd);
62 unsigned int irq_off = irq % 32;
63 int reg = irq / 32;
64 u32 val;
65
66 val = readl(irq_ic_data->irq_base +
67 SUN4I_IRQ_ENABLE_REG(irq_ic_data, reg));
68 writel(val & ~(1 << irq_off),
69 irq_ic_data->irq_base + SUN4I_IRQ_ENABLE_REG(irq_ic_data, reg));
70 }
71
sun4i_irq_unmask(struct irq_data * irqd)72 static void sun4i_irq_unmask(struct irq_data *irqd)
73 {
74 unsigned int irq = irqd_to_hwirq(irqd);
75 unsigned int irq_off = irq % 32;
76 int reg = irq / 32;
77 u32 val;
78
79 val = readl(irq_ic_data->irq_base +
80 SUN4I_IRQ_ENABLE_REG(irq_ic_data, reg));
81 writel(val | (1 << irq_off),
82 irq_ic_data->irq_base + SUN4I_IRQ_ENABLE_REG(irq_ic_data, reg));
83 }
84
85 static struct irq_chip sun4i_irq_chip = {
86 .name = "sun4i_irq",
87 .irq_eoi = sun4i_irq_ack,
88 .irq_mask = sun4i_irq_mask,
89 .irq_unmask = sun4i_irq_unmask,
90 .flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED,
91 };
92
sun4i_irq_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hw)93 static int sun4i_irq_map(struct irq_domain *d, unsigned int virq,
94 irq_hw_number_t hw)
95 {
96 irq_set_chip_and_handler(virq, &sun4i_irq_chip, handle_fasteoi_irq);
97 irq_set_probe(virq);
98
99 return 0;
100 }
101
102 static const struct irq_domain_ops sun4i_irq_ops = {
103 .map = sun4i_irq_map,
104 .xlate = irq_domain_xlate_onecell,
105 };
106
sun4i_of_init(struct device_node * node,struct device_node * parent)107 static int __init sun4i_of_init(struct device_node *node,
108 struct device_node *parent)
109 {
110 irq_ic_data->irq_base = of_iomap(node, 0);
111 if (!irq_ic_data->irq_base)
112 panic("%pOF: unable to map IC registers\n",
113 node);
114
115 /* Disable all interrupts */
116 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_ENABLE_REG(irq_ic_data, 0));
117 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_ENABLE_REG(irq_ic_data, 1));
118 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_ENABLE_REG(irq_ic_data, 2));
119
120 /* Unmask all the interrupts, ENABLE_REG(x) is used for masking */
121 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_MASK_REG(irq_ic_data, 0));
122 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_MASK_REG(irq_ic_data, 1));
123 writel(0, irq_ic_data->irq_base + SUN4I_IRQ_MASK_REG(irq_ic_data, 2));
124
125 /* Clear all the pending interrupts */
126 writel(0xffffffff, irq_ic_data->irq_base + SUN4I_IRQ_PENDING_REG(0));
127 writel(0xffffffff, irq_ic_data->irq_base + SUN4I_IRQ_PENDING_REG(1));
128 writel(0xffffffff, irq_ic_data->irq_base + SUN4I_IRQ_PENDING_REG(2));
129
130 /* Enable protection mode */
131 writel(0x01, irq_ic_data->irq_base + SUN4I_IRQ_PROTECTION_REG);
132
133 /* Configure the external interrupt source type */
134 writel(0x00, irq_ic_data->irq_base + SUN4I_IRQ_NMI_CTRL_REG);
135
136 irq_ic_data->irq_domain = irq_domain_add_linear(node, 3 * 32,
137 &sun4i_irq_ops, NULL);
138 if (!irq_ic_data->irq_domain)
139 panic("%pOF: unable to create IRQ domain\n", node);
140
141 set_handle_irq(sun4i_handle_irq);
142
143 return 0;
144 }
145
sun4i_ic_of_init(struct device_node * node,struct device_node * parent)146 static int __init sun4i_ic_of_init(struct device_node *node,
147 struct device_node *parent)
148 {
149 irq_ic_data = kzalloc(sizeof(struct sun4i_irq_chip_data), GFP_KERNEL);
150 if (!irq_ic_data)
151 return -ENOMEM;
152
153 irq_ic_data->enable_reg_offset = SUN4I_IRQ_ENABLE_REG_OFFSET;
154 irq_ic_data->mask_reg_offset = SUN4I_IRQ_MASK_REG_OFFSET;
155
156 return sun4i_of_init(node, parent);
157 }
158
159 IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-a10-ic", sun4i_ic_of_init);
160
suniv_ic_of_init(struct device_node * node,struct device_node * parent)161 static int __init suniv_ic_of_init(struct device_node *node,
162 struct device_node *parent)
163 {
164 irq_ic_data = kzalloc(sizeof(struct sun4i_irq_chip_data), GFP_KERNEL);
165 if (!irq_ic_data)
166 return -ENOMEM;
167
168 irq_ic_data->enable_reg_offset = SUNIV_IRQ_ENABLE_REG_OFFSET;
169 irq_ic_data->mask_reg_offset = SUNIV_IRQ_MASK_REG_OFFSET;
170
171 return sun4i_of_init(node, parent);
172 }
173
174 IRQCHIP_DECLARE(allwinner_sunvi_ic, "allwinner,suniv-f1c100s-ic",
175 suniv_ic_of_init);
176
sun4i_handle_irq(struct pt_regs * regs)177 static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs)
178 {
179 u32 hwirq;
180
181 /*
182 * hwirq == 0 can mean one of 3 things:
183 * 1) no more irqs pending
184 * 2) irq 0 pending
185 * 3) spurious irq
186 * So if we immediately get a reading of 0, check the irq-pending reg
187 * to differentiate between 2 and 3. We only do this once to avoid
188 * the extra check in the common case of 1 happening after having
189 * read the vector-reg once.
190 */
191 hwirq = readl(irq_ic_data->irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
192 if (hwirq == 0 &&
193 !(readl(irq_ic_data->irq_base + SUN4I_IRQ_PENDING_REG(0)) &
194 BIT(0)))
195 return;
196
197 do {
198 handle_domain_irq(irq_ic_data->irq_domain, hwirq, regs);
199 hwirq = readl(irq_ic_data->irq_base +
200 SUN4I_IRQ_VECTOR_REG) >> 2;
201 } while (hwirq != 0);
202 }
203
