1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2015 - Ben Herrenschmidt, IBM Corp.
4 *
5 * Driver for Aspeed "new" VIC as found in SoC generation 3 and later
6 *
7 * Based on irq-vic.c:
8 *
9 * Copyright (C) 1999 - 2003 ARM Limited
10 * Copyright (C) 2000 Deep Blue Solutions Ltd
11 */
12
13 #include <linux/export.h>
14 #include <linux/init.h>
15 #include <linux/list.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/irqchip.h>
19 #include <linux/irqchip/chained_irq.h>
20 #include <linux/irqdomain.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/of_irq.h>
24 #include <linux/syscore_ops.h>
25 #include <linux/device.h>
26 #include <linux/slab.h>
27
28 #include <asm/exception.h>
29 #include <asm/irq.h>
30
31 /* These definitions correspond to the "new mapping" of the
32 * register set that interleaves "high" and "low". The offsets
33 * below are for the "low" register, add 4 to get to the high one
34 */
35 #define AVIC_IRQ_STATUS 0x00
36 #define AVIC_FIQ_STATUS 0x08
37 #define AVIC_RAW_STATUS 0x10
38 #define AVIC_INT_SELECT 0x18
39 #define AVIC_INT_ENABLE 0x20
40 #define AVIC_INT_ENABLE_CLR 0x28
41 #define AVIC_INT_TRIGGER 0x30
42 #define AVIC_INT_TRIGGER_CLR 0x38
43 #define AVIC_INT_SENSE 0x40
44 #define AVIC_INT_DUAL_EDGE 0x48
45 #define AVIC_INT_EVENT 0x50
46 #define AVIC_EDGE_CLR 0x58
47 #define AVIC_EDGE_STATUS 0x60
48
49 #define NUM_IRQS 64
50
51 struct aspeed_vic {
52 void __iomem *base;
53 u32 edge_sources[2];
54 struct irq_domain *dom;
55 };
56 static struct aspeed_vic *system_avic;
57
vic_init_hw(struct aspeed_vic * vic)58 static void vic_init_hw(struct aspeed_vic *vic)
59 {
60 u32 sense;
61
62 /* Disable all interrupts */
63 writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR);
64 writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR + 4);
65
66 /* Make sure no soft trigger is on */
67 writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR);
68 writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR + 4);
69
70 /* Set everything to be IRQ */
71 writel(0, vic->base + AVIC_INT_SELECT);
72 writel(0, vic->base + AVIC_INT_SELECT + 4);
73
74 /* Some interrupts have a programmable high/low level trigger
75 * (4 GPIO direct inputs), for now we assume this was configured
76 * by firmware. We read which ones are edge now.
77 */
78 sense = readl(vic->base + AVIC_INT_SENSE);
79 vic->edge_sources[0] = ~sense;
80 sense = readl(vic->base + AVIC_INT_SENSE + 4);
81 vic->edge_sources[1] = ~sense;
82
83 /* Clear edge detection latches */
84 writel(0xffffffff, vic->base + AVIC_EDGE_CLR);
85 writel(0xffffffff, vic->base + AVIC_EDGE_CLR + 4);
86 }
87
avic_handle_irq(struct pt_regs * regs)88 static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
89 {
90 struct aspeed_vic *vic = system_avic;
91 u32 stat, irq;
92
93 for (;;) {
94 irq = 0;
95 stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS);
96 if (!stat) {
97 stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS + 4);
98 irq = 32;
99 }
100 if (stat == 0)
101 break;
102 irq += ffs(stat) - 1;
103 generic_handle_domain_irq(vic->dom, irq);
104 }
105 }
106
avic_ack_irq(struct irq_data * d)107 static void avic_ack_irq(struct irq_data *d)
108 {
109 struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
110 unsigned int sidx = d->hwirq >> 5;
111 unsigned int sbit = 1u << (d->hwirq & 0x1f);
112
113 /* Clear edge latch for edge interrupts, nop for level */
114 if (vic->edge_sources[sidx] & sbit)
115 writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
116 }
117
avic_mask_irq(struct irq_data * d)118 static void avic_mask_irq(struct irq_data *d)
119 {
120 struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
121 unsigned int sidx = d->hwirq >> 5;
122 unsigned int sbit = 1u << (d->hwirq & 0x1f);
123
124 writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);
125 }
126
avic_unmask_irq(struct irq_data * d)127 static void avic_unmask_irq(struct irq_data *d)
128 {
129 struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
130 unsigned int sidx = d->hwirq >> 5;
131 unsigned int sbit = 1u << (d->hwirq & 0x1f);
132
133 writel(sbit, vic->base + AVIC_INT_ENABLE + sidx * 4);
134 }
135
136 /* For level irq, faster than going through a nop "ack" and mask */
avic_mask_ack_irq(struct irq_data * d)137 static void avic_mask_ack_irq(struct irq_data *d)
138 {
139 struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
140 unsigned int sidx = d->hwirq >> 5;
141 unsigned int sbit = 1u << (d->hwirq & 0x1f);
142
143 /* First mask */
144 writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);
145
146 /* Then clear edge latch for edge interrupts */
147 if (vic->edge_sources[sidx] & sbit)
148 writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
149 }
150
151 static struct irq_chip avic_chip = {
152 .name = "AVIC",
153 .irq_ack = avic_ack_irq,
154 .irq_mask = avic_mask_irq,
155 .irq_unmask = avic_unmask_irq,
156 .irq_mask_ack = avic_mask_ack_irq,
157 };
158
avic_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)159 static int avic_map(struct irq_domain *d, unsigned int irq,
160 irq_hw_number_t hwirq)
161 {
162 struct aspeed_vic *vic = d->host_data;
163 unsigned int sidx = hwirq >> 5;
164 unsigned int sbit = 1u << (hwirq & 0x1f);
165
166 /* Check if interrupt exists */
167 if (sidx > 1)
168 return -EPERM;
169
170 if (vic->edge_sources[sidx] & sbit)
171 irq_set_chip_and_handler(irq, &avic_chip, handle_edge_irq);
172 else
173 irq_set_chip_and_handler(irq, &avic_chip, handle_level_irq);
174 irq_set_chip_data(irq, vic);
175 irq_set_probe(irq);
176 return 0;
177 }
178
179 static const struct irq_domain_ops avic_dom_ops = {
180 .map = avic_map,
181 .xlate = irq_domain_xlate_onetwocell,
182 };
183
avic_of_init(struct device_node * node,struct device_node * parent)184 static int __init avic_of_init(struct device_node *node,
185 struct device_node *parent)
186 {
187 void __iomem *regs;
188 struct aspeed_vic *vic;
189
190 if (WARN(parent, "non-root Aspeed VIC not supported"))
191 return -EINVAL;
192 if (WARN(system_avic, "duplicate Aspeed VIC not supported"))
193 return -EINVAL;
194
195 regs = of_iomap(node, 0);
196 if (WARN_ON(!regs))
197 return -EIO;
198
199 vic = kzalloc(sizeof(struct aspeed_vic), GFP_KERNEL);
200 if (WARN_ON(!vic)) {
201 iounmap(regs);
202 return -ENOMEM;
203 }
204 vic->base = regs;
205
206 /* Initialize sources, all masked */
207 vic_init_hw(vic);
208
209 /* Ready to receive interrupts */
210 system_avic = vic;
211 set_handle_irq(avic_handle_irq);
212
213 /* Register our domain */
214 vic->dom = irq_domain_add_simple(node, NUM_IRQS, 0,
215 &avic_dom_ops, vic);
216
217 return 0;
218 }
219
220 IRQCHIP_DECLARE(ast2400_vic, "aspeed,ast2400-vic", avic_of_init);
221 IRQCHIP_DECLARE(ast2500_vic, "aspeed,ast2500-vic", avic_of_init);
222