1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * arch/arm/mach-vt8500/irq.c
4 *
5 * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
6 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
7 */
8
9/*
10 * This file is copied and modified from the original irq.c provided by
11 * Alexey Charkov. Minor changes have been made for Device Tree Support.
12 */
13
14#include <linux/slab.h>
15#include <linux/io.h>
16#include <linux/irq.h>
17#include <linux/irqchip.h>
18#include <linux/irqdomain.h>
19#include <linux/interrupt.h>
20#include <linux/bitops.h>
21
22#include <linux/of.h>
23#include <linux/of_irq.h>
24#include <linux/of_address.h>
25
26#include <asm/irq.h>
27#include <asm/exception.h>
28#include <asm/mach/irq.h>
29
30#define VT8500_ICPC_IRQ 0x20
31#define VT8500_ICPC_FIQ 0x24
32#define VT8500_ICDC 0x40 /* Destination Control 64*u32 */
33#define VT8500_ICIS 0x80 /* Interrupt status, 16*u32 */
34
35/* ICPC */
36#define ICPC_MASK 0x3F
37#define ICPC_ROTATE BIT(6)
38
39/* IC_DCTR */
40#define ICDC_IRQ 0x00
41#define ICDC_FIQ 0x01
42#define ICDC_DSS0 0x02
43#define ICDC_DSS1 0x03
44#define ICDC_DSS2 0x04
45#define ICDC_DSS3 0x05
46#define ICDC_DSS4 0x06
47#define ICDC_DSS5 0x07
48
49#define VT8500_INT_DISABLE 0
50#define VT8500_INT_ENABLE BIT(3)
51
52#define VT8500_TRIGGER_HIGH 0
53#define VT8500_TRIGGER_RISING BIT(5)
54#define VT8500_TRIGGER_FALLING BIT(6)
55#define VT8500_EDGE ( VT8500_TRIGGER_RISING \
56 | VT8500_TRIGGER_FALLING)
57
58/* vt8500 has 1 intc, wm8505 and wm8650 have 2 */
59#define VT8500_INTC_MAX 2
60
61struct vt8500_irq_data {
62 void __iomem *base; /* IO Memory base address */
63 struct irq_domain *domain; /* Domain for this controller */
64};
65
66/* Global variable for accessing io-mem addresses */
67static struct vt8500_irq_data intc[VT8500_INTC_MAX];
68static u32 active_cnt = 0;
69
70static void vt8500_irq_mask(struct irq_data *d)
71{
72 struct vt8500_irq_data *priv = d->domain->host_data;
73 void __iomem *base = priv->base;
74 void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4);
75 u8 edge, dctr;
76 u32 status;
77
78 edge = readb(addr: base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
79 if (edge) {
80 status = readl(addr: stat_reg);
81
82 status |= (1 << (d->hwirq & 0x1f));
83 writel(val: status, addr: stat_reg);
84 } else {
85 dctr = readb(addr: base + VT8500_ICDC + d->hwirq);
86 dctr &= ~VT8500_INT_ENABLE;
87 writeb(val: dctr, addr: base + VT8500_ICDC + d->hwirq);
88 }
89}
90
91static void vt8500_irq_unmask(struct irq_data *d)
92{
93 struct vt8500_irq_data *priv = d->domain->host_data;
94 void __iomem *base = priv->base;
95 u8 dctr;
96
97 dctr = readb(addr: base + VT8500_ICDC + d->hwirq);
98 dctr |= VT8500_INT_ENABLE;
99 writeb(val: dctr, addr: base + VT8500_ICDC + d->hwirq);
100}
101
102static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type)
103{
104 struct vt8500_irq_data *priv = d->domain->host_data;
105 void __iomem *base = priv->base;
106 u8 dctr;
107
108 dctr = readb(addr: base + VT8500_ICDC + d->hwirq);
109 dctr &= ~VT8500_EDGE;
110
111 switch (flow_type) {
112 case IRQF_TRIGGER_LOW:
113 return -EINVAL;
114 case IRQF_TRIGGER_HIGH:
115 dctr |= VT8500_TRIGGER_HIGH;
116 irq_set_handler_locked(data: d, handler: handle_level_irq);
117 break;
118 case IRQF_TRIGGER_FALLING:
119 dctr |= VT8500_TRIGGER_FALLING;
120 irq_set_handler_locked(data: d, handler: handle_edge_irq);
121 break;
122 case IRQF_TRIGGER_RISING:
123 dctr |= VT8500_TRIGGER_RISING;
124 irq_set_handler_locked(data: d, handler: handle_edge_irq);
125 break;
126 }
127 writeb(val: dctr, addr: base + VT8500_ICDC + d->hwirq);
128
129 return 0;
130}
131
132static struct irq_chip vt8500_irq_chip = {
133 .name = "vt8500",
134 .irq_ack = vt8500_irq_mask,
135 .irq_mask = vt8500_irq_mask,
136 .irq_unmask = vt8500_irq_unmask,
137 .irq_set_type = vt8500_irq_set_type,
138};
139
140static void __init vt8500_init_irq_hw(void __iomem *base)
141{
142 u32 i;
143
144 /* Enable rotating priority for IRQ */
145 writel(ICPC_ROTATE, addr: base + VT8500_ICPC_IRQ);
146 writel(val: 0x00, addr: base + VT8500_ICPC_FIQ);
147
148 /* Disable all interrupts and route them to IRQ */
149 for (i = 0; i < 64; i++)
150 writeb(VT8500_INT_DISABLE | ICDC_IRQ, addr: base + VT8500_ICDC + i);
151}
152
153static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
154 irq_hw_number_t hw)
155{
156 irq_set_chip_and_handler(irq: virq, chip: &vt8500_irq_chip, handle: handle_level_irq);
157
158 return 0;
159}
160
161static const struct irq_domain_ops vt8500_irq_domain_ops = {
162 .map = vt8500_irq_map,
163 .xlate = irq_domain_xlate_onecell,
164};
165
166static void __exception_irq_entry vt8500_handle_irq(struct pt_regs *regs)
167{
168 u32 stat, i;
169 int irqnr;
170 void __iomem *base;
171
172 /* Loop through each active controller */
173 for (i=0; i<active_cnt; i++) {
174 base = intc[i].base;
175 irqnr = readl_relaxed(base) & 0x3F;
176 /*
177 Highest Priority register default = 63, so check that this
178 is a real interrupt by checking the status register
179 */
180 if (irqnr == 63) {
181 stat = readl_relaxed(base + VT8500_ICIS + 4);
182 if (!(stat & BIT(31)))
183 continue;
184 }
185
186 generic_handle_domain_irq(intc[i].domain, irqnr);
187 }
188}
189
190static int __init vt8500_irq_init(struct device_node *node,
191 struct device_node *parent)
192{
193 int irq, i;
194 struct device_node *np = node;
195
196 if (active_cnt == VT8500_INTC_MAX) {
197 pr_err("%s: Interrupt controllers > VT8500_INTC_MAX\n",
198 __func__);
199 goto out;
200 }
201
202 intc[active_cnt].base = of_iomap(node: np, index: 0);
203 intc[active_cnt].domain = irq_domain_add_linear(of_node: node, size: 64,
204 ops: &vt8500_irq_domain_ops, host_data: &intc[active_cnt]);
205
206 if (!intc[active_cnt].base) {
207 pr_err("%s: Unable to map IO memory\n", __func__);
208 goto out;
209 }
210
211 if (!intc[active_cnt].domain) {
212 pr_err("%s: Unable to add irq domain!\n", __func__);
213 goto out;
214 }
215
216 set_handle_irq(vt8500_handle_irq);
217
218 vt8500_init_irq_hw(base: intc[active_cnt].base);
219
220 pr_info("vt8500-irq: Added interrupt controller\n");
221
222 active_cnt++;
223
224 /* check if this is a slaved controller */
225 if (of_irq_count(dev: np) != 0) {
226 /* check that we have the correct number of interrupts */
227 if (of_irq_count(dev: np) != 8) {
228 pr_err("%s: Incorrect IRQ map for slaved controller\n",
229 __func__);
230 return -EINVAL;
231 }
232
233 for (i = 0; i < 8; i++) {
234 irq = irq_of_parse_and_map(node: np, index: i);
235 enable_irq(irq);
236 }
237
238 pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
239 }
240out:
241 return 0;
242}
243
244IRQCHIP_DECLARE(vt8500_irq, "via,vt8500-intc", vt8500_irq_init);
245

source code of linux/drivers/irqchip/irq-vt8500.c