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
61 struct 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 */
67 static struct vt8500_irq_data intc[VT8500_INTC_MAX];
68 static u32 active_cnt = 0;
69
vt8500_irq_mask(struct irq_data * d)70 static 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(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE;
79 if (edge) {
80 status = readl(stat_reg);
81
82 status |= (1 << (d->hwirq & 0x1f));
83 writel(status, stat_reg);
84 } else {
85 dctr = readb(base + VT8500_ICDC + d->hwirq);
86 dctr &= ~VT8500_INT_ENABLE;
87 writeb(dctr, base + VT8500_ICDC + d->hwirq);
88 }
89 }
90
vt8500_irq_unmask(struct irq_data * d)91 static 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(base + VT8500_ICDC + d->hwirq);
98 dctr |= VT8500_INT_ENABLE;
99 writeb(dctr, base + VT8500_ICDC + d->hwirq);
100 }
101
vt8500_irq_set_type(struct irq_data * d,unsigned int flow_type)102 static 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(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(d, handle_level_irq);
117 break;
118 case IRQF_TRIGGER_FALLING:
119 dctr |= VT8500_TRIGGER_FALLING;
120 irq_set_handler_locked(d, handle_edge_irq);
121 break;
122 case IRQF_TRIGGER_RISING:
123 dctr |= VT8500_TRIGGER_RISING;
124 irq_set_handler_locked(d, handle_edge_irq);
125 break;
126 }
127 writeb(dctr, base + VT8500_ICDC + d->hwirq);
128
129 return 0;
130 }
131
132 static 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
vt8500_init_irq_hw(void __iomem * base)140 static void __init vt8500_init_irq_hw(void __iomem *base)
141 {
142 u32 i;
143
144 /* Enable rotating priority for IRQ */
145 writel(ICPC_ROTATE, base + VT8500_ICPC_IRQ);
146 writel(0x00, 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, base + VT8500_ICDC + i);
151 }
152
vt8500_irq_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)153 static int vt8500_irq_map(struct irq_domain *h, unsigned int virq,
154 irq_hw_number_t hw)
155 {
156 irq_set_chip_and_handler(virq, &vt8500_irq_chip, handle_level_irq);
157
158 return 0;
159 }
160
161 static const struct irq_domain_ops vt8500_irq_domain_ops = {
162 .map = vt8500_irq_map,
163 .xlate = irq_domain_xlate_onecell,
164 };
165
vt8500_handle_irq(struct pt_regs * regs)166 static 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 handle_domain_irq(intc[i].domain, irqnr, regs);
187 }
188 }
189
vt8500_irq_init(struct device_node * node,struct device_node * parent)190 static 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(np, 0);
203 intc[active_cnt].domain = irq_domain_add_linear(node, 64,
204 &vt8500_irq_domain_ops, &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(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(np) != 0) {
226 /* check that we have the correct number of interrupts */
227 if (of_irq_count(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(np, i);
235 enable_irq(irq);
236 }
237
238 pr_info("vt8500-irq: Enabled slave->parent interrupts\n");
239 }
240 out:
241 return 0;
242 }
243
244 IRQCHIP_DECLARE(vt8500_irq, "via,vt8500-intc", vt8500_irq_init);
245
