1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Abilis Systems interrupt controller driver
4 *
5 * Copyright (C) Abilis Systems 2012
6 *
7 * Author: Christian Ruppert <christian.ruppert@abilis.com>
8 */
9
10 #include <linux/interrupt.h>
11 #include <linux/irqdomain.h>
12 #include <linux/irq.h>
13 #include <linux/irqchip.h>
14 #include <linux/of_irq.h>
15 #include <linux/of_address.h>
16 #include <linux/io.h>
17 #include <linux/slab.h>
18 #include <linux/bitops.h>
19
20 #define AB_IRQCTL_INT_ENABLE 0x00
21 #define AB_IRQCTL_INT_STATUS 0x04
22 #define AB_IRQCTL_SRC_MODE 0x08
23 #define AB_IRQCTL_SRC_POLARITY 0x0C
24 #define AB_IRQCTL_INT_MODE 0x10
25 #define AB_IRQCTL_INT_POLARITY 0x14
26 #define AB_IRQCTL_INT_FORCE 0x18
27
28 #define AB_IRQCTL_MAXIRQ 32
29
ab_irqctl_writereg(struct irq_chip_generic * gc,u32 reg,u32 val)30 static inline void ab_irqctl_writereg(struct irq_chip_generic *gc, u32 reg,
31 u32 val)
32 {
33 irq_reg_writel(gc, val, reg);
34 }
35
ab_irqctl_readreg(struct irq_chip_generic * gc,u32 reg)36 static inline u32 ab_irqctl_readreg(struct irq_chip_generic *gc, u32 reg)
37 {
38 return irq_reg_readl(gc, reg);
39 }
40
tb10x_irq_set_type(struct irq_data * data,unsigned int flow_type)41 static int tb10x_irq_set_type(struct irq_data *data, unsigned int flow_type)
42 {
43 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
44 uint32_t im, mod, pol;
45
46 im = data->mask;
47
48 irq_gc_lock(gc);
49
50 mod = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_MODE) | im;
51 pol = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_POLARITY) | im;
52
53 switch (flow_type & IRQF_TRIGGER_MASK) {
54 case IRQ_TYPE_EDGE_FALLING:
55 pol ^= im;
56 break;
57 case IRQ_TYPE_LEVEL_HIGH:
58 mod ^= im;
59 break;
60 case IRQ_TYPE_NONE:
61 flow_type = IRQ_TYPE_LEVEL_LOW;
62 fallthrough;
63 case IRQ_TYPE_LEVEL_LOW:
64 mod ^= im;
65 pol ^= im;
66 break;
67 case IRQ_TYPE_EDGE_RISING:
68 break;
69 default:
70 irq_gc_unlock(gc);
71 pr_err("%s: Cannot assign multiple trigger modes to IRQ %d.\n",
72 __func__, data->irq);
73 return -EBADR;
74 }
75
76 irqd_set_trigger_type(data, flow_type);
77 irq_setup_alt_chip(data, flow_type);
78
79 ab_irqctl_writereg(gc, AB_IRQCTL_SRC_MODE, mod);
80 ab_irqctl_writereg(gc, AB_IRQCTL_SRC_POLARITY, pol);
81 ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, im);
82
83 irq_gc_unlock(gc);
84
85 return IRQ_SET_MASK_OK;
86 }
87
tb10x_irq_cascade(struct irq_desc * desc)88 static void tb10x_irq_cascade(struct irq_desc *desc)
89 {
90 struct irq_domain *domain = irq_desc_get_handler_data(desc);
91 unsigned int irq = irq_desc_get_irq(desc);
92
93 generic_handle_domain_irq(domain, irq);
94 }
95
of_tb10x_init_irq(struct device_node * ictl,struct device_node * parent)96 static int __init of_tb10x_init_irq(struct device_node *ictl,
97 struct device_node *parent)
98 {
99 int i, ret, nrirqs = of_irq_count(ictl);
100 struct resource mem;
101 struct irq_chip_generic *gc;
102 struct irq_domain *domain;
103 void __iomem *reg_base;
104
105 if (of_address_to_resource(ictl, 0, &mem)) {
106 pr_err("%pOFn: No registers declared in DeviceTree.\n",
107 ictl);
108 return -EINVAL;
109 }
110
111 if (!request_mem_region(mem.start, resource_size(&mem),
112 ictl->full_name)) {
113 pr_err("%pOFn: Request mem region failed.\n", ictl);
114 return -EBUSY;
115 }
116
117 reg_base = ioremap(mem.start, resource_size(&mem));
118 if (!reg_base) {
119 ret = -EBUSY;
120 pr_err("%pOFn: ioremap failed.\n", ictl);
121 goto ioremap_fail;
122 }
123
124 domain = irq_domain_add_linear(ictl, AB_IRQCTL_MAXIRQ,
125 &irq_generic_chip_ops, NULL);
126 if (!domain) {
127 ret = -ENOMEM;
128 pr_err("%pOFn: Could not register interrupt domain.\n",
129 ictl);
130 goto irq_domain_add_fail;
131 }
132
133 ret = irq_alloc_domain_generic_chips(domain, AB_IRQCTL_MAXIRQ,
134 2, ictl->name, handle_level_irq,
135 IRQ_NOREQUEST, IRQ_NOPROBE,
136 IRQ_GC_INIT_MASK_CACHE);
137 if (ret) {
138 pr_err("%pOFn: Could not allocate generic interrupt chip.\n",
139 ictl);
140 goto gc_alloc_fail;
141 }
142
143 gc = domain->gc->gc[0];
144 gc->reg_base = reg_base;
145
146 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
147 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
148 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
149 gc->chip_types[0].chip.irq_set_type = tb10x_irq_set_type;
150 gc->chip_types[0].regs.mask = AB_IRQCTL_INT_ENABLE;
151
152 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
153 gc->chip_types[1].chip.name = gc->chip_types[0].chip.name;
154 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
155 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
156 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
157 gc->chip_types[1].chip.irq_set_type = tb10x_irq_set_type;
158 gc->chip_types[1].regs.ack = AB_IRQCTL_INT_STATUS;
159 gc->chip_types[1].regs.mask = AB_IRQCTL_INT_ENABLE;
160 gc->chip_types[1].handler = handle_edge_irq;
161
162 for (i = 0; i < nrirqs; i++) {
163 unsigned int irq = irq_of_parse_and_map(ictl, i);
164
165 irq_set_chained_handler_and_data(irq, tb10x_irq_cascade,
166 domain);
167 }
168
169 ab_irqctl_writereg(gc, AB_IRQCTL_INT_ENABLE, 0);
170 ab_irqctl_writereg(gc, AB_IRQCTL_INT_MODE, 0);
171 ab_irqctl_writereg(gc, AB_IRQCTL_INT_POLARITY, 0);
172 ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, ~0UL);
173
174 return 0;
175
176 gc_alloc_fail:
177 irq_domain_remove(domain);
178 irq_domain_add_fail:
179 iounmap(reg_base);
180 ioremap_fail:
181 release_mem_region(mem.start, resource_size(&mem));
182 return ret;
183 }
184 IRQCHIP_DECLARE(tb10x_intc, "abilis,tb10x-ictl", of_tb10x_init_irq);
185