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 
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 
36 static inline u32 ab_irqctl_readreg(struct irq_chip_generic *gc, u32 reg)
37 {
38 	return irq_reg_readl(gc, reg);
39 }
40 
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 mod, pol, im = data->mask;
45 
46 	guard(raw_spinlock)(&gc->lock);
47 
48 	mod = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_MODE) | im;
49 	pol = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_POLARITY) | im;
50 
51 	switch (flow_type & IRQF_TRIGGER_MASK) {
52 	case IRQ_TYPE_EDGE_FALLING:
53 		pol ^= im;
54 		break;
55 	case IRQ_TYPE_LEVEL_HIGH:
56 		mod ^= im;
57 		break;
58 	case IRQ_TYPE_NONE:
59 		flow_type = IRQ_TYPE_LEVEL_LOW;
60 		fallthrough;
61 	case IRQ_TYPE_LEVEL_LOW:
62 		mod ^= im;
63 		pol ^= im;
64 		break;
65 	case IRQ_TYPE_EDGE_RISING:
66 		break;
67 	default:
68 		pr_err("%s: Cannot assign multiple trigger modes to IRQ %d.\n",	__func__, data->irq);
69 		return -EBADR;
70 	}
71 
72 	irqd_set_trigger_type(data, flow_type);
73 	irq_setup_alt_chip(data, flow_type);
74 
75 	ab_irqctl_writereg(gc, AB_IRQCTL_SRC_MODE, mod);
76 	ab_irqctl_writereg(gc, AB_IRQCTL_SRC_POLARITY, pol);
77 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, im);
78 	return IRQ_SET_MASK_OK;
79 }
80 
81 static void tb10x_irq_cascade(struct irq_desc *desc)
82 {
83 	struct irq_domain *domain = irq_desc_get_handler_data(desc);
84 	unsigned int irq = irq_desc_get_irq(desc);
85 
86 	generic_handle_domain_irq(domain, irq);
87 }
88 
89 static int __init of_tb10x_init_irq(struct device_node *ictl,
90 					struct device_node *parent)
91 {
92 	int i, ret, nrirqs = of_irq_count(ictl);
93 	struct resource mem;
94 	struct irq_chip_generic *gc;
95 	struct irq_domain *domain;
96 	void __iomem *reg_base;
97 
98 	if (of_address_to_resource(ictl, 0, &mem)) {
99 		pr_err("%pOFn: No registers declared in DeviceTree.\n",
100 			ictl);
101 		return -EINVAL;
102 	}
103 
104 	if (!request_mem_region(mem.start, resource_size(&mem),
105 		ictl->full_name)) {
106 		pr_err("%pOFn: Request mem region failed.\n", ictl);
107 		return -EBUSY;
108 	}
109 
110 	reg_base = ioremap(mem.start, resource_size(&mem));
111 	if (!reg_base) {
112 		ret = -EBUSY;
113 		pr_err("%pOFn: ioremap failed.\n", ictl);
114 		goto ioremap_fail;
115 	}
116 
117 	domain = irq_domain_create_linear(of_fwnode_handle(ictl), AB_IRQCTL_MAXIRQ,
118 					  &irq_generic_chip_ops, NULL);
119 	if (!domain) {
120 		ret = -ENOMEM;
121 		pr_err("%pOFn: Could not register interrupt domain.\n",
122 			ictl);
123 		goto irq_domain_create_fail;
124 	}
125 
126 	ret = irq_alloc_domain_generic_chips(domain, AB_IRQCTL_MAXIRQ,
127 				2, ictl->name, handle_level_irq,
128 				IRQ_NOREQUEST, IRQ_NOPROBE,
129 				IRQ_GC_INIT_MASK_CACHE);
130 	if (ret) {
131 		pr_err("%pOFn: Could not allocate generic interrupt chip.\n",
132 			ictl);
133 		goto gc_alloc_fail;
134 	}
135 
136 	gc = domain->gc->gc[0];
137 	gc->reg_base                         = reg_base;
138 
139 	gc->chip_types[0].type               = IRQ_TYPE_LEVEL_MASK;
140 	gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
141 	gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
142 	gc->chip_types[0].chip.irq_set_type  = tb10x_irq_set_type;
143 	gc->chip_types[0].regs.mask          = AB_IRQCTL_INT_ENABLE;
144 
145 	gc->chip_types[1].type               = IRQ_TYPE_EDGE_BOTH;
146 	gc->chip_types[1].chip.irq_ack       = irq_gc_ack_set_bit;
147 	gc->chip_types[1].chip.irq_mask      = irq_gc_mask_clr_bit;
148 	gc->chip_types[1].chip.irq_unmask    = irq_gc_mask_set_bit;
149 	gc->chip_types[1].chip.irq_set_type  = tb10x_irq_set_type;
150 	gc->chip_types[1].regs.ack           = AB_IRQCTL_INT_STATUS;
151 	gc->chip_types[1].regs.mask          = AB_IRQCTL_INT_ENABLE;
152 	gc->chip_types[1].handler            = handle_edge_irq;
153 
154 	for (i = 0; i < nrirqs; i++) {
155 		unsigned int irq = irq_of_parse_and_map(ictl, i);
156 
157 		irq_set_chained_handler_and_data(irq, tb10x_irq_cascade,
158 						 domain);
159 	}
160 
161 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_ENABLE, 0);
162 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_MODE, 0);
163 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_POLARITY, 0);
164 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, ~0UL);
165 
166 	return 0;
167 
168 gc_alloc_fail:
169 	irq_domain_remove(domain);
170 irq_domain_create_fail:
171 	iounmap(reg_base);
172 ioremap_fail:
173 	release_mem_region(mem.start, resource_size(&mem));
174 	return ret;
175 }
176 IRQCHIP_DECLARE(tb10x_intc, "abilis,tb10x-ictl", of_tb10x_init_irq);
177