xref: /openbmc/linux/drivers/irqchip/irq-tb10x.c (revision 8fc4e4aa)
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/of_platform.h>
17 #include <linux/io.h>
18 #include <linux/slab.h>
19 #include <linux/bitops.h>
20 
21 #define AB_IRQCTL_INT_ENABLE   0x00
22 #define AB_IRQCTL_INT_STATUS   0x04
23 #define AB_IRQCTL_SRC_MODE     0x08
24 #define AB_IRQCTL_SRC_POLARITY 0x0C
25 #define AB_IRQCTL_INT_MODE     0x10
26 #define AB_IRQCTL_INT_POLARITY 0x14
27 #define AB_IRQCTL_INT_FORCE    0x18
28 
29 #define AB_IRQCTL_MAXIRQ       32
30 
31 static inline void ab_irqctl_writereg(struct irq_chip_generic *gc, u32 reg,
32 	u32 val)
33 {
34 	irq_reg_writel(gc, val, reg);
35 }
36 
37 static inline u32 ab_irqctl_readreg(struct irq_chip_generic *gc, u32 reg)
38 {
39 	return irq_reg_readl(gc, reg);
40 }
41 
42 static int tb10x_irq_set_type(struct irq_data *data, unsigned int flow_type)
43 {
44 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
45 	uint32_t im, mod, pol;
46 
47 	im = data->mask;
48 
49 	irq_gc_lock(gc);
50 
51 	mod = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_MODE) | im;
52 	pol = ab_irqctl_readreg(gc, AB_IRQCTL_SRC_POLARITY) | im;
53 
54 	switch (flow_type & IRQF_TRIGGER_MASK) {
55 	case IRQ_TYPE_EDGE_FALLING:
56 		pol ^= im;
57 		break;
58 	case IRQ_TYPE_LEVEL_HIGH:
59 		mod ^= im;
60 		break;
61 	case IRQ_TYPE_NONE:
62 		flow_type = IRQ_TYPE_LEVEL_LOW;
63 		fallthrough;
64 	case IRQ_TYPE_LEVEL_LOW:
65 		mod ^= im;
66 		pol ^= im;
67 		break;
68 	case IRQ_TYPE_EDGE_RISING:
69 		break;
70 	default:
71 		irq_gc_unlock(gc);
72 		pr_err("%s: Cannot assign multiple trigger modes to IRQ %d.\n",
73 			__func__, data->irq);
74 		return -EBADR;
75 	}
76 
77 	irqd_set_trigger_type(data, flow_type);
78 	irq_setup_alt_chip(data, flow_type);
79 
80 	ab_irqctl_writereg(gc, AB_IRQCTL_SRC_MODE, mod);
81 	ab_irqctl_writereg(gc, AB_IRQCTL_SRC_POLARITY, pol);
82 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, im);
83 
84 	irq_gc_unlock(gc);
85 
86 	return IRQ_SET_MASK_OK;
87 }
88 
89 static void tb10x_irq_cascade(struct irq_desc *desc)
90 {
91 	struct irq_domain *domain = irq_desc_get_handler_data(desc);
92 	unsigned int irq = irq_desc_get_irq(desc);
93 
94 	generic_handle_irq(irq_find_mapping(domain, irq));
95 }
96 
97 static int __init of_tb10x_init_irq(struct device_node *ictl,
98 					struct device_node *parent)
99 {
100 	int i, ret, nrirqs = of_irq_count(ictl);
101 	struct resource mem;
102 	struct irq_chip_generic *gc;
103 	struct irq_domain *domain;
104 	void __iomem *reg_base;
105 
106 	if (of_address_to_resource(ictl, 0, &mem)) {
107 		pr_err("%pOFn: No registers declared in DeviceTree.\n",
108 			ictl);
109 		return -EINVAL;
110 	}
111 
112 	if (!request_mem_region(mem.start, resource_size(&mem),
113 		ictl->full_name)) {
114 		pr_err("%pOFn: Request mem region failed.\n", ictl);
115 		return -EBUSY;
116 	}
117 
118 	reg_base = ioremap(mem.start, resource_size(&mem));
119 	if (!reg_base) {
120 		ret = -EBUSY;
121 		pr_err("%pOFn: ioremap failed.\n", ictl);
122 		goto ioremap_fail;
123 	}
124 
125 	domain = irq_domain_add_linear(ictl, AB_IRQCTL_MAXIRQ,
126 					&irq_generic_chip_ops, NULL);
127 	if (!domain) {
128 		ret = -ENOMEM;
129 		pr_err("%pOFn: Could not register interrupt domain.\n",
130 			ictl);
131 		goto irq_domain_add_fail;
132 	}
133 
134 	ret = irq_alloc_domain_generic_chips(domain, AB_IRQCTL_MAXIRQ,
135 				2, ictl->name, handle_level_irq,
136 				IRQ_NOREQUEST, IRQ_NOPROBE,
137 				IRQ_GC_INIT_MASK_CACHE);
138 	if (ret) {
139 		pr_err("%pOFn: Could not allocate generic interrupt chip.\n",
140 			ictl);
141 		goto gc_alloc_fail;
142 	}
143 
144 	gc = domain->gc->gc[0];
145 	gc->reg_base                         = reg_base;
146 
147 	gc->chip_types[0].type               = IRQ_TYPE_LEVEL_MASK;
148 	gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
149 	gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
150 	gc->chip_types[0].chip.irq_set_type  = tb10x_irq_set_type;
151 	gc->chip_types[0].regs.mask          = AB_IRQCTL_INT_ENABLE;
152 
153 	gc->chip_types[1].type               = IRQ_TYPE_EDGE_BOTH;
154 	gc->chip_types[1].chip.name          = gc->chip_types[0].chip.name;
155 	gc->chip_types[1].chip.irq_ack       = irq_gc_ack_set_bit;
156 	gc->chip_types[1].chip.irq_mask      = irq_gc_mask_clr_bit;
157 	gc->chip_types[1].chip.irq_unmask    = irq_gc_mask_set_bit;
158 	gc->chip_types[1].chip.irq_set_type  = tb10x_irq_set_type;
159 	gc->chip_types[1].regs.ack           = AB_IRQCTL_INT_STATUS;
160 	gc->chip_types[1].regs.mask          = AB_IRQCTL_INT_ENABLE;
161 	gc->chip_types[1].handler            = handle_edge_irq;
162 
163 	for (i = 0; i < nrirqs; i++) {
164 		unsigned int irq = irq_of_parse_and_map(ictl, i);
165 
166 		irq_set_chained_handler_and_data(irq, tb10x_irq_cascade,
167 						 domain);
168 	}
169 
170 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_ENABLE, 0);
171 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_MODE, 0);
172 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_POLARITY, 0);
173 	ab_irqctl_writereg(gc, AB_IRQCTL_INT_STATUS, ~0UL);
174 
175 	return 0;
176 
177 gc_alloc_fail:
178 	irq_domain_remove(domain);
179 irq_domain_add_fail:
180 	iounmap(reg_base);
181 ioremap_fail:
182 	release_mem_region(mem.start, resource_size(&mem));
183 	return ret;
184 }
185 IRQCHIP_DECLARE(tb10x_intc, "abilis,tb10x-ictl", of_tb10x_init_irq);
186