1 /*
2  * Copyright (C) 2014 Mans Rullgard <mans@mansr.com>
3  *
4  * This program is free software; you can redistribute  it and/or modify it
5  * under  the terms of  the GNU General  Public License as published by the
6  * Free Software Foundation;  either version 2 of the  License, or (at your
7  * option) any later version.
8  */
9 
10 #include <linux/init.h>
11 #include <linux/irq.h>
12 #include <linux/irqchip.h>
13 #include <linux/irqchip/chained_irq.h>
14 #include <linux/ioport.h>
15 #include <linux/io.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <linux/slab.h>
19 
20 #define IRQ0_CTL_BASE		0x0000
21 #define IRQ1_CTL_BASE		0x0100
22 #define EDGE_CTL_BASE		0x0200
23 #define IRQ2_CTL_BASE		0x0300
24 
25 #define IRQ_CTL_HI		0x18
26 #define EDGE_CTL_HI		0x20
27 
28 #define IRQ_STATUS		0x00
29 #define IRQ_RAWSTAT		0x04
30 #define IRQ_EN_SET		0x08
31 #define IRQ_EN_CLR		0x0c
32 #define IRQ_SOFT_SET		0x10
33 #define IRQ_SOFT_CLR		0x14
34 
35 #define EDGE_STATUS		0x00
36 #define EDGE_RAWSTAT		0x04
37 #define EDGE_CFG_RISE		0x08
38 #define EDGE_CFG_FALL		0x0c
39 #define EDGE_CFG_RISE_SET	0x10
40 #define EDGE_CFG_RISE_CLR	0x14
41 #define EDGE_CFG_FALL_SET	0x18
42 #define EDGE_CFG_FALL_CLR	0x1c
43 
44 struct tangox_irq_chip {
45 	void __iomem *base;
46 	unsigned long ctl;
47 };
48 
intc_readl(struct tangox_irq_chip * chip,int reg)49 static inline u32 intc_readl(struct tangox_irq_chip *chip, int reg)
50 {
51 	return readl_relaxed(chip->base + reg);
52 }
53 
intc_writel(struct tangox_irq_chip * chip,int reg,u32 val)54 static inline void intc_writel(struct tangox_irq_chip *chip, int reg, u32 val)
55 {
56 	writel_relaxed(val, chip->base + reg);
57 }
58 
tangox_dispatch_irqs(struct irq_domain * dom,unsigned int status,int base)59 static void tangox_dispatch_irqs(struct irq_domain *dom, unsigned int status,
60 				 int base)
61 {
62 	unsigned int hwirq;
63 	unsigned int virq;
64 
65 	while (status) {
66 		hwirq = __ffs(status);
67 		virq = irq_find_mapping(dom, base + hwirq);
68 		if (virq)
69 			generic_handle_irq(virq);
70 		status &= ~BIT(hwirq);
71 	}
72 }
73 
tangox_irq_handler(struct irq_desc * desc)74 static void tangox_irq_handler(struct irq_desc *desc)
75 {
76 	struct irq_domain *dom = irq_desc_get_handler_data(desc);
77 	struct irq_chip *host_chip = irq_desc_get_chip(desc);
78 	struct tangox_irq_chip *chip = dom->host_data;
79 	unsigned int status_lo, status_hi;
80 
81 	chained_irq_enter(host_chip, desc);
82 
83 	status_lo = intc_readl(chip, chip->ctl + IRQ_STATUS);
84 	status_hi = intc_readl(chip, chip->ctl + IRQ_CTL_HI + IRQ_STATUS);
85 
86 	tangox_dispatch_irqs(dom, status_lo, 0);
87 	tangox_dispatch_irqs(dom, status_hi, 32);
88 
89 	chained_irq_exit(host_chip, desc);
90 }
91 
tangox_irq_set_type(struct irq_data * d,unsigned int flow_type)92 static int tangox_irq_set_type(struct irq_data *d, unsigned int flow_type)
93 {
94 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
95 	struct tangox_irq_chip *chip = gc->domain->host_data;
96 	struct irq_chip_regs *regs = &gc->chip_types[0].regs;
97 
98 	switch (flow_type & IRQ_TYPE_SENSE_MASK) {
99 	case IRQ_TYPE_EDGE_RISING:
100 		intc_writel(chip, regs->type + EDGE_CFG_RISE_SET, d->mask);
101 		intc_writel(chip, regs->type + EDGE_CFG_FALL_CLR, d->mask);
102 		break;
103 
104 	case IRQ_TYPE_EDGE_FALLING:
105 		intc_writel(chip, regs->type + EDGE_CFG_RISE_CLR, d->mask);
106 		intc_writel(chip, regs->type + EDGE_CFG_FALL_SET, d->mask);
107 		break;
108 
109 	case IRQ_TYPE_LEVEL_HIGH:
110 		intc_writel(chip, regs->type + EDGE_CFG_RISE_CLR, d->mask);
111 		intc_writel(chip, regs->type + EDGE_CFG_FALL_CLR, d->mask);
112 		break;
113 
114 	case IRQ_TYPE_LEVEL_LOW:
115 		intc_writel(chip, regs->type + EDGE_CFG_RISE_SET, d->mask);
116 		intc_writel(chip, regs->type + EDGE_CFG_FALL_SET, d->mask);
117 		break;
118 
119 	default:
120 		pr_err("Invalid trigger mode %x for IRQ %d\n",
121 		       flow_type, d->irq);
122 		return -EINVAL;
123 	}
124 
125 	return irq_setup_alt_chip(d, flow_type);
126 }
127 
tangox_irq_init_chip(struct irq_chip_generic * gc,unsigned long ctl_offs,unsigned long edge_offs)128 static void __init tangox_irq_init_chip(struct irq_chip_generic *gc,
129 					unsigned long ctl_offs,
130 					unsigned long edge_offs)
131 {
132 	struct tangox_irq_chip *chip = gc->domain->host_data;
133 	struct irq_chip_type *ct = gc->chip_types;
134 	unsigned long ctl_base = chip->ctl + ctl_offs;
135 	unsigned long edge_base = EDGE_CTL_BASE + edge_offs;
136 	int i;
137 
138 	gc->reg_base = chip->base;
139 	gc->unused = 0;
140 
141 	for (i = 0; i < 2; i++) {
142 		ct[i].chip.irq_ack = irq_gc_ack_set_bit;
143 		ct[i].chip.irq_mask = irq_gc_mask_disable_reg;
144 		ct[i].chip.irq_mask_ack = irq_gc_mask_disable_and_ack_set;
145 		ct[i].chip.irq_unmask = irq_gc_unmask_enable_reg;
146 		ct[i].chip.irq_set_type = tangox_irq_set_type;
147 		ct[i].chip.name = gc->domain->name;
148 
149 		ct[i].regs.enable = ctl_base + IRQ_EN_SET;
150 		ct[i].regs.disable = ctl_base + IRQ_EN_CLR;
151 		ct[i].regs.ack = edge_base + EDGE_RAWSTAT;
152 		ct[i].regs.type = edge_base;
153 	}
154 
155 	ct[0].type = IRQ_TYPE_LEVEL_MASK;
156 	ct[0].handler = handle_level_irq;
157 
158 	ct[1].type = IRQ_TYPE_EDGE_BOTH;
159 	ct[1].handler = handle_edge_irq;
160 
161 	intc_writel(chip, ct->regs.disable, 0xffffffff);
162 	intc_writel(chip, ct->regs.ack, 0xffffffff);
163 }
164 
tangox_irq_domain_init(struct irq_domain * dom)165 static void __init tangox_irq_domain_init(struct irq_domain *dom)
166 {
167 	struct irq_chip_generic *gc;
168 	int i;
169 
170 	for (i = 0; i < 2; i++) {
171 		gc = irq_get_domain_generic_chip(dom, i * 32);
172 		tangox_irq_init_chip(gc, i * IRQ_CTL_HI, i * EDGE_CTL_HI);
173 	}
174 }
175 
tangox_irq_init(void __iomem * base,struct resource * baseres,struct device_node * node)176 static int __init tangox_irq_init(void __iomem *base, struct resource *baseres,
177 				  struct device_node *node)
178 {
179 	struct tangox_irq_chip *chip;
180 	struct irq_domain *dom;
181 	struct resource res;
182 	int irq;
183 	int err;
184 
185 	irq = irq_of_parse_and_map(node, 0);
186 	if (!irq)
187 		panic("%s: failed to get IRQ", node->name);
188 
189 	err = of_address_to_resource(node, 0, &res);
190 	if (err)
191 		panic("%s: failed to get address", node->name);
192 
193 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
194 	chip->ctl = res.start - baseres->start;
195 	chip->base = base;
196 
197 	dom = irq_domain_add_linear(node, 64, &irq_generic_chip_ops, chip);
198 	if (!dom)
199 		panic("%s: failed to create irqdomain", node->name);
200 
201 	err = irq_alloc_domain_generic_chips(dom, 32, 2, node->name,
202 					     handle_level_irq, 0, 0, 0);
203 	if (err)
204 		panic("%s: failed to allocate irqchip", node->name);
205 
206 	tangox_irq_domain_init(dom);
207 
208 	irq_set_chained_handler_and_data(irq, tangox_irq_handler, dom);
209 
210 	return 0;
211 }
212 
tangox_of_irq_init(struct device_node * node,struct device_node * parent)213 static int __init tangox_of_irq_init(struct device_node *node,
214 				     struct device_node *parent)
215 {
216 	struct device_node *c;
217 	struct resource res;
218 	void __iomem *base;
219 
220 	base = of_iomap(node, 0);
221 	if (!base)
222 		panic("%s: of_iomap failed", node->name);
223 
224 	of_address_to_resource(node, 0, &res);
225 
226 	for_each_child_of_node(node, c)
227 		tangox_irq_init(base, &res, c);
228 
229 	return 0;
230 }
231 IRQCHIP_DECLARE(tangox_intc, "sigma,smp8642-intc", tangox_of_irq_init);
232