1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * irqchip for the Faraday Technology FTINTC010 Copyright (C) 2017 Linus
4  * Walleij <linus.walleij@linaro.org>
5  *
6  * Based on arch/arm/mach-gemini/irq.c
7  * Copyright (C) 2001-2006 Storlink, Corp.
8  * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@gmail.com>
9  */
10 #include <linux/bitops.h>
11 #include <linux/irq.h>
12 #include <linux/io.h>
13 #include <linux/irqchip.h>
14 #include <linux/irqchip/versatile-fpga.h>
15 #include <linux/irqdomain.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/cpu.h>
21 
22 #include <asm/exception.h>
23 #include <asm/mach/irq.h>
24 
25 #define FT010_NUM_IRQS 32
26 
27 #define FT010_IRQ_SOURCE(base_addr)	(base_addr + 0x00)
28 #define FT010_IRQ_MASK(base_addr)	(base_addr + 0x04)
29 #define FT010_IRQ_CLEAR(base_addr)	(base_addr + 0x08)
30 /* Selects level- or edge-triggered */
31 #define FT010_IRQ_MODE(base_addr)	(base_addr + 0x0C)
32 /* Selects active low/high or falling/rising edge */
33 #define FT010_IRQ_POLARITY(base_addr)	(base_addr + 0x10)
34 #define FT010_IRQ_STATUS(base_addr)	(base_addr + 0x14)
35 #define FT010_FIQ_SOURCE(base_addr)	(base_addr + 0x20)
36 #define FT010_FIQ_MASK(base_addr)	(base_addr + 0x24)
37 #define FT010_FIQ_CLEAR(base_addr)	(base_addr + 0x28)
38 #define FT010_FIQ_MODE(base_addr)	(base_addr + 0x2C)
39 #define FT010_FIQ_POLARITY(base_addr)	(base_addr + 0x30)
40 #define FT010_FIQ_STATUS(base_addr)	(base_addr + 0x34)
41 
42 /**
43  * struct ft010_irq_data - irq data container for the Faraday IRQ controller
44  * @base: memory offset in virtual memory
45  * @chip: chip container for this instance
46  * @domain: IRQ domain for this instance
47  */
48 struct ft010_irq_data {
49 	void __iomem *base;
50 	struct irq_chip chip;
51 	struct irq_domain *domain;
52 };
53 
54 static void ft010_irq_mask(struct irq_data *d)
55 {
56 	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
57 	unsigned int mask;
58 
59 	mask = readl(FT010_IRQ_MASK(f->base));
60 	mask &= ~BIT(irqd_to_hwirq(d));
61 	writel(mask, FT010_IRQ_MASK(f->base));
62 }
63 
64 static void ft010_irq_unmask(struct irq_data *d)
65 {
66 	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
67 	unsigned int mask;
68 
69 	mask = readl(FT010_IRQ_MASK(f->base));
70 	mask |= BIT(irqd_to_hwirq(d));
71 	writel(mask, FT010_IRQ_MASK(f->base));
72 }
73 
74 static void ft010_irq_ack(struct irq_data *d)
75 {
76 	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
77 
78 	writel(BIT(irqd_to_hwirq(d)), FT010_IRQ_CLEAR(f->base));
79 }
80 
81 static int ft010_irq_set_type(struct irq_data *d, unsigned int trigger)
82 {
83 	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
84 	int offset = irqd_to_hwirq(d);
85 	u32 mode, polarity;
86 
87 	mode = readl(FT010_IRQ_MODE(f->base));
88 	polarity = readl(FT010_IRQ_POLARITY(f->base));
89 
90 	if (trigger & (IRQ_TYPE_LEVEL_LOW)) {
91 		irq_set_handler_locked(d, handle_level_irq);
92 		mode &= ~BIT(offset);
93 		polarity |= BIT(offset);
94 	} else if (trigger & (IRQ_TYPE_LEVEL_HIGH)) {
95 		irq_set_handler_locked(d, handle_level_irq);
96 		mode &= ~BIT(offset);
97 		polarity &= ~BIT(offset);
98 	} else if (trigger & IRQ_TYPE_EDGE_FALLING) {
99 		irq_set_handler_locked(d, handle_edge_irq);
100 		mode |= BIT(offset);
101 		polarity |= BIT(offset);
102 	} else if (trigger & IRQ_TYPE_EDGE_RISING) {
103 		irq_set_handler_locked(d, handle_edge_irq);
104 		mode |= BIT(offset);
105 		polarity &= ~BIT(offset);
106 	} else {
107 		irq_set_handler_locked(d, handle_bad_irq);
108 		pr_warn("Faraday IRQ: no supported trigger selected for line %d\n",
109 			offset);
110 	}
111 
112 	writel(mode, FT010_IRQ_MODE(f->base));
113 	writel(polarity, FT010_IRQ_POLARITY(f->base));
114 
115 	return 0;
116 }
117 
118 static struct irq_chip ft010_irq_chip = {
119 	.name		= "FTINTC010",
120 	.irq_ack	= ft010_irq_ack,
121 	.irq_mask	= ft010_irq_mask,
122 	.irq_unmask	= ft010_irq_unmask,
123 	.irq_set_type	= ft010_irq_set_type,
124 };
125 
126 /* Local static for the IRQ entry call */
127 static struct ft010_irq_data firq;
128 
129 asmlinkage void __exception_irq_entry ft010_irqchip_handle_irq(struct pt_regs *regs)
130 {
131 	struct ft010_irq_data *f = &firq;
132 	int irq;
133 	u32 status;
134 
135 	while ((status = readl(FT010_IRQ_STATUS(f->base)))) {
136 		irq = ffs(status) - 1;
137 		generic_handle_domain_irq(f->domain, irq);
138 	}
139 }
140 
141 static int ft010_irqdomain_map(struct irq_domain *d, unsigned int irq,
142 				irq_hw_number_t hwirq)
143 {
144 	struct ft010_irq_data *f = d->host_data;
145 
146 	irq_set_chip_data(irq, f);
147 	/* All IRQs should set up their type, flags as bad by default */
148 	irq_set_chip_and_handler(irq, &ft010_irq_chip, handle_bad_irq);
149 	irq_set_probe(irq);
150 
151 	return 0;
152 }
153 
154 static void ft010_irqdomain_unmap(struct irq_domain *d, unsigned int irq)
155 {
156 	irq_set_chip_and_handler(irq, NULL, NULL);
157 	irq_set_chip_data(irq, NULL);
158 }
159 
160 static const struct irq_domain_ops ft010_irqdomain_ops = {
161 	.map = ft010_irqdomain_map,
162 	.unmap = ft010_irqdomain_unmap,
163 	.xlate = irq_domain_xlate_onetwocell,
164 };
165 
166 int __init ft010_of_init_irq(struct device_node *node,
167 			      struct device_node *parent)
168 {
169 	struct ft010_irq_data *f = &firq;
170 
171 	/*
172 	 * Disable the idle handler by default since it is buggy
173 	 * For more info see arch/arm/mach-gemini/idle.c
174 	 */
175 	cpu_idle_poll_ctrl(true);
176 
177 	f->base = of_iomap(node, 0);
178 	WARN(!f->base, "unable to map gemini irq registers\n");
179 
180 	/* Disable all interrupts */
181 	writel(0, FT010_IRQ_MASK(f->base));
182 	writel(0, FT010_FIQ_MASK(f->base));
183 
184 	f->domain = irq_domain_add_simple(node, FT010_NUM_IRQS, 0,
185 					  &ft010_irqdomain_ops, f);
186 	set_handle_irq(ft010_irqchip_handle_irq);
187 
188 	return 0;
189 }
190 IRQCHIP_DECLARE(faraday, "faraday,ftintc010",
191 		ft010_of_init_irq);
192 IRQCHIP_DECLARE(gemini, "cortina,gemini-interrupt-controller",
193 		ft010_of_init_irq);
194 IRQCHIP_DECLARE(moxa, "moxa,moxart-ic",
195 		ft010_of_init_irq);
196