1 /*
2  *  CLPS711X IRQ driver
3  *
4  *  Copyright (C) 2013 Alexander Shiyan <shc_work@mail.ru>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/of_address.h>
16 #include <linux/of_irq.h>
17 #include <linux/slab.h>
18 
19 #include <asm/exception.h>
20 #include <asm/mach/irq.h>
21 
22 #include "irqchip.h"
23 
24 #define CLPS711X_INTSR1	(0x0240)
25 #define CLPS711X_INTMR1	(0x0280)
26 #define CLPS711X_BLEOI	(0x0600)
27 #define CLPS711X_MCEOI	(0x0640)
28 #define CLPS711X_TEOI	(0x0680)
29 #define CLPS711X_TC1EOI	(0x06c0)
30 #define CLPS711X_TC2EOI	(0x0700)
31 #define CLPS711X_RTCEOI	(0x0740)
32 #define CLPS711X_UMSEOI	(0x0780)
33 #define CLPS711X_COEOI	(0x07c0)
34 #define CLPS711X_INTSR2	(0x1240)
35 #define CLPS711X_INTMR2	(0x1280)
36 #define CLPS711X_SRXEOF	(0x1600)
37 #define CLPS711X_KBDEOI	(0x1700)
38 #define CLPS711X_INTSR3	(0x2240)
39 #define CLPS711X_INTMR3	(0x2280)
40 
41 static const struct {
42 #define CLPS711X_FLAG_EN	(1 << 0)
43 #define CLPS711X_FLAG_FIQ	(1 << 1)
44 	unsigned int	flags;
45 	phys_addr_t	eoi;
46 } clps711x_irqs[] = {
47 	[1]	= { CLPS711X_FLAG_FIQ, CLPS711X_BLEOI, },
48 	[3]	= { CLPS711X_FLAG_FIQ, CLPS711X_MCEOI, },
49 	[4]	= { CLPS711X_FLAG_EN, CLPS711X_COEOI, },
50 	[5]	= { CLPS711X_FLAG_EN, },
51 	[6]	= { CLPS711X_FLAG_EN, },
52 	[7]	= { CLPS711X_FLAG_EN, },
53 	[8]	= { CLPS711X_FLAG_EN, CLPS711X_TC1EOI, },
54 	[9]	= { CLPS711X_FLAG_EN, CLPS711X_TC2EOI, },
55 	[10]	= { CLPS711X_FLAG_EN, CLPS711X_RTCEOI, },
56 	[11]	= { CLPS711X_FLAG_EN, CLPS711X_TEOI, },
57 	[12]	= { CLPS711X_FLAG_EN, },
58 	[13]	= { CLPS711X_FLAG_EN, },
59 	[14]	= { CLPS711X_FLAG_EN, CLPS711X_UMSEOI, },
60 	[15]	= { CLPS711X_FLAG_EN, CLPS711X_SRXEOF, },
61 	[16]	= { CLPS711X_FLAG_EN, CLPS711X_KBDEOI, },
62 	[17]	= { CLPS711X_FLAG_EN, },
63 	[18]	= { CLPS711X_FLAG_EN, },
64 	[28]	= { CLPS711X_FLAG_EN, },
65 	[29]	= { CLPS711X_FLAG_EN, },
66 	[32]	= { CLPS711X_FLAG_FIQ, },
67 };
68 
69 static struct {
70 	void __iomem		*base;
71 	void __iomem		*intmr[3];
72 	void __iomem		*intsr[3];
73 	struct irq_domain	*domain;
74 	struct irq_domain_ops	ops;
75 } *clps711x_intc;
76 
77 static asmlinkage void __exception_irq_entry clps711x_irqh(struct pt_regs *regs)
78 {
79 	u32 irqnr, irqstat;
80 
81 	do {
82 		irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
83 			  readw_relaxed(clps711x_intc->intsr[0]);
84 		if (irqstat) {
85 			irqnr =	irq_find_mapping(clps711x_intc->domain,
86 						 fls(irqstat) - 1);
87 			handle_IRQ(irqnr, regs);
88 		}
89 
90 		irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
91 			  readw_relaxed(clps711x_intc->intsr[1]);
92 		if (irqstat) {
93 			irqnr =	irq_find_mapping(clps711x_intc->domain,
94 						 fls(irqstat) - 1 + 16);
95 			handle_IRQ(irqnr, regs);
96 		}
97 	} while (irqstat);
98 }
99 
100 static void clps711x_intc_eoi(struct irq_data *d)
101 {
102 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
103 
104 	writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
105 }
106 
107 static void clps711x_intc_mask(struct irq_data *d)
108 {
109 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
110 	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
111 	u32 tmp;
112 
113 	tmp = readl_relaxed(intmr);
114 	tmp &= ~(1 << (hwirq % 16));
115 	writel_relaxed(tmp, intmr);
116 }
117 
118 static void clps711x_intc_unmask(struct irq_data *d)
119 {
120 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
121 	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
122 	u32 tmp;
123 
124 	tmp = readl_relaxed(intmr);
125 	tmp |= 1 << (hwirq % 16);
126 	writel_relaxed(tmp, intmr);
127 }
128 
129 static struct irq_chip clps711x_intc_chip = {
130 	.name		= "clps711x-intc",
131 	.irq_eoi	= clps711x_intc_eoi,
132 	.irq_mask	= clps711x_intc_mask,
133 	.irq_unmask	= clps711x_intc_unmask,
134 };
135 
136 static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
137 					irq_hw_number_t hw)
138 {
139 	irq_flow_handler_t handler = handle_level_irq;
140 	unsigned int flags = IRQF_VALID | IRQF_PROBE;
141 
142 	if (!clps711x_irqs[hw].flags)
143 		return 0;
144 
145 	if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
146 		handler = handle_bad_irq;
147 		flags |= IRQF_NOAUTOEN;
148 	} else if (clps711x_irqs[hw].eoi) {
149 		handler = handle_fasteoi_irq;
150 	}
151 
152 	/* Clear down pending interrupt */
153 	if (clps711x_irqs[hw].eoi)
154 		writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);
155 
156 	irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);
157 	set_irq_flags(virq, flags);
158 
159 	return 0;
160 }
161 
162 static int __init _clps711x_intc_init(struct device_node *np,
163 				      phys_addr_t base, resource_size_t size)
164 {
165 	int err;
166 
167 	clps711x_intc = kzalloc(sizeof(*clps711x_intc), GFP_KERNEL);
168 	if (!clps711x_intc)
169 		return -ENOMEM;
170 
171 	clps711x_intc->base = ioremap(base, size);
172 	if (!clps711x_intc->base) {
173 		err = -ENOMEM;
174 		goto out_kfree;
175 	}
176 
177 	clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
178 	clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
179 	clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
180 	clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
181 	clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
182 	clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;
183 
184 	/* Mask all interrupts */
185 	writel_relaxed(0, clps711x_intc->intmr[0]);
186 	writel_relaxed(0, clps711x_intc->intmr[1]);
187 	writel_relaxed(0, clps711x_intc->intmr[2]);
188 
189 	err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());
190 	if (IS_ERR_VALUE(err))
191 		goto out_iounmap;
192 
193 	clps711x_intc->ops.map = clps711x_intc_irq_map;
194 	clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
195 	clps711x_intc->domain =
196 		irq_domain_add_legacy(np, ARRAY_SIZE(clps711x_irqs),
197 				      0, 0, &clps711x_intc->ops, NULL);
198 	if (!clps711x_intc->domain) {
199 		err = -ENOMEM;
200 		goto out_irqfree;
201 	}
202 
203 	irq_set_default_host(clps711x_intc->domain);
204 	set_handle_irq(clps711x_irqh);
205 
206 #ifdef CONFIG_FIQ
207 	init_FIQ(0);
208 #endif
209 
210 	return 0;
211 
212 out_irqfree:
213 	irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));
214 
215 out_iounmap:
216 	iounmap(clps711x_intc->base);
217 
218 out_kfree:
219 	kfree(clps711x_intc);
220 
221 	return err;
222 }
223 
224 void __init clps711x_intc_init(phys_addr_t base, resource_size_t size)
225 {
226 	BUG_ON(_clps711x_intc_init(NULL, base, size));
227 }
228 
229 #ifdef CONFIG_IRQCHIP
230 static int __init clps711x_intc_init_dt(struct device_node *np,
231 					struct device_node *parent)
232 {
233 	struct resource res;
234 	int err;
235 
236 	err = of_address_to_resource(np, 0, &res);
237 	if (err)
238 		return err;
239 
240 	return _clps711x_intc_init(np, res.start, resource_size(&res));
241 }
242 IRQCHIP_DECLARE(clps711x, "cirrus,clps711x-intc", clps711x_intc_init_dt);
243 #endif
244