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 irqstat;
80 
81 	do {
82 		irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
83 			  readw_relaxed(clps711x_intc->intsr[0]);
84 		if (irqstat)
85 			handle_domain_irq(clps711x_intc->domain,
86 					  fls(irqstat) - 1, regs);
87 
88 		irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
89 			  readw_relaxed(clps711x_intc->intsr[1]);
90 		if (irqstat)
91 			handle_domain_irq(clps711x_intc->domain,
92 					  fls(irqstat) - 1 + 16, regs);
93 	} while (irqstat);
94 }
95 
96 static void clps711x_intc_eoi(struct irq_data *d)
97 {
98 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
99 
100 	writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
101 }
102 
103 static void clps711x_intc_mask(struct irq_data *d)
104 {
105 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
106 	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
107 	u32 tmp;
108 
109 	tmp = readl_relaxed(intmr);
110 	tmp &= ~(1 << (hwirq % 16));
111 	writel_relaxed(tmp, intmr);
112 }
113 
114 static void clps711x_intc_unmask(struct irq_data *d)
115 {
116 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
117 	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
118 	u32 tmp;
119 
120 	tmp = readl_relaxed(intmr);
121 	tmp |= 1 << (hwirq % 16);
122 	writel_relaxed(tmp, intmr);
123 }
124 
125 static struct irq_chip clps711x_intc_chip = {
126 	.name		= "clps711x-intc",
127 	.irq_eoi	= clps711x_intc_eoi,
128 	.irq_mask	= clps711x_intc_mask,
129 	.irq_unmask	= clps711x_intc_unmask,
130 };
131 
132 static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
133 					irq_hw_number_t hw)
134 {
135 	irq_flow_handler_t handler = handle_level_irq;
136 	unsigned int flags = IRQF_VALID | IRQF_PROBE;
137 
138 	if (!clps711x_irqs[hw].flags)
139 		return 0;
140 
141 	if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
142 		handler = handle_bad_irq;
143 		flags |= IRQF_NOAUTOEN;
144 	} else if (clps711x_irqs[hw].eoi) {
145 		handler = handle_fasteoi_irq;
146 	}
147 
148 	/* Clear down pending interrupt */
149 	if (clps711x_irqs[hw].eoi)
150 		writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);
151 
152 	irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);
153 	set_irq_flags(virq, flags);
154 
155 	return 0;
156 }
157 
158 static int __init _clps711x_intc_init(struct device_node *np,
159 				      phys_addr_t base, resource_size_t size)
160 {
161 	int err;
162 
163 	clps711x_intc = kzalloc(sizeof(*clps711x_intc), GFP_KERNEL);
164 	if (!clps711x_intc)
165 		return -ENOMEM;
166 
167 	clps711x_intc->base = ioremap(base, size);
168 	if (!clps711x_intc->base) {
169 		err = -ENOMEM;
170 		goto out_kfree;
171 	}
172 
173 	clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
174 	clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
175 	clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
176 	clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
177 	clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
178 	clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;
179 
180 	/* Mask all interrupts */
181 	writel_relaxed(0, clps711x_intc->intmr[0]);
182 	writel_relaxed(0, clps711x_intc->intmr[1]);
183 	writel_relaxed(0, clps711x_intc->intmr[2]);
184 
185 	err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());
186 	if (IS_ERR_VALUE(err))
187 		goto out_iounmap;
188 
189 	clps711x_intc->ops.map = clps711x_intc_irq_map;
190 	clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
191 	clps711x_intc->domain =
192 		irq_domain_add_legacy(np, ARRAY_SIZE(clps711x_irqs),
193 				      0, 0, &clps711x_intc->ops, NULL);
194 	if (!clps711x_intc->domain) {
195 		err = -ENOMEM;
196 		goto out_irqfree;
197 	}
198 
199 	irq_set_default_host(clps711x_intc->domain);
200 	set_handle_irq(clps711x_irqh);
201 
202 #ifdef CONFIG_FIQ
203 	init_FIQ(0);
204 #endif
205 
206 	return 0;
207 
208 out_irqfree:
209 	irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));
210 
211 out_iounmap:
212 	iounmap(clps711x_intc->base);
213 
214 out_kfree:
215 	kfree(clps711x_intc);
216 
217 	return err;
218 }
219 
220 void __init clps711x_intc_init(phys_addr_t base, resource_size_t size)
221 {
222 	BUG_ON(_clps711x_intc_init(NULL, base, size));
223 }
224 
225 #ifdef CONFIG_IRQCHIP
226 static int __init clps711x_intc_init_dt(struct device_node *np,
227 					struct device_node *parent)
228 {
229 	struct resource res;
230 	int err;
231 
232 	err = of_address_to_resource(np, 0, &res);
233 	if (err)
234 		return err;
235 
236 	return _clps711x_intc_init(np, res.start, resource_size(&res));
237 }
238 IRQCHIP_DECLARE(clps711x, "cirrus,clps711x-intc", clps711x_intc_init_dt);
239 #endif
240