1 /*
2  * Atmel AT91 AIC (Advanced Interrupt Controller) driver
3  *
4  *  Copyright (C) 2004 SAN People
5  *  Copyright (C) 2004 ATMEL
6  *  Copyright (C) Rick Bronson
7  *  Copyright (C) 2014 Free Electrons
8  *
9  *  Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2.  This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/mm.h>
19 #include <linux/bitmap.h>
20 #include <linux/types.h>
21 #include <linux/irq.h>
22 #include <linux/irqchip.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/irqdomain.h>
27 #include <linux/err.h>
28 #include <linux/slab.h>
29 #include <linux/io.h>
30 
31 #include <asm/exception.h>
32 #include <asm/mach/irq.h>
33 
34 #include "irq-atmel-aic-common.h"
35 
36 /* Number of irq lines managed by AIC */
37 #define NR_AIC_IRQS	32
38 
39 #define AT91_AIC_SMR(n)			((n) * 4)
40 
41 #define AT91_AIC_SVR(n)			(0x80 + ((n) * 4))
42 #define AT91_AIC_IVR			0x100
43 #define AT91_AIC_FVR			0x104
44 #define AT91_AIC_ISR			0x108
45 
46 #define AT91_AIC_IPR			0x10c
47 #define AT91_AIC_IMR			0x110
48 #define AT91_AIC_CISR			0x114
49 
50 #define AT91_AIC_IECR			0x120
51 #define AT91_AIC_IDCR			0x124
52 #define AT91_AIC_ICCR			0x128
53 #define AT91_AIC_ISCR			0x12c
54 #define AT91_AIC_EOICR			0x130
55 #define AT91_AIC_SPU			0x134
56 #define AT91_AIC_DCR			0x138
57 
58 static struct irq_domain *aic_domain;
59 
60 static asmlinkage void __exception_irq_entry
61 aic_handle(struct pt_regs *regs)
62 {
63 	struct irq_domain_chip_generic *dgc = aic_domain->gc;
64 	struct irq_chip_generic *gc = dgc->gc[0];
65 	u32 irqnr;
66 	u32 irqstat;
67 
68 	irqnr = irq_reg_readl(gc, AT91_AIC_IVR);
69 	irqstat = irq_reg_readl(gc, AT91_AIC_ISR);
70 
71 	if (!irqstat)
72 		irq_reg_writel(gc, 0, AT91_AIC_EOICR);
73 	else
74 		generic_handle_domain_irq(aic_domain, irqnr);
75 }
76 
77 static int aic_retrigger(struct irq_data *d)
78 {
79 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
80 
81 	/* Enable interrupt on AIC5 */
82 	irq_gc_lock(gc);
83 	irq_reg_writel(gc, d->mask, AT91_AIC_ISCR);
84 	irq_gc_unlock(gc);
85 
86 	return 1;
87 }
88 
89 static int aic_set_type(struct irq_data *d, unsigned type)
90 {
91 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
92 	unsigned int smr;
93 	int ret;
94 
95 	smr = irq_reg_readl(gc, AT91_AIC_SMR(d->hwirq));
96 	ret = aic_common_set_type(d, type, &smr);
97 	if (ret)
98 		return ret;
99 
100 	irq_reg_writel(gc, smr, AT91_AIC_SMR(d->hwirq));
101 
102 	return 0;
103 }
104 
105 #ifdef CONFIG_PM
106 static void aic_suspend(struct irq_data *d)
107 {
108 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
109 
110 	irq_gc_lock(gc);
111 	irq_reg_writel(gc, gc->mask_cache, AT91_AIC_IDCR);
112 	irq_reg_writel(gc, gc->wake_active, AT91_AIC_IECR);
113 	irq_gc_unlock(gc);
114 }
115 
116 static void aic_resume(struct irq_data *d)
117 {
118 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
119 
120 	irq_gc_lock(gc);
121 	irq_reg_writel(gc, gc->wake_active, AT91_AIC_IDCR);
122 	irq_reg_writel(gc, gc->mask_cache, AT91_AIC_IECR);
123 	irq_gc_unlock(gc);
124 }
125 
126 static void aic_pm_shutdown(struct irq_data *d)
127 {
128 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
129 
130 	irq_gc_lock(gc);
131 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_IDCR);
132 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_ICCR);
133 	irq_gc_unlock(gc);
134 }
135 #else
136 #define aic_suspend		NULL
137 #define aic_resume		NULL
138 #define aic_pm_shutdown		NULL
139 #endif /* CONFIG_PM */
140 
141 static void __init aic_hw_init(struct irq_domain *domain)
142 {
143 	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
144 	int i;
145 
146 	/*
147 	 * Perform 8 End Of Interrupt Command to make sure AIC
148 	 * will not Lock out nIRQ
149 	 */
150 	for (i = 0; i < 8; i++)
151 		irq_reg_writel(gc, 0, AT91_AIC_EOICR);
152 
153 	/*
154 	 * Spurious Interrupt ID in Spurious Vector Register.
155 	 * When there is no current interrupt, the IRQ Vector Register
156 	 * reads the value stored in AIC_SPU
157 	 */
158 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_SPU);
159 
160 	/* No debugging in AIC: Debug (Protect) Control Register */
161 	irq_reg_writel(gc, 0, AT91_AIC_DCR);
162 
163 	/* Disable and clear all interrupts initially */
164 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_IDCR);
165 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_ICCR);
166 
167 	for (i = 0; i < 32; i++)
168 		irq_reg_writel(gc, i, AT91_AIC_SVR(i));
169 }
170 
171 static int aic_irq_domain_xlate(struct irq_domain *d,
172 				struct device_node *ctrlr,
173 				const u32 *intspec, unsigned int intsize,
174 				irq_hw_number_t *out_hwirq,
175 				unsigned int *out_type)
176 {
177 	struct irq_domain_chip_generic *dgc = d->gc;
178 	struct irq_chip_generic *gc;
179 	unsigned long flags;
180 	unsigned smr;
181 	int idx;
182 	int ret;
183 
184 	if (!dgc)
185 		return -EINVAL;
186 
187 	ret = aic_common_irq_domain_xlate(d, ctrlr, intspec, intsize,
188 					  out_hwirq, out_type);
189 	if (ret)
190 		return ret;
191 
192 	idx = intspec[0] / dgc->irqs_per_chip;
193 	if (idx >= dgc->num_chips)
194 		return -EINVAL;
195 
196 	gc = dgc->gc[idx];
197 
198 	irq_gc_lock_irqsave(gc, flags);
199 	smr = irq_reg_readl(gc, AT91_AIC_SMR(*out_hwirq));
200 	aic_common_set_priority(intspec[2], &smr);
201 	irq_reg_writel(gc, smr, AT91_AIC_SMR(*out_hwirq));
202 	irq_gc_unlock_irqrestore(gc, flags);
203 
204 	return ret;
205 }
206 
207 static const struct irq_domain_ops aic_irq_ops = {
208 	.map	= irq_map_generic_chip,
209 	.xlate	= aic_irq_domain_xlate,
210 };
211 
212 static void __init at91rm9200_aic_irq_fixup(void)
213 {
214 	aic_common_rtc_irq_fixup();
215 }
216 
217 static void __init at91sam9260_aic_irq_fixup(void)
218 {
219 	aic_common_rtt_irq_fixup();
220 }
221 
222 static void __init at91sam9g45_aic_irq_fixup(void)
223 {
224 	aic_common_rtc_irq_fixup();
225 	aic_common_rtt_irq_fixup();
226 }
227 
228 static const struct of_device_id aic_irq_fixups[] __initconst = {
229 	{ .compatible = "atmel,at91rm9200", .data = at91rm9200_aic_irq_fixup },
230 	{ .compatible = "atmel,at91sam9g45", .data = at91sam9g45_aic_irq_fixup },
231 	{ .compatible = "atmel,at91sam9n12", .data = at91rm9200_aic_irq_fixup },
232 	{ .compatible = "atmel,at91sam9rl", .data = at91sam9g45_aic_irq_fixup },
233 	{ .compatible = "atmel,at91sam9x5", .data = at91rm9200_aic_irq_fixup },
234 	{ .compatible = "atmel,at91sam9260", .data = at91sam9260_aic_irq_fixup },
235 	{ .compatible = "atmel,at91sam9261", .data = at91sam9260_aic_irq_fixup },
236 	{ .compatible = "atmel,at91sam9263", .data = at91sam9260_aic_irq_fixup },
237 	{ .compatible = "atmel,at91sam9g20", .data = at91sam9260_aic_irq_fixup },
238 	{ /* sentinel */ },
239 };
240 
241 static int __init aic_of_init(struct device_node *node,
242 			      struct device_node *parent)
243 {
244 	struct irq_chip_generic *gc;
245 	struct irq_domain *domain;
246 
247 	if (aic_domain)
248 		return -EEXIST;
249 
250 	domain = aic_common_of_init(node, &aic_irq_ops, "atmel-aic",
251 				    NR_AIC_IRQS, aic_irq_fixups);
252 	if (IS_ERR(domain))
253 		return PTR_ERR(domain);
254 
255 	aic_domain = domain;
256 	gc = irq_get_domain_generic_chip(domain, 0);
257 
258 	gc->chip_types[0].regs.eoi = AT91_AIC_EOICR;
259 	gc->chip_types[0].regs.enable = AT91_AIC_IECR;
260 	gc->chip_types[0].regs.disable = AT91_AIC_IDCR;
261 	gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
262 	gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
263 	gc->chip_types[0].chip.irq_retrigger = aic_retrigger;
264 	gc->chip_types[0].chip.irq_set_type = aic_set_type;
265 	gc->chip_types[0].chip.irq_suspend = aic_suspend;
266 	gc->chip_types[0].chip.irq_resume = aic_resume;
267 	gc->chip_types[0].chip.irq_pm_shutdown = aic_pm_shutdown;
268 
269 	aic_hw_init(domain);
270 	set_handle_irq(aic_handle);
271 
272 	return 0;
273 }
274 IRQCHIP_DECLARE(at91rm9200_aic, "atmel,at91rm9200-aic", aic_of_init);
275