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 void __exception_irq_entry aic_handle(struct pt_regs *regs)
61 {
62 	struct irq_domain_chip_generic *dgc = aic_domain->gc;
63 	struct irq_chip_generic *gc = dgc->gc[0];
64 	u32 irqnr;
65 	u32 irqstat;
66 
67 	irqnr = irq_reg_readl(gc, AT91_AIC_IVR);
68 	irqstat = irq_reg_readl(gc, AT91_AIC_ISR);
69 
70 	if (!irqstat)
71 		irq_reg_writel(gc, 0, AT91_AIC_EOICR);
72 	else
73 		generic_handle_domain_irq(aic_domain, irqnr);
74 }
75 
76 static int aic_retrigger(struct irq_data *d)
77 {
78 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
79 
80 	/* Enable interrupt on AIC5 */
81 	guard(raw_spinlock)(&gc->lock);
82 	irq_reg_writel(gc, d->mask, AT91_AIC_ISCR);
83 
84 	return 1;
85 }
86 
87 static int aic_set_type(struct irq_data *d, unsigned type)
88 {
89 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
90 	unsigned int smr;
91 	int ret;
92 
93 	smr = irq_reg_readl(gc, AT91_AIC_SMR(d->hwirq));
94 	ret = aic_common_set_type(d, type, &smr);
95 	if (ret)
96 		return ret;
97 
98 	irq_reg_writel(gc, smr, AT91_AIC_SMR(d->hwirq));
99 
100 	return 0;
101 }
102 
103 #ifdef CONFIG_PM
104 static void aic_suspend(struct irq_data *d)
105 {
106 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
107 
108 	guard(raw_spinlock)(&gc->lock);
109 	irq_reg_writel(gc, gc->mask_cache, AT91_AIC_IDCR);
110 	irq_reg_writel(gc, gc->wake_active, AT91_AIC_IECR);
111 }
112 
113 static void aic_resume(struct irq_data *d)
114 {
115 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
116 
117 	guard(raw_spinlock)(&gc->lock);
118 	irq_reg_writel(gc, gc->wake_active, AT91_AIC_IDCR);
119 	irq_reg_writel(gc, gc->mask_cache, AT91_AIC_IECR);
120 }
121 
122 static void aic_pm_shutdown(struct irq_data *d)
123 {
124 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
125 
126 	guard(raw_spinlock)(&gc->lock);
127 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_IDCR);
128 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_ICCR);
129 }
130 #else
131 #define aic_suspend		NULL
132 #define aic_resume		NULL
133 #define aic_pm_shutdown		NULL
134 #endif /* CONFIG_PM */
135 
136 static void __init aic_hw_init(struct irq_domain *domain)
137 {
138 	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
139 	int i;
140 
141 	/*
142 	 * Perform 8 End Of Interrupt Command to make sure AIC
143 	 * will not Lock out nIRQ
144 	 */
145 	for (i = 0; i < 8; i++)
146 		irq_reg_writel(gc, 0, AT91_AIC_EOICR);
147 
148 	/*
149 	 * Spurious Interrupt ID in Spurious Vector Register.
150 	 * When there is no current interrupt, the IRQ Vector Register
151 	 * reads the value stored in AIC_SPU
152 	 */
153 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_SPU);
154 
155 	/* No debugging in AIC: Debug (Protect) Control Register */
156 	irq_reg_writel(gc, 0, AT91_AIC_DCR);
157 
158 	/* Disable and clear all interrupts initially */
159 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_IDCR);
160 	irq_reg_writel(gc, 0xffffffff, AT91_AIC_ICCR);
161 
162 	for (i = 0; i < 32; i++)
163 		irq_reg_writel(gc, i, AT91_AIC_SVR(i));
164 }
165 
166 static int aic_irq_domain_xlate(struct irq_domain *d,
167 				struct device_node *ctrlr,
168 				const u32 *intspec, unsigned int intsize,
169 				irq_hw_number_t *out_hwirq,
170 				unsigned int *out_type)
171 {
172 	struct irq_domain_chip_generic *dgc = d->gc;
173 	struct irq_chip_generic *gc;
174 	unsigned smr;
175 	int idx, ret;
176 
177 	if (!dgc)
178 		return -EINVAL;
179 
180 	ret = aic_common_irq_domain_xlate(d, ctrlr, intspec, intsize,
181 					  out_hwirq, out_type);
182 	if (ret)
183 		return ret;
184 
185 	idx = intspec[0] / dgc->irqs_per_chip;
186 	if (idx >= dgc->num_chips)
187 		return -EINVAL;
188 
189 	gc = dgc->gc[idx];
190 
191 	guard(raw_spinlock_irq)(&gc->lock);
192 	smr = irq_reg_readl(gc, AT91_AIC_SMR(*out_hwirq));
193 	aic_common_set_priority(intspec[2], &smr);
194 	irq_reg_writel(gc, smr, AT91_AIC_SMR(*out_hwirq));
195 
196 	return ret;
197 }
198 
199 static const struct irq_domain_ops aic_irq_ops = {
200 	.map	= irq_map_generic_chip,
201 	.xlate	= aic_irq_domain_xlate,
202 };
203 
204 static void __init at91rm9200_aic_irq_fixup(void)
205 {
206 	aic_common_rtc_irq_fixup();
207 }
208 
209 static void __init at91sam9260_aic_irq_fixup(void)
210 {
211 	aic_common_rtt_irq_fixup();
212 }
213 
214 static void __init at91sam9g45_aic_irq_fixup(void)
215 {
216 	aic_common_rtc_irq_fixup();
217 	aic_common_rtt_irq_fixup();
218 }
219 
220 static const struct of_device_id aic_irq_fixups[] __initconst = {
221 	{ .compatible = "atmel,at91rm9200", .data = at91rm9200_aic_irq_fixup },
222 	{ .compatible = "atmel,at91sam9g45", .data = at91sam9g45_aic_irq_fixup },
223 	{ .compatible = "atmel,at91sam9n12", .data = at91rm9200_aic_irq_fixup },
224 	{ .compatible = "atmel,at91sam9rl", .data = at91sam9g45_aic_irq_fixup },
225 	{ .compatible = "atmel,at91sam9x5", .data = at91rm9200_aic_irq_fixup },
226 	{ .compatible = "atmel,at91sam9260", .data = at91sam9260_aic_irq_fixup },
227 	{ .compatible = "atmel,at91sam9261", .data = at91sam9260_aic_irq_fixup },
228 	{ .compatible = "atmel,at91sam9263", .data = at91sam9260_aic_irq_fixup },
229 	{ .compatible = "atmel,at91sam9g20", .data = at91sam9260_aic_irq_fixup },
230 	{ /* sentinel */ },
231 };
232 
233 static int __init aic_of_init(struct device_node *node,
234 			      struct device_node *parent)
235 {
236 	struct irq_chip_generic *gc;
237 	struct irq_domain *domain;
238 
239 	if (aic_domain)
240 		return -EEXIST;
241 
242 	domain = aic_common_of_init(node, &aic_irq_ops, "atmel-aic",
243 				    NR_AIC_IRQS, aic_irq_fixups);
244 	if (IS_ERR(domain))
245 		return PTR_ERR(domain);
246 
247 	aic_domain = domain;
248 	gc = irq_get_domain_generic_chip(domain, 0);
249 
250 	gc->chip_types[0].regs.eoi = AT91_AIC_EOICR;
251 	gc->chip_types[0].regs.enable = AT91_AIC_IECR;
252 	gc->chip_types[0].regs.disable = AT91_AIC_IDCR;
253 	gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
254 	gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
255 	gc->chip_types[0].chip.irq_retrigger = aic_retrigger;
256 	gc->chip_types[0].chip.irq_set_type = aic_set_type;
257 	gc->chip_types[0].chip.irq_suspend = aic_suspend;
258 	gc->chip_types[0].chip.irq_resume = aic_resume;
259 	gc->chip_types[0].chip.irq_pm_shutdown = aic_pm_shutdown;
260 
261 	aic_hw_init(domain);
262 	set_handle_irq(aic_handle);
263 
264 	return 0;
265 }
266 IRQCHIP_DECLARE(at91rm9200_aic, "atmel,at91rm9200-aic", aic_of_init);
267