1 /*
2  * Atmel AT91 common AIC (Advanced Interrupt Controller) code shared by
3  * irq-atmel-aic and irq-atmel-aic5 drivers
4  *
5  *  Copyright (C) 2004 SAN People
6  *  Copyright (C) 2004 ATMEL
7  *  Copyright (C) Rick Bronson
8  *  Copyright (C) 2014 Free Electrons
9  *
10  *  Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
11  *
12  * This file is licensed under the terms of the GNU General Public
13  * License version 2.  This program is licensed "as is" without any
14  * warranty of any kind, whether express or implied.
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/io.h>
19 #include <linux/irq.h>
20 #include <linux/irqdomain.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/slab.h>
24 
25 #include "irq-atmel-aic-common.h"
26 
27 #define AT91_AIC_PRIOR			GENMASK(2, 0)
28 #define AT91_AIC_IRQ_MIN_PRIORITY	0
29 #define AT91_AIC_IRQ_MAX_PRIORITY	7
30 
31 #define AT91_AIC_SRCTYPE		GENMASK(6, 5)
32 #define AT91_AIC_SRCTYPE_LOW		(0 << 5)
33 #define AT91_AIC_SRCTYPE_FALLING	(1 << 5)
34 #define AT91_AIC_SRCTYPE_HIGH		(2 << 5)
35 #define AT91_AIC_SRCTYPE_RISING		(3 << 5)
36 
37 struct aic_chip_data {
38 	u32 ext_irqs;
39 };
40 
41 static void aic_common_shutdown(struct irq_data *d)
42 {
43 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
44 
45 	ct->chip.irq_mask(d);
46 }
47 
48 int aic_common_set_type(struct irq_data *d, unsigned type, unsigned *val)
49 {
50 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
51 	struct aic_chip_data *aic = gc->private;
52 	unsigned aic_type;
53 
54 	switch (type) {
55 	case IRQ_TYPE_LEVEL_HIGH:
56 		aic_type = AT91_AIC_SRCTYPE_HIGH;
57 		break;
58 	case IRQ_TYPE_EDGE_RISING:
59 		aic_type = AT91_AIC_SRCTYPE_RISING;
60 		break;
61 	case IRQ_TYPE_LEVEL_LOW:
62 		if (!(d->mask & aic->ext_irqs))
63 			return -EINVAL;
64 
65 		aic_type = AT91_AIC_SRCTYPE_LOW;
66 		break;
67 	case IRQ_TYPE_EDGE_FALLING:
68 		if (!(d->mask & aic->ext_irqs))
69 			return -EINVAL;
70 
71 		aic_type = AT91_AIC_SRCTYPE_FALLING;
72 		break;
73 	default:
74 		return -EINVAL;
75 	}
76 
77 	*val &= ~AT91_AIC_SRCTYPE;
78 	*val |= aic_type;
79 
80 	return 0;
81 }
82 
83 int aic_common_set_priority(int priority, unsigned *val)
84 {
85 	if (priority < AT91_AIC_IRQ_MIN_PRIORITY ||
86 	    priority > AT91_AIC_IRQ_MAX_PRIORITY)
87 		return -EINVAL;
88 
89 	*val &= ~AT91_AIC_PRIOR;
90 	*val |= priority;
91 
92 	return 0;
93 }
94 
95 int aic_common_irq_domain_xlate(struct irq_domain *d,
96 				struct device_node *ctrlr,
97 				const u32 *intspec,
98 				unsigned int intsize,
99 				irq_hw_number_t *out_hwirq,
100 				unsigned int *out_type)
101 {
102 	if (WARN_ON(intsize < 3))
103 		return -EINVAL;
104 
105 	if (WARN_ON((intspec[2] < AT91_AIC_IRQ_MIN_PRIORITY) ||
106 		    (intspec[2] > AT91_AIC_IRQ_MAX_PRIORITY)))
107 		return -EINVAL;
108 
109 	*out_hwirq = intspec[0];
110 	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
111 
112 	return 0;
113 }
114 
115 static void __init aic_common_ext_irq_of_init(struct irq_domain *domain)
116 {
117 	struct device_node *node = irq_domain_get_of_node(domain);
118 	struct irq_chip_generic *gc;
119 	struct aic_chip_data *aic;
120 	struct property *prop;
121 	const __be32 *p;
122 	u32 hwirq;
123 
124 	gc = irq_get_domain_generic_chip(domain, 0);
125 
126 	aic = gc->private;
127 	aic->ext_irqs |= 1;
128 
129 	of_property_for_each_u32(node, "atmel,external-irqs", prop, p, hwirq) {
130 		gc = irq_get_domain_generic_chip(domain, hwirq);
131 		if (!gc) {
132 			pr_warn("AIC: external irq %d >= %d skip it\n",
133 				hwirq, domain->revmap_size);
134 			continue;
135 		}
136 
137 		aic = gc->private;
138 		aic->ext_irqs |= (1 << (hwirq % 32));
139 	}
140 }
141 
142 #define AT91_RTC_IDR           0x24
143 #define AT91_RTC_IMR           0x28
144 #define AT91_RTC_IRQ_MASK      0x1f
145 
146 void __init aic_common_rtc_irq_fixup(struct device_node *root)
147 {
148 	struct device_node *np;
149 	void __iomem *regs;
150 
151 	np = of_find_compatible_node(root, NULL, "atmel,at91rm9200-rtc");
152 	if (!np)
153 		np = of_find_compatible_node(root, NULL,
154 					     "atmel,at91sam9x5-rtc");
155 
156 	if (!np)
157 		return;
158 
159 	regs = of_iomap(np, 0);
160 	of_node_put(np);
161 
162 	if (!regs)
163 		return;
164 
165 	writel(AT91_RTC_IRQ_MASK, regs + AT91_RTC_IDR);
166 
167 	iounmap(regs);
168 }
169 
170 #define AT91_RTT_MR		0x00			/* Real-time Mode Register */
171 #define AT91_RTT_ALMIEN		(1 << 16)		/* Alarm Interrupt Enable */
172 #define AT91_RTT_RTTINCIEN	(1 << 17)		/* Real Time Timer Increment Interrupt Enable */
173 
174 void __init aic_common_rtt_irq_fixup(struct device_node *root)
175 {
176 	struct device_node *np;
177 	void __iomem *regs;
178 
179 	/*
180 	 * The at91sam9263 SoC has 2 instances of the RTT block, hence we
181 	 * iterate over the DT to find each occurrence.
182 	 */
183 	for_each_compatible_node(np, NULL, "atmel,at91sam9260-rtt") {
184 		regs = of_iomap(np, 0);
185 		if (!regs)
186 			continue;
187 
188 		writel(readl(regs + AT91_RTT_MR) &
189 		       ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN),
190 		       regs + AT91_RTT_MR);
191 
192 		iounmap(regs);
193 	}
194 }
195 
196 void __init aic_common_irq_fixup(const struct of_device_id *matches)
197 {
198 	struct device_node *root = of_find_node_by_path("/");
199 	const struct of_device_id *match;
200 
201 	if (!root)
202 		return;
203 
204 	match = of_match_node(matches, root);
205 	of_node_put(root);
206 
207 	if (match) {
208 		void (*fixup)(struct device_node *) = match->data;
209 		fixup(root);
210 	}
211 
212 	of_node_put(root);
213 }
214 
215 struct irq_domain *__init aic_common_of_init(struct device_node *node,
216 					     const struct irq_domain_ops *ops,
217 					     const char *name, int nirqs)
218 {
219 	struct irq_chip_generic *gc;
220 	struct irq_domain *domain;
221 	struct aic_chip_data *aic;
222 	void __iomem *reg_base;
223 	int nchips;
224 	int ret;
225 	int i;
226 
227 	nchips = DIV_ROUND_UP(nirqs, 32);
228 
229 	reg_base = of_iomap(node, 0);
230 	if (!reg_base)
231 		return ERR_PTR(-ENOMEM);
232 
233 	aic = kcalloc(nchips, sizeof(*aic), GFP_KERNEL);
234 	if (!aic) {
235 		ret = -ENOMEM;
236 		goto err_iounmap;
237 	}
238 
239 	domain = irq_domain_add_linear(node, nchips * 32, ops, aic);
240 	if (!domain) {
241 		ret = -ENOMEM;
242 		goto err_free_aic;
243 	}
244 
245 	ret = irq_alloc_domain_generic_chips(domain, 32, 1, name,
246 					     handle_fasteoi_irq,
247 					     IRQ_NOREQUEST | IRQ_NOPROBE |
248 					     IRQ_NOAUTOEN, 0, 0);
249 	if (ret)
250 		goto err_domain_remove;
251 
252 	for (i = 0; i < nchips; i++) {
253 		gc = irq_get_domain_generic_chip(domain, i * 32);
254 
255 		gc->reg_base = reg_base;
256 
257 		gc->unused = 0;
258 		gc->wake_enabled = ~0;
259 		gc->chip_types[0].type = IRQ_TYPE_SENSE_MASK;
260 		gc->chip_types[0].chip.irq_eoi = irq_gc_eoi;
261 		gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
262 		gc->chip_types[0].chip.irq_shutdown = aic_common_shutdown;
263 		gc->private = &aic[i];
264 	}
265 
266 	aic_common_ext_irq_of_init(domain);
267 
268 	return domain;
269 
270 err_domain_remove:
271 	irq_domain_remove(domain);
272 
273 err_free_aic:
274 	kfree(aic);
275 
276 err_iounmap:
277 	iounmap(reg_base);
278 
279 	return ERR_PTR(ret);
280 }
281