xref: /linux/drivers/irqchip/spear-shirq.c (revision 4ecc832f4ef25dcb684ca986de3612e881748c0e)
1 /*
2  * SPEAr platform shared irq layer source file
3  *
4  * Copyright (C) 2009-2012 ST Microelectronics
5  * Viresh Kumar <viresh.linux@gmail.com>
6  *
7  * Copyright (C) 2012 ST Microelectronics
8  * Shiraz Hashim <shiraz.linux.kernel@gmail.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2. This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  */
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 
16 #include <linux/err.h>
17 #include <linux/export.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/irqdomain.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25 #include <linux/spinlock.h>
26 
27 #include "irqchip.h"
28 
29 /*
30  * struct shirq_regs: shared irq register configuration
31  *
32  * enb_reg: enable register offset
33  * reset_to_enb: val 1 indicates, we need to clear bit for enabling interrupt
34  * status_reg: status register offset
35  * status_reg_mask: status register valid mask
36  * clear_reg: clear register offset
37  * reset_to_clear: val 1 indicates, we need to clear bit for clearing interrupt
38  */
39 struct shirq_regs {
40 	u32 enb_reg;
41 	u32 reset_to_enb;
42 	u32 status_reg;
43 	u32 clear_reg;
44 	u32 reset_to_clear;
45 };
46 
47 /*
48  * struct spear_shirq: shared irq structure
49  *
50  * base:	Base register address
51  * regs:	Register configuration for shared irq block
52  * mask:	Mask to apply to the status register
53  * virq_base:	Base virtual interrupt number
54  * nr_irqs:	Number of interrupts handled by this block
55  * offset:	Bit offset of the first interrupt
56  * disabled:	Group is disabled, but accounted
57  */
58 struct spear_shirq {
59 	void __iomem		*base;
60 	struct shirq_regs	regs;
61 	u32			mask;
62 	u32			virq_base;
63 	u32			nr_irqs;
64 	u32			offset;
65 	bool			disabled;
66 };
67 
68 static DEFINE_SPINLOCK(lock);
69 
70 /* spear300 shared irq registers offsets and masks */
71 #define SPEAR300_INT_ENB_MASK_REG	0x54
72 #define SPEAR300_INT_STS_MASK_REG	0x58
73 
74 static struct spear_shirq spear300_shirq_ras1 = {
75 	.offset		= 0,
76 	.nr_irqs	= 9,
77 	.mask		= ((0x1 << 9) - 1) << 0,
78 	.regs = {
79 		.enb_reg = SPEAR300_INT_ENB_MASK_REG,
80 		.status_reg = SPEAR300_INT_STS_MASK_REG,
81 		.clear_reg = -1,
82 	},
83 };
84 
85 static struct spear_shirq *spear300_shirq_blocks[] = {
86 	&spear300_shirq_ras1,
87 };
88 
89 /* spear310 shared irq registers offsets and masks */
90 #define SPEAR310_INT_STS_MASK_REG	0x04
91 
92 static struct spear_shirq spear310_shirq_ras1 = {
93 	.offset		= 0,
94 	.nr_irqs	= 8,
95 	.mask		= ((0x1 << 8) - 1) << 0,
96 	.regs = {
97 		.enb_reg = -1,
98 		.status_reg = SPEAR310_INT_STS_MASK_REG,
99 		.clear_reg = -1,
100 	},
101 };
102 
103 static struct spear_shirq spear310_shirq_ras2 = {
104 	.offset		= 8,
105 	.nr_irqs	= 5,
106 	.mask		= ((0x1 << 5) - 1) << 8,
107 	.regs = {
108 		.enb_reg = -1,
109 		.status_reg = SPEAR310_INT_STS_MASK_REG,
110 		.clear_reg = -1,
111 	},
112 };
113 
114 static struct spear_shirq spear310_shirq_ras3 = {
115 	.offset		= 13,
116 	.nr_irqs	= 1,
117 	.mask		= ((0x1 << 1) - 1) << 13,
118 	.regs = {
119 		.enb_reg = -1,
120 		.status_reg = SPEAR310_INT_STS_MASK_REG,
121 		.clear_reg = -1,
122 	},
123 };
124 
125 static struct spear_shirq spear310_shirq_intrcomm_ras = {
126 	.offset		= 14,
127 	.nr_irqs	= 3,
128 	.mask		= ((0x1 << 3) - 1) << 14,
129 	.regs = {
130 		.enb_reg = -1,
131 		.status_reg = SPEAR310_INT_STS_MASK_REG,
132 		.clear_reg = -1,
133 	},
134 };
135 
136 static struct spear_shirq *spear310_shirq_blocks[] = {
137 	&spear310_shirq_ras1,
138 	&spear310_shirq_ras2,
139 	&spear310_shirq_ras3,
140 	&spear310_shirq_intrcomm_ras,
141 };
142 
143 /* spear320 shared irq registers offsets and masks */
144 #define SPEAR320_INT_STS_MASK_REG		0x04
145 #define SPEAR320_INT_CLR_MASK_REG		0x04
146 #define SPEAR320_INT_ENB_MASK_REG		0x08
147 
148 static struct spear_shirq spear320_shirq_ras3 = {
149 	.offset		= 0,
150 	.nr_irqs	= 7,
151 	.mask		= ((0x1 << 7) - 1) << 0,
152 	.disabled	= 1,
153 	.regs = {
154 		.enb_reg = SPEAR320_INT_ENB_MASK_REG,
155 		.reset_to_enb = 1,
156 		.status_reg = SPEAR320_INT_STS_MASK_REG,
157 		.clear_reg = SPEAR320_INT_CLR_MASK_REG,
158 		.reset_to_clear = 1,
159 	},
160 };
161 
162 static struct spear_shirq spear320_shirq_ras1 = {
163 	.offset		= 7,
164 	.nr_irqs	= 3,
165 	.mask		= ((0x1 << 3) - 1) << 7,
166 	.regs = {
167 		.enb_reg = -1,
168 		.status_reg = SPEAR320_INT_STS_MASK_REG,
169 		.clear_reg = SPEAR320_INT_CLR_MASK_REG,
170 		.reset_to_clear = 1,
171 	},
172 };
173 
174 static struct spear_shirq spear320_shirq_ras2 = {
175 	.offset		= 10,
176 	.nr_irqs	= 1,
177 	.mask		= ((0x1 << 1) - 1) << 10,
178 	.regs = {
179 		.enb_reg = -1,
180 		.status_reg = SPEAR320_INT_STS_MASK_REG,
181 		.clear_reg = SPEAR320_INT_CLR_MASK_REG,
182 		.reset_to_clear = 1,
183 	},
184 };
185 
186 static struct spear_shirq spear320_shirq_intrcomm_ras = {
187 	.offset		= 11,
188 	.nr_irqs	= 11,
189 	.mask		= ((0x1 << 11) - 1) << 11,
190 	.regs = {
191 		.enb_reg = -1,
192 		.status_reg = SPEAR320_INT_STS_MASK_REG,
193 		.clear_reg = SPEAR320_INT_CLR_MASK_REG,
194 		.reset_to_clear = 1,
195 	},
196 };
197 
198 static struct spear_shirq *spear320_shirq_blocks[] = {
199 	&spear320_shirq_ras3,
200 	&spear320_shirq_ras1,
201 	&spear320_shirq_ras2,
202 	&spear320_shirq_intrcomm_ras,
203 };
204 
205 static void shirq_irq_mask_unmask(struct irq_data *d, bool mask)
206 {
207 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
208 	u32 val, offset = d->irq - shirq->virq_base;
209 	unsigned long flags;
210 
211 	if (shirq->regs.enb_reg == -1)
212 		return;
213 
214 	spin_lock_irqsave(&lock, flags);
215 	val = readl(shirq->base + shirq->regs.enb_reg);
216 
217 	if (mask ^ shirq->regs.reset_to_enb)
218 		val &= ~(0x1 << shirq->offset << offset);
219 	else
220 		val |= 0x1 << shirq->offset << offset;
221 
222 	writel(val, shirq->base + shirq->regs.enb_reg);
223 	spin_unlock_irqrestore(&lock, flags);
224 
225 }
226 
227 static void shirq_irq_mask(struct irq_data *d)
228 {
229 	shirq_irq_mask_unmask(d, 1);
230 }
231 
232 static void shirq_irq_unmask(struct irq_data *d)
233 {
234 	shirq_irq_mask_unmask(d, 0);
235 }
236 
237 static struct irq_chip shirq_chip = {
238 	.name		= "spear-shirq",
239 	.irq_ack	= shirq_irq_mask,
240 	.irq_mask	= shirq_irq_mask,
241 	.irq_unmask	= shirq_irq_unmask,
242 };
243 
244 static void shirq_handler(unsigned irq, struct irq_desc *desc)
245 {
246 	struct spear_shirq *shirq = irq_get_handler_data(irq);
247 	struct irq_data *idata = irq_desc_get_irq_data(desc);
248 	struct irq_chip *chip = irq_data_get_irq_chip(idata);
249 	u32 i, j, val, mask, tmp;
250 
251 	chip->irq_ack(idata);
252 
253 	mask = shirq->mask;
254 	while ((val = readl(shirq->base + shirq->regs.status_reg) &
255 				mask)) {
256 
257 		val >>= shirq->offset;
258 		for (i = 0, j = 1; i < shirq->nr_irqs; i++, j <<= 1) {
259 
260 			if (!(j & val))
261 				continue;
262 
263 			generic_handle_irq(shirq->virq_base + i);
264 
265 			/* clear interrupt */
266 			if (shirq->regs.clear_reg == -1)
267 				continue;
268 
269 			tmp = readl(shirq->base + shirq->regs.clear_reg);
270 			if (shirq->regs.reset_to_clear)
271 				tmp &= ~(j << shirq->offset);
272 			else
273 				tmp |= (j << shirq->offset);
274 			writel(tmp, shirq->base + shirq->regs.clear_reg);
275 		}
276 	}
277 	chip->irq_unmask(idata);
278 }
279 
280 static void __init spear_shirq_register(struct spear_shirq *shirq,
281 					int parent_irq)
282 {
283 	int i;
284 
285 	if (shirq->disabled)
286 		return;
287 
288 	irq_set_chained_handler(parent_irq, shirq_handler);
289 	irq_set_handler_data(parent_irq, shirq);
290 
291 	for (i = 0; i < shirq->nr_irqs; i++) {
292 		irq_set_chip_and_handler(shirq->virq_base + i,
293 					 &shirq_chip, handle_simple_irq);
294 		set_irq_flags(shirq->virq_base + i, IRQF_VALID);
295 		irq_set_chip_data(shirq->virq_base + i, shirq);
296 	}
297 }
298 
299 static int __init shirq_init(struct spear_shirq **shirq_blocks, int block_nr,
300 		struct device_node *np)
301 {
302 	int i, parent_irq, virq_base, hwirq = 0, nr_irqs = 0;
303 	struct irq_domain *shirq_domain;
304 	void __iomem *base;
305 
306 	base = of_iomap(np, 0);
307 	if (!base) {
308 		pr_err("%s: failed to map shirq registers\n", __func__);
309 		return -ENXIO;
310 	}
311 
312 	for (i = 0; i < block_nr; i++)
313 		nr_irqs += shirq_blocks[i]->nr_irqs;
314 
315 	virq_base = irq_alloc_descs(-1, 0, nr_irqs, 0);
316 	if (IS_ERR_VALUE(virq_base)) {
317 		pr_err("%s: irq desc alloc failed\n", __func__);
318 		goto err_unmap;
319 	}
320 
321 	shirq_domain = irq_domain_add_legacy(np, nr_irqs, virq_base, 0,
322 			&irq_domain_simple_ops, NULL);
323 	if (WARN_ON(!shirq_domain)) {
324 		pr_warn("%s: irq domain init failed\n", __func__);
325 		goto err_free_desc;
326 	}
327 
328 	for (i = 0; i < block_nr; i++) {
329 		shirq_blocks[i]->base = base;
330 		shirq_blocks[i]->virq_base = irq_find_mapping(shirq_domain,
331 				hwirq);
332 
333 		parent_irq = irq_of_parse_and_map(np, i);
334 		spear_shirq_register(shirq_blocks[i], parent_irq);
335 		hwirq += shirq_blocks[i]->nr_irqs;
336 	}
337 
338 	return 0;
339 
340 err_free_desc:
341 	irq_free_descs(virq_base, nr_irqs);
342 err_unmap:
343 	iounmap(base);
344 	return -ENXIO;
345 }
346 
347 static int __init spear300_shirq_of_init(struct device_node *np,
348 					 struct device_node *parent)
349 {
350 	return shirq_init(spear300_shirq_blocks,
351 			ARRAY_SIZE(spear300_shirq_blocks), np);
352 }
353 IRQCHIP_DECLARE(spear300_shirq, "st,spear300-shirq", spear300_shirq_of_init);
354 
355 static int __init spear310_shirq_of_init(struct device_node *np,
356 					 struct device_node *parent)
357 {
358 	return shirq_init(spear310_shirq_blocks,
359 			ARRAY_SIZE(spear310_shirq_blocks), np);
360 }
361 IRQCHIP_DECLARE(spear310_shirq, "st,spear310-shirq", spear310_shirq_of_init);
362 
363 static int __init spear320_shirq_of_init(struct device_node *np,
364 					 struct device_node *parent)
365 {
366 	return shirq_init(spear320_shirq_blocks,
367 			ARRAY_SIZE(spear320_shirq_blocks), np);
368 }
369 IRQCHIP_DECLARE(spear320_shirq, "st,spear320-shirq", spear320_shirq_of_init);
370