xref: /openbmc/linux/drivers/irqchip/spear-shirq.c (revision c819e2cf)
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 spear_shirq: shared irq structure
31  *
32  * base:	Base register address
33  * status_reg:	Status register offset for chained interrupt handler
34  * mask_reg:	Mask register offset for irq chip
35  * mask:	Mask to apply to the status register
36  * virq_base:	Base virtual interrupt number
37  * nr_irqs:	Number of interrupts handled by this block
38  * offset:	Bit offset of the first interrupt
39  * irq_chip:	Interrupt controller chip used for this instance,
40  *		if NULL group is disabled, but accounted
41  */
42 struct spear_shirq {
43 	void __iomem		*base;
44 	u32			status_reg;
45 	u32			mask_reg;
46 	u32			mask;
47 	u32			virq_base;
48 	u32			nr_irqs;
49 	u32			offset;
50 	struct irq_chip		*irq_chip;
51 };
52 
53 /* spear300 shared irq registers offsets and masks */
54 #define SPEAR300_INT_ENB_MASK_REG	0x54
55 #define SPEAR300_INT_STS_MASK_REG	0x58
56 
57 static DEFINE_RAW_SPINLOCK(shirq_lock);
58 
59 static void shirq_irq_mask(struct irq_data *d)
60 {
61 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
62 	u32 val, shift = d->irq - shirq->virq_base + shirq->offset;
63 	u32 __iomem *reg = shirq->base + shirq->mask_reg;
64 
65 	raw_spin_lock(&shirq_lock);
66 	val = readl(reg) & ~(0x1 << shift);
67 	writel(val, reg);
68 	raw_spin_unlock(&shirq_lock);
69 }
70 
71 static void shirq_irq_unmask(struct irq_data *d)
72 {
73 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
74 	u32 val, shift = d->irq - shirq->virq_base + shirq->offset;
75 	u32 __iomem *reg = shirq->base + shirq->mask_reg;
76 
77 	raw_spin_lock(&shirq_lock);
78 	val = readl(reg) | (0x1 << shift);
79 	writel(val, reg);
80 	raw_spin_unlock(&shirq_lock);
81 }
82 
83 static struct irq_chip shirq_chip = {
84 	.name		= "spear-shirq",
85 	.irq_mask	= shirq_irq_mask,
86 	.irq_unmask	= shirq_irq_unmask,
87 };
88 
89 static struct spear_shirq spear300_shirq_ras1 = {
90 	.offset		= 0,
91 	.nr_irqs	= 9,
92 	.mask		= ((0x1 << 9) - 1) << 0,
93 	.irq_chip	= &shirq_chip,
94 	.status_reg	= SPEAR300_INT_STS_MASK_REG,
95 	.mask_reg	= SPEAR300_INT_ENB_MASK_REG,
96 };
97 
98 static struct spear_shirq *spear300_shirq_blocks[] = {
99 	&spear300_shirq_ras1,
100 };
101 
102 /* spear310 shared irq registers offsets and masks */
103 #define SPEAR310_INT_STS_MASK_REG	0x04
104 
105 static struct spear_shirq spear310_shirq_ras1 = {
106 	.offset		= 0,
107 	.nr_irqs	= 8,
108 	.mask		= ((0x1 << 8) - 1) << 0,
109 	.irq_chip	= &dummy_irq_chip,
110 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
111 };
112 
113 static struct spear_shirq spear310_shirq_ras2 = {
114 	.offset		= 8,
115 	.nr_irqs	= 5,
116 	.mask		= ((0x1 << 5) - 1) << 8,
117 	.irq_chip	= &dummy_irq_chip,
118 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
119 };
120 
121 static struct spear_shirq spear310_shirq_ras3 = {
122 	.offset		= 13,
123 	.nr_irqs	= 1,
124 	.mask		= ((0x1 << 1) - 1) << 13,
125 	.irq_chip	= &dummy_irq_chip,
126 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
127 };
128 
129 static struct spear_shirq spear310_shirq_intrcomm_ras = {
130 	.offset		= 14,
131 	.nr_irqs	= 3,
132 	.mask		= ((0x1 << 3) - 1) << 14,
133 	.irq_chip	= &dummy_irq_chip,
134 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
135 };
136 
137 static struct spear_shirq *spear310_shirq_blocks[] = {
138 	&spear310_shirq_ras1,
139 	&spear310_shirq_ras2,
140 	&spear310_shirq_ras3,
141 	&spear310_shirq_intrcomm_ras,
142 };
143 
144 /* spear320 shared irq registers offsets and masks */
145 #define SPEAR320_INT_STS_MASK_REG		0x04
146 #define SPEAR320_INT_CLR_MASK_REG		0x04
147 #define SPEAR320_INT_ENB_MASK_REG		0x08
148 
149 static struct spear_shirq spear320_shirq_ras3 = {
150 	.offset		= 0,
151 	.nr_irqs	= 7,
152 	.mask		= ((0x1 << 7) - 1) << 0,
153 };
154 
155 static struct spear_shirq spear320_shirq_ras1 = {
156 	.offset		= 7,
157 	.nr_irqs	= 3,
158 	.mask		= ((0x1 << 3) - 1) << 7,
159 	.irq_chip	= &dummy_irq_chip,
160 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
161 };
162 
163 static struct spear_shirq spear320_shirq_ras2 = {
164 	.offset		= 10,
165 	.nr_irqs	= 1,
166 	.mask		= ((0x1 << 1) - 1) << 10,
167 	.irq_chip	= &dummy_irq_chip,
168 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
169 };
170 
171 static struct spear_shirq spear320_shirq_intrcomm_ras = {
172 	.offset		= 11,
173 	.nr_irqs	= 11,
174 	.mask		= ((0x1 << 11) - 1) << 11,
175 	.irq_chip	= &dummy_irq_chip,
176 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
177 };
178 
179 static struct spear_shirq *spear320_shirq_blocks[] = {
180 	&spear320_shirq_ras3,
181 	&spear320_shirq_ras1,
182 	&spear320_shirq_ras2,
183 	&spear320_shirq_intrcomm_ras,
184 };
185 
186 static void shirq_handler(unsigned irq, struct irq_desc *desc)
187 {
188 	struct spear_shirq *shirq = irq_get_handler_data(irq);
189 	u32 pend;
190 
191 	pend = readl(shirq->base + shirq->status_reg) & shirq->mask;
192 	pend >>= shirq->offset;
193 
194 	while (pend) {
195 		int irq = __ffs(pend);
196 
197 		pend &= ~(0x1 << irq);
198 		generic_handle_irq(shirq->virq_base + irq);
199 	}
200 }
201 
202 static void __init spear_shirq_register(struct spear_shirq *shirq,
203 					int parent_irq)
204 {
205 	int i;
206 
207 	if (!shirq->irq_chip)
208 		return;
209 
210 	irq_set_chained_handler(parent_irq, shirq_handler);
211 	irq_set_handler_data(parent_irq, shirq);
212 
213 	for (i = 0; i < shirq->nr_irqs; i++) {
214 		irq_set_chip_and_handler(shirq->virq_base + i,
215 					 shirq->irq_chip, handle_simple_irq);
216 		set_irq_flags(shirq->virq_base + i, IRQF_VALID);
217 		irq_set_chip_data(shirq->virq_base + i, shirq);
218 	}
219 }
220 
221 static int __init shirq_init(struct spear_shirq **shirq_blocks, int block_nr,
222 		struct device_node *np)
223 {
224 	int i, parent_irq, virq_base, hwirq = 0, nr_irqs = 0;
225 	struct irq_domain *shirq_domain;
226 	void __iomem *base;
227 
228 	base = of_iomap(np, 0);
229 	if (!base) {
230 		pr_err("%s: failed to map shirq registers\n", __func__);
231 		return -ENXIO;
232 	}
233 
234 	for (i = 0; i < block_nr; i++)
235 		nr_irqs += shirq_blocks[i]->nr_irqs;
236 
237 	virq_base = irq_alloc_descs(-1, 0, nr_irqs, 0);
238 	if (IS_ERR_VALUE(virq_base)) {
239 		pr_err("%s: irq desc alloc failed\n", __func__);
240 		goto err_unmap;
241 	}
242 
243 	shirq_domain = irq_domain_add_legacy(np, nr_irqs, virq_base, 0,
244 			&irq_domain_simple_ops, NULL);
245 	if (WARN_ON(!shirq_domain)) {
246 		pr_warn("%s: irq domain init failed\n", __func__);
247 		goto err_free_desc;
248 	}
249 
250 	for (i = 0; i < block_nr; i++) {
251 		shirq_blocks[i]->base = base;
252 		shirq_blocks[i]->virq_base = irq_find_mapping(shirq_domain,
253 				hwirq);
254 
255 		parent_irq = irq_of_parse_and_map(np, i);
256 		spear_shirq_register(shirq_blocks[i], parent_irq);
257 		hwirq += shirq_blocks[i]->nr_irqs;
258 	}
259 
260 	return 0;
261 
262 err_free_desc:
263 	irq_free_descs(virq_base, nr_irqs);
264 err_unmap:
265 	iounmap(base);
266 	return -ENXIO;
267 }
268 
269 static int __init spear300_shirq_of_init(struct device_node *np,
270 					 struct device_node *parent)
271 {
272 	return shirq_init(spear300_shirq_blocks,
273 			ARRAY_SIZE(spear300_shirq_blocks), np);
274 }
275 IRQCHIP_DECLARE(spear300_shirq, "st,spear300-shirq", spear300_shirq_of_init);
276 
277 static int __init spear310_shirq_of_init(struct device_node *np,
278 					 struct device_node *parent)
279 {
280 	return shirq_init(spear310_shirq_blocks,
281 			ARRAY_SIZE(spear310_shirq_blocks), np);
282 }
283 IRQCHIP_DECLARE(spear310_shirq, "st,spear310-shirq", spear310_shirq_of_init);
284 
285 static int __init spear320_shirq_of_init(struct device_node *np,
286 					 struct device_node *parent)
287 {
288 	return shirq_init(spear320_shirq_blocks,
289 			ARRAY_SIZE(spear320_shirq_blocks), np);
290 }
291 IRQCHIP_DECLARE(spear320_shirq, "st,spear320-shirq", spear320_shirq_of_init);
292