xref: /openbmc/linux/drivers/irqchip/spear-shirq.c (revision 6d99a79c)
1 /*
2  * SPEAr platform shared irq layer source file
3  *
4  * Copyright (C) 2009-2012 ST Microelectronics
5  * Viresh Kumar <vireshk@kernel.org>
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/irqchip.h>
22 #include <linux/irqdomain.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/spinlock.h>
27 
28 /*
29  * struct spear_shirq: shared irq structure
30  *
31  * base:	Base register address
32  * status_reg:	Status register offset for chained interrupt handler
33  * mask_reg:	Mask register offset for irq chip
34  * mask:	Mask to apply to the status register
35  * virq_base:	Base virtual interrupt number
36  * nr_irqs:	Number of interrupts handled by this block
37  * offset:	Bit offset of the first interrupt
38  * irq_chip:	Interrupt controller chip used for this instance,
39  *		if NULL group is disabled, but accounted
40  */
41 struct spear_shirq {
42 	void __iomem		*base;
43 	u32			status_reg;
44 	u32			mask_reg;
45 	u32			mask;
46 	u32			virq_base;
47 	u32			nr_irqs;
48 	u32			offset;
49 	struct irq_chip		*irq_chip;
50 };
51 
52 /* spear300 shared irq registers offsets and masks */
53 #define SPEAR300_INT_ENB_MASK_REG	0x54
54 #define SPEAR300_INT_STS_MASK_REG	0x58
55 
56 static DEFINE_RAW_SPINLOCK(shirq_lock);
57 
58 static void shirq_irq_mask(struct irq_data *d)
59 {
60 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
61 	u32 val, shift = d->irq - shirq->virq_base + shirq->offset;
62 	u32 __iomem *reg = shirq->base + shirq->mask_reg;
63 
64 	raw_spin_lock(&shirq_lock);
65 	val = readl(reg) & ~(0x1 << shift);
66 	writel(val, reg);
67 	raw_spin_unlock(&shirq_lock);
68 }
69 
70 static void shirq_irq_unmask(struct irq_data *d)
71 {
72 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
73 	u32 val, shift = d->irq - shirq->virq_base + shirq->offset;
74 	u32 __iomem *reg = shirq->base + shirq->mask_reg;
75 
76 	raw_spin_lock(&shirq_lock);
77 	val = readl(reg) | (0x1 << shift);
78 	writel(val, reg);
79 	raw_spin_unlock(&shirq_lock);
80 }
81 
82 static struct irq_chip shirq_chip = {
83 	.name		= "spear-shirq",
84 	.irq_mask	= shirq_irq_mask,
85 	.irq_unmask	= shirq_irq_unmask,
86 };
87 
88 static struct spear_shirq spear300_shirq_ras1 = {
89 	.offset		= 0,
90 	.nr_irqs	= 9,
91 	.mask		= ((0x1 << 9) - 1) << 0,
92 	.irq_chip	= &shirq_chip,
93 	.status_reg	= SPEAR300_INT_STS_MASK_REG,
94 	.mask_reg	= SPEAR300_INT_ENB_MASK_REG,
95 };
96 
97 static struct spear_shirq *spear300_shirq_blocks[] = {
98 	&spear300_shirq_ras1,
99 };
100 
101 /* spear310 shared irq registers offsets and masks */
102 #define SPEAR310_INT_STS_MASK_REG	0x04
103 
104 static struct spear_shirq spear310_shirq_ras1 = {
105 	.offset		= 0,
106 	.nr_irqs	= 8,
107 	.mask		= ((0x1 << 8) - 1) << 0,
108 	.irq_chip	= &dummy_irq_chip,
109 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
110 };
111 
112 static struct spear_shirq spear310_shirq_ras2 = {
113 	.offset		= 8,
114 	.nr_irqs	= 5,
115 	.mask		= ((0x1 << 5) - 1) << 8,
116 	.irq_chip	= &dummy_irq_chip,
117 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
118 };
119 
120 static struct spear_shirq spear310_shirq_ras3 = {
121 	.offset		= 13,
122 	.nr_irqs	= 1,
123 	.mask		= ((0x1 << 1) - 1) << 13,
124 	.irq_chip	= &dummy_irq_chip,
125 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
126 };
127 
128 static struct spear_shirq spear310_shirq_intrcomm_ras = {
129 	.offset		= 14,
130 	.nr_irqs	= 3,
131 	.mask		= ((0x1 << 3) - 1) << 14,
132 	.irq_chip	= &dummy_irq_chip,
133 	.status_reg	= SPEAR310_INT_STS_MASK_REG,
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 };
153 
154 static struct spear_shirq spear320_shirq_ras1 = {
155 	.offset		= 7,
156 	.nr_irqs	= 3,
157 	.mask		= ((0x1 << 3) - 1) << 7,
158 	.irq_chip	= &dummy_irq_chip,
159 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
160 };
161 
162 static struct spear_shirq spear320_shirq_ras2 = {
163 	.offset		= 10,
164 	.nr_irqs	= 1,
165 	.mask		= ((0x1 << 1) - 1) << 10,
166 	.irq_chip	= &dummy_irq_chip,
167 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
168 };
169 
170 static struct spear_shirq spear320_shirq_intrcomm_ras = {
171 	.offset		= 11,
172 	.nr_irqs	= 11,
173 	.mask		= ((0x1 << 11) - 1) << 11,
174 	.irq_chip	= &dummy_irq_chip,
175 	.status_reg	= SPEAR320_INT_STS_MASK_REG,
176 };
177 
178 static struct spear_shirq *spear320_shirq_blocks[] = {
179 	&spear320_shirq_ras3,
180 	&spear320_shirq_ras1,
181 	&spear320_shirq_ras2,
182 	&spear320_shirq_intrcomm_ras,
183 };
184 
185 static void shirq_handler(struct irq_desc *desc)
186 {
187 	struct spear_shirq *shirq = irq_desc_get_handler_data(desc);
188 	u32 pend;
189 
190 	pend = readl(shirq->base + shirq->status_reg) & shirq->mask;
191 	pend >>= shirq->offset;
192 
193 	while (pend) {
194 		int irq = __ffs(pend);
195 
196 		pend &= ~(0x1 << irq);
197 		generic_handle_irq(shirq->virq_base + irq);
198 	}
199 }
200 
201 static void __init spear_shirq_register(struct spear_shirq *shirq,
202 					int parent_irq)
203 {
204 	int i;
205 
206 	if (!shirq->irq_chip)
207 		return;
208 
209 	irq_set_chained_handler_and_data(parent_irq, shirq_handler, shirq);
210 
211 	for (i = 0; i < shirq->nr_irqs; i++) {
212 		irq_set_chip_and_handler(shirq->virq_base + i,
213 					 shirq->irq_chip, handle_simple_irq);
214 		irq_set_chip_data(shirq->virq_base + i, shirq);
215 	}
216 }
217 
218 static int __init shirq_init(struct spear_shirq **shirq_blocks, int block_nr,
219 		struct device_node *np)
220 {
221 	int i, parent_irq, virq_base, hwirq = 0, nr_irqs = 0;
222 	struct irq_domain *shirq_domain;
223 	void __iomem *base;
224 
225 	base = of_iomap(np, 0);
226 	if (!base) {
227 		pr_err("%s: failed to map shirq registers\n", __func__);
228 		return -ENXIO;
229 	}
230 
231 	for (i = 0; i < block_nr; i++)
232 		nr_irqs += shirq_blocks[i]->nr_irqs;
233 
234 	virq_base = irq_alloc_descs(-1, 0, nr_irqs, 0);
235 	if (virq_base < 0) {
236 		pr_err("%s: irq desc alloc failed\n", __func__);
237 		goto err_unmap;
238 	}
239 
240 	shirq_domain = irq_domain_add_legacy(np, nr_irqs, virq_base, 0,
241 			&irq_domain_simple_ops, NULL);
242 	if (WARN_ON(!shirq_domain)) {
243 		pr_warn("%s: irq domain init failed\n", __func__);
244 		goto err_free_desc;
245 	}
246 
247 	for (i = 0; i < block_nr; i++) {
248 		shirq_blocks[i]->base = base;
249 		shirq_blocks[i]->virq_base = irq_find_mapping(shirq_domain,
250 				hwirq);
251 
252 		parent_irq = irq_of_parse_and_map(np, i);
253 		spear_shirq_register(shirq_blocks[i], parent_irq);
254 		hwirq += shirq_blocks[i]->nr_irqs;
255 	}
256 
257 	return 0;
258 
259 err_free_desc:
260 	irq_free_descs(virq_base, nr_irqs);
261 err_unmap:
262 	iounmap(base);
263 	return -ENXIO;
264 }
265 
266 static int __init spear300_shirq_of_init(struct device_node *np,
267 					 struct device_node *parent)
268 {
269 	return shirq_init(spear300_shirq_blocks,
270 			ARRAY_SIZE(spear300_shirq_blocks), np);
271 }
272 IRQCHIP_DECLARE(spear300_shirq, "st,spear300-shirq", spear300_shirq_of_init);
273 
274 static int __init spear310_shirq_of_init(struct device_node *np,
275 					 struct device_node *parent)
276 {
277 	return shirq_init(spear310_shirq_blocks,
278 			ARRAY_SIZE(spear310_shirq_blocks), np);
279 }
280 IRQCHIP_DECLARE(spear310_shirq, "st,spear310-shirq", spear310_shirq_of_init);
281 
282 static int __init spear320_shirq_of_init(struct device_node *np,
283 					 struct device_node *parent)
284 {
285 	return shirq_init(spear320_shirq_blocks,
286 			ARRAY_SIZE(spear320_shirq_blocks), np);
287 }
288 IRQCHIP_DECLARE(spear320_shirq, "st,spear320-shirq", spear320_shirq_of_init);
289