1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
4  *		http://www.samsung.com
5  *
6  * Combiner irqchip for EXYNOS
7  */
8 #include <linux/err.h>
9 #include <linux/export.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/slab.h>
13 #include <linux/syscore_ops.h>
14 #include <linux/irqdomain.h>
15 #include <linux/irqchip.h>
16 #include <linux/irqchip/chained_irq.h>
17 #include <linux/interrupt.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 
21 #define COMBINER_ENABLE_SET	0x0
22 #define COMBINER_ENABLE_CLEAR	0x4
23 #define COMBINER_INT_STATUS	0xC
24 
25 #define IRQ_IN_COMBINER		8
26 
27 static DEFINE_SPINLOCK(irq_controller_lock);
28 
29 struct combiner_chip_data {
30 	unsigned int hwirq_offset;
31 	unsigned int irq_mask;
32 	void __iomem *base;
33 	unsigned int parent_irq;
34 #ifdef CONFIG_PM
35 	u32 pm_save;
36 #endif
37 };
38 
39 static struct combiner_chip_data *combiner_data;
40 static struct irq_domain *combiner_irq_domain;
41 static unsigned int max_nr = 20;
42 
43 static inline void __iomem *combiner_base(struct irq_data *data)
44 {
45 	struct combiner_chip_data *combiner_data =
46 		irq_data_get_irq_chip_data(data);
47 
48 	return combiner_data->base;
49 }
50 
51 static void combiner_mask_irq(struct irq_data *data)
52 {
53 	u32 mask = 1 << (data->hwirq % 32);
54 
55 	writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
56 }
57 
58 static void combiner_unmask_irq(struct irq_data *data)
59 {
60 	u32 mask = 1 << (data->hwirq % 32);
61 
62 	writel_relaxed(mask, combiner_base(data) + COMBINER_ENABLE_SET);
63 }
64 
65 static void combiner_handle_cascade_irq(struct irq_desc *desc)
66 {
67 	struct combiner_chip_data *chip_data = irq_desc_get_handler_data(desc);
68 	struct irq_chip *chip = irq_desc_get_chip(desc);
69 	unsigned int cascade_irq, combiner_irq;
70 	unsigned long status;
71 
72 	chained_irq_enter(chip, desc);
73 
74 	spin_lock(&irq_controller_lock);
75 	status = readl_relaxed(chip_data->base + COMBINER_INT_STATUS);
76 	spin_unlock(&irq_controller_lock);
77 	status &= chip_data->irq_mask;
78 
79 	if (status == 0)
80 		goto out;
81 
82 	combiner_irq = chip_data->hwirq_offset + __ffs(status);
83 	cascade_irq = irq_find_mapping(combiner_irq_domain, combiner_irq);
84 
85 	if (unlikely(!cascade_irq))
86 		handle_bad_irq(desc);
87 	else
88 		generic_handle_irq(cascade_irq);
89 
90  out:
91 	chained_irq_exit(chip, desc);
92 }
93 
94 #ifdef CONFIG_SMP
95 static int combiner_set_affinity(struct irq_data *d,
96 				 const struct cpumask *mask_val, bool force)
97 {
98 	struct combiner_chip_data *chip_data = irq_data_get_irq_chip_data(d);
99 	struct irq_chip *chip = irq_get_chip(chip_data->parent_irq);
100 	struct irq_data *data = irq_get_irq_data(chip_data->parent_irq);
101 
102 	if (chip && chip->irq_set_affinity)
103 		return chip->irq_set_affinity(data, mask_val, force);
104 	else
105 		return -EINVAL;
106 }
107 #endif
108 
109 static struct irq_chip combiner_chip = {
110 	.name			= "COMBINER",
111 	.irq_mask		= combiner_mask_irq,
112 	.irq_unmask		= combiner_unmask_irq,
113 #ifdef CONFIG_SMP
114 	.irq_set_affinity	= combiner_set_affinity,
115 #endif
116 };
117 
118 static void __init combiner_cascade_irq(struct combiner_chip_data *combiner_data,
119 					unsigned int irq)
120 {
121 	irq_set_chained_handler_and_data(irq, combiner_handle_cascade_irq,
122 					 combiner_data);
123 }
124 
125 static void __init combiner_init_one(struct combiner_chip_data *combiner_data,
126 				     unsigned int combiner_nr,
127 				     void __iomem *base, unsigned int irq)
128 {
129 	combiner_data->base = base;
130 	combiner_data->hwirq_offset = (combiner_nr & ~3) * IRQ_IN_COMBINER;
131 	combiner_data->irq_mask = 0xff << ((combiner_nr % 4) << 3);
132 	combiner_data->parent_irq = irq;
133 
134 	/* Disable all interrupts */
135 	writel_relaxed(combiner_data->irq_mask, base + COMBINER_ENABLE_CLEAR);
136 }
137 
138 static int combiner_irq_domain_xlate(struct irq_domain *d,
139 				     struct device_node *controller,
140 				     const u32 *intspec, unsigned int intsize,
141 				     unsigned long *out_hwirq,
142 				     unsigned int *out_type)
143 {
144 	if (irq_domain_get_of_node(d) != controller)
145 		return -EINVAL;
146 
147 	if (intsize < 2)
148 		return -EINVAL;
149 
150 	*out_hwirq = intspec[0] * IRQ_IN_COMBINER + intspec[1];
151 	*out_type = 0;
152 
153 	return 0;
154 }
155 
156 static int combiner_irq_domain_map(struct irq_domain *d, unsigned int irq,
157 				   irq_hw_number_t hw)
158 {
159 	struct combiner_chip_data *combiner_data = d->host_data;
160 
161 	irq_set_chip_and_handler(irq, &combiner_chip, handle_level_irq);
162 	irq_set_chip_data(irq, &combiner_data[hw >> 3]);
163 	irq_set_probe(irq);
164 
165 	return 0;
166 }
167 
168 static const struct irq_domain_ops combiner_irq_domain_ops = {
169 	.xlate	= combiner_irq_domain_xlate,
170 	.map	= combiner_irq_domain_map,
171 };
172 
173 static void __init combiner_init(void __iomem *combiner_base,
174 				 struct device_node *np)
175 {
176 	int i, irq;
177 	unsigned int nr_irq;
178 
179 	nr_irq = max_nr * IRQ_IN_COMBINER;
180 
181 	combiner_data = kcalloc(max_nr, sizeof (*combiner_data), GFP_KERNEL);
182 	if (!combiner_data) {
183 		pr_warn("%s: could not allocate combiner data\n", __func__);
184 		return;
185 	}
186 
187 	combiner_irq_domain = irq_domain_add_linear(np, nr_irq,
188 				&combiner_irq_domain_ops, combiner_data);
189 	if (WARN_ON(!combiner_irq_domain)) {
190 		pr_warn("%s: irq domain init failed\n", __func__);
191 		return;
192 	}
193 
194 	for (i = 0; i < max_nr; i++) {
195 		irq = irq_of_parse_and_map(np, i);
196 
197 		combiner_init_one(&combiner_data[i], i,
198 				  combiner_base + (i >> 2) * 0x10, irq);
199 		combiner_cascade_irq(&combiner_data[i], irq);
200 	}
201 }
202 
203 #ifdef CONFIG_PM
204 
205 /**
206  * combiner_suspend - save interrupt combiner state before suspend
207  *
208  * Save the interrupt enable set register for all combiner groups since
209  * the state is lost when the system enters into a sleep state.
210  *
211  */
212 static int combiner_suspend(void)
213 {
214 	int i;
215 
216 	for (i = 0; i < max_nr; i++)
217 		combiner_data[i].pm_save =
218 			readl_relaxed(combiner_data[i].base + COMBINER_ENABLE_SET);
219 
220 	return 0;
221 }
222 
223 /**
224  * combiner_resume - restore interrupt combiner state after resume
225  *
226  * Restore the interrupt enable set register for all combiner groups since
227  * the state is lost when the system enters into a sleep state on suspend.
228  *
229  */
230 static void combiner_resume(void)
231 {
232 	int i;
233 
234 	for (i = 0; i < max_nr; i++) {
235 		writel_relaxed(combiner_data[i].irq_mask,
236 			     combiner_data[i].base + COMBINER_ENABLE_CLEAR);
237 		writel_relaxed(combiner_data[i].pm_save,
238 			     combiner_data[i].base + COMBINER_ENABLE_SET);
239 	}
240 }
241 
242 #else
243 #define combiner_suspend	NULL
244 #define combiner_resume		NULL
245 #endif
246 
247 static struct syscore_ops combiner_syscore_ops = {
248 	.suspend	= combiner_suspend,
249 	.resume		= combiner_resume,
250 };
251 
252 static int __init combiner_of_init(struct device_node *np,
253 				   struct device_node *parent)
254 {
255 	void __iomem *combiner_base;
256 
257 	combiner_base = of_iomap(np, 0);
258 	if (!combiner_base) {
259 		pr_err("%s: failed to map combiner registers\n", __func__);
260 		return -ENXIO;
261 	}
262 
263 	if (of_property_read_u32(np, "samsung,combiner-nr", &max_nr)) {
264 		pr_info("%s: number of combiners not specified, "
265 			"setting default as %d.\n",
266 			__func__, max_nr);
267 	}
268 
269 	combiner_init(combiner_base, np);
270 
271 	register_syscore_ops(&combiner_syscore_ops);
272 
273 	return 0;
274 }
275 IRQCHIP_DECLARE(exynos4210_combiner, "samsung,exynos4210-combiner",
276 		combiner_of_init);
277