1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016 MediaTek Inc.
4  * Author: Youlin.Pei <youlin.pei@mediatek.com>
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/irq.h>
10 #include <linux/irqchip.h>
11 #include <linux/irqdomain.h>
12 #include <linux/of.h>
13 #include <linux/of_irq.h>
14 #include <linux/of_address.h>
15 #include <linux/slab.h>
16 #include <linux/syscore_ops.h>
17 
18 #define CIRQ_ACK	0x40
19 #define CIRQ_MASK_SET	0xc0
20 #define CIRQ_MASK_CLR	0x100
21 #define CIRQ_SENS_SET	0x180
22 #define CIRQ_SENS_CLR	0x1c0
23 #define CIRQ_POL_SET	0x240
24 #define CIRQ_POL_CLR	0x280
25 #define CIRQ_CONTROL	0x300
26 
27 #define CIRQ_EN	0x1
28 #define CIRQ_EDGE	0x2
29 #define CIRQ_FLUSH	0x4
30 
31 struct mtk_cirq_chip_data {
32 	void __iomem *base;
33 	unsigned int ext_irq_start;
34 	unsigned int ext_irq_end;
35 	struct irq_domain *domain;
36 };
37 
38 static struct mtk_cirq_chip_data *cirq_data;
39 
40 static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
41 {
42 	struct mtk_cirq_chip_data *chip_data = data->chip_data;
43 	unsigned int cirq_num = data->hwirq;
44 	u32 mask = 1 << (cirq_num % 32);
45 
46 	writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
47 }
48 
49 static void mtk_cirq_mask(struct irq_data *data)
50 {
51 	mtk_cirq_write_mask(data, CIRQ_MASK_SET);
52 	irq_chip_mask_parent(data);
53 }
54 
55 static void mtk_cirq_unmask(struct irq_data *data)
56 {
57 	mtk_cirq_write_mask(data, CIRQ_MASK_CLR);
58 	irq_chip_unmask_parent(data);
59 }
60 
61 static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)
62 {
63 	int ret;
64 
65 	switch (type & IRQ_TYPE_SENSE_MASK) {
66 	case IRQ_TYPE_EDGE_FALLING:
67 		mtk_cirq_write_mask(data, CIRQ_POL_CLR);
68 		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
69 		break;
70 	case IRQ_TYPE_EDGE_RISING:
71 		mtk_cirq_write_mask(data, CIRQ_POL_SET);
72 		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
73 		break;
74 	case IRQ_TYPE_LEVEL_LOW:
75 		mtk_cirq_write_mask(data, CIRQ_POL_CLR);
76 		mtk_cirq_write_mask(data, CIRQ_SENS_SET);
77 		break;
78 	case IRQ_TYPE_LEVEL_HIGH:
79 		mtk_cirq_write_mask(data, CIRQ_POL_SET);
80 		mtk_cirq_write_mask(data, CIRQ_SENS_SET);
81 		break;
82 	default:
83 		break;
84 	}
85 
86 	data = data->parent_data;
87 	ret = data->chip->irq_set_type(data, type);
88 	return ret;
89 }
90 
91 static struct irq_chip mtk_cirq_chip = {
92 	.name			= "MT_CIRQ",
93 	.irq_mask		= mtk_cirq_mask,
94 	.irq_unmask		= mtk_cirq_unmask,
95 	.irq_eoi		= irq_chip_eoi_parent,
96 	.irq_set_type		= mtk_cirq_set_type,
97 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
98 #ifdef CONFIG_SMP
99 	.irq_set_affinity	= irq_chip_set_affinity_parent,
100 #endif
101 };
102 
103 static int mtk_cirq_domain_translate(struct irq_domain *d,
104 				     struct irq_fwspec *fwspec,
105 				     unsigned long *hwirq,
106 				     unsigned int *type)
107 {
108 	if (is_of_node(fwspec->fwnode)) {
109 		if (fwspec->param_count != 3)
110 			return -EINVAL;
111 
112 		/* No PPI should point to this domain */
113 		if (fwspec->param[0] != 0)
114 			return -EINVAL;
115 
116 		/* cirq support irq number check */
117 		if (fwspec->param[1] < cirq_data->ext_irq_start ||
118 		    fwspec->param[1] > cirq_data->ext_irq_end)
119 			return -EINVAL;
120 
121 		*hwirq = fwspec->param[1] - cirq_data->ext_irq_start;
122 		*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
123 		return 0;
124 	}
125 
126 	return -EINVAL;
127 }
128 
129 static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
130 				 unsigned int nr_irqs, void *arg)
131 {
132 	int ret;
133 	irq_hw_number_t hwirq;
134 	unsigned int type;
135 	struct irq_fwspec *fwspec = arg;
136 	struct irq_fwspec parent_fwspec = *fwspec;
137 
138 	ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);
139 	if (ret)
140 		return ret;
141 
142 	if (WARN_ON(nr_irqs != 1))
143 		return -EINVAL;
144 
145 	irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
146 				      &mtk_cirq_chip,
147 				      domain->host_data);
148 
149 	parent_fwspec.fwnode = domain->parent->fwnode;
150 	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
151 					    &parent_fwspec);
152 }
153 
154 static const struct irq_domain_ops cirq_domain_ops = {
155 	.translate	= mtk_cirq_domain_translate,
156 	.alloc		= mtk_cirq_domain_alloc,
157 	.free		= irq_domain_free_irqs_common,
158 };
159 
160 #ifdef CONFIG_PM_SLEEP
161 static int mtk_cirq_suspend(void)
162 {
163 	u32 value, mask;
164 	unsigned int irq, hwirq_num;
165 	bool pending, masked;
166 	int i, pendret, maskret;
167 
168 	/*
169 	 * When external interrupts happened, CIRQ will record the status
170 	 * even CIRQ is not enabled. When execute flush command, CIRQ will
171 	 * resend the signals according to the status. So if don't clear the
172 	 * status, CIRQ will resend the wrong signals.
173 	 *
174 	 * arch_suspend_disable_irqs() will be called before CIRQ suspend
175 	 * callback. If clear all the status simply, the external interrupts
176 	 * which happened between arch_suspend_disable_irqs and CIRQ suspend
177 	 * callback will be lost. Using following steps to avoid this issue;
178 	 *
179 	 * - Iterate over all the CIRQ supported interrupts;
180 	 * - For each interrupt, inspect its pending and masked status at GIC
181 	 *   level;
182 	 * - If pending and unmasked, it happened between
183 	 *   arch_suspend_disable_irqs and CIRQ suspend callback, don't ACK
184 	 *   it. Otherwise, ACK it.
185 	 */
186 	hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
187 	for (i = 0; i < hwirq_num; i++) {
188 		irq = irq_find_mapping(cirq_data->domain, i);
189 		if (irq) {
190 			pendret = irq_get_irqchip_state(irq,
191 							IRQCHIP_STATE_PENDING,
192 							&pending);
193 
194 			maskret = irq_get_irqchip_state(irq,
195 							IRQCHIP_STATE_MASKED,
196 							&masked);
197 
198 			if (pendret == 0 && maskret == 0 &&
199 			    (pending && !masked))
200 				continue;
201 		}
202 
203 		mask = 1 << (i % 32);
204 		writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
205 	}
206 
207 	/* set edge_only mode, record edge-triggerd interrupts */
208 	/* enable cirq */
209 	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
210 	value |= (CIRQ_EDGE | CIRQ_EN);
211 	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
212 
213 	return 0;
214 }
215 
216 static void mtk_cirq_resume(void)
217 {
218 	u32 value;
219 
220 	/* flush recorded interrupts, will send signals to parent controller */
221 	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
222 	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
223 
224 	/* disable cirq */
225 	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
226 	value &= ~(CIRQ_EDGE | CIRQ_EN);
227 	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
228 }
229 
230 static struct syscore_ops mtk_cirq_syscore_ops = {
231 	.suspend	= mtk_cirq_suspend,
232 	.resume		= mtk_cirq_resume,
233 };
234 
235 static void mtk_cirq_syscore_init(void)
236 {
237 	register_syscore_ops(&mtk_cirq_syscore_ops);
238 }
239 #else
240 static inline void mtk_cirq_syscore_init(void) {}
241 #endif
242 
243 static int __init mtk_cirq_of_init(struct device_node *node,
244 				   struct device_node *parent)
245 {
246 	struct irq_domain *domain, *domain_parent;
247 	unsigned int irq_num;
248 	int ret;
249 
250 	domain_parent = irq_find_host(parent);
251 	if (!domain_parent) {
252 		pr_err("mtk_cirq: interrupt-parent not found\n");
253 		return -EINVAL;
254 	}
255 
256 	cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
257 	if (!cirq_data)
258 		return -ENOMEM;
259 
260 	cirq_data->base = of_iomap(node, 0);
261 	if (!cirq_data->base) {
262 		pr_err("mtk_cirq: unable to map cirq register\n");
263 		ret = -ENXIO;
264 		goto out_free;
265 	}
266 
267 	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,
268 					 &cirq_data->ext_irq_start);
269 	if (ret)
270 		goto out_unmap;
271 
272 	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,
273 					 &cirq_data->ext_irq_end);
274 	if (ret)
275 		goto out_unmap;
276 
277 	irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
278 	domain = irq_domain_add_hierarchy(domain_parent, 0,
279 					  irq_num, node,
280 					  &cirq_domain_ops, cirq_data);
281 	if (!domain) {
282 		ret = -ENOMEM;
283 		goto out_unmap;
284 	}
285 	cirq_data->domain = domain;
286 
287 	mtk_cirq_syscore_init();
288 
289 	return 0;
290 
291 out_unmap:
292 	iounmap(cirq_data->base);
293 out_free:
294 	kfree(cirq_data);
295 	return ret;
296 }
297 
298 IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);
299