xref: /openbmc/linux/drivers/mfd/lp8788-irq.c (revision 287dcc2b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI LP8788 MFD - interrupt handler
4  *
5  * Copyright 2012 Texas Instruments
6  *
7  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/device.h>
16 #include <linux/mfd/lp8788.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 
20 /* register address */
21 #define LP8788_INT_1			0x00
22 #define LP8788_INTEN_1			0x03
23 
24 #define BASE_INTEN_ADDR			LP8788_INTEN_1
25 #define SIZE_REG			8
26 #define NUM_REGS			3
27 
28 /*
29  * struct lp8788_irq_data
30  * @lp               : used for accessing to lp8788 registers
31  * @irq_lock         : mutex for enabling/disabling the interrupt
32  * @domain           : IRQ domain for handling nested interrupt
33  * @enabled          : status of enabled interrupt
34  */
35 struct lp8788_irq_data {
36 	struct lp8788 *lp;
37 	struct mutex irq_lock;
38 	struct irq_domain *domain;
39 	int enabled[LP8788_INT_MAX];
40 };
41 
42 static inline u8 _irq_to_addr(enum lp8788_int_id id)
43 {
44 	return id / SIZE_REG;
45 }
46 
47 static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
48 {
49 	return _irq_to_addr(id) + BASE_INTEN_ADDR;
50 }
51 
52 static inline u8 _irq_to_mask(enum lp8788_int_id id)
53 {
54 	return 1 << (id % SIZE_REG);
55 }
56 
57 static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
58 {
59 	return enable << (id % SIZE_REG);
60 }
61 
62 static void lp8788_irq_enable(struct irq_data *data)
63 {
64 	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
65 
66 	irqd->enabled[data->hwirq] = 1;
67 }
68 
69 static void lp8788_irq_disable(struct irq_data *data)
70 {
71 	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
72 
73 	irqd->enabled[data->hwirq] = 0;
74 }
75 
76 static void lp8788_irq_bus_lock(struct irq_data *data)
77 {
78 	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
79 
80 	mutex_lock(&irqd->irq_lock);
81 }
82 
83 static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
84 {
85 	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
86 	enum lp8788_int_id irq = data->hwirq;
87 	u8 addr, mask, val;
88 
89 	addr = _irq_to_enable_addr(irq);
90 	mask = _irq_to_mask(irq);
91 	val = _irq_to_val(irq, irqd->enabled[irq]);
92 
93 	lp8788_update_bits(irqd->lp, addr, mask, val);
94 
95 	mutex_unlock(&irqd->irq_lock);
96 }
97 
98 static struct irq_chip lp8788_irq_chip = {
99 	.name			= "lp8788",
100 	.irq_enable		= lp8788_irq_enable,
101 	.irq_disable		= lp8788_irq_disable,
102 	.irq_bus_lock		= lp8788_irq_bus_lock,
103 	.irq_bus_sync_unlock	= lp8788_irq_bus_sync_unlock,
104 };
105 
106 static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
107 {
108 	struct lp8788_irq_data *irqd = ptr;
109 	struct lp8788 *lp = irqd->lp;
110 	u8 status[NUM_REGS], addr, mask;
111 	bool handled = false;
112 	int i;
113 
114 	if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
115 		return IRQ_NONE;
116 
117 	for (i = 0 ; i < LP8788_INT_MAX ; i++) {
118 		addr = _irq_to_addr(i);
119 		mask = _irq_to_mask(i);
120 
121 		/* reporting only if the irq is enabled */
122 		if (status[addr] & mask) {
123 			handle_nested_irq(irq_find_mapping(irqd->domain, i));
124 			handled = true;
125 		}
126 	}
127 
128 	return handled ? IRQ_HANDLED : IRQ_NONE;
129 }
130 
131 static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
132 			irq_hw_number_t hwirq)
133 {
134 	struct lp8788_irq_data *irqd = d->host_data;
135 	struct irq_chip *chip = &lp8788_irq_chip;
136 
137 	irq_set_chip_data(virq, irqd);
138 	irq_set_chip_and_handler(virq, chip, handle_edge_irq);
139 	irq_set_nested_thread(virq, 1);
140 	irq_set_noprobe(virq);
141 
142 	return 0;
143 }
144 
145 static const struct irq_domain_ops lp8788_domain_ops = {
146 	.map = lp8788_irq_map,
147 };
148 
149 int lp8788_irq_init(struct lp8788 *lp, int irq)
150 {
151 	struct lp8788_irq_data *irqd;
152 	int ret;
153 
154 	if (irq <= 0) {
155 		dev_warn(lp->dev, "invalid irq number: %d\n", irq);
156 		return 0;
157 	}
158 
159 	irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
160 	if (!irqd)
161 		return -ENOMEM;
162 
163 	irqd->lp = lp;
164 	irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
165 					&lp8788_domain_ops, irqd);
166 	if (!irqd->domain) {
167 		dev_err(lp->dev, "failed to add irq domain err\n");
168 		return -EINVAL;
169 	}
170 
171 	lp->irqdm = irqd->domain;
172 	mutex_init(&irqd->irq_lock);
173 
174 	ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
175 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
176 				"lp8788-irq", irqd);
177 	if (ret) {
178 		irq_domain_remove(lp->irqdm);
179 		dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
180 		return ret;
181 	}
182 
183 	lp->irq = irq;
184 
185 	return 0;
186 }
187 
188 void lp8788_irq_exit(struct lp8788 *lp)
189 {
190 	if (lp->irq)
191 		free_irq(lp->irq, lp->irqdm);
192 	if (lp->irqdm)
193 		irq_domain_remove(lp->irqdm);
194 }
195