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 */
35struct 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
42static inline u8 _irq_to_addr(enum lp8788_int_id id)
43{
44 return id / SIZE_REG;
45}
46
47static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
48{
49 return _irq_to_addr(id) + BASE_INTEN_ADDR;
50}
51
52static inline u8 _irq_to_mask(enum lp8788_int_id id)
53{
54 return 1 << (id % SIZE_REG);
55}
56
57static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
58{
59 return enable << (id % SIZE_REG);
60}
61
62static void lp8788_irq_enable(struct irq_data *data)
63{
64 struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(d: data);
65
66 irqd->enabled[data->hwirq] = 1;
67}
68
69static void lp8788_irq_disable(struct irq_data *data)
70{
71 struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(d: data);
72
73 irqd->enabled[data->hwirq] = 0;
74}
75
76static void lp8788_irq_bus_lock(struct irq_data *data)
77{
78 struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(d: data);
79
80 mutex_lock(&irqd->irq_lock);
81}
82
83static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
84{
85 struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(d: data);
86 enum lp8788_int_id irq = data->hwirq;
87 u8 addr, mask, val;
88
89 addr = _irq_to_enable_addr(id: irq);
90 mask = _irq_to_mask(id: irq);
91 val = _irq_to_val(id: irq, enable: irqd->enabled[irq]);
92
93 lp8788_update_bits(lp: irqd->lp, reg: addr, mask, data: val);
94
95 mutex_unlock(lock: &irqd->irq_lock);
96}
97
98static 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
106static 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, data: status, NUM_REGS))
115 return IRQ_NONE;
116
117 for (i = 0 ; i < LP8788_INT_MAX ; i++) {
118 addr = _irq_to_addr(id: i);
119 mask = _irq_to_mask(id: i);
120
121 /* reporting only if the irq is enabled */
122 if (status[addr] & mask) {
123 handle_nested_irq(irq: irq_find_mapping(domain: irqd->domain, hwirq: i));
124 handled = true;
125 }
126 }
127
128 return handled ? IRQ_HANDLED : IRQ_NONE;
129}
130
131static 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(irq: virq, data: irqd);
138 irq_set_chip_and_handler(irq: virq, chip, handle: handle_edge_irq);
139 irq_set_nested_thread(irq: virq, nest: 1);
140 irq_set_noprobe(irq: virq);
141
142 return 0;
143}
144
145static const struct irq_domain_ops lp8788_domain_ops = {
146 .map = lp8788_irq_map,
147};
148
149int 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(dev: lp->dev, size: sizeof(*irqd), GFP_KERNEL);
160 if (!irqd)
161 return -ENOMEM;
162
163 irqd->lp = lp;
164 irqd->domain = irq_domain_add_linear(of_node: lp->dev->of_node, size: LP8788_INT_MAX,
165 ops: &lp8788_domain_ops, host_data: 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, thread_fn: lp8788_irq_handler,
175 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
176 name: "lp8788-irq", dev: irqd);
177 if (ret) {
178 irq_domain_remove(host: 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
188void 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(host: lp->irqdm);
194}
195

source code of linux/drivers/mfd/lp8788-irq.c