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(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(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(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(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
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, 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
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(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
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(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
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(lp->irqdm);
194}
195