1/*
2 * TI LP8788 MFD - interrupt handler
3 *
4 * Copyright 2012 Texas Instruments
5 *
6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/delay.h>
15#include <linux/err.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/irqdomain.h>
19#include <linux/device.h>
20#include <linux/mfd/lp8788.h>
21#include <linux/module.h>
22#include <linux/slab.h>
23
24/* register address */
25#define LP8788_INT_1			0x00
26#define LP8788_INTEN_1			0x03
27
28#define BASE_INTEN_ADDR			LP8788_INTEN_1
29#define SIZE_REG			8
30#define NUM_REGS			3
31
32/*
33 * struct lp8788_irq_data
34 * @lp               : used for accessing to lp8788 registers
35 * @irq_lock         : mutex for enabling/disabling the interrupt
36 * @domain           : IRQ domain for handling nested interrupt
37 * @enabled          : status of enabled interrupt
38 */
39struct lp8788_irq_data {
40	struct lp8788 *lp;
41	struct mutex irq_lock;
42	struct irq_domain *domain;
43	int enabled[LP8788_INT_MAX];
44};
45
46static inline u8 _irq_to_addr(enum lp8788_int_id id)
47{
48	return id / SIZE_REG;
49}
50
51static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
52{
53	return _irq_to_addr(id) + BASE_INTEN_ADDR;
54}
55
56static inline u8 _irq_to_mask(enum lp8788_int_id id)
57{
58	return 1 << (id % SIZE_REG);
59}
60
61static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
62{
63	return enable << (id % SIZE_REG);
64}
65
66static void lp8788_irq_enable(struct irq_data *data)
67{
68	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
69
70	irqd->enabled[data->hwirq] = 1;
71}
72
73static void lp8788_irq_disable(struct irq_data *data)
74{
75	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
76
77	irqd->enabled[data->hwirq] = 0;
78}
79
80static void lp8788_irq_bus_lock(struct irq_data *data)
81{
82	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
83
84	mutex_lock(&irqd->irq_lock);
85}
86
87static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
88{
89	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
90	enum lp8788_int_id irq = data->hwirq;
91	u8 addr, mask, val;
92
93	addr = _irq_to_enable_addr(irq);
94	mask = _irq_to_mask(irq);
95	val = _irq_to_val(irq, irqd->enabled[irq]);
96
97	lp8788_update_bits(irqd->lp, addr, mask, val);
98
99	mutex_unlock(&irqd->irq_lock);
100}
101
102static struct irq_chip lp8788_irq_chip = {
103	.name			= "lp8788",
104	.irq_enable		= lp8788_irq_enable,
105	.irq_disable		= lp8788_irq_disable,
106	.irq_bus_lock		= lp8788_irq_bus_lock,
107	.irq_bus_sync_unlock	= lp8788_irq_bus_sync_unlock,
108};
109
110static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
111{
112	struct lp8788_irq_data *irqd = ptr;
113	struct lp8788 *lp = irqd->lp;
114	u8 status[NUM_REGS], addr, mask;
115	bool handled;
116	int i;
117
118	if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
119		return IRQ_NONE;
120
121	for (i = 0 ; i < LP8788_INT_MAX ; i++) {
122		addr = _irq_to_addr(i);
123		mask = _irq_to_mask(i);
124
125		/* reporting only if the irq is enabled */
126		if (status[addr] & mask) {
127			handle_nested_irq(irq_find_mapping(irqd->domain, i));
128			handled = true;
129		}
130	}
131
132	return handled ? IRQ_HANDLED : IRQ_NONE;
133}
134
135static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
136			irq_hw_number_t hwirq)
137{
138	struct lp8788_irq_data *irqd = d->host_data;
139	struct irq_chip *chip = &lp8788_irq_chip;
140
141	irq_set_chip_data(virq, irqd);
142	irq_set_chip_and_handler(virq, chip, handle_edge_irq);
143	irq_set_nested_thread(virq, 1);
144
145#ifdef CONFIG_ARM
146	set_irq_flags(virq, IRQF_VALID);
147#else
148	irq_set_noprobe(virq);
149#endif
150
151	return 0;
152}
153
154static struct irq_domain_ops lp8788_domain_ops = {
155	.map = lp8788_irq_map,
156};
157
158int lp8788_irq_init(struct lp8788 *lp, int irq)
159{
160	struct lp8788_irq_data *irqd;
161	int ret;
162
163	if (irq <= 0) {
164		dev_warn(lp->dev, "invalid irq number: %d\n", irq);
165		return 0;
166	}
167
168	irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
169	if (!irqd)
170		return -ENOMEM;
171
172	irqd->lp = lp;
173	irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
174					&lp8788_domain_ops, irqd);
175	if (!irqd->domain) {
176		dev_err(lp->dev, "failed to add irq domain err\n");
177		return -EINVAL;
178	}
179
180	lp->irqdm = irqd->domain;
181	mutex_init(&irqd->irq_lock);
182
183	ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
184				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
185				"lp8788-irq", irqd);
186	if (ret) {
187		dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
188		return ret;
189	}
190
191	lp->irq = irq;
192
193	return 0;
194}
195
196void lp8788_irq_exit(struct lp8788 *lp)
197{
198	if (lp->irq)
199		free_irq(lp->irq, lp->irqdm);
200}
201