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		dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
179		return ret;
180	}
181
182	lp->irq = irq;
183
184	return 0;
185}
186
187void lp8788_irq_exit(struct lp8788 *lp)
188{
189	if (lp->irq)
190		free_irq(lp->irq, lp->irqdm);
191}