1/*
2 * tps65912-irq.c  --  TI TPS6591x
3 *
4 * Copyright 2011 Texas Instruments Inc.
5 *
6 * Author: Margarita Olaya <magi@slimlogic.co.uk>
7 *
8 *  This program is free software; you can redistribute it and/or modify it
9 *  under  the terms of the GNU General  Public License as published by the
10 *  Free Software Foundation;  either version 2 of the License, or (at your
11 *  option) any later version.
12 *
13 * This driver is based on wm8350 implementation.
14 */
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/bug.h>
20#include <linux/device.h>
21#include <linux/interrupt.h>
22#include <linux/irq.h>
23#include <linux/gpio.h>
24#include <linux/mfd/tps65912.h>
25
26static inline int irq_to_tps65912_irq(struct tps65912 *tps65912,
27							int irq)
28{
29	return irq - tps65912->irq_base;
30}
31
32/*
33 * This is a threaded IRQ handler so can access I2C/SPI.  Since the
34 * IRQ handler explicitly clears the IRQ it handles the IRQ line
35 * will be reasserted and the physical IRQ will be handled again if
36 * another interrupt is asserted while we run - in the normal course
37 * of events this is a rare occurrence so we save I2C/SPI reads. We're
38 * also assuming that it's rare to get lots of interrupts firing
39 * simultaneously so try to minimise I/O.
40 */
41static irqreturn_t tps65912_irq(int irq, void *irq_data)
42{
43	struct tps65912 *tps65912 = irq_data;
44	u32 irq_sts;
45	u32 irq_mask;
46	u8 reg;
47	int i;
48
49
50	tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
51	irq_sts = reg;
52	tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
53	irq_sts |= reg << 8;
54	tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
55	irq_sts |= reg << 16;
56	tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
57	irq_sts |= reg << 24;
58
59	tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
60	irq_mask = reg;
61	tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
62	irq_mask |= reg << 8;
63	tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
64	irq_mask |= reg << 16;
65	tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
66	irq_mask |= reg << 24;
67
68	irq_sts &= ~irq_mask;
69	if (!irq_sts)
70		return IRQ_NONE;
71
72	for (i = 0; i < tps65912->irq_num; i++) {
73		if (!(irq_sts & (1 << i)))
74			continue;
75
76		handle_nested_irq(tps65912->irq_base + i);
77	}
78
79	/* Write the STS register back to clear IRQs we handled */
80	reg = irq_sts & 0xFF;
81	irq_sts >>= 8;
82	if (reg)
83		tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
84	reg = irq_sts & 0xFF;
85	irq_sts >>= 8;
86	if (reg)
87		tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
88	reg = irq_sts & 0xFF;
89	irq_sts >>= 8;
90	if (reg)
91		tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
92	reg = irq_sts & 0xFF;
93	if (reg)
94		tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
95
96	return IRQ_HANDLED;
97}
98
99static void tps65912_irq_lock(struct irq_data *data)
100{
101	struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
102
103	mutex_lock(&tps65912->irq_lock);
104}
105
106static void tps65912_irq_sync_unlock(struct irq_data *data)
107{
108	struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
109	u32 reg_mask;
110	u8 reg;
111
112	tps65912->read(tps65912, TPS65912_INT_MSK, 1, &reg);
113	reg_mask = reg;
114	tps65912->read(tps65912, TPS65912_INT_MSK2, 1, &reg);
115	reg_mask |= reg << 8;
116	tps65912->read(tps65912, TPS65912_INT_MSK3, 1, &reg);
117	reg_mask |= reg << 16;
118	tps65912->read(tps65912, TPS65912_INT_MSK4, 1, &reg);
119	reg_mask |= reg << 24;
120
121	if (tps65912->irq_mask != reg_mask) {
122		reg = tps65912->irq_mask & 0xFF;
123		tps65912->write(tps65912, TPS65912_INT_MSK, 1, &reg);
124		reg = tps65912->irq_mask >> 8 & 0xFF;
125		tps65912->write(tps65912, TPS65912_INT_MSK2, 1, &reg);
126		reg = tps65912->irq_mask >> 16 & 0xFF;
127		tps65912->write(tps65912, TPS65912_INT_MSK3, 1, &reg);
128		reg = tps65912->irq_mask >> 24 & 0xFF;
129		tps65912->write(tps65912, TPS65912_INT_MSK4, 1, &reg);
130	}
131
132	mutex_unlock(&tps65912->irq_lock);
133}
134
135static void tps65912_irq_enable(struct irq_data *data)
136{
137	struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
138
139	tps65912->irq_mask &= ~(1 << irq_to_tps65912_irq(tps65912, data->irq));
140}
141
142static void tps65912_irq_disable(struct irq_data *data)
143{
144	struct tps65912 *tps65912 = irq_data_get_irq_chip_data(data);
145
146	tps65912->irq_mask |= (1 << irq_to_tps65912_irq(tps65912, data->irq));
147}
148
149static struct irq_chip tps65912_irq_chip = {
150	.name = "tps65912",
151	.irq_bus_lock = tps65912_irq_lock,
152	.irq_bus_sync_unlock = tps65912_irq_sync_unlock,
153	.irq_disable = tps65912_irq_disable,
154	.irq_enable = tps65912_irq_enable,
155};
156
157int tps65912_irq_init(struct tps65912 *tps65912, int irq,
158			    struct tps65912_platform_data *pdata)
159{
160	int ret, cur_irq;
161	int flags = IRQF_ONESHOT;
162	u8 reg;
163
164	if (!irq) {
165		dev_warn(tps65912->dev, "No interrupt support, no core IRQ\n");
166		return 0;
167	}
168
169	if (!pdata || !pdata->irq_base) {
170		dev_warn(tps65912->dev, "No interrupt support, no IRQ base\n");
171		return 0;
172	}
173
174	/* Clear unattended interrupts */
175	tps65912->read(tps65912, TPS65912_INT_STS, 1, &reg);
176	tps65912->write(tps65912, TPS65912_INT_STS, 1, &reg);
177	tps65912->read(tps65912, TPS65912_INT_STS2, 1, &reg);
178	tps65912->write(tps65912, TPS65912_INT_STS2, 1, &reg);
179	tps65912->read(tps65912, TPS65912_INT_STS3, 1, &reg);
180	tps65912->write(tps65912, TPS65912_INT_STS3, 1, &reg);
181	tps65912->read(tps65912, TPS65912_INT_STS4, 1, &reg);
182	tps65912->write(tps65912, TPS65912_INT_STS4, 1, &reg);
183
184	/* Mask top level interrupts */
185	tps65912->irq_mask = 0xFFFFFFFF;
186
187	mutex_init(&tps65912->irq_lock);
188	tps65912->chip_irq = irq;
189	tps65912->irq_base = pdata->irq_base;
190
191	tps65912->irq_num = TPS65912_NUM_IRQ;
192
193	/* Register with genirq */
194	for (cur_irq = tps65912->irq_base;
195	     cur_irq < tps65912->irq_num + tps65912->irq_base;
196	     cur_irq++) {
197		irq_set_chip_data(cur_irq, tps65912);
198		irq_set_chip_and_handler(cur_irq, &tps65912_irq_chip,
199					 handle_edge_irq);
200		irq_set_nested_thread(cur_irq, 1);
201		/* ARM needs us to explicitly flag the IRQ as valid
202		 * and will set them noprobe when we do so. */
203#ifdef CONFIG_ARM
204		set_irq_flags(cur_irq, IRQF_VALID);
205#else
206		irq_set_noprobe(cur_irq);
207#endif
208	}
209
210	ret = request_threaded_irq(irq, NULL, tps65912_irq, flags,
211				   "tps65912", tps65912);
212
213	irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
214	if (ret != 0)
215		dev_err(tps65912->dev, "Failed to request IRQ: %d\n", ret);
216
217	return ret;
218}
219
220int tps65912_irq_exit(struct tps65912 *tps65912)
221{
222	free_irq(tps65912->chip_irq, tps65912);
223	return 0;
224}
225