1/*
  2 * tps65910-irq.c  --  TI TPS6591x
  3 *
  4 * Copyright 2010 Texas Instruments Inc.
  5 *
  6 * Author: Graeme Gregory <gg@slimlogic.co.uk>
  7 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
  8 *
  9 *  This program is free software; you can redistribute it and/or modify it
 10 *  under  the terms of the GNU General  Public License as published by the
 11 *  Free Software Foundation;  either version 2 of the License, or (at your
 12 *  option) any later version.
 13 *
 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/tps65910.h>
 25
 26static inline int irq_to_tps65910_irq(struct tps65910 *tps65910,
 27							int irq)
 28{
 29	return (irq - tps65910->irq_base);
 30}
 31
 32/*
 33 * This is a threaded IRQ handler so can access I2C/SPI.  Since all
 34 * interrupts are clear on read the IRQ line will be reasserted and
 35 * the physical IRQ will be handled again if another interrupt is
 36 * asserted while we run - in the normal course of events this is a
 37 * rare occurrence so we save I2C/SPI reads.  We're also assuming that
 38 * it's rare to get lots of interrupts firing simultaneously so try to
 39 * minimise I/O.
 40 */
 41static irqreturn_t tps65910_irq(int irq, void *irq_data)
 42{
 43	struct tps65910 *tps65910 = irq_data;
 44	u32 irq_sts;
 45	u32 irq_mask;
 46	u8 reg;
 47	int i;
 48
 49	tps65910->read(tps65910, TPS65910_INT_STS, 1, &reg);
 50	irq_sts = reg;
 51	tps65910->read(tps65910, TPS65910_INT_STS2, 1, &reg);
 52	irq_sts |= reg << 8;
 53	switch (tps65910_chip_id(tps65910)) {
 54	case TPS65911:
 55		tps65910->read(tps65910, TPS65910_INT_STS3, 1, &reg);
 56		irq_sts |= reg << 16;
 57	}
 58
 59	tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
 60	irq_mask = reg;
 61	tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
 62	irq_mask |= reg << 8;
 63	switch (tps65910_chip_id(tps65910)) {
 64	case TPS65911:
 65		tps65910->read(tps65910, TPS65910_INT_MSK3, 1, &reg);
 66		irq_mask |= reg << 16;
 67	}
 68
 69	irq_sts &= ~irq_mask;
 70
 71	if (!irq_sts)
 72		return IRQ_NONE;
 73
 74	for (i = 0; i < tps65910->irq_num; i++) {
 75
 76		if (!(irq_sts & (1 << i)))
 77			continue;
 78
 79		handle_nested_irq(tps65910->irq_base + i);
 80	}
 81
 82	/* Write the STS register back to clear IRQs we handled */
 83	reg = irq_sts & 0xFF;
 84	irq_sts >>= 8;
 85	tps65910->write(tps65910, TPS65910_INT_STS, 1, &reg);
 86	reg = irq_sts & 0xFF;
 87	tps65910->write(tps65910, TPS65910_INT_STS2, 1, &reg);
 88	switch (tps65910_chip_id(tps65910)) {
 89	case TPS65911:
 90		reg = irq_sts >> 8;
 91		tps65910->write(tps65910, TPS65910_INT_STS3, 1, &reg);
 92	}
 93
 94	return IRQ_HANDLED;
 95}
 96
 97static void tps65910_irq_lock(struct irq_data *data)
 98{
 99	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
100
101	mutex_lock(&tps65910->irq_lock);
102}
103
104static void tps65910_irq_sync_unlock(struct irq_data *data)
105{
106	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
107	u32 reg_mask;
108	u8 reg;
109
110	tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
111	reg_mask = reg;
112	tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
113	reg_mask |= reg << 8;
114	switch (tps65910_chip_id(tps65910)) {
115	case TPS65911:
116		tps65910->read(tps65910, TPS65910_INT_MSK3, 1, &reg);
117		reg_mask |= reg << 16;
118	}
119
120	if (tps65910->irq_mask != reg_mask) {
121		reg = tps65910->irq_mask & 0xFF;
122		tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);
123		reg = tps65910->irq_mask >> 8 & 0xFF;
124		tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);
125		switch (tps65910_chip_id(tps65910)) {
126		case TPS65911:
127			reg = tps65910->irq_mask >> 16;
128			tps65910->write(tps65910, TPS65910_INT_MSK3, 1, &reg);
129		}
130	}
131	mutex_unlock(&tps65910->irq_lock);
132}
133
134static void tps65910_irq_enable(struct irq_data *data)
135{
136	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
137
138	tps65910->irq_mask &= ~( 1 << irq_to_tps65910_irq(tps65910, data->irq));
139}
140
141static void tps65910_irq_disable(struct irq_data *data)
142{
143	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
144
145	tps65910->irq_mask |= ( 1 << irq_to_tps65910_irq(tps65910, data->irq));
146}
147
148static struct irq_chip tps65910_irq_chip = {
149	.name = "tps65910",
150	.irq_bus_lock = tps65910_irq_lock,
151	.irq_bus_sync_unlock = tps65910_irq_sync_unlock,
152	.irq_disable = tps65910_irq_disable,
153	.irq_enable = tps65910_irq_enable,
154};
155
156int tps65910_irq_init(struct tps65910 *tps65910, int irq,
157		    struct tps65910_platform_data *pdata)
158{
159	int ret, cur_irq;
160	int flags = IRQF_ONESHOT;
161
162	if (!irq) {
163		dev_warn(tps65910->dev, "No interrupt support, no core IRQ\n");
164		return -EINVAL;
165	}
166
167	if (!pdata || !pdata->irq_base) {
168		dev_warn(tps65910->dev, "No interrupt support, no IRQ base\n");
169		return -EINVAL;
170	}
171
172	tps65910->irq_mask = 0xFFFFFF;
173
174	mutex_init(&tps65910->irq_lock);
175	tps65910->chip_irq = irq;
176	tps65910->irq_base = pdata->irq_base;
177
178	switch (tps65910_chip_id(tps65910)) {
179	case TPS65910:
180		tps65910->irq_num = TPS65910_NUM_IRQ;
181		break;
182	case TPS65911:
183		tps65910->irq_num = TPS65911_NUM_IRQ;
184		break;
185	}
186
187	/* Register with genirq */
188	for (cur_irq = tps65910->irq_base;
189	     cur_irq < tps65910->irq_num + tps65910->irq_base;
190	     cur_irq++) {
191		irq_set_chip_data(cur_irq, tps65910);
192		irq_set_chip_and_handler(cur_irq, &tps65910_irq_chip,
193					 handle_edge_irq);
194		irq_set_nested_thread(cur_irq, 1);
195
196		/* ARM needs us to explicitly flag the IRQ as valid
197		 * and will set them noprobe when we do so. */
198#ifdef CONFIG_ARM
199		set_irq_flags(cur_irq, IRQF_VALID);
200#else
201		irq_set_noprobe(cur_irq);
202#endif
203	}
204
205	ret = request_threaded_irq(irq, NULL, tps65910_irq, flags,
206				   "tps65910", tps65910);
207
208	irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
209
210	if (ret != 0)
211		dev_err(tps65910->dev, "Failed to request IRQ: %d\n", ret);
212
213	return ret;
214}
215
216int tps65910_irq_exit(struct tps65910 *tps65910)
217{
218	free_irq(tps65910->chip_irq, tps65910);
219	return 0;
220}