aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sh/boards/mach-x3proto/gpio.c
blob: f035a7ac6456213f94d0ddae409f8746d4b9b9f5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
 * arch/sh/boards/mach-x3proto/gpio.c
 *
 * Renesas SH-X3 Prototype Baseboard GPIO Support.
 *
 * Copyright (C) 2010 - 2012  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/irqdomain.h>
#include <linux/io.h>
#include <mach/ilsel.h>
#include <mach/hardware.h>

#define KEYCTLR	0xb81c0000
#define KEYOUTR	0xb81c0002
#define KEYDETR 0xb81c0004

static DEFINE_SPINLOCK(x3proto_gpio_lock);
static struct irq_domain *x3proto_irq_domain;

static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
	unsigned long flags;
	unsigned int data;

	spin_lock_irqsave(&x3proto_gpio_lock, flags);
	data = __raw_readw(KEYCTLR);
	data |= (1 << gpio);
	__raw_writew(data, KEYCTLR);
	spin_unlock_irqrestore(&x3proto_gpio_lock, flags);

	return 0;
}

static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
	return !!(__raw_readw(KEYDETR) & (1 << gpio));
}

static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
{
	int virq;

	if (gpio < chip->ngpio)
		virq = irq_create_mapping(x3proto_irq_domain, gpio);
	else
		virq = -ENXIO;

	return virq;
}

static void x3proto_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
{
	struct irq_data *data = irq_get_irq_data(irq);
	struct irq_chip *chip = irq_data_get_irq_chip(data);
	unsigned long mask;
	int pin;

	chip->irq_mask_ack(data);

	mask = __raw_readw(KEYDETR);
	for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
		generic_handle_irq(irq_linear_revmap(x3proto_irq_domain, pin));

	chip->irq_unmask(data);
}

struct gpio_chip x3proto_gpio_chip = {
	.label			= "x3proto-gpio",
	.direction_input	= x3proto_gpio_direction_input,
	.get			= x3proto_gpio_get,
	.to_irq			= x3proto_gpio_to_irq,
	.base			= -1,
	.ngpio			= NR_BASEBOARD_GPIOS,
};

static int x3proto_gpio_irq_map(struct irq_domain *domain, unsigned int virq,
				irq_hw_number_t hwirq)
{
	irq_set_chip_and_handler_name(virq, &dummy_irq_chip, handle_simple_irq,
				      "gpio");

	return 0;
}

static struct irq_domain_ops x3proto_gpio_irq_ops = {
	.map	= x3proto_gpio_irq_map,
	.xlate	= irq_domain_xlate_twocell,
};

int __init x3proto_gpio_setup(void)
{
	int ilsel, ret;

	ilsel = ilsel_enable(ILSEL_KEY);
	if (unlikely(ilsel < 0))
		return ilsel;

	ret = gpiochip_add(&x3proto_gpio_chip);
	if (unlikely(ret))
		goto err_gpio;

	x3proto_irq_domain = irq_domain_add_linear(NULL, NR_BASEBOARD_GPIOS,
						   &x3proto_gpio_irq_ops, NULL);
	if (unlikely(!x3proto_irq_domain))
		goto err_irq;

	pr_info("registering '%s' support, handling GPIOs %u -> %u, "
		"bound to IRQ %u\n",
		x3proto_gpio_chip.label, x3proto_gpio_chip.base,
		x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
		ilsel);

	irq_set_chained_handler(ilsel, x3proto_gpio_irq_handler);
	irq_set_irq_wake(ilsel, 1);

	return 0;

err_irq:
	gpiochip_remove(&x3proto_gpio_chip);
	ret = 0;
err_gpio:
	synchronize_irq(ilsel);

	ilsel_disable(ILSEL_KEY);

	return ret;
}