1/*
2 *  Loongson-2F/3A/3B GPIO Support
3 *
4 *  Copyright (c) 2008 Richard Liu,  STMicroelectronics	 <richard.liu@st.com>
5 *  Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
6 *  Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
7 *  Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License as published by
11 *  the Free Software Foundation; either version 2 of the License, or
12 *  (at your option) any later version.
13 */
14
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/spinlock.h>
19#include <linux/err.h>
20#include <asm/types.h>
21#include <loongson.h>
22#include <linux/gpio.h>
23
24#define STLS2F_N_GPIO		4
25#define STLS3A_N_GPIO		16
26
27#ifdef CONFIG_CPU_LOONGSON3
28#define LOONGSON_N_GPIO	STLS3A_N_GPIO
29#else
30#define LOONGSON_N_GPIO	STLS2F_N_GPIO
31#endif
32
33#define LOONGSON_GPIO_IN_OFFSET	16
34
35static DEFINE_SPINLOCK(gpio_lock);
36
37static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
38{
39	u32 temp;
40	u32 mask;
41
42	spin_lock(&gpio_lock);
43	mask = 1 << gpio;
44	temp = LOONGSON_GPIOIE;
45	temp |= mask;
46	LOONGSON_GPIOIE = temp;
47	spin_unlock(&gpio_lock);
48
49	return 0;
50}
51
52static int loongson_gpio_direction_output(struct gpio_chip *chip,
53		unsigned gpio, int level)
54{
55	u32 temp;
56	u32 mask;
57
58	gpio_set_value(gpio, level);
59	spin_lock(&gpio_lock);
60	mask = 1 << gpio;
61	temp = LOONGSON_GPIOIE;
62	temp &= (~mask);
63	LOONGSON_GPIOIE = temp;
64	spin_unlock(&gpio_lock);
65
66	return 0;
67}
68
69static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
70{
71	u32 val;
72	u32 mask;
73
74	mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET);
75	spin_lock(&gpio_lock);
76	val = LOONGSON_GPIODATA;
77	spin_unlock(&gpio_lock);
78
79	return (val & mask) != 0;
80}
81
82static void loongson_gpio_set_value(struct gpio_chip *chip,
83		unsigned gpio, int value)
84{
85	u32 val;
86	u32 mask;
87
88	mask = 1 << gpio;
89
90	spin_lock(&gpio_lock);
91	val = LOONGSON_GPIODATA;
92	if (value)
93		val |= mask;
94	else
95		val &= (~mask);
96	LOONGSON_GPIODATA = val;
97	spin_unlock(&gpio_lock);
98}
99
100static struct gpio_chip loongson_chip = {
101	.label                  = "Loongson-gpio-chip",
102	.direction_input        = loongson_gpio_direction_input,
103	.get                    = loongson_gpio_get_value,
104	.direction_output       = loongson_gpio_direction_output,
105	.set                    = loongson_gpio_set_value,
106	.base			= 0,
107	.ngpio                  = LOONGSON_N_GPIO,
108	.can_sleep		= false,
109};
110
111static int __init loongson_gpio_setup(void)
112{
113	return gpiochip_add(&loongson_chip);
114}
115postcore_initcall(loongson_gpio_setup);
116