aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-moxart.c
blob: ccd45704e5fdc1f5c4a089e9dd6f994c8eb10a67 (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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * MOXA ART SoCs GPIO driver.
 *
 * Copyright (C) 2013 Jonas Jensen
 *
 * Jonas Jensen <jonas.jensen@gmail.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/bitops.h>

#define GPIO_DATA_OUT		0x00
#define GPIO_DATA_IN		0x04
#define GPIO_PIN_DIRECTION	0x08

struct moxart_gpio_chip {
	struct gpio_chip gpio;
	void __iomem *base;
};

static inline struct moxart_gpio_chip *to_moxart_gpio(struct gpio_chip *chip)
{
	return container_of(chip, struct moxart_gpio_chip, gpio);
}

static int moxart_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	return pinctrl_request_gpio(offset);
}

static void moxart_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	pinctrl_free_gpio(offset);
}

static void moxart_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
	void __iomem *ioaddr = gc->base + GPIO_DATA_OUT;
	u32 reg = readl(ioaddr);

	if (value)
		reg = reg | BIT(offset);
	else
		reg = reg & ~BIT(offset);

	writel(reg, ioaddr);
}

static int moxart_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
	u32 ret = readl(gc->base + GPIO_PIN_DIRECTION);

	if (ret & BIT(offset))
		return !!(readl(gc->base + GPIO_DATA_OUT) & BIT(offset));
	else
		return !!(readl(gc->base + GPIO_DATA_IN) & BIT(offset));
}

static int moxart_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
	void __iomem *ioaddr = gc->base + GPIO_PIN_DIRECTION;

	writel(readl(ioaddr) & ~BIT(offset), ioaddr);
	return 0;
}

static int moxart_gpio_direction_output(struct gpio_chip *chip,
					unsigned offset, int value)
{
	struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
	void __iomem *ioaddr = gc->base + GPIO_PIN_DIRECTION;

	moxart_gpio_set(chip, offset, value);
	writel(readl(ioaddr) | BIT(offset), ioaddr);
	return 0;
}

static struct gpio_chip moxart_template_chip = {
	.label			= "moxart-gpio",
	.request		= moxart_gpio_request,
	.free			= moxart_gpio_free,
	.direction_input	= moxart_gpio_direction_input,
	.direction_output	= moxart_gpio_direction_output,
	.set			= moxart_gpio_set,
	.get			= moxart_gpio_get,
	.ngpio			= 32,
	.owner			= THIS_MODULE,
};

static int moxart_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct moxart_gpio_chip *mgc;
	int ret;

	mgc = devm_kzalloc(dev, sizeof(*mgc), GFP_KERNEL);
	if (!mgc) {
		dev_err(dev, "can't allocate GPIO chip container\n");
		return -ENOMEM;
	}
	mgc->gpio = moxart_template_chip;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	mgc->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(mgc->base))
		return PTR_ERR(mgc->base);

	mgc->gpio.dev = dev;

	ret = gpiochip_add(&mgc->gpio);
	if (ret) {
		dev_err(dev, "%s: gpiochip_add failed\n",
			dev->of_node->full_name);
		return ret;
	}

	return 0;
}

static const struct of_device_id moxart_gpio_match[] = {
	{ .compatible = "moxa,moxart-gpio" },
	{ }
};

static struct platform_driver moxart_gpio_driver = {
	.driver	= {
		.name		= "moxart-gpio",
		.owner		= THIS_MODULE,
		.of_match_table	= moxart_gpio_match,
	},
	.probe	= moxart_gpio_probe,
};
module_platform_driver(moxart_gpio_driver);

MODULE_DESCRIPTION("MOXART GPIO chip driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");