summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-mockup.c
blob: 82a9efd021dbc9eb93c3d56b243063eeaf60d652 (plain)
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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 * GPIO Testing Device Driver
 *
 * Copyright (C) 2014  Kamlakant Patel <kamlakant.patel@broadcom.com>
 * Copyright (C) 2015-2016  Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>

#define GPIO_NAME	"gpio-mockup"
#define	MAX_GC		10

enum direction {
	OUT,
	IN
};

/*
 * struct gpio_pin_status - structure describing a GPIO status
 * @dir:       Configures direction of gpio as "in" or "out", 0=in, 1=out
 * @value:     Configures status of the gpio as 0(low) or 1(high)
 */
struct gpio_pin_status {
	enum direction dir;
	bool value;
};

struct mockup_gpio_controller {
	struct gpio_chip gc;
	struct gpio_pin_status *stats;
};

static int gpio_mockup_ranges[MAX_GC << 1];
static int gpio_mockup_params_nr;
module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400);

static const char pins_name_start = 'A';

static int mockup_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
	struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);

	return cntr->stats[offset].value;
}

static void mockup_gpio_set(struct gpio_chip *gc, unsigned int offset,
			    int value)
{
	struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);

	cntr->stats[offset].value = !!value;
}

static int mockup_gpio_dirout(struct gpio_chip *gc, unsigned int offset,
			      int value)
{
	struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);

	mockup_gpio_set(gc, offset, value);
	cntr->stats[offset].dir = OUT;
	return 0;
}

static int mockup_gpio_dirin(struct gpio_chip *gc, unsigned int offset)
{
	struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);

	cntr->stats[offset].dir = IN;
	return 0;
}

static int mockup_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
	struct mockup_gpio_controller *cntr = gpiochip_get_data(gc);

	return cntr->stats[offset].dir;
}

static int mockup_gpio_add(struct device *dev,
			   struct mockup_gpio_controller *cntr,
			   const char *name, int base, int ngpio)
{
	int ret;

	cntr->gc.base = base;
	cntr->gc.ngpio = ngpio;
	cntr->gc.label = name;
	cntr->gc.owner = THIS_MODULE;
	cntr->gc.parent = dev;
	cntr->gc.get = mockup_gpio_get;
	cntr->gc.set = mockup_gpio_set;
	cntr->gc.direction_output = mockup_gpio_dirout;
	cntr->gc.direction_input = mockup_gpio_dirin;
	cntr->gc.get_direction = mockup_gpio_get_direction;
	cntr->stats = devm_kzalloc(dev, sizeof(*cntr->stats) * cntr->gc.ngpio,
				   GFP_KERNEL);
	if (!cntr->stats) {
		ret = -ENOMEM;
		goto err;
	}
	ret = devm_gpiochip_add_data(dev, &cntr->gc, cntr);
	if (ret)
		goto err;

	dev_info(dev, "gpio<%d..%d> add successful!", base, base + ngpio);
	return 0;
err:
	dev_err(dev, "gpio<%d..%d> add failed!", base, base + ngpio);
	return ret;
}

static int mockup_gpio_probe(struct platform_device *pdev)
{
	struct mockup_gpio_controller *cntr;
	struct device *dev = &pdev->dev;
	int ret, i, base, ngpio;
	char *chip_name;

	if (gpio_mockup_params_nr < 2)
		return -EINVAL;

	cntr = devm_kzalloc(dev, sizeof(*cntr) * (gpio_mockup_params_nr >> 1),
			    GFP_KERNEL);
	if (!cntr)
		return -ENOMEM;

	platform_set_drvdata(pdev, cntr);

	for (i = 0; i < gpio_mockup_params_nr >> 1; i++) {
		base = gpio_mockup_ranges[i * 2];
		if (base == -1)
			ngpio = gpio_mockup_ranges[i * 2 + 1];
		else
			ngpio = gpio_mockup_ranges[i * 2 + 1] - base;

		if (ngpio >= 0) {
			chip_name = devm_kasprintf(dev, GFP_KERNEL,
						   "%s-%c", GPIO_NAME,
						   pins_name_start + i);
			if (!chip_name)
				return -ENOMEM;

			ret = mockup_gpio_add(dev, &cntr[i],
					      chip_name, base, ngpio);
		} else {
			ret = -1;
		}
		if (ret) {
			if (base < 0)
				dev_err(dev, "gpio<%d..%d> add failed\n",
					base, ngpio);
			else
				dev_err(dev, "gpio<%d..%d> add failed\n",
					base, base + ngpio);

			return ret;
		}
	}

	return 0;
}

static struct platform_driver mockup_gpio_driver = {
	.driver = {
		.name = GPIO_NAME,
	},
	.probe = mockup_gpio_probe,
};

static struct platform_device *pdev;
static int __init mock_device_init(void)
{
	int err;

	pdev = platform_device_alloc(GPIO_NAME, -1);
	if (!pdev)
		return -ENOMEM;

	err = platform_device_add(pdev);
	if (err) {
		platform_device_put(pdev);
		return err;
	}

	err = platform_driver_register(&mockup_gpio_driver);
	if (err) {
		platform_device_unregister(pdev);
		return err;
	}

	return 0;
}

static void __exit mock_device_exit(void)
{
	platform_driver_unregister(&mockup_gpio_driver);
	platform_device_unregister(pdev);
}

module_init(mock_device_init);
module_exit(mock_device_exit);

MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>");
MODULE_DESCRIPTION("GPIO Testing driver");
MODULE_LICENSE("GPL v2");