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0f98dd1b BJZ |
1 | /* |
2 | * GPIO Testing Device Driver | |
3 | * | |
4 | * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com> | |
5 | * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/gpio/driver.h> | |
17 | #include <linux/platform_device.h> | |
18 | ||
19 | #define GPIO_NAME "gpio-mockup" | |
20 | #define MAX_GC 10 | |
21 | ||
22 | enum direction { | |
23 | OUT, | |
24 | IN | |
25 | }; | |
26 | ||
27 | /* | |
28 | * struct gpio_pin_status - structure describing a GPIO status | |
29 | * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out | |
30 | * @value: Configures status of the gpio as 0(low) or 1(high) | |
31 | */ | |
32 | struct gpio_pin_status { | |
33 | enum direction dir; | |
34 | bool value; | |
35 | }; | |
36 | ||
37 | struct mockup_gpio_controller { | |
38 | struct gpio_chip gc; | |
39 | struct gpio_pin_status *stats; | |
40 | }; | |
41 | ||
42 | static int gpio_mockup_ranges[MAX_GC << 1]; | |
43 | static int gpio_mockup_params_nr; | |
44 | module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400); | |
45 | ||
e53c6028 | 46 | static const char pins_name_start = 'A'; |
0f98dd1b BJZ |
47 | |
48 | static int mockup_gpio_get(struct gpio_chip *gc, unsigned int offset) | |
49 | { | |
50 | struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); | |
51 | ||
52 | return cntr->stats[offset].value; | |
53 | } | |
54 | ||
55 | static void mockup_gpio_set(struct gpio_chip *gc, unsigned int offset, | |
56 | int value) | |
57 | { | |
58 | struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); | |
59 | ||
60 | cntr->stats[offset].value = !!value; | |
61 | } | |
62 | ||
63 | static int mockup_gpio_dirout(struct gpio_chip *gc, unsigned int offset, | |
64 | int value) | |
65 | { | |
66 | struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); | |
67 | ||
68 | mockup_gpio_set(gc, offset, value); | |
69 | cntr->stats[offset].dir = OUT; | |
70 | return 0; | |
71 | } | |
72 | ||
73 | static int mockup_gpio_dirin(struct gpio_chip *gc, unsigned int offset) | |
74 | { | |
75 | struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); | |
76 | ||
77 | cntr->stats[offset].dir = IN; | |
78 | return 0; | |
79 | } | |
80 | ||
81 | static int mockup_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) | |
82 | { | |
83 | struct mockup_gpio_controller *cntr = gpiochip_get_data(gc); | |
84 | ||
85 | return cntr->stats[offset].dir; | |
86 | } | |
87 | ||
88 | static int mockup_gpio_add(struct device *dev, | |
89 | struct mockup_gpio_controller *cntr, | |
90 | const char *name, int base, int ngpio) | |
91 | { | |
92 | int ret; | |
93 | ||
94 | cntr->gc.base = base; | |
95 | cntr->gc.ngpio = ngpio; | |
96 | cntr->gc.label = name; | |
97 | cntr->gc.owner = THIS_MODULE; | |
98 | cntr->gc.parent = dev; | |
99 | cntr->gc.get = mockup_gpio_get; | |
100 | cntr->gc.set = mockup_gpio_set; | |
101 | cntr->gc.direction_output = mockup_gpio_dirout; | |
102 | cntr->gc.direction_input = mockup_gpio_dirin; | |
103 | cntr->gc.get_direction = mockup_gpio_get_direction; | |
104 | cntr->stats = devm_kzalloc(dev, sizeof(*cntr->stats) * cntr->gc.ngpio, | |
105 | GFP_KERNEL); | |
106 | if (!cntr->stats) { | |
107 | ret = -ENOMEM; | |
108 | goto err; | |
109 | } | |
110 | ret = devm_gpiochip_add_data(dev, &cntr->gc, cntr); | |
111 | if (ret) | |
112 | goto err; | |
113 | ||
114 | dev_info(dev, "gpio<%d..%d> add successful!", base, base + ngpio); | |
115 | return 0; | |
116 | err: | |
117 | dev_err(dev, "gpio<%d..%d> add failed!", base, base + ngpio); | |
118 | return ret; | |
119 | } | |
120 | ||
121 | static int mockup_gpio_probe(struct platform_device *pdev) | |
122 | { | |
123 | struct device *dev = &pdev->dev; | |
124 | struct mockup_gpio_controller *cntr; | |
125 | int ret; | |
126 | int i; | |
127 | int base; | |
128 | int ngpio; | |
129 | char chip_name[sizeof(GPIO_NAME) + 3]; | |
130 | ||
131 | if (gpio_mockup_params_nr < 2) | |
132 | return -EINVAL; | |
133 | ||
134 | cntr = devm_kzalloc(dev, sizeof(*cntr) * (gpio_mockup_params_nr >> 1), | |
135 | GFP_KERNEL); | |
136 | if (!cntr) | |
137 | return -ENOMEM; | |
138 | ||
139 | platform_set_drvdata(pdev, cntr); | |
140 | ||
141 | for (i = 0; i < gpio_mockup_params_nr >> 1; i++) { | |
142 | base = gpio_mockup_ranges[i * 2]; | |
143 | if (base == -1) | |
144 | ngpio = gpio_mockup_ranges[i * 2 + 1]; | |
145 | else | |
146 | ngpio = gpio_mockup_ranges[i * 2 + 1] - base; | |
147 | ||
148 | if (ngpio >= 0) { | |
149 | sprintf(chip_name, "%s-%c", GPIO_NAME, | |
150 | pins_name_start + i); | |
151 | ret = mockup_gpio_add(dev, &cntr[i], | |
152 | chip_name, base, ngpio); | |
153 | } else { | |
154 | ret = -1; | |
155 | } | |
156 | if (ret) { | |
157 | if (base < 0) | |
158 | dev_err(dev, "gpio<%d..%d> add failed\n", | |
159 | base, ngpio); | |
160 | else | |
161 | dev_err(dev, "gpio<%d..%d> add failed\n", | |
162 | base, base + ngpio); | |
163 | ||
164 | return ret; | |
165 | } | |
166 | } | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | static struct platform_driver mockup_gpio_driver = { | |
172 | .driver = { | |
173 | .name = GPIO_NAME, | |
174 | }, | |
175 | .probe = mockup_gpio_probe, | |
176 | }; | |
177 | ||
178 | static struct platform_device *pdev; | |
179 | static int __init mock_device_init(void) | |
180 | { | |
181 | int err; | |
182 | ||
183 | pdev = platform_device_alloc(GPIO_NAME, -1); | |
184 | if (!pdev) | |
185 | return -ENOMEM; | |
186 | ||
187 | err = platform_device_add(pdev); | |
188 | if (err) { | |
189 | platform_device_put(pdev); | |
190 | return err; | |
191 | } | |
192 | ||
193 | err = platform_driver_register(&mockup_gpio_driver); | |
194 | if (err) { | |
195 | platform_device_unregister(pdev); | |
196 | return err; | |
197 | } | |
198 | ||
199 | return 0; | |
200 | } | |
201 | ||
202 | static void __exit mock_device_exit(void) | |
203 | { | |
204 | platform_driver_unregister(&mockup_gpio_driver); | |
205 | platform_device_unregister(pdev); | |
206 | } | |
207 | ||
208 | module_init(mock_device_init); | |
209 | module_exit(mock_device_exit); | |
210 | ||
211 | MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>"); | |
212 | MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>"); | |
213 | MODULE_DESCRIPTION("GPIO Testing driver"); | |
214 | MODULE_LICENSE("GPL v2"); |