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61cd4822 LZ |
1 | /* |
2 | * Supports for the button array on SoC tablets originally running | |
3 | * Windows 8. | |
4 | * | |
5 | * (C) Copyright 2014 Intel Corporation | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; version 2 | |
10 | * of the License. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/input.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/acpi.h> | |
18 | #include <linux/gpio/consumer.h> | |
19 | #include <linux/gpio_keys.h> | |
61cd4822 LZ |
20 | #include <linux/platform_device.h> |
21 | #include <linux/pnp.h> | |
22 | ||
23 | /* | |
24 | * Definition of buttons on the tablet. The ACPI index of each button | |
25 | * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC | |
26 | * Platforms" | |
27 | */ | |
28 | #define MAX_NBUTTONS 5 | |
29 | ||
30 | struct soc_button_info { | |
31 | const char *name; | |
32 | int acpi_index; | |
33 | unsigned int event_type; | |
34 | unsigned int event_code; | |
35 | bool autorepeat; | |
36 | bool wakeup; | |
37 | }; | |
38 | ||
39 | /* | |
40 | * Some of the buttons like volume up/down are auto repeat, while others | |
41 | * are not. To support both, we register two platform devices, and put | |
42 | * buttons into them based on whether the key should be auto repeat. | |
43 | */ | |
44 | #define BUTTON_TYPES 2 | |
45 | ||
46 | struct soc_button_data { | |
47 | struct platform_device *children[BUTTON_TYPES]; | |
48 | }; | |
49 | ||
50 | /* | |
51 | * Get the Nth GPIO number from the ACPI object. | |
52 | */ | |
53 | static int soc_button_lookup_gpio(struct device *dev, int acpi_index) | |
54 | { | |
55 | struct gpio_desc *desc; | |
56 | int gpio; | |
57 | ||
58 | desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index); | |
59 | if (IS_ERR(desc)) | |
60 | return PTR_ERR(desc); | |
61 | ||
62 | gpio = desc_to_gpio(desc); | |
63 | ||
64 | gpiod_put(desc); | |
65 | ||
66 | return gpio; | |
67 | } | |
68 | ||
69 | static struct platform_device * | |
70 | soc_button_device_create(struct pnp_dev *pdev, | |
71 | const struct soc_button_info *button_info, | |
72 | bool autorepeat) | |
73 | { | |
74 | const struct soc_button_info *info; | |
75 | struct platform_device *pd; | |
76 | struct gpio_keys_button *gpio_keys; | |
77 | struct gpio_keys_platform_data *gpio_keys_pdata; | |
78 | int n_buttons = 0; | |
79 | int gpio; | |
80 | int error; | |
81 | ||
82 | gpio_keys_pdata = devm_kzalloc(&pdev->dev, | |
83 | sizeof(*gpio_keys_pdata) + | |
84 | sizeof(*gpio_keys) * MAX_NBUTTONS, | |
85 | GFP_KERNEL); | |
86 | gpio_keys = (void *)(gpio_keys_pdata + 1); | |
87 | ||
88 | for (info = button_info; info->name; info++) { | |
89 | if (info->autorepeat != autorepeat) | |
90 | continue; | |
91 | ||
92 | gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index); | |
93 | if (gpio < 0) | |
94 | continue; | |
95 | ||
96 | gpio_keys[n_buttons].type = info->event_type; | |
97 | gpio_keys[n_buttons].code = info->event_code; | |
98 | gpio_keys[n_buttons].gpio = gpio; | |
99 | gpio_keys[n_buttons].active_low = 1; | |
100 | gpio_keys[n_buttons].desc = info->name; | |
101 | gpio_keys[n_buttons].wakeup = info->wakeup; | |
102 | n_buttons++; | |
103 | } | |
104 | ||
105 | if (n_buttons == 0) { | |
106 | error = -ENODEV; | |
107 | goto err_free_mem; | |
108 | } | |
109 | ||
110 | gpio_keys_pdata->buttons = gpio_keys; | |
111 | gpio_keys_pdata->nbuttons = n_buttons; | |
112 | gpio_keys_pdata->rep = autorepeat; | |
113 | ||
114 | pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO); | |
115 | if (!pd) { | |
116 | error = -ENOMEM; | |
117 | goto err_free_mem; | |
118 | } | |
119 | ||
120 | error = platform_device_add_data(pd, gpio_keys_pdata, | |
121 | sizeof(*gpio_keys_pdata)); | |
122 | if (error) | |
123 | goto err_free_pdev; | |
124 | ||
125 | error = platform_device_add(pd); | |
126 | if (error) | |
127 | goto err_free_pdev; | |
128 | ||
129 | return pd; | |
130 | ||
131 | err_free_pdev: | |
132 | platform_device_put(pd); | |
133 | err_free_mem: | |
134 | devm_kfree(&pdev->dev, gpio_keys_pdata); | |
135 | return ERR_PTR(error); | |
136 | } | |
137 | ||
138 | static void soc_button_remove(struct pnp_dev *pdev) | |
139 | { | |
140 | struct soc_button_data *priv = pnp_get_drvdata(pdev); | |
141 | int i; | |
142 | ||
143 | for (i = 0; i < BUTTON_TYPES; i++) | |
144 | if (priv->children[i]) | |
145 | platform_device_unregister(priv->children[i]); | |
146 | } | |
147 | ||
148 | static int soc_button_pnp_probe(struct pnp_dev *pdev, | |
149 | const struct pnp_device_id *id) | |
150 | { | |
151 | const struct soc_button_info *button_info = (void *)id->driver_data; | |
152 | struct soc_button_data *priv; | |
153 | struct platform_device *pd; | |
154 | int i; | |
155 | int error; | |
156 | ||
157 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
158 | if (!priv) | |
159 | return -ENOMEM; | |
160 | ||
161 | pnp_set_drvdata(pdev, priv); | |
162 | ||
163 | for (i = 0; i < BUTTON_TYPES; i++) { | |
164 | pd = soc_button_device_create(pdev, button_info, i == 0); | |
165 | if (IS_ERR(pd)) { | |
166 | error = PTR_ERR(pd); | |
167 | if (error != -ENODEV) { | |
168 | soc_button_remove(pdev); | |
169 | return error; | |
170 | } | |
7740fc52 | 171 | continue; |
61cd4822 LZ |
172 | } |
173 | ||
174 | priv->children[i] = pd; | |
175 | } | |
176 | ||
177 | if (!priv->children[0] && !priv->children[1]) | |
178 | return -ENODEV; | |
179 | ||
180 | return 0; | |
181 | } | |
182 | ||
183 | static struct soc_button_info soc_button_PNP0C40[] = { | |
184 | { "power", 0, EV_KEY, KEY_POWER, false, true }, | |
185 | { "home", 1, EV_KEY, KEY_HOME, false, true }, | |
186 | { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false }, | |
187 | { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false }, | |
188 | { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false }, | |
189 | { } | |
190 | }; | |
191 | ||
192 | static const struct pnp_device_id soc_button_pnp_match[] = { | |
193 | { .id = "PNP0C40", .driver_data = (long)soc_button_PNP0C40 }, | |
194 | { .id = "" } | |
195 | }; | |
196 | MODULE_DEVICE_TABLE(pnp, soc_button_pnp_match); | |
197 | ||
198 | static struct pnp_driver soc_button_pnp_driver = { | |
199 | .name = KBUILD_MODNAME, | |
200 | .id_table = soc_button_pnp_match, | |
201 | .probe = soc_button_pnp_probe, | |
202 | .remove = soc_button_remove, | |
203 | }; | |
204 | ||
205 | static int __init soc_button_init(void) | |
206 | { | |
207 | return pnp_register_driver(&soc_button_pnp_driver); | |
208 | } | |
209 | ||
210 | static void __exit soc_button_exit(void) | |
211 | { | |
212 | pnp_unregister_driver(&soc_button_pnp_driver); | |
213 | } | |
214 | ||
215 | module_init(soc_button_init); | |
216 | module_exit(soc_button_exit); | |
217 | ||
218 | MODULE_LICENSE("GPL"); |