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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 | 20 | #include <linux/platform_device.h> |
042e1c79 | 21 | #include <linux/acpi.h> |
61cd4822 LZ |
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 | ||
4668546f | 58 | desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS); |
61cd4822 LZ |
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 * | |
042e1c79 | 70 | soc_button_device_create(struct platform_device *pdev, |
61cd4822 LZ |
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); | |
91cf07cd PG |
86 | if (!gpio_keys_pdata) |
87 | return ERR_PTR(-ENOMEM); | |
88 | ||
61cd4822 LZ |
89 | gpio_keys = (void *)(gpio_keys_pdata + 1); |
90 | ||
91 | for (info = button_info; info->name; info++) { | |
92 | if (info->autorepeat != autorepeat) | |
93 | continue; | |
94 | ||
95 | gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index); | |
96 | if (gpio < 0) | |
97 | continue; | |
98 | ||
99 | gpio_keys[n_buttons].type = info->event_type; | |
100 | gpio_keys[n_buttons].code = info->event_code; | |
101 | gpio_keys[n_buttons].gpio = gpio; | |
102 | gpio_keys[n_buttons].active_low = 1; | |
103 | gpio_keys[n_buttons].desc = info->name; | |
104 | gpio_keys[n_buttons].wakeup = info->wakeup; | |
105 | n_buttons++; | |
106 | } | |
107 | ||
108 | if (n_buttons == 0) { | |
109 | error = -ENODEV; | |
110 | goto err_free_mem; | |
111 | } | |
112 | ||
113 | gpio_keys_pdata->buttons = gpio_keys; | |
114 | gpio_keys_pdata->nbuttons = n_buttons; | |
115 | gpio_keys_pdata->rep = autorepeat; | |
116 | ||
117 | pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO); | |
118 | if (!pd) { | |
119 | error = -ENOMEM; | |
120 | goto err_free_mem; | |
121 | } | |
122 | ||
123 | error = platform_device_add_data(pd, gpio_keys_pdata, | |
124 | sizeof(*gpio_keys_pdata)); | |
125 | if (error) | |
126 | goto err_free_pdev; | |
127 | ||
128 | error = platform_device_add(pd); | |
129 | if (error) | |
130 | goto err_free_pdev; | |
131 | ||
132 | return pd; | |
133 | ||
134 | err_free_pdev: | |
135 | platform_device_put(pd); | |
136 | err_free_mem: | |
137 | devm_kfree(&pdev->dev, gpio_keys_pdata); | |
138 | return ERR_PTR(error); | |
139 | } | |
140 | ||
042e1c79 | 141 | static int soc_button_remove(struct platform_device *pdev) |
61cd4822 | 142 | { |
042e1c79 JY |
143 | struct soc_button_data *priv = platform_get_drvdata(pdev); |
144 | ||
61cd4822 LZ |
145 | int i; |
146 | ||
147 | for (i = 0; i < BUTTON_TYPES; i++) | |
148 | if (priv->children[i]) | |
149 | platform_device_unregister(priv->children[i]); | |
042e1c79 JY |
150 | |
151 | return 0; | |
61cd4822 LZ |
152 | } |
153 | ||
042e1c79 | 154 | static int soc_button_probe(struct platform_device *pdev) |
61cd4822 | 155 | { |
042e1c79 JY |
156 | struct device *dev = &pdev->dev; |
157 | const struct acpi_device_id *id; | |
158 | struct soc_button_info *button_info; | |
61cd4822 LZ |
159 | struct soc_button_data *priv; |
160 | struct platform_device *pd; | |
161 | int i; | |
162 | int error; | |
163 | ||
042e1c79 JY |
164 | id = acpi_match_device(dev->driver->acpi_match_table, dev); |
165 | if (!id) | |
166 | return -ENODEV; | |
167 | ||
168 | button_info = (struct soc_button_info *)id->driver_data; | |
169 | ||
61cd4822 LZ |
170 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
171 | if (!priv) | |
172 | return -ENOMEM; | |
173 | ||
042e1c79 | 174 | platform_set_drvdata(pdev, priv); |
61cd4822 LZ |
175 | |
176 | for (i = 0; i < BUTTON_TYPES; i++) { | |
177 | pd = soc_button_device_create(pdev, button_info, i == 0); | |
178 | if (IS_ERR(pd)) { | |
179 | error = PTR_ERR(pd); | |
180 | if (error != -ENODEV) { | |
181 | soc_button_remove(pdev); | |
182 | return error; | |
183 | } | |
7740fc52 | 184 | continue; |
61cd4822 LZ |
185 | } |
186 | ||
187 | priv->children[i] = pd; | |
188 | } | |
189 | ||
190 | if (!priv->children[0] && !priv->children[1]) | |
191 | return -ENODEV; | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | static struct soc_button_info soc_button_PNP0C40[] = { | |
197 | { "power", 0, EV_KEY, KEY_POWER, false, true }, | |
198 | { "home", 1, EV_KEY, KEY_HOME, false, true }, | |
199 | { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false }, | |
200 | { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false }, | |
201 | { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false }, | |
202 | { } | |
203 | }; | |
204 | ||
042e1c79 JY |
205 | static const struct acpi_device_id soc_button_acpi_match[] = { |
206 | { "PNP0C40", (unsigned long)soc_button_PNP0C40 }, | |
207 | { } | |
61cd4822 | 208 | }; |
61cd4822 | 209 | |
042e1c79 JY |
210 | MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); |
211 | ||
212 | static struct platform_driver soc_button_driver = { | |
213 | .probe = soc_button_probe, | |
61cd4822 | 214 | .remove = soc_button_remove, |
042e1c79 JY |
215 | .driver = { |
216 | .name = KBUILD_MODNAME, | |
217 | .owner = THIS_MODULE, | |
218 | .acpi_match_table = ACPI_PTR(soc_button_acpi_match), | |
219 | }, | |
61cd4822 | 220 | }; |
042e1c79 | 221 | module_platform_driver(soc_button_driver); |
61cd4822 LZ |
222 | |
223 | MODULE_LICENSE("GPL"); |