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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> |
61cd4822 LZ |
21 | |
22 | /* | |
23 | * Definition of buttons on the tablet. The ACPI index of each button | |
24 | * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC | |
25 | * Platforms" | |
26 | */ | |
27 | #define MAX_NBUTTONS 5 | |
28 | ||
29 | struct soc_button_info { | |
30 | const char *name; | |
31 | int acpi_index; | |
32 | unsigned int event_type; | |
33 | unsigned int event_code; | |
34 | bool autorepeat; | |
35 | bool wakeup; | |
36 | }; | |
37 | ||
38 | /* | |
39 | * Some of the buttons like volume up/down are auto repeat, while others | |
40 | * are not. To support both, we register two platform devices, and put | |
41 | * buttons into them based on whether the key should be auto repeat. | |
42 | */ | |
43 | #define BUTTON_TYPES 2 | |
44 | ||
45 | struct soc_button_data { | |
46 | struct platform_device *children[BUTTON_TYPES]; | |
47 | }; | |
48 | ||
49 | /* | |
50 | * Get the Nth GPIO number from the ACPI object. | |
51 | */ | |
52 | static int soc_button_lookup_gpio(struct device *dev, int acpi_index) | |
53 | { | |
54 | struct gpio_desc *desc; | |
55 | int gpio; | |
56 | ||
4668546f | 57 | desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS); |
61cd4822 LZ |
58 | if (IS_ERR(desc)) |
59 | return PTR_ERR(desc); | |
60 | ||
61 | gpio = desc_to_gpio(desc); | |
62 | ||
63 | gpiod_put(desc); | |
64 | ||
65 | return gpio; | |
66 | } | |
67 | ||
68 | static struct platform_device * | |
042e1c79 | 69 | soc_button_device_create(struct platform_device *pdev, |
61cd4822 LZ |
70 | const struct soc_button_info *button_info, |
71 | bool autorepeat) | |
72 | { | |
73 | const struct soc_button_info *info; | |
74 | struct platform_device *pd; | |
75 | struct gpio_keys_button *gpio_keys; | |
76 | struct gpio_keys_platform_data *gpio_keys_pdata; | |
77 | int n_buttons = 0; | |
78 | int gpio; | |
79 | int error; | |
80 | ||
81 | gpio_keys_pdata = devm_kzalloc(&pdev->dev, | |
82 | sizeof(*gpio_keys_pdata) + | |
83 | sizeof(*gpio_keys) * MAX_NBUTTONS, | |
84 | GFP_KERNEL); | |
91cf07cd PG |
85 | if (!gpio_keys_pdata) |
86 | return ERR_PTR(-ENOMEM); | |
87 | ||
61cd4822 LZ |
88 | gpio_keys = (void *)(gpio_keys_pdata + 1); |
89 | ||
90 | for (info = button_info; info->name; info++) { | |
91 | if (info->autorepeat != autorepeat) | |
92 | continue; | |
93 | ||
94 | gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index); | |
95 | if (gpio < 0) | |
96 | continue; | |
97 | ||
98 | gpio_keys[n_buttons].type = info->event_type; | |
99 | gpio_keys[n_buttons].code = info->event_code; | |
100 | gpio_keys[n_buttons].gpio = gpio; | |
101 | gpio_keys[n_buttons].active_low = 1; | |
102 | gpio_keys[n_buttons].desc = info->name; | |
103 | gpio_keys[n_buttons].wakeup = info->wakeup; | |
104 | n_buttons++; | |
105 | } | |
106 | ||
107 | if (n_buttons == 0) { | |
108 | error = -ENODEV; | |
109 | goto err_free_mem; | |
110 | } | |
111 | ||
112 | gpio_keys_pdata->buttons = gpio_keys; | |
113 | gpio_keys_pdata->nbuttons = n_buttons; | |
114 | gpio_keys_pdata->rep = autorepeat; | |
115 | ||
116 | pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO); | |
117 | if (!pd) { | |
118 | error = -ENOMEM; | |
119 | goto err_free_mem; | |
120 | } | |
121 | ||
122 | error = platform_device_add_data(pd, gpio_keys_pdata, | |
123 | sizeof(*gpio_keys_pdata)); | |
124 | if (error) | |
125 | goto err_free_pdev; | |
126 | ||
127 | error = platform_device_add(pd); | |
128 | if (error) | |
129 | goto err_free_pdev; | |
130 | ||
131 | return pd; | |
132 | ||
133 | err_free_pdev: | |
134 | platform_device_put(pd); | |
135 | err_free_mem: | |
136 | devm_kfree(&pdev->dev, gpio_keys_pdata); | |
137 | return ERR_PTR(error); | |
138 | } | |
139 | ||
042e1c79 | 140 | static int soc_button_remove(struct platform_device *pdev) |
61cd4822 | 141 | { |
042e1c79 JY |
142 | struct soc_button_data *priv = platform_get_drvdata(pdev); |
143 | ||
61cd4822 LZ |
144 | int i; |
145 | ||
146 | for (i = 0; i < BUTTON_TYPES; i++) | |
147 | if (priv->children[i]) | |
148 | platform_device_unregister(priv->children[i]); | |
042e1c79 JY |
149 | |
150 | return 0; | |
61cd4822 LZ |
151 | } |
152 | ||
042e1c79 | 153 | static int soc_button_probe(struct platform_device *pdev) |
61cd4822 | 154 | { |
042e1c79 JY |
155 | struct device *dev = &pdev->dev; |
156 | const struct acpi_device_id *id; | |
157 | struct soc_button_info *button_info; | |
61cd4822 LZ |
158 | struct soc_button_data *priv; |
159 | struct platform_device *pd; | |
160 | int i; | |
161 | int error; | |
162 | ||
042e1c79 JY |
163 | id = acpi_match_device(dev->driver->acpi_match_table, dev); |
164 | if (!id) | |
165 | return -ENODEV; | |
166 | ||
167 | button_info = (struct soc_button_info *)id->driver_data; | |
168 | ||
61cd4822 LZ |
169 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
170 | if (!priv) | |
171 | return -ENOMEM; | |
172 | ||
042e1c79 | 173 | platform_set_drvdata(pdev, priv); |
61cd4822 LZ |
174 | |
175 | for (i = 0; i < BUTTON_TYPES; i++) { | |
176 | pd = soc_button_device_create(pdev, button_info, i == 0); | |
177 | if (IS_ERR(pd)) { | |
178 | error = PTR_ERR(pd); | |
179 | if (error != -ENODEV) { | |
180 | soc_button_remove(pdev); | |
181 | return error; | |
182 | } | |
7740fc52 | 183 | continue; |
61cd4822 LZ |
184 | } |
185 | ||
186 | priv->children[i] = pd; | |
187 | } | |
188 | ||
189 | if (!priv->children[0] && !priv->children[1]) | |
190 | return -ENODEV; | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | static struct soc_button_info soc_button_PNP0C40[] = { | |
196 | { "power", 0, EV_KEY, KEY_POWER, false, true }, | |
791738be | 197 | { "home", 1, EV_KEY, KEY_LEFTMETA, false, true }, |
61cd4822 LZ |
198 | { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false }, |
199 | { "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false }, | |
200 | { "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false }, | |
201 | { } | |
202 | }; | |
203 | ||
042e1c79 JY |
204 | static const struct acpi_device_id soc_button_acpi_match[] = { |
205 | { "PNP0C40", (unsigned long)soc_button_PNP0C40 }, | |
206 | { } | |
61cd4822 | 207 | }; |
61cd4822 | 208 | |
042e1c79 JY |
209 | MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); |
210 | ||
211 | static struct platform_driver soc_button_driver = { | |
212 | .probe = soc_button_probe, | |
61cd4822 | 213 | .remove = soc_button_remove, |
042e1c79 JY |
214 | .driver = { |
215 | .name = KBUILD_MODNAME, | |
042e1c79 JY |
216 | .acpi_match_table = ACPI_PTR(soc_button_acpi_match), |
217 | }, | |
61cd4822 | 218 | }; |
042e1c79 | 219 | module_platform_driver(soc_button_driver); |
61cd4822 LZ |
220 | |
221 | MODULE_LICENSE("GPL"); |