Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / drivers / input / misc / soc_button_array.c
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>
20 #include <linux/platform_device.h>
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
57 desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS);
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 *
69 soc_button_device_create(struct platform_device *pdev,
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);
85 if (!gpio_keys_pdata)
86 return ERR_PTR(-ENOMEM);
87
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
140 static int soc_button_remove(struct platform_device *pdev)
141 {
142 struct soc_button_data *priv = platform_get_drvdata(pdev);
143
144 int i;
145
146 for (i = 0; i < BUTTON_TYPES; i++)
147 if (priv->children[i])
148 platform_device_unregister(priv->children[i]);
149
150 return 0;
151 }
152
153 static int soc_button_probe(struct platform_device *pdev)
154 {
155 struct device *dev = &pdev->dev;
156 const struct acpi_device_id *id;
157 struct soc_button_info *button_info;
158 struct soc_button_data *priv;
159 struct platform_device *pd;
160 int i;
161 int error;
162
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
169 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
170 if (!priv)
171 return -ENOMEM;
172
173 platform_set_drvdata(pdev, priv);
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 }
183 continue;
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 },
197 { "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
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
204 static const struct acpi_device_id soc_button_acpi_match[] = {
205 { "PNP0C40", (unsigned long)soc_button_PNP0C40 },
206 { }
207 };
208
209 MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match);
210
211 static struct platform_driver soc_button_driver = {
212 .probe = soc_button_probe,
213 .remove = soc_button_remove,
214 .driver = {
215 .name = KBUILD_MODNAME,
216 .acpi_match_table = ACPI_PTR(soc_button_acpi_match),
217 },
218 };
219 module_platform_driver(soc_button_driver);
220
221 MODULE_LICENSE("GPL");
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