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