2 * Supports for the button array on SoC tablets originally running
5 * (C) Copyright 2014 Intel Corporation
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
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 #include <linux/pnp.h>
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
28 #define MAX_NBUTTONS 5
30 struct soc_button_info {
33 unsigned int event_type;
34 unsigned int event_code;
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.
44 #define BUTTON_TYPES 2
46 struct soc_button_data {
47 struct platform_device *children[BUTTON_TYPES];
51 * Get the Nth GPIO number from the ACPI object.
53 static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
55 struct gpio_desc *desc;
58 desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index);
62 gpio = desc_to_gpio(desc);
69 static struct platform_device *
70 soc_button_device_create(struct pnp_dev *pdev,
71 const struct soc_button_info *button_info,
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;
82 gpio_keys_pdata = devm_kzalloc(&pdev->dev,
83 sizeof(*gpio_keys_pdata) +
84 sizeof(*gpio_keys) * MAX_NBUTTONS,
86 gpio_keys = (void *)(gpio_keys_pdata + 1);
88 for (info = button_info; info->name; info++) {
89 if (info->autorepeat != autorepeat)
92 gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
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;
105 if (n_buttons == 0) {
110 gpio_keys_pdata->buttons = gpio_keys;
111 gpio_keys_pdata->nbuttons = n_buttons;
112 gpio_keys_pdata->rep = autorepeat;
114 pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);
120 error = platform_device_add_data(pd, gpio_keys_pdata,
121 sizeof(*gpio_keys_pdata));
125 error = platform_device_add(pd);
132 platform_device_put(pd);
134 devm_kfree(&pdev->dev, gpio_keys_pdata);
135 return ERR_PTR(error);
138 static void soc_button_remove(struct pnp_dev *pdev)
140 struct soc_button_data *priv = pnp_get_drvdata(pdev);
143 for (i = 0; i < BUTTON_TYPES; i++)
144 if (priv->children[i])
145 platform_device_unregister(priv->children[i]);
148 static int soc_button_pnp_probe(struct pnp_dev *pdev,
149 const struct pnp_device_id *id)
151 const struct soc_button_info *button_info = (void *)id->driver_data;
152 struct soc_button_data *priv;
153 struct platform_device *pd;
157 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
161 pnp_set_drvdata(pdev, priv);
163 for (i = 0; i < BUTTON_TYPES; i++) {
164 pd = soc_button_device_create(pdev, button_info, i == 0);
167 if (error != -ENODEV) {
168 soc_button_remove(pdev);
174 priv->children[i] = pd;
177 if (!priv->children[0] && !priv->children[1])
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 },
192 static const struct pnp_device_id soc_button_pnp_match[] = {
193 { .id = "PNP0C40", .driver_data = (long)soc_button_PNP0C40 },
196 MODULE_DEVICE_TABLE(pnp, soc_button_pnp_match);
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,
205 static int __init soc_button_init(void)
207 return pnp_register_driver(&soc_button_pnp_driver);
210 static void __exit soc_button_exit(void)
212 pnp_unregister_driver(&soc_button_pnp_driver);
215 module_init(soc_button_init);
216 module_exit(soc_button_exit);
218 MODULE_LICENSE("GPL");