/* * Supports for the button array on SoC tablets originally running * Windows 8. * * (C) Copyright 2014 Intel Corporation * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; version 2 * of the License. */ #include <linux/module.h>#include <linux/input.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/acpi.h>#include <linux/gpio/consumer.h>#include <linux/gpio_keys.h>#include <linux/platform_device.h> /* * Definition of buttons on the tablet. The ACPI index of each button * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC * Platforms" */#define MAX_NBUTTONS	5 struct soc_button_info {	const char *name;	int acpi_index;	unsigned int event_type;	unsigned int event_code;	bool autorepeat;	bool wakeup;}; /* * Some of the buttons like volume up/down are auto repeat, while others * are not. To support both, we register two platform devices, and put * buttons into them based on whether the key should be auto repeat. */#define BUTTON_TYPES	2 struct soc_button_data {	struct platform_device *children[BUTTON_TYPES];}; /* * Get the Nth GPIO number from the ACPI object. */static int soc_button_lookup_gpio(struct device *dev, int acpi_index){	struct gpio_desc *desc;	int gpio; 	desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS);	if (IS_ERR(desc))		return PTR_ERR(desc); 	gpio = desc_to_gpio(desc); 	gpiod_put(desc); 	return gpio;} static struct platform_device *soc_button_device_create(struct platform_device *pdev,			 const struct soc_button_info *button_info,			 bool autorepeat){	const struct soc_button_info *info;	struct platform_device *pd;	struct gpio_keys_button *gpio_keys;	struct gpio_keys_platform_data *gpio_keys_pdata;	int n_buttons = 0;	int gpio;	int error; 	gpio_keys_pdata = devm_kzalloc(&pdev->dev,				       sizeof(*gpio_keys_pdata) +					sizeof(*gpio_keys) * MAX_NBUTTONS,				       GFP_KERNEL);	if (!gpio_keys_pdata)		return ERR_PTR(-ENOMEM); 	gpio_keys = (void *)(gpio_keys_pdata + 1); 	for (info = button_info; info->name; info++) {		if (info->autorepeat != autorepeat)			continue; 		gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);		if (gpio < 0)			continue; 		gpio_keys[n_buttons].type = info->event_type;		gpio_keys[n_buttons].code = info->event_code;		gpio_keys[n_buttons].gpio = gpio;		gpio_keys[n_buttons].active_low = 1;		gpio_keys[n_buttons].desc = info->name;		gpio_keys[n_buttons].wakeup = info->wakeup;		n_buttons++;	} 	if (n_buttons == 0) {		error = -ENODEV;		goto err_free_mem;	} 	gpio_keys_pdata->buttons = gpio_keys;	gpio_keys_pdata->nbuttons = n_buttons;	gpio_keys_pdata->rep = autorepeat; 	pd = platform_device_alloc("gpio-keys", PLATFORM_DEVID_AUTO);	if (!pd) {		error = -ENOMEM;		goto err_free_mem;	} 	error = platform_device_add_data(pd, gpio_keys_pdata,					 sizeof(*gpio_keys_pdata));	if (error)		goto err_free_pdev; 	error = platform_device_add(pd);	if (error)		goto err_free_pdev; 	return pd; err_free_pdev:	platform_device_put(pd);err_free_mem:	devm_kfree(&pdev->dev, gpio_keys_pdata);	return ERR_PTR(error);} static int soc_button_remove(struct platform_device *pdev){	struct soc_button_data *priv = platform_get_drvdata(pdev); 	int i; 	for (i = 0; i < BUTTON_TYPES; i++)		if (priv->children[i])			platform_device_unregister(priv->children[i]); 	return 0;} static int soc_button_probe(struct platform_device *pdev){	struct device *dev = &pdev->dev;	const struct acpi_device_id *id;	struct soc_button_info *button_info;	struct soc_button_data *priv;	struct platform_device *pd;	int i;	int error; 	id = acpi_match_device(dev->driver->acpi_match_table, dev);	if (!id)		return -ENODEV; 	button_info = (struct soc_button_info *)id->driver_data; 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);	if (!priv)		return -ENOMEM; 	platform_set_drvdata(pdev, priv); 	for (i = 0; i < BUTTON_TYPES; i++) {		pd = soc_button_device_create(pdev, button_info, i == 0);		if (IS_ERR(pd)) {			error = PTR_ERR(pd);			if (error != -ENODEV) {				soc_button_remove(pdev);				return error;			}			continue;		} 		priv->children[i] = pd;	} 	if (!priv->children[0] && !priv->children[1])		return -ENODEV; 	return 0;} static struct soc_button_info soc_button_PNP0C40[] = {	{ "power", 0, EV_KEY, KEY_POWER, false, true },	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true },	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },	{ "volume_down", 3, EV_KEY, KEY_VOLUMEDOWN, true, false },	{ "rotation_lock", 4, EV_SW, SW_ROTATE_LOCK, false, false },	{ }}; static const struct acpi_device_id soc_button_acpi_match[] = {	{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },	{ }}; MODULE_DEVICE_TABLE(acpi, soc_button_acpi_match); static struct platform_driver soc_button_driver = {	.probe          = soc_button_probe,	.remove		= soc_button_remove,	.driver		= {		.name = KBUILD_MODNAME,		.acpi_match_table = ACPI_PTR(soc_button_acpi_match),	},};module_platform_driver(soc_button_driver); MODULE_LICENSE("GPL");