/* * 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/gpio.h>#include <linux/platform_device.h> 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, NULL, 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; 	for (info = button_info; info->name; info++)		if (info->autorepeat == autorepeat)			n_buttons++; 	gpio_keys_pdata = devm_kzalloc(&pdev->dev,				       sizeof(*gpio_keys_pdata) +					sizeof(*gpio_keys) * n_buttons,				       GFP_KERNEL);	if (!gpio_keys_pdata)		return ERR_PTR(-ENOMEM); 	gpio_keys = (void *)(gpio_keys_pdata + 1);	n_buttons = 0; 	for (info = button_info; info->name; info++) {		if (info->autorepeat != autorepeat)			continue; 		gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);		if (!gpio_is_valid(gpio))			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;		/* These devices often use cheap buttons, use 50 ms debounce */		gpio_keys[n_buttons].debounce_interval = 50;		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_get_acpi_object_int(const union acpi_object *obj){	if (obj->type != ACPI_TYPE_INTEGER)		return -1; 	return obj->integer.value;} /* Parse a single ACPI0011 _DSD button descriptor */static int soc_button_parse_btn_desc(struct device *dev,				     const union acpi_object *desc,				     int collection_uid,				     struct soc_button_info *info){	int upage, usage; 	if (desc->type != ACPI_TYPE_PACKAGE ||	    desc->package.count != 5 ||	    /* First byte should be 1 (control) */	    soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||	    /* Third byte should be collection uid */	    soc_button_get_acpi_object_int(&desc->package.elements[2]) !=							    collection_uid) {		dev_err(dev, "Invalid ACPI Button Descriptor\n");		return -ENODEV;	} 	info->event_type = EV_KEY;	info->acpi_index =		soc_button_get_acpi_object_int(&desc->package.elements[1]);	upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);	usage = soc_button_get_acpi_object_int(&desc->package.elements[4]); 	/*	 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID	 * usage page and usage codes, but otherwise the device is not HID	 * compliant: it uses one irq per button instead of generating HID	 * input reports and some buttons should generate wakeups where as	 * others should not, so we cannot use the HID subsystem.	 *	 * Luckily all devices only use a few usage page + usage combinations,	 * so we can simply check for the known combinations here.	 */	if (upage == 0x01 && usage == 0x81) {		info->name = "power";		info->event_code = KEY_POWER;		info->wakeup = true;	} else if (upage == 0x01 && usage == 0xca) {		info->name = "rotation lock switch";		info->event_type = EV_SW;		info->event_code = SW_ROTATE_LOCK;	} else if (upage == 0x07 && usage == 0xe3) {		info->name = "home";		info->event_code = KEY_LEFTMETA;		info->wakeup = true;	} else if (upage == 0x0c && usage == 0xe9) {		info->name = "volume_up";		info->event_code = KEY_VOLUMEUP;		info->autorepeat = true;	} else if (upage == 0x0c && usage == 0xea) {		info->name = "volume_down";		info->event_code = KEY_VOLUMEDOWN;		info->autorepeat = true;	} else {		dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",			 info->acpi_index, upage, usage);		info->name = "unknown";		info->event_code = KEY_RESERVED;	} 	return 0;} /* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */static const u8 btns_desc_uuid[16] = {	0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,	0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e}; /* Parse ACPI0011 _DSD button descriptors */static struct soc_button_info *soc_button_get_button_info(struct device *dev){	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };	const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;	struct soc_button_info *button_info;	acpi_status status;	int i, btn, collection_uid = -1; 	status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,					    &buf, ACPI_TYPE_PACKAGE);	if (ACPI_FAILURE(status)) {		dev_err(dev, "ACPI _DSD object not found\n");		return ERR_PTR(-ENODEV);	} 	/* Look for the Button Descriptors UUID */	desc = buf.pointer;	for (i = 0; (i + 1) < desc->package.count; i += 2) {		uuid = &desc->package.elements[i]; 		if (uuid->type != ACPI_TYPE_BUFFER ||		    uuid->buffer.length != 16 ||		    desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {			break;		} 		if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {			btns_desc = &desc->package.elements[i + 1];			break;		}	} 	if (!btns_desc) {		dev_err(dev, "ACPI Button Descriptors not found\n");		button_info = ERR_PTR(-ENODEV);		goto out;	} 	/* The first package describes the collection */	el0 = &btns_desc->package.elements[0];	if (el0->type == ACPI_TYPE_PACKAGE &&	    el0->package.count == 5 &&	    /* First byte should be 0 (collection) */	    soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&	    /* Third byte should be 0 (top level collection) */	    soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {		collection_uid = soc_button_get_acpi_object_int(						&el0->package.elements[1]);	}	if (collection_uid == -1) {		dev_err(dev, "Invalid Button Collection Descriptor\n");		button_info = ERR_PTR(-ENODEV);		goto out;	} 	/* There are package.count - 1 buttons + 1 terminating empty entry */	button_info = devm_kcalloc(dev, btns_desc->package.count,				   sizeof(*button_info), GFP_KERNEL);	if (!button_info) {		button_info = ERR_PTR(-ENOMEM);		goto out;	} 	/* Parse the button descriptors */	for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {		if (soc_button_parse_btn_desc(dev,					      &btns_desc->package.elements[i],					      collection_uid,					      &button_info[btn])) {			button_info = ERR_PTR(-ENODEV);			goto out;		}	} out:	kfree(buf.pointer);	return button_info;} 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; 	if (!id->driver_data) {		button_info = soc_button_get_button_info(dev);		if (IS_ERR(button_info))			return PTR_ERR(button_info);	} else {		button_info = (struct soc_button_info *)id->driver_data;	} 	error = gpiod_count(dev, NULL);	if (error < 0) {		dev_dbg(dev, "no GPIO attached, ignoring...\n");		return -ENODEV;	} 	priv = devm_kzalloc(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; 	if (!id->driver_data)		devm_kfree(dev, button_info); 	return 0;} /* * 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" */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_KEY, KEY_ROTATE_LOCK_TOGGLE, false, false },	{ }}; static const struct acpi_device_id soc_button_acpi_match[] = {	{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },	{ "ACPI0011", 0 },	{ }}; 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");