drivers/platform/chrome/cros_ec_sysfs.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 // Expose the ChromeOS EC through sysfs
 //
 // Copyright (C) 2014 Google, Inc.

 #include <linux/ctype.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/kobject.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/printk.h>
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>

 #define DRV_NAME "cros-ec-sysfs"

 /* Accessor functions */

 static ssize_t reboot_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	int count = 0;

 	count += scnprintf(buf + count, PAGE_SIZE - count,
 			   "ro|rw|cancel|cold|disable-jump|hibernate");
 	count += scnprintf(buf + count, PAGE_SIZE - count,
 			   " [at-shutdown]\n");
 	return count;
 }

 static ssize_t reboot_store(struct device *dev,
 			    struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
 	static const struct {
 		const char * const str;
 		uint8_t cmd;
 		uint8_t flags;
 	} words[] = {
 		{"cancel",       EC_REBOOT_CANCEL, 0},
 		{"ro",           EC_REBOOT_JUMP_RO, 0},
 		{"rw",           EC_REBOOT_JUMP_RW, 0},
 		{"cold",         EC_REBOOT_COLD, 0},
 		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
 		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
 		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
 	};
 	struct cros_ec_command *msg;
 	struct ec_params_reboot_ec *param;
 	int got_cmd = 0, offset = 0;
 	int i;
 	int ret;
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	param = (struct ec_params_reboot_ec *)msg->data;

 	param->flags = 0;
 	while (1) {
 		/* Find word to start scanning */
 		while (buf[offset] && isspace(buf[offset]))
 			offset++;
 		if (!buf[offset])
 			break;

 		for (i = 0; i < ARRAY_SIZE(words); i++) {
 			if (!strncasecmp(words[i].str, buf+offset,
 					 strlen(words[i].str))) {
 				if (words[i].flags) {
 					param->flags |= words[i].flags;
 				} else {
 					param->cmd = words[i].cmd;
 					got_cmd = 1;
 				}
 				break;
 			}
 		}

 		/* On to the next word, if any */
 		while (buf[offset] && !isspace(buf[offset]))
 			offset++;
 	}

 	if (!got_cmd) {
 		count = -EINVAL;
 		goto exit;
 	}

 	msg->version = 0;
 	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
 	msg->outsize = sizeof(*param);
 	msg->insize = 0;
 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 	if (ret < 0)
 		count = ret;
 exit:
 	kfree(msg);
 	return count;
 }

 static ssize_t version_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
 	static const char * const image_names[] = {"unknown", "RO", "RW"};
 	struct ec_response_get_version *r_ver;
 	struct ec_response_get_chip_info *r_chip;
 	struct ec_response_board_version *r_board;
 	struct cros_ec_command *msg;
 	int ret;
 	int count = 0;
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	/* Get versions. RW may change. */
 	msg->version = 0;
 	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
 	msg->insize = sizeof(*r_ver);
 	msg->outsize = 0;
 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 	if (ret < 0) {
 		count = ret;
 		goto exit;
 	}
 	r_ver = (struct ec_response_get_version *)msg->data;
 	/* Strings should be null-terminated, but let's be sure. */
 	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
 	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
 	count += scnprintf(buf + count, PAGE_SIZE - count,
 			   "RO version:    %s\n", r_ver->version_string_ro);
 	count += scnprintf(buf + count, PAGE_SIZE - count,
 			   "RW version:    %s\n", r_ver->version_string_rw);
 	count += scnprintf(buf + count, PAGE_SIZE - count,
 			   "Firmware copy: %s\n",
 			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
 			    image_names[r_ver->current_image] : "?"));

 	/* Get build info. */
 	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
 	msg->insize = EC_HOST_PARAM_SIZE;
 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Build info:    XFER ERROR %d\n", ret);
 	else if (msg->result != EC_RES_SUCCESS)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Build info:    EC error %d\n", msg->result);
 	else {
 		msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Build info:    %s\n", msg->data);
 	}

 	/* Get chip info. */
 	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
 	msg->insize = sizeof(*r_chip);
 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip info:     XFER ERROR %d\n", ret);
 	else if (msg->result != EC_RES_SUCCESS)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip info:     EC error %d\n", msg->result);
 	else {
 		r_chip = (struct ec_response_get_chip_info *)msg->data;

 		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
 		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
 		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip vendor:   %s\n", r_chip->vendor);
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip name:     %s\n", r_chip->name);
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip revision: %s\n", r_chip->revision);
 	}

 	/* Get board version */
 	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
 	msg->insize = sizeof(*r_board);
 	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Board version: XFER ERROR %d\n", ret);
 	else if (msg->result != EC_RES_SUCCESS)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Board version: EC error %d\n", msg->result);
 	else {
 		r_board = (struct ec_response_board_version *)msg->data;

 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Board version: %d\n",
 				   r_board->board_version);
 	}

 exit:
 	kfree(msg);
 	return count;
 }

 static ssize_t flashinfo_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
 	struct ec_response_flash_info *resp;
 	struct cros_ec_command *msg;
 	int ret;
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	/* The flash info shouldn't ever change, but ask each time anyway. */
 	msg->version = 0;
 	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
 	msg->insize = sizeof(*resp);
 	msg->outsize = 0;
 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;

 	resp = (struct ec_response_flash_info *)msg->data;

 	ret = scnprintf(buf, PAGE_SIZE,
 			"FlashSize %d\nWriteSize %d\n"
 			"EraseSize %d\nProtectSize %d\n",
 			resp->flash_size, resp->write_block_size,
 			resp->erase_block_size, resp->protect_block_size);
 exit:
 	kfree(msg);
 	return ret;
 }

 /* Keyboard wake angle control */
 static ssize_t kb_wake_angle_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
 	struct ec_response_motion_sense *resp;
 	struct ec_params_motion_sense *param;
 	struct cros_ec_command *msg;
 	int ret;

 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	param = (struct ec_params_motion_sense *)msg->data;
 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 	msg->version = 2;
 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
 	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
 	msg->outsize = sizeof(*param);
 	msg->insize = sizeof(*resp);

 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;

 	resp = (struct ec_response_motion_sense *)msg->data;
 	ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->kb_wake_angle.ret);
 exit:
 	kfree(msg);
 	return ret;
 }

 static ssize_t kb_wake_angle_store(struct device *dev,
 				   struct device_attribute *attr,
 				   const char *buf, size_t count)
 {
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
 	struct ec_params_motion_sense *param;
 	struct cros_ec_command *msg;
 	u16 angle;
 	int ret;

 	ret = kstrtou16(buf, 0, &angle);
 	if (ret)
 		return ret;

 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	param = (struct ec_params_motion_sense *)msg->data;
 	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 	msg->version = 2;
 	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
 	param->kb_wake_angle.data = angle;
 	msg->outsize = sizeof(*param);
 	msg->insize = sizeof(struct ec_response_motion_sense);

 	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 	kfree(msg);
 	if (ret < 0)
 		return ret;
 	return count;
 }

 /* Module initialization */

 static DEVICE_ATTR_RW(reboot);
 static DEVICE_ATTR_RO(version);
 static DEVICE_ATTR_RO(flashinfo);
 static DEVICE_ATTR_RW(kb_wake_angle);

 static struct attribute *__ec_attrs[] = {
 	&dev_attr_kb_wake_angle.attr,
 	&dev_attr_reboot.attr,
 	&dev_attr_version.attr,
 	&dev_attr_flashinfo.attr,
 	NULL,
 };

 static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
 				    struct attribute *a, int n)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

 	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
 		return 0;

 	return a->mode;
 }

 static struct attribute_group cros_ec_attr_group = {
 	.attrs = __ec_attrs,
 	.is_visible = cros_ec_ctrl_visible,
 };

 static int cros_ec_sysfs_probe(struct platform_device *pd)
 {
 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
 	struct device *dev = &pd->dev;
 	int ret;

 	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
 	if (ret < 0)
 		dev_err(dev, "failed to create attributes. err=%d\n", ret);

 	return ret;
 }

 static int cros_ec_sysfs_remove(struct platform_device *pd)
 {
 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);

 	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);

 	return 0;
 }

 static struct platform_driver cros_ec_sysfs_driver = {
 	.driver = {
 		.name = DRV_NAME,
 	},
 	.probe = cros_ec_sysfs_probe,
 	.remove = cros_ec_sysfs_remove,
 };

 module_platform_driver(cros_ec_sysfs_driver);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
 MODULE_ALIAS("platform:" DRV_NAME);
	// SPDX-License-Identifier: GPL-2.0+
	// Expose the ChromeOS EC through sysfs
	//
	// Copyright (C) 2014 Google, Inc.

	#include <linux/ctype.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/fs.h>
	#include <linux/kobject.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/mfd/cros_ec_commands.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/printk.h>
	#include <linux/slab.h>
	#include <linux/stat.h>
	#include <linux/types.h>
	#include <linux/uaccess.h>

	#define DRV_NAME "cros-ec-sysfs"

	/* Accessor functions */

	static ssize_t reboot_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int count = 0;

	count += scnprintf(buf + count, PAGE_SIZE - count,
	"ro\|rw\|cancel\|cold\|disable-jump\|hibernate");
	count += scnprintf(buf + count, PAGE_SIZE - count,
	" [at-shutdown]\n");
	return count;
	}

	static ssize_t reboot_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	static const struct {
	const char * const str;
	uint8_t cmd;
	uint8_t flags;
	} words[] = {
	{"cancel", EC_REBOOT_CANCEL, 0},
	{"ro", EC_REBOOT_JUMP_RO, 0},
	{"rw", EC_REBOOT_JUMP_RW, 0},
	{"cold", EC_REBOOT_COLD, 0},
	{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
	{"hibernate", EC_REBOOT_HIBERNATE, 0},
	{"at-shutdown", -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
	};
	struct cros_ec_command *msg;
	struct ec_params_reboot_ec *param;
	int got_cmd = 0, offset = 0;
	int i;
	int ret;
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

	msg = kmalloc(sizeof(msg) + sizeof(param), GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	param = (struct ec_params_reboot_ec *)msg->data;

	param->flags = 0;
	while (1) {
	/* Find word to start scanning */
	while (buf[offset] && isspace(buf[offset]))
	offset++;
	if (!buf[offset])
	break;

	for (i = 0; i < ARRAY_SIZE(words); i++) {
	if (!strncasecmp(words[i].str, buf+offset,
	strlen(words[i].str))) {
	if (words[i].flags) {
	param->flags \|= words[i].flags;
	} else {
	param->cmd = words[i].cmd;
	got_cmd = 1;
	}
	break;
	}
	}

	/* On to the next word, if any */
	while (buf[offset] && !isspace(buf[offset]))
	offset++;
	}

	if (!got_cmd) {
	count = -EINVAL;
	goto exit;
	}

	msg->version = 0;
	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
	msg->outsize = sizeof(*param);
	msg->insize = 0;
	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0)
	count = ret;
	exit:
	kfree(msg);
	return count;
	}

	static ssize_t version_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	static const char * const image_names[] = {"unknown", "RO", "RW"};
	struct ec_response_get_version *r_ver;
	struct ec_response_get_chip_info *r_chip;
	struct ec_response_board_version *r_board;
	struct cros_ec_command *msg;
	int ret;
	int count = 0;
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	/* Get versions. RW may change. */
	msg->version = 0;
	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
	msg->insize = sizeof(*r_ver);
	msg->outsize = 0;
	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0) {
	count = ret;
	goto exit;
	}
	r_ver = (struct ec_response_get_version *)msg->data;
	/* Strings should be null-terminated, but let's be sure. */
	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"RO version: %s\n", r_ver->version_string_ro);
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"RW version: %s\n", r_ver->version_string_rw);
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Firmware copy: %s\n",
	(r_ver->current_image < ARRAY_SIZE(image_names) ?
	image_names[r_ver->current_image] : "?"));

	/* Get build info. */
	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
	msg->insize = EC_HOST_PARAM_SIZE;
	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
	if (ret < 0)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Build info: XFER ERROR %d\n", ret);
	else if (msg->result != EC_RES_SUCCESS)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Build info: EC error %d\n", msg->result);
	else {
	msg->data[EC_HOST_PARAM_SIZE - 1] = '\0';
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Build info: %s\n", msg->data);
	}

	/* Get chip info. */
	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
	msg->insize = sizeof(*r_chip);
	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
	if (ret < 0)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Chip info: XFER ERROR %d\n", ret);
	else if (msg->result != EC_RES_SUCCESS)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Chip info: EC error %d\n", msg->result);
	else {
	r_chip = (struct ec_response_get_chip_info *)msg->data;

	r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
	r_chip->name[sizeof(r_chip->name) - 1] = '\0';
	r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Chip vendor: %s\n", r_chip->vendor);
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Chip name: %s\n", r_chip->name);
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Chip revision: %s\n", r_chip->revision);
	}

	/* Get board version */
	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
	msg->insize = sizeof(*r_board);
	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
	if (ret < 0)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Board version: XFER ERROR %d\n", ret);
	else if (msg->result != EC_RES_SUCCESS)
	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Board version: EC error %d\n", msg->result);
	else {
	r_board = (struct ec_response_board_version *)msg->data;

	count += scnprintf(buf + count, PAGE_SIZE - count,
	"Board version: %d\n",
	r_board->board_version);
	}

	exit:
	kfree(msg);
	return count;
	}

	static ssize_t flashinfo_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ec_response_flash_info *resp;
	struct cros_ec_command *msg;
	int ret;
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

	msg = kmalloc(sizeof(msg) + sizeof(resp), GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	/* The flash info shouldn't ever change, but ask each time anyway. */
	msg->version = 0;
	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
	msg->insize = sizeof(*resp);
	msg->outsize = 0;
	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0)
	goto exit;

	resp = (struct ec_response_flash_info *)msg->data;

	ret = scnprintf(buf, PAGE_SIZE,
	"FlashSize %d\nWriteSize %d\n"
	"EraseSize %d\nProtectSize %d\n",
	resp->flash_size, resp->write_block_size,
	resp->erase_block_size, resp->protect_block_size);
	exit:
	kfree(msg);
	return ret;
	}

	/* Keyboard wake angle control */
	static ssize_t kb_wake_angle_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
	struct ec_response_motion_sense *resp;
	struct ec_params_motion_sense *param;
	struct cros_ec_command *msg;
	int ret;

	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	param = (struct ec_params_motion_sense *)msg->data;
	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
	msg->version = 2;
	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
	param->kb_wake_angle.data = EC_MOTION_SENSE_NO_VALUE;
	msg->outsize = sizeof(*param);
	msg->insize = sizeof(*resp);

	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0)
	goto exit;

	resp = (struct ec_response_motion_sense *)msg->data;
	ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->kb_wake_angle.ret);
	exit:
	kfree(msg);
	return ret;
	}

	static ssize_t kb_wake_angle_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);
	struct ec_params_motion_sense *param;
	struct cros_ec_command *msg;
	u16 angle;
	int ret;

	ret = kstrtou16(buf, 0, &angle);
	if (ret)
	return ret;

	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	param = (struct ec_params_motion_sense *)msg->data;
	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
	msg->version = 2;
	param->cmd = MOTIONSENSE_CMD_KB_WAKE_ANGLE;
	param->kb_wake_angle.data = angle;
	msg->outsize = sizeof(*param);
	msg->insize = sizeof(struct ec_response_motion_sense);

	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	kfree(msg);
	if (ret < 0)
	return ret;
	return count;
	}

	/* Module initialization */

	static DEVICE_ATTR_RW(reboot);
	static DEVICE_ATTR_RO(version);
	static DEVICE_ATTR_RO(flashinfo);
	static DEVICE_ATTR_RW(kb_wake_angle);

	static struct attribute *__ec_attrs[] = {
	&dev_attr_kb_wake_angle.attr,
	&dev_attr_reboot.attr,
	&dev_attr_version.attr,
	&dev_attr_flashinfo.attr,
	NULL,
	};

	static umode_t cros_ec_ctrl_visible(struct kobject *kobj,
	struct attribute *a, int n)
	{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct cros_ec_dev *ec = to_cros_ec_dev(dev);

	if (a == &dev_attr_kb_wake_angle.attr && !ec->has_kb_wake_angle)
	return 0;

	return a->mode;
	}

	static struct attribute_group cros_ec_attr_group = {
	.attrs = __ec_attrs,
	.is_visible = cros_ec_ctrl_visible,
	};

	static int cros_ec_sysfs_probe(struct platform_device *pd)
	{
	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
	struct device *dev = &pd->dev;
	int ret;

	ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
	if (ret < 0)
	dev_err(dev, "failed to create attributes. err=%d\n", ret);

	return ret;
	}

	static int cros_ec_sysfs_remove(struct platform_device *pd)
	{
	struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);

	sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);

	return 0;
	}

	static struct platform_driver cros_ec_sysfs_driver = {
	.driver = {
	.name = DRV_NAME,
	},
	.probe = cros_ec_sysfs_probe,
	.remove = cros_ec_sysfs_remove,
	};

	module_platform_driver(cros_ec_sysfs_driver);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Expose the ChromeOS EC through sysfs");
	MODULE_ALIAS("platform:" DRV_NAME);