/*
* Toshiba HDD Active Protection Sensor (HAPS) driver
*
* Copyright (C) 2014 Azael Avalos <coproscefalo@gmail.com>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.h>
MODULE_AUTHOR("Azael Avalos <coproscefalo@gmail.com>");
MODULE_DESCRIPTION("Toshiba HDD Active Protection Sensor");
MODULE_LICENSE("GPL");
struct toshiba_haps_dev {
struct acpi_device *acpi_dev;
int protection_level;
};
static struct toshiba_haps_dev *toshiba_haps;
/* HAPS functions */
static int toshiba_haps_reset_protection(acpi_handle handle)
{
acpi_status status;
status = acpi_evaluate_object(handle, "RSSS", NULL, NULL);
if (ACPI_FAILURE(status)) {
pr_err("Unable to reset the HDD protection\n");
return -EIO;
}
return 0;
}
static int toshiba_haps_protection_level(acpi_handle handle, int level)
{
acpi_status status;
status = acpi_execute_simple_method(handle, "PTLV", level);
if (ACPI_FAILURE(status)) {
pr_err("Error while setting the protection level\n");
return -EIO;
}
pr_debug("HDD protection level set to: %d\n", level);
return 0;
}
/* sysfs files */
static ssize_t protection_level_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
return sprintf(buf, "%i\n", haps->protection_level);
}
static ssize_t protection_level_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
int level;
int ret;
ret = kstrtoint(buf, 0, &level);
if (ret)
return ret;
/*
* Check for supported levels, which can be:
* 0 - Disabled | 1 - Low | 2 - Medium | 3 - High
*/
if (level < 0 || level > 3)
return -EINVAL;
/* Set the sensor level */
ret = toshiba_haps_protection_level(haps->acpi_dev->handle, level);
if (ret != 0)
return ret;
haps->protection_level = level;
return count;
}
static DEVICE_ATTR_RW(protection_level);
static ssize_t reset_protection_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct toshiba_haps_dev *haps = dev_get_drvdata(dev);
int reset;
int ret;
ret = kstrtoint(buf, 0, &reset);
if (ret)
return ret;
/* The only accepted value is 1 */
if (reset != 1)
return -EINVAL;
/* Reset the protection interface */
ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
if (ret != 0)
return ret;
return count;
}
static DEVICE_ATTR_WO(reset_protection);
static struct attribute *haps_attributes[] = {
&dev_attr_protection_level.attr,
&dev_attr_reset_protection.attr,
NULL,
};
static struct attribute_group haps_attr_group = {
.attrs = haps_attributes,
};
/*
* ACPI stuff
*/
static void toshiba_haps_notify(struct acpi_device *device, u32 event)
{
pr_debug("Received event: 0x%x", event);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev),
event, 0);
}
static int toshiba_haps_remove(struct acpi_device *device)
{
sysfs_remove_group(&device->dev.kobj, &haps_attr_group);
if (toshiba_haps)
toshiba_haps = NULL;
return 0;
}
/* Helper function */
static int toshiba_haps_available(acpi_handle handle)
{
acpi_status status;
u64 hdd_present;
/*
* A non existent device as well as having (only)
* Solid State Drives can cause the call to fail.
*/
status = acpi_evaluate_integer(handle, "_STA", NULL, &hdd_present);
if (ACPI_FAILURE(status)) {
pr_err("ACPI call to query HDD protection failed\n");
return 0;
}
if (!hdd_present) {
pr_info("HDD protection not available or using SSD\n");
return 0;
}
return 1;
}
static int toshiba_haps_add(struct acpi_device *acpi_dev)
{
struct toshiba_haps_dev *haps;
int ret;
if (toshiba_haps)
return -EBUSY;
if (!toshiba_haps_available(acpi_dev->handle))
return -ENODEV;
pr_info("Toshiba HDD Active Protection Sensor device\n");
haps = kzalloc(sizeof(struct toshiba_haps_dev), GFP_KERNEL);
if (!haps)
return -ENOMEM;
haps->acpi_dev = acpi_dev;
haps->protection_level = 2;
acpi_dev->driver_data = haps;
dev_set_drvdata(&acpi_dev->dev, haps);
/* Set the protection level, currently at level 2 (Medium) */
ret = toshiba_haps_protection_level(acpi_dev->handle, 2);
if (ret != 0)
return ret;
ret = sysfs_create_group(&acpi_dev->dev.kobj, &haps_attr_group);
if (ret)
return ret;
toshiba_haps = haps;
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int toshiba_haps_suspend(struct device *device)
{
struct toshiba_haps_dev *haps;
int ret;
haps = acpi_driver_data(to_acpi_device(device));
/* Deactivate the protection on suspend */
ret = toshiba_haps_protection_level(haps->acpi_dev->handle, 0);
return ret;
}
static int toshiba_haps_resume(struct device *device)
{
struct toshiba_haps_dev *haps;
int ret;
haps = acpi_driver_data(to_acpi_device(device));
/* Set the stored protection level */
ret = toshiba_haps_protection_level(haps->acpi_dev->handle,
haps->protection_level);
/* Reset the protection on resume */
ret = toshiba_haps_reset_protection(haps->acpi_dev->handle);
if (ret != 0)
return ret;
return ret;
}
#endif
static SIMPLE_DEV_PM_OPS(toshiba_haps_pm,
toshiba_haps_suspend, toshiba_haps_resume);
static const struct acpi_device_id haps_device_ids[] = {
{"TOS620A", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, haps_device_ids);
static struct acpi_driver toshiba_haps_driver = {
.name = "Toshiba HAPS",
.owner = THIS_MODULE,
.ids = haps_device_ids,
.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
.ops = {
.add = toshiba_haps_add,
.remove = toshiba_haps_remove,
.notify = toshiba_haps_notify,
},
.drv.pm = &toshiba_haps_pm,
};
module_acpi_driver(toshiba_haps_driver);
