intel_menlow.c

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/*
 *  intel_menlow.c - Intel menlow Driver for thermal management extension
 *
 *  Copyright (C) 2008 Intel Corp
 *  Copyright (C) 2008 Sujith Thomas <[email protected]>
 *  Copyright (C) 2008 Zhang Rui <[email protected]>
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This driver creates the sys I/F for programming the sensors.
 *  It also implements the driver for intel menlow memory controller (hardware
 *  id is INT0002) which makes use of the platform specific ACPI methods
 *  to get/set bandwidth.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pm.h>

#include <linux/thermal.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

MODULE_AUTHOR("Thomas Sujith");
MODULE_AUTHOR("Zhang Rui");
MODULE_DESCRIPTION("Intel Menlow platform specific driver");
MODULE_LICENSE("GPL");

/*
 * Memory controller device control
 */

#define MEMORY_GET_BANDWIDTH "GTHS"
#define MEMORY_SET_BANDWIDTH "STHS"
#define MEMORY_ARG_CUR_BANDWIDTH 1
#define MEMORY_ARG_MAX_BANDWIDTH 0

static void intel_menlow_unregister_sensor(void);

/*
 * GTHS returning 'n' would mean that [0,n-1] states are supported
 * In that case max_cstate would be n-1
 * GTHS returning '0' would mean that no bandwidth control states are supported
 */
static int memory_get_max_bandwidth(struct thermal_cooling_device *cdev,
                    unsigned long *max_state)
{
    struct acpi_device *device = cdev->devdata;
    acpi_handle handle = device->handle;
    unsigned long long value;
    struct acpi_object_list arg_list;
    union acpi_object arg;
    acpi_status status = AE_OK;

    arg_list.count = 1;
    arg_list.pointer = &arg;
    arg.type = ACPI_TYPE_INTEGER;
    arg.integer.value = MEMORY_ARG_MAX_BANDWIDTH;
    status = acpi_evaluate_integer(handle, MEMORY_GET_BANDWIDTH,
                       &arg_list, &value);
    if (ACPI_FAILURE(status))
        return -EFAULT;

    if (!value)
        return -EINVAL;

    *max_state = value - 1;
    return 0;
}

static int memory_get_cur_bandwidth(struct thermal_cooling_device *cdev,
                    unsigned long *value)
{
    struct acpi_device *device = cdev->devdata;
    acpi_handle handle = device->handle;
    unsigned long long result;
    struct acpi_object_list arg_list;
    union acpi_object arg;
    acpi_status status = AE_OK;

    arg_list.count = 1;
    arg_list.pointer = &arg;
    arg.type = ACPI_TYPE_INTEGER;
    arg.integer.value = MEMORY_ARG_CUR_BANDWIDTH;
    status = acpi_evaluate_integer(handle, MEMORY_GET_BANDWIDTH,
                       &arg_list, &result);
    if (ACPI_FAILURE(status))
        return -EFAULT;

    *value = result;
    return 0;
}

static int memory_set_cur_bandwidth(struct thermal_cooling_device *cdev,
                    unsigned long state)
{
    struct acpi_device *device = cdev->devdata;
    acpi_handle handle = device->handle;
    struct acpi_object_list arg_list;
    union acpi_object arg;
    acpi_status status;
    unsigned long long temp;
    unsigned long max_state;

    if (memory_get_max_bandwidth(cdev, &max_state))
        return -EFAULT;

    if (state > max_state)
        return -EINVAL;

    arg_list.count = 1;
    arg_list.pointer = &arg;
    arg.type = ACPI_TYPE_INTEGER;
    arg.integer.value = state;

    status =
        acpi_evaluate_integer(handle, MEMORY_SET_BANDWIDTH, &arg_list,
                  &temp);

    pr_info("Bandwidth value was %ld: status is %d\n", state, status);
    if (ACPI_FAILURE(status))
        return -EFAULT;

    return 0;
}

static struct thermal_cooling_device_ops memory_cooling_ops = {
    .get_max_state = memory_get_max_bandwidth,
    .get_cur_state = memory_get_cur_bandwidth,
    .set_cur_state = memory_set_cur_bandwidth,
};

/*
 * Memory Device Management
 */
static int intel_menlow_memory_add(struct acpi_device *device)
{
    int result = -ENODEV;
    acpi_status status = AE_OK;
    acpi_handle dummy;
    struct thermal_cooling_device *cdev;

    if (!device)
        return -EINVAL;

    status = acpi_get_handle(device->handle, MEMORY_GET_BANDWIDTH, &dummy);
    if (ACPI_FAILURE(status))
        goto end;

    status = acpi_get_handle(device->handle, MEMORY_SET_BANDWIDTH, &dummy);
    if (ACPI_FAILURE(status))
        goto end;

    cdev = thermal_cooling_device_register("Memory controller", device,
                           &memory_cooling_ops);
    if (IS_ERR(cdev)) {
        result = PTR_ERR(cdev);
        goto end;
    }

    device->driver_data = cdev;
    result = sysfs_create_link(&device->dev.kobj,
                &cdev->device.kobj, "thermal_cooling");
    if (result)
        goto unregister;

    result = sysfs_create_link(&cdev->device.kobj,
                &device->dev.kobj, "device");
    if (result) {
        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
        goto unregister;
    }

 end:
    return result;

 unregister:
    thermal_cooling_device_unregister(cdev);
    return result;

}

static int intel_menlow_memory_remove(struct acpi_device *device, int type)
{
    struct thermal_cooling_device *cdev = acpi_driver_data(device);

    if (!device || !cdev)
        return -EINVAL;

    sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
    sysfs_remove_link(&cdev->device.kobj, "device");
    thermal_cooling_device_unregister(cdev);

    return 0;
}

static const struct acpi_device_id intel_menlow_memory_ids[] = {
    {"INT0002", 0},
    {"", 0},
};

static struct acpi_driver intel_menlow_memory_driver = {
    .name = "intel_menlow_thermal_control",
    .ids = intel_menlow_memory_ids,
    .ops = {
        .add = intel_menlow_memory_add,
        .remove = intel_menlow_memory_remove,
        },
};

/*
 * Sensor control on menlow platform
 */

#define THERMAL_AUX0 0
#define THERMAL_AUX1 1
#define GET_AUX0 "GAX0"
#define GET_AUX1 "GAX1"
#define SET_AUX0 "SAX0"
#define SET_AUX1 "SAX1"

struct intel_menlow_attribute {
    struct device_attribute attr;
    struct device *device;
    acpi_handle handle;
    struct list_head node;
};

static LIST_HEAD(intel_menlow_attr_list);
static DEFINE_MUTEX(intel_menlow_attr_lock);

/*
 * sensor_get_auxtrip - get the current auxtrip value from sensor
 * @name: Thermalzone name
 * @auxtype : AUX0/AUX1
 * @buf: syfs buffer
 */
static int sensor_get_auxtrip(acpi_handle handle, int index,
                            unsigned long long *value)
{
    acpi_status status;

    if ((index != 0 && index != 1) || !value)
        return -EINVAL;

    status = acpi_evaluate_integer(handle, index ? GET_AUX1 : GET_AUX0,
                       NULL, value);
    if (ACPI_FAILURE(status))
        return -EIO;

    return 0;
}

/*
 * sensor_set_auxtrip - set the new auxtrip value to sensor
 * @name: Thermalzone name
 * @auxtype : AUX0/AUX1
 * @buf: syfs buffer
 */
static int sensor_set_auxtrip(acpi_handle handle, int index, int value)
{
    acpi_status status;
    union acpi_object arg = {
        ACPI_TYPE_INTEGER
    };
    struct acpi_object_list args = {
        1, &arg
    };
    unsigned long long temp;

    if (index != 0 && index != 1)
        return -EINVAL;

    status = acpi_evaluate_integer(handle, index ? GET_AUX0 : GET_AUX1,
                       NULL, &temp);
    if (ACPI_FAILURE(status))
        return -EIO;
    if ((index && value < temp) || (!index && value > temp))
        return -EINVAL;

    arg.integer.value = value;
    status = acpi_evaluate_integer(handle, index ? SET_AUX1 : SET_AUX0,
                       &args, &temp);
    if (ACPI_FAILURE(status))
        return -EIO;

    /* do we need to check the return value of SAX0/SAX1 ? */

    return 0;
}

#define to_intel_menlow_attr(_attr) \
    container_of(_attr, struct intel_menlow_attribute, attr)

static ssize_t aux0_show(struct device *dev,
             struct device_attribute *dev_attr, char *buf)
{
    struct intel_menlow_attribute *attr = to_intel_menlow_attr(dev_attr);
    unsigned long long value;
    int result;

    result = sensor_get_auxtrip(attr->handle, 0, &value);

    return result ? result : sprintf(buf, "%lu", KELVIN_TO_CELSIUS(value));
}

static ssize_t aux1_show(struct device *dev,
             struct device_attribute *dev_attr, char *buf)
{
    struct intel_menlow_attribute *attr = to_intel_menlow_attr(dev_attr);
    unsigned long long value;
    int result;

    result = sensor_get_auxtrip(attr->handle, 1, &value);

    return result ? result : sprintf(buf, "%lu", KELVIN_TO_CELSIUS(value));
}

static ssize_t aux0_store(struct device *dev,
              struct device_attribute *dev_attr,
              const char *buf, size_t count)
{
    struct intel_menlow_attribute *attr = to_intel_menlow_attr(dev_attr);
    int value;
    int result;

    /*Sanity check; should be a positive integer */
    if (!sscanf(buf, "%d", &value))
        return -EINVAL;

    if (value < 0)
        return -EINVAL;

    result = sensor_set_auxtrip(attr->handle, 0, CELSIUS_TO_KELVIN(value));
    return result ? result : count;
}

static ssize_t aux1_store(struct device *dev,
              struct device_attribute *dev_attr,
              const char *buf, size_t count)
{
    struct intel_menlow_attribute *attr = to_intel_menlow_attr(dev_attr);
    int value;
    int result;

    /*Sanity check; should be a positive integer */
    if (!sscanf(buf, "%d", &value))
        return -EINVAL;

    if (value < 0)
        return -EINVAL;

    result = sensor_set_auxtrip(attr->handle, 1, CELSIUS_TO_KELVIN(value));
    return result ? result : count;
}

/* BIOS can enable/disable the thermal user application in dabney platform */
#define BIOS_ENABLED "\\_TZ.GSTS"
static ssize_t bios_enabled_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    acpi_status status;
    unsigned long long bios_enabled;

    status = acpi_evaluate_integer(NULL, BIOS_ENABLED, NULL, &bios_enabled);
    if (ACPI_FAILURE(status))
        return -ENODEV;

    return sprintf(buf, "%s\n", bios_enabled ? "enabled" : "disabled");
}

static int intel_menlow_add_one_attribute(char *name, umode_t mode, void *show,
                      void *store, struct device *dev,
                      acpi_handle handle)
{
    struct intel_menlow_attribute *attr;
    int result;

    attr = kzalloc(sizeof(struct intel_menlow_attribute), GFP_KERNEL);
    if (!attr)
        return -ENOMEM;

    sysfs_attr_init(&attr->attr.attr); /* That is consistent naming :D */
    attr->attr.attr.name = name;
    attr->attr.attr.mode = mode;
    attr->attr.show = show;
    attr->attr.store = store;
    attr->device = dev;
    attr->handle = handle;

    result = device_create_file(dev, &attr->attr);
    if (result) {
        kfree(attr);
        return result;
    }

    mutex_lock(&intel_menlow_attr_lock);
    list_add_tail(&attr->node, &intel_menlow_attr_list);
    mutex_unlock(&intel_menlow_attr_lock);

    return 0;
}

static acpi_status intel_menlow_register_sensor(acpi_handle handle, u32 lvl,
                        void *context, void **rv)
{
    acpi_status status;
    acpi_handle dummy;
    struct thermal_zone_device *thermal;
    int result;

    result = acpi_bus_get_private_data(handle, (void **)&thermal);
    if (result)
        return 0;

    /* _TZ must have the AUX0/1 methods */
    status = acpi_get_handle(handle, GET_AUX0, &dummy);
    if (ACPI_FAILURE(status))
        return (status == AE_NOT_FOUND) ? AE_OK : status;

    status = acpi_get_handle(handle, SET_AUX0, &dummy);
    if (ACPI_FAILURE(status))
        return (status == AE_NOT_FOUND) ? AE_OK : status;

    result = intel_menlow_add_one_attribute("aux0", 0644,
                        aux0_show, aux0_store,
                        &thermal->device, handle);
    if (result)
        return AE_ERROR;

    status = acpi_get_handle(handle, GET_AUX1, &dummy);
    if (ACPI_FAILURE(status))
        goto aux1_not_found;

    status = acpi_get_handle(handle, SET_AUX1, &dummy);
    if (ACPI_FAILURE(status))
        goto aux1_not_found;

    result = intel_menlow_add_one_attribute("aux1", 0644,
                        aux1_show, aux1_store,
                        &thermal->device, handle);
    if (result) {
        intel_menlow_unregister_sensor();
        return AE_ERROR;
    }

    /*
     * create the "dabney_enabled" attribute which means the user app
     * should be loaded or not
     */

    result = intel_menlow_add_one_attribute("bios_enabled", 0444,
                        bios_enabled_show, NULL,
                        &thermal->device, handle);
    if (result) {
        intel_menlow_unregister_sensor();
        return AE_ERROR;
    }

    return AE_OK;

 aux1_not_found:
    if (status == AE_NOT_FOUND)
        return AE_OK;

    intel_menlow_unregister_sensor();
    return status;
}

static void intel_menlow_unregister_sensor(void)
{
    struct intel_menlow_attribute *pos, *next;

    mutex_lock(&intel_menlow_attr_lock);
    list_for_each_entry_safe(pos, next, &intel_menlow_attr_list, node) {
        list_del(&pos->node);
        device_remove_file(pos->device, &pos->attr);
        kfree(pos);
    }
    mutex_unlock(&intel_menlow_attr_lock);

    return;
}

static int __init intel_menlow_module_init(void)
{
    int result = -ENODEV;
    acpi_status status;
    unsigned long long enable;

    if (acpi_disabled)
        return result;

    /* Looking for the \_TZ.GSTS method */
    status = acpi_evaluate_integer(NULL, BIOS_ENABLED, NULL, &enable);
    if (ACPI_FAILURE(status) || !enable)
        return -ENODEV;

    /* Looking for ACPI device MEM0 with hardware id INT0002 */
    result = acpi_bus_register_driver(&intel_menlow_memory_driver);
    if (result)
        return result;

    /* Looking for sensors in each ACPI thermal zone */
    status = acpi_walk_namespace(ACPI_TYPE_THERMAL, ACPI_ROOT_OBJECT,
                     ACPI_UINT32_MAX,
                     intel_menlow_register_sensor, NULL, NULL, NULL);
    if (ACPI_FAILURE(status)) {
        acpi_bus_unregister_driver(&intel_menlow_memory_driver);
        return -ENODEV;
    }

    return 0;
}

static void __exit intel_menlow_module_exit(void)
{
    acpi_bus_unregister_driver(&intel_menlow_memory_driver);
    intel_menlow_unregister_sensor();
}

module_init(intel_menlow_module_init);
module_exit(intel_menlow_module_exit);