linux/arch/powerpc/platforms/powernv/opal-sensor.c

87 lines
2.3 KiB
C

/*
* PowerNV sensor code
*
* Copyright (C) 2013 IBM
*
* 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.
*
* 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
*/
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <asm/opal.h>
#include <asm/machdep.h>
static DEFINE_MUTEX(opal_sensor_mutex);
/*
* This will return sensor information to driver based on the requested sensor
* handle. A handle is an opaque id for the powernv, read by the driver from the
* device tree..
*/
int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
{
int ret, token;
struct opal_msg msg;
__be32 data;
token = opal_async_get_token_interruptible();
if (token < 0) {
pr_err("%s: Couldn't get the token, returning\n", __func__);
ret = token;
goto out;
}
mutex_lock(&opal_sensor_mutex);
ret = opal_sensor_read(sensor_hndl, token, &data);
if (ret != OPAL_ASYNC_COMPLETION)
goto out_token;
ret = opal_async_wait_response(token, &msg);
if (ret) {
pr_err("%s: Failed to wait for the async response, %d\n",
__func__, ret);
goto out_token;
}
*sensor_data = be32_to_cpu(data);
ret = be64_to_cpu(msg.params[1]);
out_token:
mutex_unlock(&opal_sensor_mutex);
opal_async_release_token(token);
out:
return ret;
}
EXPORT_SYMBOL_GPL(opal_get_sensor_data);
static __init int opal_sensor_init(void)
{
struct platform_device *pdev;
struct device_node *sensor;
sensor = of_find_node_by_path("/ibm,opal/sensors");
if (!sensor) {
pr_err("Opal node 'sensors' not found\n");
return -ENODEV;
}
pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
of_node_put(sensor);
return PTR_ERR_OR_ZERO(pdev);
}
machine_subsys_initcall(powernv, opal_sensor_init);