1 /*
2 * PowerNV sensor code
3 *
4 * Copyright (C) 2013 IBM
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include <linux/delay.h>
22 #include <linux/mutex.h>
23 #include <asm/opal.h>
24
25 static DEFINE_MUTEX(opal_sensor_mutex);
26
27 /*
28 * This will return sensor information to driver based on the requested sensor
29 * handle. A handle is an opaque id for the powernv, read by the driver from the
30 * device tree..
31 */
opal_get_sensor_data(u32 sensor_hndl,u32 * sensor_data)32 int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
33 {
34 int ret, token;
35 struct opal_msg msg;
36 __be32 data;
37
38 token = opal_async_get_token_interruptible();
39 if (token < 0) {
40 pr_err("%s: Couldn't get the token, returning\n", __func__);
41 ret = token;
42 goto out;
43 }
44
45 mutex_lock(&opal_sensor_mutex);
46 ret = opal_sensor_read(sensor_hndl, token, &data);
47 if (ret != OPAL_ASYNC_COMPLETION)
48 goto out_token;
49
50 ret = opal_async_wait_response(token, &msg);
51 if (ret) {
52 pr_err("%s: Failed to wait for the async response, %d\n",
53 __func__, ret);
54 goto out_token;
55 }
56
57 *sensor_data = be32_to_cpu(data);
58 ret = be64_to_cpu(msg.params[1]);
59
60 out_token:
61 mutex_unlock(&opal_sensor_mutex);
62 opal_async_release_token(token);
63 out:
64 return ret;
65 }
66 EXPORT_SYMBOL_GPL(opal_get_sensor_data);
67