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 <linux/of_platform.h>
24#include <asm/opal.h>
25#include <asm/machdep.h>
26
27static DEFINE_MUTEX(opal_sensor_mutex);
28
29/*
30 * This will return sensor information to driver based on the requested sensor
31 * handle. A handle is an opaque id for the powernv, read by the driver from the
32 * device tree..
33 */
34int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
35{
36	int ret, token;
37	struct opal_msg msg;
38	__be32 data;
39
40	token = opal_async_get_token_interruptible();
41	if (token < 0) {
42		pr_err("%s: Couldn't get the token, returning\n", __func__);
43		ret = token;
44		goto out;
45	}
46
47	mutex_lock(&opal_sensor_mutex);
48	ret = opal_sensor_read(sensor_hndl, token, &data);
49	switch (ret) {
50	case OPAL_ASYNC_COMPLETION:
51		ret = opal_async_wait_response(token, &msg);
52		if (ret) {
53			pr_err("%s: Failed to wait for the async response, %d\n",
54			       __func__, ret);
55			goto out_token;
56		}
57
58		ret = opal_error_code(be64_to_cpu(msg.params[1]));
59		*sensor_data = be32_to_cpu(data);
60		break;
61
62	case OPAL_SUCCESS:
63		ret = 0;
64		*sensor_data = be32_to_cpu(data);
65		break;
66
67	default:
68		ret = opal_error_code(ret);
69		break;
70	}
71
72out_token:
73	mutex_unlock(&opal_sensor_mutex);
74	opal_async_release_token(token);
75out:
76	return ret;
77}
78EXPORT_SYMBOL_GPL(opal_get_sensor_data);
79
80static __init int opal_sensor_init(void)
81{
82	struct platform_device *pdev;
83	struct device_node *sensor;
84
85	sensor = of_find_node_by_path("/ibm,opal/sensors");
86	if (!sensor) {
87		pr_err("Opal node 'sensors' not found\n");
88		return -ENODEV;
89	}
90
91	pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
92	of_node_put(sensor);
93
94	return PTR_ERR_OR_ZERO(pdev);
95}
96machine_subsys_initcall(powernv, opal_sensor_init);
97