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/of_platform.h>
23 #include <asm/opal.h>
24 #include <asm/machdep.h>
25 
26 /*
27  * This will return sensor information to driver based on the requested sensor
28  * handle. A handle is an opaque id for the powernv, read by the driver from the
29  * device tree..
30  */
31 int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
32 {
33 	int ret, token;
34 	struct opal_msg msg;
35 	__be32 data;
36 
37 	token = opal_async_get_token_interruptible();
38 	if (token < 0)
39 		return token;
40 
41 	ret = opal_sensor_read(sensor_hndl, token, &data);
42 	switch (ret) {
43 	case OPAL_ASYNC_COMPLETION:
44 		ret = opal_async_wait_response(token, &msg);
45 		if (ret) {
46 			pr_err("%s: Failed to wait for the async response, %d\n",
47 			       __func__, ret);
48 			goto out;
49 		}
50 
51 		ret = opal_error_code(opal_get_async_rc(msg));
52 		*sensor_data = be32_to_cpu(data);
53 		break;
54 
55 	case OPAL_SUCCESS:
56 		ret = 0;
57 		*sensor_data = be32_to_cpu(data);
58 		break;
59 
60 	case OPAL_WRONG_STATE:
61 		ret = -EIO;
62 		break;
63 
64 	default:
65 		ret = opal_error_code(ret);
66 		break;
67 	}
68 
69 out:
70 	opal_async_release_token(token);
71 	return ret;
72 }
73 EXPORT_SYMBOL_GPL(opal_get_sensor_data);
74 
75 int opal_get_sensor_data_u64(u32 sensor_hndl, u64 *sensor_data)
76 {
77 	int ret, token;
78 	struct opal_msg msg;
79 	__be64 data;
80 
81 	if (!opal_check_token(OPAL_SENSOR_READ_U64)) {
82 		u32 sdata;
83 
84 		ret = opal_get_sensor_data(sensor_hndl, &sdata);
85 		if (!ret)
86 			*sensor_data = sdata;
87 		return ret;
88 	}
89 
90 	token = opal_async_get_token_interruptible();
91 	if (token < 0)
92 		return token;
93 
94 	ret = opal_sensor_read_u64(sensor_hndl, token, &data);
95 	switch (ret) {
96 	case OPAL_ASYNC_COMPLETION:
97 		ret = opal_async_wait_response(token, &msg);
98 		if (ret) {
99 			pr_err("%s: Failed to wait for the async response, %d\n",
100 			       __func__, ret);
101 			goto out_token;
102 		}
103 
104 		ret = opal_error_code(opal_get_async_rc(msg));
105 		*sensor_data = be64_to_cpu(data);
106 		break;
107 
108 	case OPAL_SUCCESS:
109 		ret = 0;
110 		*sensor_data = be64_to_cpu(data);
111 		break;
112 
113 	case OPAL_WRONG_STATE:
114 		ret = -EIO;
115 		break;
116 
117 	default:
118 		ret = opal_error_code(ret);
119 		break;
120 	}
121 
122 out_token:
123 	opal_async_release_token(token);
124 	return ret;
125 }
126 EXPORT_SYMBOL_GPL(opal_get_sensor_data_u64);
127 
128 int __init opal_sensor_init(void)
129 {
130 	struct platform_device *pdev;
131 	struct device_node *sensor;
132 
133 	sensor = of_find_node_by_path("/ibm,opal/sensors");
134 	if (!sensor) {
135 		pr_err("Opal node 'sensors' not found\n");
136 		return -ENODEV;
137 	}
138 
139 	pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
140 	of_node_put(sensor);
141 
142 	return PTR_ERR_OR_ZERO(pdev);
143 }
144