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 */ 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