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 37 token = opal_async_get_token_interruptible(); 38 if (token < 0) { 39 pr_err("%s: Couldn't get the token, returning\n", __func__); 40 ret = token; 41 goto out; 42 } 43 44 mutex_lock(&opal_sensor_mutex); 45 ret = opal_sensor_read(sensor_hndl, token, sensor_data); 46 if (ret != OPAL_ASYNC_COMPLETION) 47 goto out_token; 48 49 ret = opal_async_wait_response(token, &msg); 50 if (ret) { 51 pr_err("%s: Failed to wait for the async response, %d\n", 52 __func__, ret); 53 goto out_token; 54 } 55 56 ret = msg.params[1]; 57 58 out_token: 59 mutex_unlock(&opal_sensor_mutex); 60 opal_async_release_token(token); 61 out: 62 return ret; 63 } 64 EXPORT_SYMBOL_GPL(opal_get_sensor_data); 65