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 27 static 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 */ 34 int 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 if (ret != OPAL_ASYNC_COMPLETION) 50 goto out_token; 51 52 ret = opal_async_wait_response(token, &msg); 53 if (ret) { 54 pr_err("%s: Failed to wait for the async response, %d\n", 55 __func__, ret); 56 goto out_token; 57 } 58 59 *sensor_data = be32_to_cpu(data); 60 ret = be64_to_cpu(msg.params[1]); 61 62 out_token: 63 mutex_unlock(&opal_sensor_mutex); 64 opal_async_release_token(token); 65 out: 66 return ret; 67 } 68 EXPORT_SYMBOL_GPL(opal_get_sensor_data); 69 70 static __init int opal_sensor_init(void) 71 { 72 struct platform_device *pdev; 73 struct device_node *sensor; 74 75 sensor = of_find_node_by_path("/ibm,opal/sensors"); 76 if (!sensor) { 77 pr_err("Opal node 'sensors' not found\n"); 78 return -ENODEV; 79 } 80 81 pdev = of_platform_device_create(sensor, "opal-sensor", NULL); 82 of_node_put(sensor); 83 84 return PTR_ERR_OR_ZERO(pdev); 85 } 86 machine_subsys_initcall(powernv, opal_sensor_init); 87