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 __init opal_sensor_init(void) 76 { 77 struct platform_device *pdev; 78 struct device_node *sensor; 79 80 sensor = of_find_node_by_path("/ibm,opal/sensors"); 81 if (!sensor) { 82 pr_err("Opal node 'sensors' not found\n"); 83 return -ENODEV; 84 } 85 86 pdev = of_platform_device_create(sensor, "opal-sensor", NULL); 87 of_node_put(sensor); 88 89 return PTR_ERR_OR_ZERO(pdev); 90 } 91