arch/powerpc/platforms/powernv/opal-sensor.c

   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 }