drivers/thermal/qcom/tsens-8996.c

   1 /*
   2  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include "tsens.h"
  18
  19 #define STATUS_OFFSET   0x10a0
  20 #define LAST_TEMP_MASK  0xfff
  21 #define STATUS_VALID_BIT        BIT(21)
  22 #define CODE_SIGN_BIT           BIT(11)
  23
  24 static int get_temp_8996(struct tsens_device *tmdev, int id, int *temp)
  25 {
  26         struct tsens_sensor *s = &tmdev->sensor[id];
  27         u32 code;
  28         unsigned int sensor_addr;
  29         int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret;
  30
  31         sensor_addr = STATUS_OFFSET + s->hw_id * 4;
  32         ret = regmap_read(tmdev->map, sensor_addr, &code);
  33         if (ret)
  34                 return ret;
  35         last_temp = code & LAST_TEMP_MASK;
  36         if (code & STATUS_VALID_BIT)
  37                 goto done;
  38
  39         /* Try a second time */
  40         ret = regmap_read(tmdev->map, sensor_addr, &code);
  41         if (ret)
  42                 return ret;
  43         if (code & STATUS_VALID_BIT) {
  44                 last_temp = code & LAST_TEMP_MASK;
  45                 goto done;
  46         } else {
  47                 last_temp2 = code & LAST_TEMP_MASK;
  48         }
  49
  50         /* Try a third/last time */
  51         ret = regmap_read(tmdev->map, sensor_addr, &code);
  52         if (ret)
  53                 return ret;
  54         if (code & STATUS_VALID_BIT) {
  55                 last_temp = code & LAST_TEMP_MASK;
  56                 goto done;
  57         } else {
  58                 last_temp3 = code & LAST_TEMP_MASK;
  59         }
  60
  61         if (last_temp == last_temp2)
  62                 last_temp = last_temp2;
  63         else if (last_temp2 == last_temp3)
  64                 last_temp = last_temp3;
  65 done:
  66         /* Code sign bit is the sign extension for a negative value */
  67         if (last_temp & CODE_SIGN_BIT)
  68                 last_temp |= ~CODE_SIGN_BIT;
  69
  70         /* Temperatures are in deciCelicius */
  71         *temp = last_temp * 100;
  72
  73         return 0;
  74 }
  75
  76 static const struct tsens_ops ops_8996 = {
  77         .init           = init_common,
  78         .get_temp       = get_temp_8996,
  79 };
  80
  81 const struct tsens_data data_8996 = {
  82         .num_sensors    = 13,
  83         .ops            = &ops_8996,
  84 };