summaryrefslogtreecommitdiff
path: root/cpukit/dev/i2c/sensor-lm75a.c
blob: 4cc1ae681ee5e4f3e95f9078cd65933d2c083d75 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
/**
 * @file
 *
 * @brief Temperature Sensor LM75A Driver Implementation
 *
 * @ingroup I2CSensorLM75A
 */

/*
 * Copyright (c) 2017 embedded brains GmbH.  All rights reserved.
 *
 *  embedded brains GmbH
 *  Dornierstr. 4
 *  82178 Puchheim
 *  Germany
 *  <rtems@embedded-brains.de>
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <dev/i2c/sensor-lm75a.h>

typedef enum {
  SENSOR_LM75A_PTR_TEMP,
  SENSOR_LM75A_PTR_CONF,
  SENSOR_LM75A_PTR_THYST,
  SENSOR_LM75A_PTR_TOS
} sensor_lm75a_ptr;

static int sensor_lm75a_get_reg_8(
  i2c_dev *dev,
  sensor_lm75a_ptr ptr,
  uint8_t *val
)
{
  uint8_t out[1] = { ptr };
  uint8_t in[sizeof(*val)];
  i2c_msg msgs[2] = {
    {
      .addr = dev->address,
      .flags = 0,
      .len = (uint16_t) sizeof(out),
      .buf = &out[0]
    }, {
      .addr = dev->address,
      .flags = I2C_M_RD,
      .len = (uint16_t) sizeof(in),
      .buf = &in[0]
    }
  };
  int err;

  err = i2c_bus_transfer(dev->bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
  *val = in[0];

  return err;
}

static int sensor_lm75a_set_reg_8(
  i2c_dev *dev,
  sensor_lm75a_ptr ptr,
  uint8_t val
)
{
  uint8_t out[2] = { ptr, val };
  i2c_msg msgs[1] = {
    {
      .addr = dev->address,
      .flags = 0,
      .len = (uint16_t) sizeof(out),
      .buf = &out[0]
    }
  };

  return i2c_bus_transfer(dev->bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
}

static int sensor_lm75a_get_reg_16(
  i2c_dev *dev,
  sensor_lm75a_ptr ptr,
  uint16_t *val
)
{
  uint8_t out[1] = { ptr };
  uint8_t in[sizeof(*val)];
  i2c_msg msgs[2] = {
    {
      .addr = dev->address,
      .flags = 0,
      .len = (uint16_t) sizeof(out),
      .buf = &out[0]
    }, {
      .addr = dev->address,
      .flags = I2C_M_RD,
      .len = (uint16_t) sizeof(in),
      .buf = &in[0]
    }
  };
  int err;

  err = i2c_bus_transfer(dev->bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
  *val = (in[0] << 8) | in[1];

  return err;
}

static int sensor_lm75a_set_reg_16(
  i2c_dev *dev,
  sensor_lm75a_ptr ptr,
  uint16_t val
)
{
  uint8_t out[3] = { ptr, (uint8_t) (val >> 8), (uint8_t) val };
  i2c_msg msgs[1] = {
    {
      .addr = dev->address,
      .flags = 0,
      .len = (uint16_t) sizeof(out),
      .buf = &out[0]
    }
  };

  return i2c_bus_transfer(dev->bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
}

static int sensor_lm75a_ioctl(
  i2c_dev *dev,
  ioctl_command_t command,
  void *arg
)
{
  uint8_t v8 = (uint8_t) (uintptr_t) arg;
  uint16_t v16 = (uint16_t) (uintptr_t) arg;
  int err;

  switch (command) {
    case SENSOR_LM75A_GET_CONF:
      err = sensor_lm75a_get_reg_8(dev, SENSOR_LM75A_PTR_CONF, arg);
      break;
    case SENSOR_LM75A_SET_CONF:
      err = sensor_lm75a_set_reg_8(dev, SENSOR_LM75A_PTR_CONF, v8);
      break;
    case SENSOR_LM75A_CLEAR_AND_SET_CONF:
      i2c_bus_obtain(dev->bus);
      err = sensor_lm75a_get_reg_8(dev, SENSOR_LM75A_PTR_CONF, &v8);
      if (err == 0) {
        v8 &= ~((uint8_t) v16);
        v8 |= (uint8_t) (v16 >> 8);
        err = sensor_lm75a_set_reg_8(dev, SENSOR_LM75A_PTR_CONF, v8);
      }
      i2c_bus_release(dev->bus);
      break;
    case SENSOR_LM75A_GET_TEMP:
      err = sensor_lm75a_get_reg_16(dev, SENSOR_LM75A_PTR_TEMP, arg);
      break;
    case SENSOR_LM75A_GET_TOS:
      err = sensor_lm75a_get_reg_16(dev, SENSOR_LM75A_PTR_TOS, arg);
      break;
    case SENSOR_LM75A_SET_TOS:
      err = sensor_lm75a_set_reg_16(dev, SENSOR_LM75A_PTR_TOS, v16);
      break;
    case SENSOR_LM75A_GET_THYST:
      err = sensor_lm75a_get_reg_16(dev, SENSOR_LM75A_PTR_THYST, arg);
      break;
    case SENSOR_LM75A_SET_THYST:
      err = sensor_lm75a_set_reg_16(dev, SENSOR_LM75A_PTR_THYST, v16);
      break;
    default:
      err = -ENOTTY;
      break;
  }

  return err;
}

int i2c_dev_register_sensor_lm75a(
  const char *bus_path,
  const char *dev_path,
  uint16_t address
)
{
  i2c_dev *dev;

  dev = i2c_dev_alloc_and_init(sizeof(*dev), bus_path, address);
  if (dev == NULL) {
    return -1;
  }

  dev->ioctl = sensor_lm75a_ioctl;

  return i2c_dev_register(dev, dev_path);
}