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43e53407 LT |
1 | /* |
2 | * tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor | |
3 | * | |
4 | * Copyright (c) 2015 Measurement-Specialties | |
5 | * | |
6 | * Licensed under the GPL-2. | |
7 | * | |
8 | * Datasheet: | |
9 | * http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf | |
10 | */ | |
11 | ||
12 | #include <linux/iio/iio.h> | |
13 | #include <linux/iio/sysfs.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/mutex.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/stat.h> | |
20 | #include "../common/ms_sensors/ms_sensors_i2c.h" | |
21 | ||
22 | /* TSYS01 Commands */ | |
23 | #define TSYS01_RESET 0x1E | |
24 | #define TSYS01_CONVERSION_START 0x48 | |
25 | #define TSYS01_ADC_READ 0x00 | |
26 | #define TSYS01_PROM_READ 0xA0 | |
27 | ||
28 | #define TSYS01_PROM_WORDS_NB 8 | |
29 | ||
30 | struct tsys01_dev { | |
31 | void *client; | |
32 | struct mutex lock; /* lock during conversion */ | |
33 | ||
34 | int (*reset)(void *cli, u8 cmd, unsigned int delay); | |
35 | int (*convert_and_read)(void *cli, u8 conv, u8 rd, | |
36 | unsigned int delay, u32 *adc); | |
37 | int (*read_prom_word)(void *cli, int cmd, u16 *word); | |
38 | ||
39 | u16 prom[TSYS01_PROM_WORDS_NB]; | |
40 | }; | |
41 | ||
42 | /* Multiplication coefficients for temperature computation */ | |
43 | static const int coeff_mul[] = { -1500000, 1000000, -2000000, | |
44 | 4000000, -2000000 }; | |
45 | ||
46 | static int tsys01_read_temperature(struct iio_dev *indio_dev, | |
47 | s32 *temperature) | |
48 | { | |
49 | int ret, i; | |
50 | u32 adc; | |
51 | s64 temp = 0; | |
52 | struct tsys01_dev *dev_data = iio_priv(indio_dev); | |
53 | ||
54 | mutex_lock(&dev_data->lock); | |
55 | ret = dev_data->convert_and_read(dev_data->client, | |
56 | TSYS01_CONVERSION_START, | |
57 | TSYS01_ADC_READ, 9000, &adc); | |
58 | mutex_unlock(&dev_data->lock); | |
59 | if (ret) | |
60 | return ret; | |
61 | ||
62 | adc >>= 8; | |
63 | ||
64 | /* Temperature algorithm */ | |
65 | for (i = 4; i > 0; i--) { | |
66 | temp += coeff_mul[i] * | |
67 | (s64)dev_data->prom[5 - i]; | |
68 | temp *= (s64)adc; | |
69 | temp = div64_s64(temp, 100000); | |
70 | } | |
71 | temp *= 10; | |
72 | temp += coeff_mul[0] * (s64)dev_data->prom[5]; | |
73 | temp = div64_s64(temp, 100000); | |
74 | ||
75 | *temperature = temp; | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static int tsys01_read_raw(struct iio_dev *indio_dev, | |
81 | struct iio_chan_spec const *channel, int *val, | |
82 | int *val2, long mask) | |
83 | { | |
84 | int ret; | |
85 | s32 temperature; | |
86 | ||
87 | switch (mask) { | |
88 | case IIO_CHAN_INFO_PROCESSED: | |
89 | switch (channel->type) { | |
90 | case IIO_TEMP: /* in milli °C */ | |
91 | ret = tsys01_read_temperature(indio_dev, &temperature); | |
92 | if (ret) | |
93 | return ret; | |
94 | *val = temperature; | |
95 | ||
96 | return IIO_VAL_INT; | |
97 | default: | |
98 | return -EINVAL; | |
99 | } | |
100 | default: | |
101 | return -EINVAL; | |
102 | } | |
103 | } | |
104 | ||
105 | static const struct iio_chan_spec tsys01_channels[] = { | |
106 | { | |
107 | .type = IIO_TEMP, | |
108 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), | |
109 | } | |
110 | }; | |
111 | ||
112 | static const struct iio_info tsys01_info = { | |
113 | .read_raw = tsys01_read_raw, | |
114 | .driver_module = THIS_MODULE, | |
115 | }; | |
116 | ||
117 | static bool tsys01_crc_valid(u16 *n_prom) | |
118 | { | |
119 | u8 cnt; | |
120 | u8 sum = 0; | |
121 | ||
122 | for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++) | |
123 | sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF)); | |
124 | ||
125 | return (sum == 0); | |
126 | } | |
127 | ||
128 | static int tsys01_read_prom(struct iio_dev *indio_dev) | |
129 | { | |
130 | int i, ret; | |
131 | struct tsys01_dev *dev_data = iio_priv(indio_dev); | |
132 | char buf[7 * TSYS01_PROM_WORDS_NB + 1]; | |
133 | char *ptr = buf; | |
134 | ||
135 | for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) { | |
136 | ret = dev_data->read_prom_word(dev_data->client, | |
137 | TSYS01_PROM_READ + (i << 1), | |
138 | &dev_data->prom[i]); | |
139 | if (ret) | |
140 | return ret; | |
141 | ||
142 | ret = sprintf(ptr, "0x%04x ", dev_data->prom[i]); | |
143 | ptr += ret; | |
144 | } | |
145 | ||
146 | if (!tsys01_crc_valid(dev_data->prom)) { | |
147 | dev_err(&indio_dev->dev, "prom crc check error\n"); | |
148 | return -ENODEV; | |
149 | } | |
150 | *ptr = 0; | |
151 | dev_info(&indio_dev->dev, "PROM coefficients : %s\n", buf); | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev) | |
157 | { | |
158 | int ret; | |
159 | struct tsys01_dev *dev_data = iio_priv(indio_dev); | |
160 | ||
161 | mutex_init(&dev_data->lock); | |
162 | ||
163 | indio_dev->info = &tsys01_info; | |
164 | indio_dev->name = dev->driver->name; | |
165 | indio_dev->dev.parent = dev; | |
166 | indio_dev->modes = INDIO_DIRECT_MODE; | |
167 | indio_dev->channels = tsys01_channels; | |
168 | indio_dev->num_channels = ARRAY_SIZE(tsys01_channels); | |
169 | ||
170 | ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000); | |
171 | if (ret) | |
172 | return ret; | |
173 | ||
174 | ret = tsys01_read_prom(indio_dev); | |
175 | if (ret) | |
176 | return ret; | |
177 | ||
178 | return devm_iio_device_register(dev, indio_dev); | |
179 | } | |
180 | ||
181 | static int tsys01_i2c_probe(struct i2c_client *client, | |
182 | const struct i2c_device_id *id) | |
183 | { | |
184 | struct tsys01_dev *dev_data; | |
185 | struct iio_dev *indio_dev; | |
186 | ||
187 | if (!i2c_check_functionality(client->adapter, | |
188 | I2C_FUNC_SMBUS_WORD_DATA | | |
189 | I2C_FUNC_SMBUS_WRITE_BYTE | | |
190 | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | |
191 | dev_err(&client->dev, | |
192 | "Adapter does not support some i2c transaction\n"); | |
193 | return -ENODEV; | |
194 | } | |
195 | ||
196 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data)); | |
197 | if (!indio_dev) | |
198 | return -ENOMEM; | |
199 | ||
200 | dev_data = iio_priv(indio_dev); | |
201 | dev_data->client = client; | |
202 | dev_data->reset = ms_sensors_reset; | |
203 | dev_data->read_prom_word = ms_sensors_read_prom_word; | |
204 | dev_data->convert_and_read = ms_sensors_convert_and_read; | |
205 | ||
206 | i2c_set_clientdata(client, indio_dev); | |
207 | ||
208 | return tsys01_probe(indio_dev, &client->dev); | |
209 | } | |
210 | ||
211 | static const struct i2c_device_id tsys01_id[] = { | |
212 | {"tsys01", 0}, | |
213 | {} | |
214 | }; | |
215 | MODULE_DEVICE_TABLE(i2c, tsys01_id); | |
216 | ||
217 | static struct i2c_driver tsys01_driver = { | |
218 | .probe = tsys01_i2c_probe, | |
219 | .id_table = tsys01_id, | |
220 | .driver = { | |
221 | .name = "tsys01", | |
222 | }, | |
223 | }; | |
224 | ||
225 | module_i2c_driver(tsys01_driver); | |
226 | ||
227 | MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature driver"); | |
228 | MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>"); | |
229 | MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>"); | |
230 | MODULE_LICENSE("GPL v2"); |