1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor |
4 | * |
5 | * Copyright (c) 2015 Measurement-Specialties |
6 | * |
7 | * Datasheet: |
8 | * http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf |
9 | */ |
10 | |
11 | #include <linux/iio/iio.h> |
12 | #include <linux/iio/sysfs.h> |
13 | #include <linux/device.h> |
14 | #include <linux/mutex.h> |
15 | #include <linux/module.h> |
16 | #include <linux/mod_devicetable.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(lock: &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(dividend: temp, divisor: 100000); |
70 | } |
71 | temp *= 10; |
72 | temp += coeff_mul[0] * (s64)dev_data->prom[5]; |
73 | temp = div64_s64(dividend: temp, divisor: 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: &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 | }; |
115 | |
116 | static bool tsys01_crc_valid(u16 *n_prom) |
117 | { |
118 | u8 cnt; |
119 | u8 sum = 0; |
120 | |
121 | for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++) |
122 | sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF)); |
123 | |
124 | return (sum == 0); |
125 | } |
126 | |
127 | static int tsys01_read_prom(struct iio_dev *indio_dev) |
128 | { |
129 | int i, ret; |
130 | struct tsys01_dev *dev_data = iio_priv(indio_dev); |
131 | char buf[7 * TSYS01_PROM_WORDS_NB + 1]; |
132 | char *ptr = buf; |
133 | |
134 | for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) { |
135 | ret = dev_data->read_prom_word(dev_data->client, |
136 | TSYS01_PROM_READ + (i << 1), |
137 | &dev_data->prom[i]); |
138 | if (ret) |
139 | return ret; |
140 | |
141 | ret = sprintf(buf: ptr, fmt: "0x%04x " , dev_data->prom[i]); |
142 | ptr += ret; |
143 | } |
144 | |
145 | if (!tsys01_crc_valid(n_prom: dev_data->prom)) { |
146 | dev_err(&indio_dev->dev, "prom crc check error\n" ); |
147 | return -ENODEV; |
148 | } |
149 | *ptr = 0; |
150 | dev_info(&indio_dev->dev, "PROM coefficients : %s\n" , buf); |
151 | |
152 | return 0; |
153 | } |
154 | |
155 | static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev) |
156 | { |
157 | int ret; |
158 | struct tsys01_dev *dev_data = iio_priv(indio_dev); |
159 | |
160 | mutex_init(&dev_data->lock); |
161 | |
162 | indio_dev->info = &tsys01_info; |
163 | indio_dev->name = dev->driver->name; |
164 | indio_dev->modes = INDIO_DIRECT_MODE; |
165 | indio_dev->channels = tsys01_channels; |
166 | indio_dev->num_channels = ARRAY_SIZE(tsys01_channels); |
167 | |
168 | ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000); |
169 | if (ret) |
170 | return ret; |
171 | |
172 | ret = tsys01_read_prom(indio_dev); |
173 | if (ret) |
174 | return ret; |
175 | |
176 | return devm_iio_device_register(dev, indio_dev); |
177 | } |
178 | |
179 | static int tsys01_i2c_probe(struct i2c_client *client) |
180 | { |
181 | struct tsys01_dev *dev_data; |
182 | struct iio_dev *indio_dev; |
183 | |
184 | if (!i2c_check_functionality(adap: client->adapter, |
185 | I2C_FUNC_SMBUS_WORD_DATA | |
186 | I2C_FUNC_SMBUS_WRITE_BYTE | |
187 | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { |
188 | dev_err(&client->dev, |
189 | "Adapter does not support some i2c transaction\n" ); |
190 | return -EOPNOTSUPP; |
191 | } |
192 | |
193 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*dev_data)); |
194 | if (!indio_dev) |
195 | return -ENOMEM; |
196 | |
197 | dev_data = iio_priv(indio_dev); |
198 | dev_data->client = client; |
199 | dev_data->reset = ms_sensors_reset; |
200 | dev_data->read_prom_word = ms_sensors_read_prom_word; |
201 | dev_data->convert_and_read = ms_sensors_convert_and_read; |
202 | |
203 | i2c_set_clientdata(client, data: indio_dev); |
204 | |
205 | return tsys01_probe(indio_dev, dev: &client->dev); |
206 | } |
207 | |
208 | static const struct i2c_device_id tsys01_id[] = { |
209 | {"tsys01" , 0}, |
210 | {} |
211 | }; |
212 | MODULE_DEVICE_TABLE(i2c, tsys01_id); |
213 | |
214 | static const struct of_device_id tsys01_of_match[] = { |
215 | { .compatible = "meas,tsys01" , }, |
216 | { }, |
217 | }; |
218 | MODULE_DEVICE_TABLE(of, tsys01_of_match); |
219 | |
220 | static struct i2c_driver tsys01_driver = { |
221 | .probe = tsys01_i2c_probe, |
222 | .id_table = tsys01_id, |
223 | .driver = { |
224 | .name = "tsys01" , |
225 | .of_match_table = tsys01_of_match, |
226 | }, |
227 | }; |
228 | |
229 | module_i2c_driver(tsys01_driver); |
230 | |
231 | MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature driver" ); |
232 | MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>" ); |
233 | MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>" ); |
234 | MODULE_LICENSE("GPL v2" ); |
235 | MODULE_IMPORT_NS(IIO_MEAS_SPEC_SENSORS); |
236 | |