1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * t5403.c - Support for EPCOS T5403 pressure/temperature sensor
4 *
5 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
6 *
7 * (7-bit I2C slave address 0x77)
8 *
9 * TODO: end-of-conversion irq
10 */
11
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/delay.h>
17
18 #define T5403_DATA 0xf5 /* data, LSB first, 16 bit */
19 #define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */
20 #define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */
21 #define T5403_COMMAND 0xf1
22
23 /* command bits */
24 #define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */
25 #define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */
26 #define T5403_SCO BIT(0) /* start conversion */
27
28 #define T5403_MODE_LOW 0
29 #define T5403_MODE_STANDARD 1
30 #define T5403_MODE_HIGH 2
31 #define T5403_MODE_ULTRA_HIGH 3
32
33 #define T5403_I2C_MASK (~BIT(7))
34 #define T5403_I2C_ADDR 0x77
35
36 static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66};
37
38 struct t5403_data {
39 struct i2c_client *client;
40 struct mutex lock;
41 int mode;
42 __le16 c[10];
43 };
44
45 #define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1])
46 #define T5403_C(i) sign_extend32(T5403_C_U16(i), 15)
47
t5403_read(struct t5403_data * data,bool pressure)48 static int t5403_read(struct t5403_data *data, bool pressure)
49 {
50 int wait_time = 3; /* wakeup time in ms */
51
52 int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND,
53 (pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) |
54 T5403_SCO);
55 if (ret < 0)
56 return ret;
57
58 wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2;
59
60 msleep(wait_time);
61
62 return i2c_smbus_read_word_data(data->client, T5403_DATA);
63 }
64
t5403_comp_pressure(struct t5403_data * data,int * val,int * val2)65 static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2)
66 {
67 int ret;
68 s16 t_r;
69 u16 p_r;
70 s32 S, O, X;
71
72 mutex_lock(&data->lock);
73
74 ret = t5403_read(data, false);
75 if (ret < 0)
76 goto done;
77 t_r = ret;
78
79 ret = t5403_read(data, true);
80 if (ret < 0)
81 goto done;
82 p_r = ret;
83
84 /* see EPCOS application note */
85 S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 +
86 T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 +
87 T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000;
88
89 O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 +
90 T5403_C(8) * t_r / 0x8000 * t_r / 16 +
91 T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r;
92
93 X = (S * p_r + O) / 0x4000;
94
95 X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) *
96 T5403_C(10) / 0x10000;
97
98 *val = X / 1000;
99 *val2 = (X % 1000) * 1000;
100
101 done:
102 mutex_unlock(&data->lock);
103 return ret;
104 }
105
t5403_comp_temp(struct t5403_data * data,int * val)106 static int t5403_comp_temp(struct t5403_data *data, int *val)
107 {
108 int ret;
109 s16 t_r;
110
111 mutex_lock(&data->lock);
112 ret = t5403_read(data, false);
113 if (ret < 0)
114 goto done;
115 t_r = ret;
116
117 /* see EPCOS application note */
118 *val = ((s32) T5403_C_U16(1) * t_r / 0x100 +
119 (s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000;
120
121 done:
122 mutex_unlock(&data->lock);
123 return ret;
124 }
125
t5403_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)126 static int t5403_read_raw(struct iio_dev *indio_dev,
127 struct iio_chan_spec const *chan,
128 int *val, int *val2, long mask)
129 {
130 struct t5403_data *data = iio_priv(indio_dev);
131 int ret;
132
133 switch (mask) {
134 case IIO_CHAN_INFO_PROCESSED:
135 switch (chan->type) {
136 case IIO_PRESSURE:
137 ret = t5403_comp_pressure(data, val, val2);
138 if (ret < 0)
139 return ret;
140 return IIO_VAL_INT_PLUS_MICRO;
141 case IIO_TEMP:
142 ret = t5403_comp_temp(data, val);
143 if (ret < 0)
144 return ret;
145 return IIO_VAL_INT;
146 default:
147 return -EINVAL;
148 }
149 case IIO_CHAN_INFO_INT_TIME:
150 *val = 0;
151 *val2 = t5403_pressure_conv_ms[data->mode] * 1000;
152 return IIO_VAL_INT_PLUS_MICRO;
153 default:
154 return -EINVAL;
155 }
156 }
157
t5403_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)158 static int t5403_write_raw(struct iio_dev *indio_dev,
159 struct iio_chan_spec const *chan,
160 int val, int val2, long mask)
161 {
162 struct t5403_data *data = iio_priv(indio_dev);
163 int i;
164
165 switch (mask) {
166 case IIO_CHAN_INFO_INT_TIME:
167 if (val != 0)
168 return -EINVAL;
169 for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++)
170 if (val2 == t5403_pressure_conv_ms[i] * 1000) {
171 mutex_lock(&data->lock);
172 data->mode = i;
173 mutex_unlock(&data->lock);
174 return 0;
175 }
176 return -EINVAL;
177 default:
178 return -EINVAL;
179 }
180 }
181
182 static const struct iio_chan_spec t5403_channels[] = {
183 {
184 .type = IIO_PRESSURE,
185 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
186 BIT(IIO_CHAN_INFO_INT_TIME),
187 },
188 {
189 .type = IIO_TEMP,
190 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
191 },
192 };
193
194 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066");
195
196 static struct attribute *t5403_attributes[] = {
197 &iio_const_attr_integration_time_available.dev_attr.attr,
198 NULL
199 };
200
201 static const struct attribute_group t5403_attribute_group = {
202 .attrs = t5403_attributes,
203 };
204
205 static const struct iio_info t5403_info = {
206 .read_raw = &t5403_read_raw,
207 .write_raw = &t5403_write_raw,
208 .attrs = &t5403_attribute_group,
209 };
210
t5403_probe(struct i2c_client * client)211 static int t5403_probe(struct i2c_client *client)
212 {
213 const struct i2c_device_id *id = i2c_client_get_device_id(client);
214 struct t5403_data *data;
215 struct iio_dev *indio_dev;
216 int ret;
217
218 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
219 I2C_FUNC_SMBUS_I2C_BLOCK))
220 return -EOPNOTSUPP;
221
222 ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR);
223 if (ret < 0)
224 return ret;
225 if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR)
226 return -ENODEV;
227
228 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
229 if (!indio_dev)
230 return -ENOMEM;
231
232 data = iio_priv(indio_dev);
233 data->client = client;
234 mutex_init(&data->lock);
235
236 i2c_set_clientdata(client, indio_dev);
237 indio_dev->info = &t5403_info;
238 indio_dev->name = id->name;
239 indio_dev->modes = INDIO_DIRECT_MODE;
240 indio_dev->channels = t5403_channels;
241 indio_dev->num_channels = ARRAY_SIZE(t5403_channels);
242
243 data->mode = T5403_MODE_STANDARD;
244
245 ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA,
246 sizeof(data->c), (u8 *) data->c);
247 if (ret < 0)
248 return ret;
249
250 return devm_iio_device_register(&client->dev, indio_dev);
251 }
252
253 static const struct i2c_device_id t5403_id[] = {
254 { "t5403", 0 },
255 { }
256 };
257 MODULE_DEVICE_TABLE(i2c, t5403_id);
258
259 static struct i2c_driver t5403_driver = {
260 .driver = {
261 .name = "t5403",
262 },
263 .probe = t5403_probe,
264 .id_table = t5403_id,
265 };
266 module_i2c_driver(t5403_driver);
267
268 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
269 MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver");
270 MODULE_LICENSE("GPL");
271