xref: /openbmc/linux/drivers/iio/gyro/adis16080.c (revision 03638e62)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ADIS16080/100 Yaw Rate Gyroscope with SPI driver
4  *
5  * Copyright 2010 Analog Devices Inc.
6  */
7 #include <linux/delay.h>
8 #include <linux/mutex.h>
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/spi/spi.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/module.h>
15 
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 
19 #define ADIS16080_DIN_GYRO   (0 << 10) /* Gyroscope output */
20 #define ADIS16080_DIN_TEMP   (1 << 10) /* Temperature output */
21 #define ADIS16080_DIN_AIN1   (2 << 10)
22 #define ADIS16080_DIN_AIN2   (3 << 10)
23 
24 /*
25  * 1: Write contents on DIN to control register.
26  * 0: No changes to control register.
27  */
28 
29 #define ADIS16080_DIN_WRITE  (1 << 15)
30 
31 struct adis16080_chip_info {
32 	int scale_val;
33 	int scale_val2;
34 };
35 
36 /**
37  * struct adis16080_state - device instance specific data
38  * @us:			actual spi_device to write data
39  * @info:		chip specific parameters
40  * @buf:		transmit or receive buffer
41  **/
42 struct adis16080_state {
43 	struct spi_device		*us;
44 	const struct adis16080_chip_info *info;
45 
46 	__be16 buf ____cacheline_aligned;
47 };
48 
49 static int adis16080_read_sample(struct iio_dev *indio_dev,
50 		u16 addr, int *val)
51 {
52 	struct adis16080_state *st = iio_priv(indio_dev);
53 	int ret;
54 	struct spi_transfer	t[] = {
55 		{
56 			.tx_buf		= &st->buf,
57 			.len		= 2,
58 			.cs_change	= 1,
59 		}, {
60 			.rx_buf		= &st->buf,
61 			.len		= 2,
62 		},
63 	};
64 
65 	st->buf = cpu_to_be16(addr | ADIS16080_DIN_WRITE);
66 
67 	ret = spi_sync_transfer(st->us, t, ARRAY_SIZE(t));
68 	if (ret == 0)
69 		*val = sign_extend32(be16_to_cpu(st->buf), 11);
70 
71 	return ret;
72 }
73 
74 static int adis16080_read_raw(struct iio_dev *indio_dev,
75 			     struct iio_chan_spec const *chan,
76 			     int *val,
77 			     int *val2,
78 			     long mask)
79 {
80 	struct adis16080_state *st = iio_priv(indio_dev);
81 	int ret;
82 
83 	switch (mask) {
84 	case IIO_CHAN_INFO_RAW:
85 		mutex_lock(&indio_dev->mlock);
86 		ret = adis16080_read_sample(indio_dev, chan->address, val);
87 		mutex_unlock(&indio_dev->mlock);
88 		return ret ? ret : IIO_VAL_INT;
89 	case IIO_CHAN_INFO_SCALE:
90 		switch (chan->type) {
91 		case IIO_ANGL_VEL:
92 			*val = st->info->scale_val;
93 			*val2 = st->info->scale_val2;
94 			return IIO_VAL_FRACTIONAL;
95 		case IIO_VOLTAGE:
96 			/* VREF = 5V, 12 bits */
97 			*val = 5000;
98 			*val2 = 12;
99 			return IIO_VAL_FRACTIONAL_LOG2;
100 		case IIO_TEMP:
101 			/* 85 C = 585, 25 C = 0 */
102 			*val = 85000 - 25000;
103 			*val2 = 585;
104 			return IIO_VAL_FRACTIONAL;
105 		default:
106 			return -EINVAL;
107 		}
108 	case IIO_CHAN_INFO_OFFSET:
109 		switch (chan->type) {
110 		case IIO_VOLTAGE:
111 			/* 2.5 V = 0 */
112 			*val = 2048;
113 			return IIO_VAL_INT;
114 		case IIO_TEMP:
115 			/* 85 C = 585, 25 C = 0 */
116 			*val = DIV_ROUND_CLOSEST(25 * 585, 85 - 25);
117 			return IIO_VAL_INT;
118 		default:
119 			return -EINVAL;
120 		}
121 	default:
122 		break;
123 	}
124 
125 	return -EINVAL;
126 }
127 
128 static const struct iio_chan_spec adis16080_channels[] = {
129 	{
130 		.type = IIO_ANGL_VEL,
131 		.modified = 1,
132 		.channel2 = IIO_MOD_Z,
133 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
134 			BIT(IIO_CHAN_INFO_SCALE),
135 		.address = ADIS16080_DIN_GYRO,
136 	}, {
137 		.type = IIO_VOLTAGE,
138 		.indexed = 1,
139 		.channel = 0,
140 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
141 			BIT(IIO_CHAN_INFO_SCALE) |
142 			BIT(IIO_CHAN_INFO_OFFSET),
143 		.address = ADIS16080_DIN_AIN1,
144 	}, {
145 		.type = IIO_VOLTAGE,
146 		.indexed = 1,
147 		.channel = 1,
148 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
149 			BIT(IIO_CHAN_INFO_SCALE) |
150 			BIT(IIO_CHAN_INFO_OFFSET),
151 		.address = ADIS16080_DIN_AIN2,
152 	}, {
153 		.type = IIO_TEMP,
154 		.indexed = 1,
155 		.channel = 0,
156 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
157 			BIT(IIO_CHAN_INFO_SCALE) |
158 			BIT(IIO_CHAN_INFO_OFFSET),
159 		.address = ADIS16080_DIN_TEMP,
160 	}
161 };
162 
163 static const struct iio_info adis16080_info = {
164 	.read_raw = &adis16080_read_raw,
165 };
166 
167 enum {
168 	ID_ADIS16080,
169 	ID_ADIS16100,
170 };
171 
172 static const struct adis16080_chip_info adis16080_chip_info[] = {
173 	[ID_ADIS16080] = {
174 		/* 80 degree = 819, 819 rad = 46925 degree */
175 		.scale_val = 80,
176 		.scale_val2 = 46925,
177 	},
178 	[ID_ADIS16100] = {
179 		/* 300 degree = 1230, 1230 rad = 70474 degree */
180 		.scale_val = 300,
181 		.scale_val2 = 70474,
182 	},
183 };
184 
185 static int adis16080_probe(struct spi_device *spi)
186 {
187 	const struct spi_device_id *id = spi_get_device_id(spi);
188 	struct adis16080_state *st;
189 	struct iio_dev *indio_dev;
190 
191 	/* setup the industrialio driver allocated elements */
192 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
193 	if (!indio_dev)
194 		return -ENOMEM;
195 	st = iio_priv(indio_dev);
196 	/* this is only used for removal purposes */
197 	spi_set_drvdata(spi, indio_dev);
198 
199 	/* Allocate the comms buffers */
200 	st->us = spi;
201 	st->info = &adis16080_chip_info[id->driver_data];
202 
203 	indio_dev->name = spi->dev.driver->name;
204 	indio_dev->channels = adis16080_channels;
205 	indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
206 	indio_dev->dev.parent = &spi->dev;
207 	indio_dev->info = &adis16080_info;
208 	indio_dev->modes = INDIO_DIRECT_MODE;
209 
210 	return iio_device_register(indio_dev);
211 }
212 
213 static int adis16080_remove(struct spi_device *spi)
214 {
215 	iio_device_unregister(spi_get_drvdata(spi));
216 	return 0;
217 }
218 
219 static const struct spi_device_id adis16080_ids[] = {
220 	{ "adis16080", ID_ADIS16080 },
221 	{ "adis16100", ID_ADIS16100 },
222 	{},
223 };
224 MODULE_DEVICE_TABLE(spi, adis16080_ids);
225 
226 static struct spi_driver adis16080_driver = {
227 	.driver = {
228 		.name = "adis16080",
229 	},
230 	.probe = adis16080_probe,
231 	.remove = adis16080_remove,
232 	.id_table = adis16080_ids,
233 };
234 module_spi_driver(adis16080_driver);
235 
236 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
237 MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
238 MODULE_LICENSE("GPL v2");
239