xref: /openbmc/linux/drivers/iio/gyro/adis16080.c (revision fb574682)
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  * @lock		lock to protect buffer during reads
42  **/
43 struct adis16080_state {
44 	struct spi_device		*us;
45 	const struct adis16080_chip_info *info;
46 	struct mutex			lock;
47 
48 	__be16 buf ____cacheline_aligned;
49 };
50 
51 static int adis16080_read_sample(struct iio_dev *indio_dev,
52 		u16 addr, int *val)
53 {
54 	struct adis16080_state *st = iio_priv(indio_dev);
55 	int ret;
56 	struct spi_transfer	t[] = {
57 		{
58 			.tx_buf		= &st->buf,
59 			.len		= 2,
60 			.cs_change	= 1,
61 		}, {
62 			.rx_buf		= &st->buf,
63 			.len		= 2,
64 		},
65 	};
66 
67 	st->buf = cpu_to_be16(addr | ADIS16080_DIN_WRITE);
68 
69 	ret = spi_sync_transfer(st->us, t, ARRAY_SIZE(t));
70 	if (ret == 0)
71 		*val = sign_extend32(be16_to_cpu(st->buf), 11);
72 
73 	return ret;
74 }
75 
76 static int adis16080_read_raw(struct iio_dev *indio_dev,
77 			     struct iio_chan_spec const *chan,
78 			     int *val,
79 			     int *val2,
80 			     long mask)
81 {
82 	struct adis16080_state *st = iio_priv(indio_dev);
83 	int ret;
84 
85 	switch (mask) {
86 	case IIO_CHAN_INFO_RAW:
87 		mutex_lock(&st->lock);
88 		ret = adis16080_read_sample(indio_dev, chan->address, val);
89 		mutex_unlock(&st->lock);
90 		return ret ? ret : IIO_VAL_INT;
91 	case IIO_CHAN_INFO_SCALE:
92 		switch (chan->type) {
93 		case IIO_ANGL_VEL:
94 			*val = st->info->scale_val;
95 			*val2 = st->info->scale_val2;
96 			return IIO_VAL_FRACTIONAL;
97 		case IIO_VOLTAGE:
98 			/* VREF = 5V, 12 bits */
99 			*val = 5000;
100 			*val2 = 12;
101 			return IIO_VAL_FRACTIONAL_LOG2;
102 		case IIO_TEMP:
103 			/* 85 C = 585, 25 C = 0 */
104 			*val = 85000 - 25000;
105 			*val2 = 585;
106 			return IIO_VAL_FRACTIONAL;
107 		default:
108 			return -EINVAL;
109 		}
110 	case IIO_CHAN_INFO_OFFSET:
111 		switch (chan->type) {
112 		case IIO_VOLTAGE:
113 			/* 2.5 V = 0 */
114 			*val = 2048;
115 			return IIO_VAL_INT;
116 		case IIO_TEMP:
117 			/* 85 C = 585, 25 C = 0 */
118 			*val = DIV_ROUND_CLOSEST(25 * 585, 85 - 25);
119 			return IIO_VAL_INT;
120 		default:
121 			return -EINVAL;
122 		}
123 	default:
124 		break;
125 	}
126 
127 	return -EINVAL;
128 }
129 
130 static const struct iio_chan_spec adis16080_channels[] = {
131 	{
132 		.type = IIO_ANGL_VEL,
133 		.modified = 1,
134 		.channel2 = IIO_MOD_Z,
135 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
136 			BIT(IIO_CHAN_INFO_SCALE),
137 		.address = ADIS16080_DIN_GYRO,
138 	}, {
139 		.type = IIO_VOLTAGE,
140 		.indexed = 1,
141 		.channel = 0,
142 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
143 			BIT(IIO_CHAN_INFO_SCALE) |
144 			BIT(IIO_CHAN_INFO_OFFSET),
145 		.address = ADIS16080_DIN_AIN1,
146 	}, {
147 		.type = IIO_VOLTAGE,
148 		.indexed = 1,
149 		.channel = 1,
150 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
151 			BIT(IIO_CHAN_INFO_SCALE) |
152 			BIT(IIO_CHAN_INFO_OFFSET),
153 		.address = ADIS16080_DIN_AIN2,
154 	}, {
155 		.type = IIO_TEMP,
156 		.indexed = 1,
157 		.channel = 0,
158 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
159 			BIT(IIO_CHAN_INFO_SCALE) |
160 			BIT(IIO_CHAN_INFO_OFFSET),
161 		.address = ADIS16080_DIN_TEMP,
162 	}
163 };
164 
165 static const struct iio_info adis16080_info = {
166 	.read_raw = &adis16080_read_raw,
167 };
168 
169 enum {
170 	ID_ADIS16080,
171 	ID_ADIS16100,
172 };
173 
174 static const struct adis16080_chip_info adis16080_chip_info[] = {
175 	[ID_ADIS16080] = {
176 		/* 80 degree = 819, 819 rad = 46925 degree */
177 		.scale_val = 80,
178 		.scale_val2 = 46925,
179 	},
180 	[ID_ADIS16100] = {
181 		/* 300 degree = 1230, 1230 rad = 70474 degree */
182 		.scale_val = 300,
183 		.scale_val2 = 70474,
184 	},
185 };
186 
187 static int adis16080_probe(struct spi_device *spi)
188 {
189 	const struct spi_device_id *id = spi_get_device_id(spi);
190 	struct adis16080_state *st;
191 	struct iio_dev *indio_dev;
192 
193 	/* setup the industrialio driver allocated elements */
194 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
195 	if (!indio_dev)
196 		return -ENOMEM;
197 	st = iio_priv(indio_dev);
198 	/* this is only used for removal purposes */
199 	spi_set_drvdata(spi, indio_dev);
200 
201 	mutex_init(&st->lock);
202 
203 	/* Allocate the comms buffers */
204 	st->us = spi;
205 	st->info = &adis16080_chip_info[id->driver_data];
206 
207 	indio_dev->name = spi->dev.driver->name;
208 	indio_dev->channels = adis16080_channels;
209 	indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
210 	indio_dev->dev.parent = &spi->dev;
211 	indio_dev->info = &adis16080_info;
212 	indio_dev->modes = INDIO_DIRECT_MODE;
213 
214 	return iio_device_register(indio_dev);
215 }
216 
217 static int adis16080_remove(struct spi_device *spi)
218 {
219 	iio_device_unregister(spi_get_drvdata(spi));
220 	return 0;
221 }
222 
223 static const struct spi_device_id adis16080_ids[] = {
224 	{ "adis16080", ID_ADIS16080 },
225 	{ "adis16100", ID_ADIS16100 },
226 	{},
227 };
228 MODULE_DEVICE_TABLE(spi, adis16080_ids);
229 
230 static struct spi_driver adis16080_driver = {
231 	.driver = {
232 		.name = "adis16080",
233 	},
234 	.probe = adis16080_probe,
235 	.remove = adis16080_remove,
236 	.id_table = adis16080_ids,
237 };
238 module_spi_driver(adis16080_driver);
239 
240 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
241 MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
242 MODULE_LICENSE("GPL v2");
243