iio/gyro/adis16130.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
0004  *
0005  * Copyright 2010 Analog Devices Inc.
0006  */
0007
0008 #include <linux/mutex.h>
0009 #include <linux/kernel.h>
0010 #include <linux/spi/spi.h>
0011 #include <linux/module.h>
0012
0013 #include <linux/iio/iio.h>
0014
0015 #include <asm/unaligned.h>
0016
0017 #define ADIS16130_CON         0x0
0018 #define ADIS16130_CON_RD      (1 << 6)
0019 #define ADIS16130_IOP         0x1
0020
0021 /* 1 = data-ready signal low when unread data on all channels; */
0022 #define ADIS16130_IOP_ALL_RDY (1 << 3)
0023 #define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
0024 #define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
0025 #define ADIS16130_TEMPDATA    0xA /* Temperature output */
0026 #define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
0027 #define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
0028 #define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
0029 #define ADIS16130_TEMPCS_EN   (1 << 3)
0030 #define ADIS16130_RATECONV    0x30
0031 #define ADIS16130_TEMPCONV    0x32
0032 #define ADIS16130_MODE        0x38
0033 #define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
0034
0035 /**
0036  * struct adis16130_state - device instance specific data
0037  * @us:         actual spi_device to write data
0038  * @buf_lock:       mutex to protect tx and rx
0039  * @buf:        unified tx/rx buffer
0040  **/
0041 struct adis16130_state {
0042     struct spi_device       *us;
0043     struct mutex            buf_lock;
0044     u8              buf[4] __aligned(IIO_DMA_MINALIGN);
0045 };
0046
0047 static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
0048 {
0049     int ret;
0050     struct adis16130_state *st = iio_priv(indio_dev);
0051     struct spi_transfer xfer = {
0052         .tx_buf = st->buf,
0053         .rx_buf = st->buf,
0054         .len = 4,
0055     };
0056
0057     mutex_lock(&st->buf_lock);
0058
0059     st->buf[0] = ADIS16130_CON_RD | reg_addr;
0060     st->buf[1] = st->buf[2] = st->buf[3] = 0;
0061
0062     ret = spi_sync_transfer(st->us, &xfer, 1);
0063     if (ret == 0)
0064         *val = get_unaligned_be24(&st->buf[1]);
0065     mutex_unlock(&st->buf_lock);
0066
0067     return ret;
0068 }
0069
0070 static int adis16130_read_raw(struct iio_dev *indio_dev,
0071                   struct iio_chan_spec const *chan,
0072                   int *val, int *val2,
0073                   long mask)
0074 {
0075     int ret;
0076     u32 temp;
0077
0078     switch (mask) {
0079     case IIO_CHAN_INFO_RAW:
0080         /* Take the iio_dev status lock */
0081         ret = adis16130_spi_read(indio_dev, chan->address, &temp);
0082         if (ret)
0083             return ret;
0084         *val = temp;
0085         return IIO_VAL_INT;
0086     case IIO_CHAN_INFO_SCALE:
0087         switch (chan->type) {
0088         case IIO_ANGL_VEL:
0089             /* 0 degree = 838860, 250 degree = 14260608 */
0090             *val = 250;
0091             *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
0092             return IIO_VAL_FRACTIONAL;
0093         case IIO_TEMP:
0094             /* 0C = 8036283, 105C = 9516048 */
0095             *val = 105000;
0096             *val2 = 9516048 - 8036283;
0097             return IIO_VAL_FRACTIONAL;
0098         default:
0099             return -EINVAL;
0100         }
0101     case IIO_CHAN_INFO_OFFSET:
0102         switch (chan->type) {
0103         case IIO_ANGL_VEL:
0104             *val = -8388608;
0105             return IIO_VAL_INT;
0106         case IIO_TEMP:
0107             *val = -8036283;
0108             return IIO_VAL_INT;
0109         default:
0110             return -EINVAL;
0111         }
0112     }
0113
0114     return -EINVAL;
0115 }
0116
0117 static const struct iio_chan_spec adis16130_channels[] = {
0118     {
0119         .type = IIO_ANGL_VEL,
0120         .modified = 1,
0121         .channel2 = IIO_MOD_Z,
0122         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
0123             BIT(IIO_CHAN_INFO_SCALE) |
0124             BIT(IIO_CHAN_INFO_OFFSET),
0125         .address = ADIS16130_RATEDATA,
0126     }, {
0127         .type = IIO_TEMP,
0128         .indexed = 1,
0129         .channel = 0,
0130         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
0131             BIT(IIO_CHAN_INFO_SCALE) |
0132             BIT(IIO_CHAN_INFO_OFFSET),
0133         .address = ADIS16130_TEMPDATA,
0134     }
0135 };
0136
0137 static const struct iio_info adis16130_info = {
0138     .read_raw = &adis16130_read_raw,
0139 };
0140
0141 static int adis16130_probe(struct spi_device *spi)
0142 {
0143     struct adis16130_state *st;
0144     struct iio_dev *indio_dev;
0145
0146     /* setup the industrialio driver allocated elements */
0147     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
0148     if (!indio_dev)
0149         return -ENOMEM;
0150     st = iio_priv(indio_dev);
0151     /* this is only used for removal purposes */
0152     spi_set_drvdata(spi, indio_dev);
0153     st->us = spi;
0154     mutex_init(&st->buf_lock);
0155     indio_dev->name = spi->dev.driver->name;
0156     indio_dev->channels = adis16130_channels;
0157     indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
0158     indio_dev->info = &adis16130_info;
0159     indio_dev->modes = INDIO_DIRECT_MODE;
0160
0161     return devm_iio_device_register(&spi->dev, indio_dev);
0162 }
0163
0164 static struct spi_driver adis16130_driver = {
0165     .driver = {
0166         .name = "adis16130",
0167     },
0168     .probe = adis16130_probe,
0169 };
0170 module_spi_driver(adis16130_driver);
0171
0172 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
0173 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
0174 MODULE_LICENSE("GPL v2");
0175 MODULE_ALIAS("spi:adis16130");