1 /* 2 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver 3 * 4 * Copyright 2010 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/mutex.h> 10 #include <linux/kernel.h> 11 #include <linux/spi/spi.h> 12 #include <linux/module.h> 13 14 #include <linux/iio/iio.h> 15 16 #define ADIS16130_CON 0x0 17 #define ADIS16130_CON_RD (1 << 6) 18 #define ADIS16130_IOP 0x1 19 20 /* 1 = data-ready signal low when unread data on all channels; */ 21 #define ADIS16130_IOP_ALL_RDY (1 << 3) 22 #define ADIS16130_IOP_SYNC (1 << 0) /* 1 = synchronization enabled */ 23 #define ADIS16130_RATEDATA 0x8 /* Gyroscope output, rate of rotation */ 24 #define ADIS16130_TEMPDATA 0xA /* Temperature output */ 25 #define ADIS16130_RATECS 0x28 /* Gyroscope channel setup */ 26 #define ADIS16130_RATECS_EN (1 << 3) /* 1 = channel enable; */ 27 #define ADIS16130_TEMPCS 0x2A /* Temperature channel setup */ 28 #define ADIS16130_TEMPCS_EN (1 << 3) 29 #define ADIS16130_RATECONV 0x30 30 #define ADIS16130_TEMPCONV 0x32 31 #define ADIS16130_MODE 0x38 32 #define ADIS16130_MODE_24BIT (1 << 1) /* 1 = 24-bit resolution; */ 33 34 /** 35 * struct adis16130_state - device instance specific data 36 * @us: actual spi_device to write data 37 * @buf_lock: mutex to protect tx and rx 38 * @buf: unified tx/rx buffer 39 **/ 40 struct adis16130_state { 41 struct spi_device *us; 42 struct mutex buf_lock; 43 u8 buf[4] ____cacheline_aligned; 44 }; 45 46 static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val) 47 { 48 int ret; 49 struct adis16130_state *st = iio_priv(indio_dev); 50 struct spi_transfer xfer = { 51 .tx_buf = st->buf, 52 .rx_buf = st->buf, 53 .len = 4, 54 }; 55 56 mutex_lock(&st->buf_lock); 57 58 st->buf[0] = ADIS16130_CON_RD | reg_addr; 59 st->buf[1] = st->buf[2] = st->buf[3] = 0; 60 61 ret = spi_sync_transfer(st->us, &xfer, 1); 62 if (ret == 0) 63 *val = (st->buf[1] << 16) | (st->buf[2] << 8) | st->buf[3]; 64 mutex_unlock(&st->buf_lock); 65 66 return ret; 67 } 68 69 static int adis16130_read_raw(struct iio_dev *indio_dev, 70 struct iio_chan_spec const *chan, 71 int *val, int *val2, 72 long mask) 73 { 74 int ret; 75 u32 temp; 76 77 switch (mask) { 78 case IIO_CHAN_INFO_RAW: 79 /* Take the iio_dev status lock */ 80 mutex_lock(&indio_dev->mlock); 81 ret = adis16130_spi_read(indio_dev, chan->address, &temp); 82 mutex_unlock(&indio_dev->mlock); 83 if (ret) 84 return ret; 85 *val = temp; 86 return IIO_VAL_INT; 87 case IIO_CHAN_INFO_SCALE: 88 switch (chan->type) { 89 case IIO_ANGL_VEL: 90 /* 0 degree = 838860, 250 degree = 14260608 */ 91 *val = 250; 92 *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */ 93 return IIO_VAL_FRACTIONAL; 94 case IIO_TEMP: 95 /* 0C = 8036283, 105C = 9516048 */ 96 *val = 105000; 97 *val2 = 9516048 - 8036283; 98 return IIO_VAL_FRACTIONAL; 99 default: 100 return -EINVAL; 101 } 102 case IIO_CHAN_INFO_OFFSET: 103 switch (chan->type) { 104 case IIO_ANGL_VEL: 105 *val = -8388608; 106 return IIO_VAL_INT; 107 case IIO_TEMP: 108 *val = -8036283; 109 return IIO_VAL_INT; 110 default: 111 return -EINVAL; 112 } 113 } 114 115 return -EINVAL; 116 } 117 118 static const struct iio_chan_spec adis16130_channels[] = { 119 { 120 .type = IIO_ANGL_VEL, 121 .modified = 1, 122 .channel2 = IIO_MOD_Z, 123 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 124 BIT(IIO_CHAN_INFO_SCALE) | 125 BIT(IIO_CHAN_INFO_OFFSET), 126 .address = ADIS16130_RATEDATA, 127 }, { 128 .type = IIO_TEMP, 129 .indexed = 1, 130 .channel = 0, 131 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 132 BIT(IIO_CHAN_INFO_SCALE) | 133 BIT(IIO_CHAN_INFO_OFFSET), 134 .address = ADIS16130_TEMPDATA, 135 } 136 }; 137 138 static const struct iio_info adis16130_info = { 139 .read_raw = &adis16130_read_raw, 140 .driver_module = THIS_MODULE, 141 }; 142 143 static int adis16130_probe(struct spi_device *spi) 144 { 145 struct adis16130_state *st; 146 struct iio_dev *indio_dev; 147 148 /* setup the industrialio driver allocated elements */ 149 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 150 if (!indio_dev) 151 return -ENOMEM; 152 st = iio_priv(indio_dev); 153 /* this is only used for removal purposes */ 154 spi_set_drvdata(spi, indio_dev); 155 st->us = spi; 156 mutex_init(&st->buf_lock); 157 indio_dev->name = spi->dev.driver->name; 158 indio_dev->channels = adis16130_channels; 159 indio_dev->num_channels = ARRAY_SIZE(adis16130_channels); 160 indio_dev->dev.parent = &spi->dev; 161 indio_dev->info = &adis16130_info; 162 indio_dev->modes = INDIO_DIRECT_MODE; 163 164 return devm_iio_device_register(&spi->dev, indio_dev); 165 } 166 167 static struct spi_driver adis16130_driver = { 168 .driver = { 169 .name = "adis16130", 170 }, 171 .probe = adis16130_probe, 172 }; 173 module_spi_driver(adis16130_driver); 174 175 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); 176 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate"); 177 MODULE_LICENSE("GPL v2"); 178 MODULE_ALIAS("spi:adis16130"); 179