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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for Sensirion sdp500 and sdp510 pressure sensors4 *5 * Datasheet: https://sensirion.com/resource/datasheet/sdp6006 */7 8#include <linux/i2c.h>9#include <linux/crc8.h>10#include <linux/iio/iio.h>11#include <linux/mod_devicetable.h>12#include <linux/regulator/consumer.h>13#include <linux/unaligned.h>14 15#define SDP500_CRC8_POLYNOMIAL 0x31 /* x8+x5+x4+1 (normalized to 0x31) */16#define SDP500_READ_SIZE 317 18#define SDP500_I2C_START_MEAS 0xF119 20struct sdp500_data {21 struct device *dev;22};23 24DECLARE_CRC8_TABLE(sdp500_crc8_table);25 26static int sdp500_start_measurement(struct sdp500_data *data)27{28 struct i2c_client *client = to_i2c_client(data->dev);29 30 return i2c_smbus_write_byte(client, SDP500_I2C_START_MEAS);31}32 33static const struct iio_chan_spec sdp500_channels[] = {34 {35 .type = IIO_PRESSURE,36 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |37 BIT(IIO_CHAN_INFO_SCALE),38 },39};40 41static int sdp500_read_raw(struct iio_dev *indio_dev,42 struct iio_chan_spec const *chan,43 int *val, int *val2, long mask)44{45 int ret;46 u8 rxbuf[SDP500_READ_SIZE];47 u8 received_crc, calculated_crc;48 struct sdp500_data *data = iio_priv(indio_dev);49 struct i2c_client *client = to_i2c_client(data->dev);50 51 switch (mask) {52 case IIO_CHAN_INFO_RAW:53 ret = i2c_master_recv(client, rxbuf, SDP500_READ_SIZE);54 if (ret < 0) {55 dev_err(data->dev, "Failed to receive data");56 return ret;57 }58 if (ret != SDP500_READ_SIZE) {59 dev_err(data->dev, "Data is received wrongly");60 return -EIO;61 }62 63 received_crc = rxbuf[2];64 calculated_crc = crc8(sdp500_crc8_table, rxbuf,65 sizeof(rxbuf) - 1, 0x00);66 if (received_crc != calculated_crc) {67 dev_err(data->dev,68 "calculated crc = 0x%.2X, received 0x%.2X",69 calculated_crc, received_crc);70 return -EIO;71 }72 73 *val = get_unaligned_be16(rxbuf);74 return IIO_VAL_INT;75 case IIO_CHAN_INFO_SCALE:76 *val = 1;77 *val2 = 60;78 79 return IIO_VAL_FRACTIONAL;80 default:81 return -EINVAL;82 }83}84 85static const struct iio_info sdp500_info = {86 .read_raw = &sdp500_read_raw,87};88 89static int sdp500_probe(struct i2c_client *client)90{91 struct iio_dev *indio_dev;92 struct sdp500_data *data;93 struct device *dev = &client->dev;94 int ret;95 u8 rxbuf[SDP500_READ_SIZE];96 97 ret = devm_regulator_get_enable(dev, "vdd");98 if (ret)99 return dev_err_probe(dev, ret,100 "Failed to get and enable regulator\n");101 102 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));103 if (!indio_dev)104 return -ENOMEM;105 106 /* has to be done before the first i2c communication */107 crc8_populate_msb(sdp500_crc8_table, SDP500_CRC8_POLYNOMIAL);108 109 data = iio_priv(indio_dev);110 data->dev = dev;111 112 indio_dev->name = "sdp500";113 indio_dev->channels = sdp500_channels;114 indio_dev->info = &sdp500_info;115 indio_dev->modes = INDIO_DIRECT_MODE;116 indio_dev->num_channels = ARRAY_SIZE(sdp500_channels);117 118 ret = sdp500_start_measurement(data);119 if (ret)120 return dev_err_probe(dev, ret, "Failed to start measurement");121 122 /* First measurement is not correct, read it out to get rid of it */123 i2c_master_recv(client, rxbuf, SDP500_READ_SIZE);124 125 ret = devm_iio_device_register(dev, indio_dev);126 if (ret)127 return dev_err_probe(dev, ret, "Failed to register indio_dev");128 129 return 0;130}131 132static const struct i2c_device_id sdp500_id[] = {133 { "sdp500" },134 { }135};136MODULE_DEVICE_TABLE(i2c, sdp500_id);137 138static const struct of_device_id sdp500_of_match[] = {139 { .compatible = "sensirion,sdp500" },140 { }141};142MODULE_DEVICE_TABLE(of, sdp500_of_match);143 144static struct i2c_driver sdp500_driver = {145 .driver = {146 .name = "sensirion,sdp500",147 .of_match_table = sdp500_of_match,148 },149 .probe = sdp500_probe,150 .id_table = sdp500_id,151};152module_i2c_driver(sdp500_driver);153 154MODULE_AUTHOR("Thomas Sioutas <thomas.sioutas@prodrive-technologies.com>");155MODULE_DESCRIPTION("Driver for Sensirion SDP500 differential pressure sensor");156MODULE_LICENSE("GPL");157