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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * IIO driver for the 3-axis accelerometer Domintech DMARD09.4 *5 * Copyright (c) 2016, Jelle van der Waa <jelle@vdwaa.nl>6 */7 8#include <linux/unaligned.h>9#include <linux/module.h>10#include <linux/i2c.h>11#include <linux/iio/iio.h>12 13#define DMARD09_DRV_NAME "dmard09"14 15#define DMARD09_REG_CHIPID 0x1816#define DMARD09_REG_STAT 0x0A17#define DMARD09_REG_X 0x0C18#define DMARD09_REG_Y 0x0E19#define DMARD09_REG_Z 0x1020#define DMARD09_CHIPID 0x9521 22#define DMARD09_BUF_LEN 823#define DMARD09_AXIS_X 024#define DMARD09_AXIS_Y 125#define DMARD09_AXIS_Z 226#define DMARD09_AXIS_X_OFFSET ((DMARD09_AXIS_X + 1) * 2)27#define DMARD09_AXIS_Y_OFFSET ((DMARD09_AXIS_Y + 1) * 2)28#define DMARD09_AXIS_Z_OFFSET ((DMARD09_AXIS_Z + 1) * 2)29 30struct dmard09_data {31 struct i2c_client *client;32};33 34#define DMARD09_CHANNEL(_axis, offset) { \35 .type = IIO_ACCEL, \36 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \37 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \38 .modified = 1, \39 .address = offset, \40 .channel2 = IIO_MOD_##_axis, \41}42 43static const struct iio_chan_spec dmard09_channels[] = {44 DMARD09_CHANNEL(X, DMARD09_AXIS_X_OFFSET),45 DMARD09_CHANNEL(Y, DMARD09_AXIS_Y_OFFSET),46 DMARD09_CHANNEL(Z, DMARD09_AXIS_Z_OFFSET),47};48 49static int dmard09_read_raw(struct iio_dev *indio_dev,50 struct iio_chan_spec const *chan,51 int *val, int *val2, long mask)52{53 struct dmard09_data *data = iio_priv(indio_dev);54 u8 buf[DMARD09_BUF_LEN];55 int ret;56 s16 accel;57 58 switch (mask) {59 case IIO_CHAN_INFO_RAW:60 /*61 * Read from the DMAR09_REG_STAT register, since the chip62 * caches reads from the individual X, Y, Z registers.63 */64 ret = i2c_smbus_read_i2c_block_data(data->client,65 DMARD09_REG_STAT,66 DMARD09_BUF_LEN, buf);67 if (ret < 0) {68 dev_err(&data->client->dev, "Error reading reg %d\n",69 DMARD09_REG_STAT);70 return ret;71 }72 73 accel = get_unaligned_le16(&buf[chan->address]);74 75 /* Remove lower 3 bits and sign extend */76 accel <<= 4;77 accel >>= 7;78 79 *val = accel;80 81 return IIO_VAL_INT;82 default:83 return -EINVAL;84 }85}86 87static const struct iio_info dmard09_info = {88 .read_raw = dmard09_read_raw,89};90 91static int dmard09_probe(struct i2c_client *client)92{93 int ret;94 struct iio_dev *indio_dev;95 struct dmard09_data *data;96 97 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));98 if (!indio_dev) {99 dev_err(&client->dev, "iio allocation failed\n");100 return -ENOMEM;101 }102 103 data = iio_priv(indio_dev);104 data->client = client;105 106 ret = i2c_smbus_read_byte_data(data->client, DMARD09_REG_CHIPID);107 if (ret < 0) {108 dev_err(&client->dev, "Error reading chip id %d\n", ret);109 return ret;110 }111 112 if (ret != DMARD09_CHIPID) {113 dev_err(&client->dev, "Invalid chip id %d\n", ret);114 return -ENODEV;115 }116 117 i2c_set_clientdata(client, indio_dev);118 indio_dev->name = DMARD09_DRV_NAME;119 indio_dev->modes = INDIO_DIRECT_MODE;120 indio_dev->channels = dmard09_channels;121 indio_dev->num_channels = ARRAY_SIZE(dmard09_channels);122 indio_dev->info = &dmard09_info;123 124 return devm_iio_device_register(&client->dev, indio_dev);125}126 127static const struct i2c_device_id dmard09_id[] = {128 { "dmard09" },129 { }130};131 132MODULE_DEVICE_TABLE(i2c, dmard09_id);133 134static struct i2c_driver dmard09_driver = {135 .driver = {136 .name = DMARD09_DRV_NAME137 },138 .probe = dmard09_probe,139 .id_table = dmard09_id,140};141 142module_i2c_driver(dmard09_driver);143 144MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");145MODULE_DESCRIPTION("DMARD09 3-axis accelerometer driver");146MODULE_LICENSE("GPL");147