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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Copyright (C) 2021 Analog Devices, Inc.4 * Author: Cosmin Tanislav <cosmin.tanislav@analog.com>5 */6 7#include <linux/mod_devicetable.h>8#include <linux/module.h>9#include <linux/regmap.h>10#include <linux/spi/spi.h>11 12#include <linux/iio/iio.h>13 14#include "adxl367.h"15 16#define ADXL367_SPI_WRITE_COMMAND 0x0A17#define ADXL367_SPI_READ_COMMAND 0x0B18#define ADXL367_SPI_FIFO_COMMAND 0x0D19 20struct adxl367_spi_state {21 struct spi_device *spi;22 23 struct spi_message reg_write_msg;24 struct spi_transfer reg_write_xfer[2];25 26 struct spi_message reg_read_msg;27 struct spi_transfer reg_read_xfer[2];28 29 struct spi_message fifo_msg;30 struct spi_transfer fifo_xfer[2];31 32 /*33 * DMA (thus cache coherency maintenance) may require the34 * transfer buffers live in their own cache lines.35 */36 u8 reg_write_tx_buf[1] __aligned(IIO_DMA_MINALIGN);37 u8 reg_read_tx_buf[2];38 u8 fifo_tx_buf[1];39};40 41static int adxl367_read_fifo(void *context, __be16 *fifo_buf,42 unsigned int fifo_entries)43{44 struct adxl367_spi_state *st = context;45 46 st->fifo_xfer[1].rx_buf = fifo_buf;47 st->fifo_xfer[1].len = fifo_entries * sizeof(*fifo_buf);48 49 return spi_sync(st->spi, &st->fifo_msg);50}51 52static int adxl367_read(void *context, const void *reg_buf, size_t reg_size,53 void *val_buf, size_t val_size)54{55 struct adxl367_spi_state *st = context;56 u8 reg = ((const u8 *)reg_buf)[0];57 58 st->reg_read_tx_buf[1] = reg;59 st->reg_read_xfer[1].rx_buf = val_buf;60 st->reg_read_xfer[1].len = val_size;61 62 return spi_sync(st->spi, &st->reg_read_msg);63}64 65static int adxl367_write(void *context, const void *val_buf, size_t val_size)66{67 struct adxl367_spi_state *st = context;68 69 st->reg_write_xfer[1].tx_buf = val_buf;70 st->reg_write_xfer[1].len = val_size;71 72 return spi_sync(st->spi, &st->reg_write_msg);73}74 75static const struct regmap_bus adxl367_spi_regmap_bus = {76 .read = adxl367_read,77 .write = adxl367_write,78};79 80static const struct regmap_config adxl367_spi_regmap_config = {81 .reg_bits = 8,82 .val_bits = 8,83};84 85static const struct adxl367_ops adxl367_spi_ops = {86 .read_fifo = adxl367_read_fifo,87};88 89static int adxl367_spi_probe(struct spi_device *spi)90{91 struct adxl367_spi_state *st;92 struct regmap *regmap;93 94 st = devm_kzalloc(&spi->dev, sizeof(*st), GFP_KERNEL);95 if (!st)96 return -ENOMEM;97 98 st->spi = spi;99 100 /*101 * Xfer: [XFR1] [ XFR2 ]102 * Master: 0x0A ADDR DATA0 DATA1 ... DATAN103 * Slave: .... ..........................104 */105 st->reg_write_tx_buf[0] = ADXL367_SPI_WRITE_COMMAND;106 st->reg_write_xfer[0].tx_buf = st->reg_write_tx_buf;107 st->reg_write_xfer[0].len = sizeof(st->reg_write_tx_buf);108 spi_message_init_with_transfers(&st->reg_write_msg,109 st->reg_write_xfer, 2);110 111 /*112 * Xfer: [ XFR1 ] [ XFR2 ]113 * Master: 0x0B ADDR .....................114 * Slave: ......... DATA0 DATA1 ... DATAN115 */116 st->reg_read_tx_buf[0] = ADXL367_SPI_READ_COMMAND;117 st->reg_read_xfer[0].tx_buf = st->reg_read_tx_buf;118 st->reg_read_xfer[0].len = sizeof(st->reg_read_tx_buf);119 spi_message_init_with_transfers(&st->reg_read_msg,120 st->reg_read_xfer, 2);121 122 /*123 * Xfer: [XFR1] [ XFR2 ]124 * Master: 0x0D .....................125 * Slave: .... DATA0 DATA1 ... DATAN126 */127 st->fifo_tx_buf[0] = ADXL367_SPI_FIFO_COMMAND;128 st->fifo_xfer[0].tx_buf = st->fifo_tx_buf;129 st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf);130 spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer, 2);131 132 regmap = devm_regmap_init(&spi->dev, &adxl367_spi_regmap_bus, st,133 &adxl367_spi_regmap_config);134 if (IS_ERR(regmap))135 return PTR_ERR(regmap);136 137 return adxl367_probe(&spi->dev, &adxl367_spi_ops, st, regmap, spi->irq);138}139 140static const struct spi_device_id adxl367_spi_id[] = {141 { "adxl367", 0 },142 { },143};144MODULE_DEVICE_TABLE(spi, adxl367_spi_id);145 146static const struct of_device_id adxl367_of_match[] = {147 { .compatible = "adi,adxl367" },148 { },149};150MODULE_DEVICE_TABLE(of, adxl367_of_match);151 152static struct spi_driver adxl367_spi_driver = {153 .driver = {154 .name = "adxl367_spi",155 .of_match_table = adxl367_of_match,156 },157 .probe = adxl367_spi_probe,158 .id_table = adxl367_spi_id,159};160 161module_spi_driver(adxl367_spi_driver);162 163MODULE_IMPORT_NS(IIO_ADXL367);164MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");165MODULE_DESCRIPTION("Analog Devices ADXL367 3-axis accelerometer SPI driver");166MODULE_LICENSE("GPL");167