1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2021 Analog Devices, Inc.
4 * Author: Cosmin Tanislav <cosmin.tanislav@analog.com>
7 #include <linux/mod_devicetable.h>
8 #include <linux/module.h>
9 #include <linux/regmap.h>
10 #include <linux/spi/spi.h>
14 #define ADXL367_SPI_WRITE_COMMAND 0x0A
15 #define ADXL367_SPI_READ_COMMAND 0x0B
16 #define ADXL367_SPI_FIFO_COMMAND 0x0D
18 struct adxl367_spi_state {
19 struct spi_device *spi;
21 struct spi_message reg_write_msg;
22 struct spi_transfer reg_write_xfer[2];
24 struct spi_message reg_read_msg;
25 struct spi_transfer reg_read_xfer[2];
27 struct spi_message fifo_msg;
28 struct spi_transfer fifo_xfer[2];
31 * DMA (thus cache coherency maintenance) requires the
32 * transfer buffers to live in their own cache lines.
34 u8 reg_write_tx_buf[1] ____cacheline_aligned;
35 u8 reg_read_tx_buf[2];
39 static int adxl367_read_fifo(void *context, __be16 *fifo_buf,
40 unsigned int fifo_entries)
42 struct adxl367_spi_state *st = context;
44 st->fifo_xfer[1].rx_buf = fifo_buf;
45 st->fifo_xfer[1].len = fifo_entries * sizeof(*fifo_buf);
47 return spi_sync(st->spi, &st->fifo_msg);
50 static int adxl367_read(void *context, const void *reg_buf, size_t reg_size,
51 void *val_buf, size_t val_size)
53 struct adxl367_spi_state *st = context;
54 u8 reg = ((const u8 *)reg_buf)[0];
56 st->reg_read_tx_buf[1] = reg;
57 st->reg_read_xfer[1].rx_buf = val_buf;
58 st->reg_read_xfer[1].len = val_size;
60 return spi_sync(st->spi, &st->reg_read_msg);
63 static int adxl367_write(void *context, const void *val_buf, size_t val_size)
65 struct adxl367_spi_state *st = context;
67 st->reg_write_xfer[1].tx_buf = val_buf;
68 st->reg_write_xfer[1].len = val_size;
70 return spi_sync(st->spi, &st->reg_write_msg);
73 static struct regmap_bus adxl367_spi_regmap_bus = {
75 .write = adxl367_write,
78 static const struct regmap_config adxl367_spi_regmap_config = {
83 static const struct adxl367_ops adxl367_spi_ops = {
84 .read_fifo = adxl367_read_fifo,
87 static int adxl367_spi_probe(struct spi_device *spi)
89 struct adxl367_spi_state *st;
90 struct regmap *regmap;
92 st = devm_kzalloc(&spi->dev, sizeof(*st), GFP_KERNEL);
99 * Xfer: [XFR1] [ XFR2 ]
100 * Master: 0x0A ADDR DATA0 DATA1 ... DATAN
101 * Slave: .... ..........................
103 st->reg_write_tx_buf[0] = ADXL367_SPI_WRITE_COMMAND;
104 st->reg_write_xfer[0].tx_buf = st->reg_write_tx_buf;
105 st->reg_write_xfer[0].len = sizeof(st->reg_write_tx_buf);
106 spi_message_init_with_transfers(&st->reg_write_msg,
107 st->reg_write_xfer, 2);
110 * Xfer: [ XFR1 ] [ XFR2 ]
111 * Master: 0x0B ADDR .....................
112 * Slave: ......... DATA0 DATA1 ... DATAN
114 st->reg_read_tx_buf[0] = ADXL367_SPI_READ_COMMAND;
115 st->reg_read_xfer[0].tx_buf = st->reg_read_tx_buf;
116 st->reg_read_xfer[0].len = sizeof(st->reg_read_tx_buf);
117 spi_message_init_with_transfers(&st->reg_read_msg,
118 st->reg_read_xfer, 2);
121 * Xfer: [XFR1] [ XFR2 ]
122 * Master: 0x0D .....................
123 * Slave: .... DATA0 DATA1 ... DATAN
125 st->fifo_tx_buf[0] = ADXL367_SPI_FIFO_COMMAND;
126 st->fifo_xfer[0].tx_buf = st->fifo_tx_buf;
127 st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf);
128 spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer, 2);
130 regmap = devm_regmap_init(&spi->dev, &adxl367_spi_regmap_bus, st,
131 &adxl367_spi_regmap_config);
133 return PTR_ERR(regmap);
135 return adxl367_probe(&spi->dev, &adxl367_spi_ops, st, regmap, spi->irq);
138 static const struct spi_device_id adxl367_spi_id[] = {
142 MODULE_DEVICE_TABLE(spi, adxl367_spi_id);
144 static const struct of_device_id adxl367_of_match[] = {
145 { .compatible = "adi,adxl367" },
148 MODULE_DEVICE_TABLE(of, adxl367_of_match);
150 static struct spi_driver adxl367_spi_driver = {
152 .name = "adxl367_spi",
153 .of_match_table = adxl367_of_match,
155 .probe = adxl367_spi_probe,
156 .id_table = adxl367_spi_id,
159 module_spi_driver(adxl367_spi_driver);
161 MODULE_IMPORT_NS(IIO_ADXL367);
162 MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
163 MODULE_DESCRIPTION("Analog Devices ADXL367 3-axis accelerometer SPI driver");
164 MODULE_LICENSE("GPL");