diff options
Diffstat (limited to 'drivers/iio/accel/adxl367_spi.c')
| -rw-r--r-- | drivers/iio/accel/adxl367_spi.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/iio/accel/adxl367_spi.c b/drivers/iio/accel/adxl367_spi.c new file mode 100644 index 000000000000..26dfc821ebbe --- /dev/null +++ b/drivers/iio/accel/adxl367_spi.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Analog Devices, Inc. + * Author: Cosmin Tanislav <cosmin.tanislav@analog.com> + */ + +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/spi/spi.h> + +#include "adxl367.h" + +#define ADXL367_SPI_WRITE_COMMAND 0x0A +#define ADXL367_SPI_READ_COMMAND 0x0B +#define ADXL367_SPI_FIFO_COMMAND 0x0D + +struct adxl367_spi_state { + struct spi_device *spi; + + struct spi_message reg_write_msg; + struct spi_transfer reg_write_xfer[2]; + + struct spi_message reg_read_msg; + struct spi_transfer reg_read_xfer[2]; + + struct spi_message fifo_msg; + struct spi_transfer fifo_xfer[2]; + + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + */ + u8 reg_write_tx_buf[1] ____cacheline_aligned; + u8 reg_read_tx_buf[2]; + u8 fifo_tx_buf[1]; +}; + +static int adxl367_read_fifo(void *context, __be16 *fifo_buf, + unsigned int fifo_entries) +{ + struct adxl367_spi_state *st = context; + + st->fifo_xfer[1].rx_buf = fifo_buf; + st->fifo_xfer[1].len = fifo_entries * sizeof(*fifo_buf); + + return spi_sync(st->spi, &st->fifo_msg); +} + +static int adxl367_read(void *context, const void *reg_buf, size_t reg_size, + void *val_buf, size_t val_size) +{ + struct adxl367_spi_state *st = context; + u8 reg = ((const u8 *)reg_buf)[0]; + + st->reg_read_tx_buf[1] = reg; + st->reg_read_xfer[1].rx_buf = val_buf; + st->reg_read_xfer[1].len = val_size; + + return spi_sync(st->spi, &st->reg_read_msg); +} + +static int adxl367_write(void *context, const void *val_buf, size_t val_size) +{ + struct adxl367_spi_state *st = context; + + st->reg_write_xfer[1].tx_buf = val_buf; + st->reg_write_xfer[1].len = val_size; + + return spi_sync(st->spi, &st->reg_write_msg); +} + +static struct regmap_bus adxl367_spi_regmap_bus = { + .read = adxl367_read, + .write = adxl367_write, +}; + +static const struct regmap_config adxl367_spi_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static const struct adxl367_ops adxl367_spi_ops = { + .read_fifo = adxl367_read_fifo, +}; + +static int adxl367_spi_probe(struct spi_device *spi) +{ + struct adxl367_spi_state *st; + struct regmap *regmap; + + st = devm_kzalloc(&spi->dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + st->spi = spi; + + /* + * Xfer: [XFR1] [ XFR2 ] + * Master: 0x0A ADDR DATA0 DATA1 ... DATAN + * Slave: .... .......................... + */ + st->reg_write_tx_buf[0] = ADXL367_SPI_WRITE_COMMAND; + st->reg_write_xfer[0].tx_buf = st->reg_write_tx_buf; + st->reg_write_xfer[0].len = sizeof(st->reg_write_tx_buf); + spi_message_init_with_transfers(&st->reg_write_msg, + st->reg_write_xfer, 2); + + /* + * Xfer: [ XFR1 ] [ XFR2 ] + * Master: 0x0B ADDR ..................... + * Slave: ......... DATA0 DATA1 ... DATAN + */ + st->reg_read_tx_buf[0] = ADXL367_SPI_READ_COMMAND; + st->reg_read_xfer[0].tx_buf = st->reg_read_tx_buf; + st->reg_read_xfer[0].len = sizeof(st->reg_read_tx_buf); + spi_message_init_with_transfers(&st->reg_read_msg, + st->reg_read_xfer, 2); + + /* + * Xfer: [XFR1] [ XFR2 ] + * Master: 0x0D ..................... + * Slave: .... DATA0 DATA1 ... DATAN + */ + st->fifo_tx_buf[0] = ADXL367_SPI_FIFO_COMMAND; + st->fifo_xfer[0].tx_buf = st->fifo_tx_buf; + st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf); + spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer, 2); + + regmap = devm_regmap_init(&spi->dev, &adxl367_spi_regmap_bus, st, + &adxl367_spi_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + return adxl367_probe(&spi->dev, &adxl367_spi_ops, st, regmap, spi->irq); +} + +static const struct spi_device_id adxl367_spi_id[] = { + { "adxl367", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(spi, adxl367_spi_id); + +static const struct of_device_id adxl367_of_match[] = { + { .compatible = "adi,adxl367" }, + { }, +}; +MODULE_DEVICE_TABLE(of, adxl367_of_match); + +static struct spi_driver adxl367_spi_driver = { + .driver = { + .name = "adxl367_spi", + .of_match_table = adxl367_of_match, + }, + .probe = adxl367_spi_probe, + .id_table = adxl367_spi_id, +}; + +module_spi_driver(adxl367_spi_driver); + +MODULE_IMPORT_NS(IIO_ADXL367); +MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>"); +MODULE_DESCRIPTION("Analog Devices ADXL367 3-axis accelerometer SPI driver"); +MODULE_LICENSE("GPL"); |