diff options
Diffstat (limited to 'drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c')
-rw-r--r-- | drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c new file mode 100644 index 000000000000..fbe72470ed1e --- /dev/null +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c @@ -0,0 +1,118 @@ +/* + * STMicroelectronics st_lsm6dsx spi driver + * + * Copyright 2016 STMicroelectronics Inc. + * + * Lorenzo Bianconi <lorenzo.bianconi@st.com> + * Denis Ciocca <denis.ciocca@st.com> + * + * Licensed under the GPL-2. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/of.h> + +#include "st_lsm6dsx.h" + +#define SENSORS_SPI_READ BIT(7) + +static int st_lsm6dsx_spi_read(struct device *dev, u8 addr, int len, + u8 *data) +{ + struct spi_device *spi = to_spi_device(dev); + struct st_lsm6dsx_hw *hw = spi_get_drvdata(spi); + int err; + + struct spi_transfer xfers[] = { + { + .tx_buf = hw->tb.tx_buf, + .bits_per_word = 8, + .len = 1, + }, + { + .rx_buf = hw->tb.rx_buf, + .bits_per_word = 8, + .len = len, + } + }; + + hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ; + + err = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers)); + if (err < 0) + return err; + + memcpy(data, hw->tb.rx_buf, len * sizeof(u8)); + + return len; +} + +static int st_lsm6dsx_spi_write(struct device *dev, u8 addr, int len, + u8 *data) +{ + struct st_lsm6dsx_hw *hw; + struct spi_device *spi; + + if (len >= ST_LSM6DSX_TX_MAX_LENGTH) + return -ENOMEM; + + spi = to_spi_device(dev); + hw = spi_get_drvdata(spi); + + hw->tb.tx_buf[0] = addr; + memcpy(&hw->tb.tx_buf[1], data, len); + + return spi_write(spi, hw->tb.tx_buf, len + 1); +} + +static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = { + .read = st_lsm6dsx_spi_read, + .write = st_lsm6dsx_spi_write, +}; + +static int st_lsm6dsx_spi_probe(struct spi_device *spi) +{ + const struct spi_device_id *id = spi_get_device_id(spi); + + return st_lsm6dsx_probe(&spi->dev, spi->irq, + (int)id->driver_data, + &st_lsm6dsx_transfer_fn); +} + +static const struct of_device_id st_lsm6dsx_spi_of_match[] = { + { + .compatible = "st,lsm6ds3", + .data = (void *)ST_LSM6DS3_ID, + }, + { + .compatible = "st,lsm6dsm", + .data = (void *)ST_LSM6DSM_ID, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, st_lsm6dsx_spi_of_match); + +static const struct spi_device_id st_lsm6dsx_spi_id_table[] = { + { ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID }, + { ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID }, + {}, +}; +MODULE_DEVICE_TABLE(spi, st_lsm6dsx_spi_id_table); + +static struct spi_driver st_lsm6dsx_driver = { + .driver = { + .name = "st_lsm6dsx_spi", + .of_match_table = of_match_ptr(st_lsm6dsx_spi_of_match), + }, + .probe = st_lsm6dsx_spi_probe, + .id_table = st_lsm6dsx_spi_id_table, +}; +module_spi_driver(st_lsm6dsx_driver); + +MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>"); +MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); +MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx spi driver"); +MODULE_LICENSE("GPL v2"); |