LXR linux/drivers/iio/common/st_sensors/st_sensors

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * STMicroelectronics sensors spi library driver
   4 *
   5 * Copyright 2012-2013 STMicroelectronics Inc.
   6 *
   7 * Denis Ciocca <denis.ciocca@st.com>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
  13#include <linux/iio/iio.h>
  14
  15#include <linux/iio/common/st_sensors_spi.h>
  16
  17
  18#define ST_SENSORS_SPI_MULTIREAD        0xc0
  19#define ST_SENSORS_SPI_READ             0x80
  20
  21static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev)
  22{
  23        struct st_sensor_data *sdata = iio_priv(indio_dev);
  24
  25        return to_spi_device(sdata->dev)->irq;
  26}
  27
  28static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb,
  29        struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit)
  30{
  31        int err;
  32
  33        struct spi_transfer xfers[] = {
  34                {
  35                        .tx_buf = tb->tx_buf,
  36                        .bits_per_word = 8,
  37                        .len = 1,
  38                },
  39                {
  40                        .rx_buf = tb->rx_buf,
  41                        .bits_per_word = 8,
  42                        .len = len,
  43                }
  44        };
  45
  46        mutex_lock(&tb->buf_lock);
  47        if ((multiread_bit) && (len > 1))
  48                tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD;
  49        else
  50                tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ;
  51
  52        err = spi_sync_transfer(to_spi_device(dev), xfers, ARRAY_SIZE(xfers));
  53        if (err)
  54                goto acc_spi_read_error;
  55
  56        memcpy(data, tb->rx_buf, len);
  57        mutex_unlock(&tb->buf_lock);
  58        return len;
  59
  60acc_spi_read_error:
  61        mutex_unlock(&tb->buf_lock);
  62        return err;
  63}
  64
  65static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb,
  66                                struct device *dev, u8 reg_addr, u8 *res_byte)
  67{
  68        return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false);
  69}
  70
  71static int st_sensors_spi_read_multiple_byte(
  72        struct st_sensor_transfer_buffer *tb, struct device *dev,
  73                        u8 reg_addr, int len, u8 *data, bool multiread_bit)
  74{
  75        return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit);
  76}
  77
  78static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb,
  79                                struct device *dev, u8 reg_addr, u8 data)
  80{
  81        int err;
  82
  83        struct spi_transfer xfers = {
  84                .tx_buf = tb->tx_buf,
  85                .bits_per_word = 8,
  86                .len = 2,
  87        };
  88
  89        mutex_lock(&tb->buf_lock);
  90        tb->tx_buf[0] = reg_addr;
  91        tb->tx_buf[1] = data;
  92
  93        err = spi_sync_transfer(to_spi_device(dev), &xfers, 1);
  94        mutex_unlock(&tb->buf_lock);
  95
  96        return err;
  97}
  98
  99static const struct st_sensor_transfer_function st_sensors_tf_spi = {
 100        .read_byte = st_sensors_spi_read_byte,
 101        .write_byte = st_sensors_spi_write_byte,
 102        .read_multiple_byte = st_sensors_spi_read_multiple_byte,
 103};
 104
 105void st_sensors_spi_configure(struct iio_dev *indio_dev,
 106                        struct spi_device *spi, struct st_sensor_data *sdata)
 107{
 108        spi_set_drvdata(spi, indio_dev);
 109
 110        indio_dev->dev.parent = &spi->dev;
 111        indio_dev->name = spi->modalias;
 112
 113        sdata->dev = &spi->dev;
 114        sdata->tf = &st_sensors_tf_spi;
 115        sdata->get_irq_data_ready = st_sensors_spi_get_irq;
 116}
 117EXPORT_SYMBOL(st_sensors_spi_configure);
 118
 119MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 120MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
 121MODULE_LICENSE("GPL v2");
 122