| /* |
| * STMicroelectronics sensors spi library driver |
| * |
| * Copyright 2012-2013 STMicroelectronics Inc. |
| * |
| * Denis Ciocca <denis.ciocca@st.com> |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/iio/iio.h> |
| |
| #include <linux/iio/common/st_sensors_spi.h> |
| |
| |
| #define ST_SENSORS_SPI_MULTIREAD 0xc0 |
| #define ST_SENSORS_SPI_READ 0x80 |
| |
| static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev) |
| { |
| struct st_sensor_data *sdata = iio_priv(indio_dev); |
| |
| return to_spi_device(sdata->dev)->irq; |
| } |
| |
| static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb, |
| struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit) |
| { |
| int err; |
| |
| struct spi_transfer xfers[] = { |
| { |
| .tx_buf = tb->tx_buf, |
| .bits_per_word = 8, |
| .len = 1, |
| }, |
| { |
| .rx_buf = tb->rx_buf, |
| .bits_per_word = 8, |
| .len = len, |
| } |
| }; |
| |
| mutex_lock(&tb->buf_lock); |
| if ((multiread_bit) && (len > 1)) |
| tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD; |
| else |
| tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ; |
| |
| err = spi_sync_transfer(to_spi_device(dev), xfers, ARRAY_SIZE(xfers)); |
| if (err) |
| goto acc_spi_read_error; |
| |
| memcpy(data, tb->rx_buf, len*sizeof(u8)); |
| mutex_unlock(&tb->buf_lock); |
| return len; |
| |
| acc_spi_read_error: |
| mutex_unlock(&tb->buf_lock); |
| return err; |
| } |
| |
| static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb, |
| struct device *dev, u8 reg_addr, u8 *res_byte) |
| { |
| return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false); |
| } |
| |
| static int st_sensors_spi_read_multiple_byte( |
| struct st_sensor_transfer_buffer *tb, struct device *dev, |
| u8 reg_addr, int len, u8 *data, bool multiread_bit) |
| { |
| return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit); |
| } |
| |
| static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb, |
| struct device *dev, u8 reg_addr, u8 data) |
| { |
| int err; |
| |
| struct spi_transfer xfers = { |
| .tx_buf = tb->tx_buf, |
| .bits_per_word = 8, |
| .len = 2, |
| }; |
| |
| mutex_lock(&tb->buf_lock); |
| tb->tx_buf[0] = reg_addr; |
| tb->tx_buf[1] = data; |
| |
| err = spi_sync_transfer(to_spi_device(dev), &xfers, 1); |
| mutex_unlock(&tb->buf_lock); |
| |
| return err; |
| } |
| |
| static const struct st_sensor_transfer_function st_sensors_tf_spi = { |
| .read_byte = st_sensors_spi_read_byte, |
| .write_byte = st_sensors_spi_write_byte, |
| .read_multiple_byte = st_sensors_spi_read_multiple_byte, |
| }; |
| |
| void st_sensors_spi_configure(struct iio_dev *indio_dev, |
| struct spi_device *spi, struct st_sensor_data *sdata) |
| { |
| spi_set_drvdata(spi, indio_dev); |
| |
| indio_dev->dev.parent = &spi->dev; |
| indio_dev->name = spi->modalias; |
| |
| sdata->tf = &st_sensors_tf_spi; |
| sdata->get_irq_data_ready = st_sensors_spi_get_irq; |
| } |
| EXPORT_SYMBOL(st_sensors_spi_configure); |
| |
| MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); |
| MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver"); |
| MODULE_LICENSE("GPL v2"); |