Denis Ciocca | 23491b5 | 2013-01-25 23:44:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * STMicroelectronics sensors spi library driver |
| 3 | * |
| 4 | * Copyright 2012-2013 STMicroelectronics Inc. |
| 5 | * |
| 6 | * Denis Ciocca <denis.ciocca@st.com> |
| 7 | * |
| 8 | * Licensed under the GPL-2. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/iio/iio.h> |
| 15 | |
| 16 | #include <linux/iio/common/st_sensors_spi.h> |
| 17 | |
| 18 | |
| 19 | #define ST_SENSORS_SPI_MULTIREAD 0xc0 |
| 20 | #define ST_SENSORS_SPI_READ 0x80 |
| 21 | |
| 22 | static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev) |
| 23 | { |
| 24 | struct st_sensor_data *sdata = iio_priv(indio_dev); |
| 25 | |
| 26 | return to_spi_device(sdata->dev)->irq; |
| 27 | } |
| 28 | |
| 29 | static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb, |
| 30 | struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit) |
| 31 | { |
Denis Ciocca | 23491b5 | 2013-01-25 23:44:00 +0000 | [diff] [blame] | 32 | int err; |
| 33 | |
| 34 | struct spi_transfer xfers[] = { |
| 35 | { |
| 36 | .tx_buf = tb->tx_buf, |
| 37 | .bits_per_word = 8, |
| 38 | .len = 1, |
| 39 | }, |
| 40 | { |
| 41 | .rx_buf = tb->rx_buf, |
| 42 | .bits_per_word = 8, |
| 43 | .len = len, |
| 44 | } |
| 45 | }; |
| 46 | |
| 47 | mutex_lock(&tb->buf_lock); |
| 48 | if ((multiread_bit) && (len > 1)) |
| 49 | tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD; |
| 50 | else |
| 51 | tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ; |
| 52 | |
Denis Ciocca | 43bb786 | 2013-02-09 16:08:00 +0000 | [diff] [blame] | 53 | err = spi_sync_transfer(to_spi_device(dev), xfers, ARRAY_SIZE(xfers)); |
Denis Ciocca | 23491b5 | 2013-01-25 23:44:00 +0000 | [diff] [blame] | 54 | if (err) |
| 55 | goto acc_spi_read_error; |
| 56 | |
| 57 | memcpy(data, tb->rx_buf, len*sizeof(u8)); |
| 58 | mutex_unlock(&tb->buf_lock); |
| 59 | return len; |
| 60 | |
| 61 | acc_spi_read_error: |
| 62 | mutex_unlock(&tb->buf_lock); |
| 63 | return err; |
| 64 | } |
| 65 | |
| 66 | static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb, |
| 67 | struct device *dev, u8 reg_addr, u8 *res_byte) |
| 68 | { |
| 69 | return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false); |
| 70 | } |
| 71 | |
| 72 | static int st_sensors_spi_read_multiple_byte( |
| 73 | struct st_sensor_transfer_buffer *tb, struct device *dev, |
| 74 | u8 reg_addr, int len, u8 *data, bool multiread_bit) |
| 75 | { |
| 76 | return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit); |
| 77 | } |
| 78 | |
| 79 | static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb, |
| 80 | struct device *dev, u8 reg_addr, u8 data) |
| 81 | { |
Denis Ciocca | 23491b5 | 2013-01-25 23:44:00 +0000 | [diff] [blame] | 82 | int err; |
| 83 | |
| 84 | struct spi_transfer xfers = { |
| 85 | .tx_buf = tb->tx_buf, |
| 86 | .bits_per_word = 8, |
| 87 | .len = 2, |
| 88 | }; |
| 89 | |
| 90 | mutex_lock(&tb->buf_lock); |
| 91 | tb->tx_buf[0] = reg_addr; |
| 92 | tb->tx_buf[1] = data; |
| 93 | |
Denis Ciocca | 43bb786 | 2013-02-09 16:08:00 +0000 | [diff] [blame] | 94 | err = spi_sync_transfer(to_spi_device(dev), &xfers, 1); |
Denis Ciocca | 23491b5 | 2013-01-25 23:44:00 +0000 | [diff] [blame] | 95 | mutex_unlock(&tb->buf_lock); |
| 96 | |
| 97 | return err; |
| 98 | } |
| 99 | |
| 100 | static const struct st_sensor_transfer_function st_sensors_tf_spi = { |
| 101 | .read_byte = st_sensors_spi_read_byte, |
| 102 | .write_byte = st_sensors_spi_write_byte, |
| 103 | .read_multiple_byte = st_sensors_spi_read_multiple_byte, |
| 104 | }; |
| 105 | |
| 106 | void st_sensors_spi_configure(struct iio_dev *indio_dev, |
| 107 | struct spi_device *spi, struct st_sensor_data *sdata) |
| 108 | { |
| 109 | spi_set_drvdata(spi, indio_dev); |
| 110 | |
| 111 | indio_dev->dev.parent = &spi->dev; |
| 112 | indio_dev->name = spi->modalias; |
| 113 | |
| 114 | sdata->tf = &st_sensors_tf_spi; |
| 115 | sdata->get_irq_data_ready = st_sensors_spi_get_irq; |
| 116 | } |
| 117 | EXPORT_SYMBOL(st_sensors_spi_configure); |
| 118 | |
| 119 | MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); |
| 120 | MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver"); |
| 121 | MODULE_LICENSE("GPL v2"); |