diff options
Diffstat (limited to 'include/linux/iio/adc/ad_sigma_delta.h')
| -rw-r--r-- | include/linux/iio/adc/ad_sigma_delta.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h new file mode 100644 index 000000000000..2e4eab9868a3 --- /dev/null +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -0,0 +1,173 @@ +/* + * Support code for Analog Devices Sigma-Delta ADCs + * + * Copyright 2012 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ +#ifndef __AD_SIGMA_DELTA_H__ +#define __AD_SIGMA_DELTA_H__ + +enum ad_sigma_delta_mode { + AD_SD_MODE_CONTINUOUS = 0, + AD_SD_MODE_SINGLE = 1, + AD_SD_MODE_IDLE = 2, + AD_SD_MODE_POWERDOWN = 3, +}; + +/** + * struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices + * @mode: Calibration mode. + * @channel: Calibration channel. + */ +struct ad_sd_calib_data { + unsigned int mode; + unsigned int channel; +}; + +struct ad_sigma_delta; +struct iio_dev; + +/** + * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options + * @set_channel: Will be called to select the current channel, may be NULL. + * @set_mode: Will be called to select the current mode, may be NULL. + * @postprocess_sample: Is called for each sampled data word, can be used to + * modify or drop the sample data, it, may be NULL. + * @has_registers: true if the device has writable and readable registers, false + * if there is just one read-only sample data shift register. + * @addr_shift: Shift of the register address in the communications register. + * @read_mask: Mask for the communications register having the read bit set. + */ +struct ad_sigma_delta_info { + int (*set_channel)(struct ad_sigma_delta *, unsigned int channel); + int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); + int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); + bool has_registers; + unsigned int addr_shift; + unsigned int read_mask; +}; + +/** + * struct ad_sigma_delta - Sigma Delta device struct + * @spi: The spi device associated with the Sigma Delta device. + * @trig: The IIO trigger associated with the Sigma Delta device. + * + * Most of the fields are private to the sigma delta library code and should not + * be accessed by individual drivers. + */ +struct ad_sigma_delta { + struct spi_device *spi; + struct iio_trigger *trig; + +/* private: */ + struct completion completion; + bool irq_dis; + + bool bus_locked; + + uint8_t comm; + + const struct ad_sigma_delta_info *info; + + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + */ + uint8_t data[4] ____cacheline_aligned; +}; + +static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd, + unsigned int channel) +{ + if (sd->info->set_channel) + return sd->info->set_channel(sd, channel); + + return 0; +} + +static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd, + unsigned int mode) +{ + if (sd->info->set_mode) + return sd->info->set_mode(sd, mode); + + return 0; +} + +static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd, + unsigned int raw_sample) +{ + if (sd->info->postprocess_sample) + return sd->info->postprocess_sample(sd, raw_sample); + + return 0; +} + +void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm); +int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, + unsigned int size, unsigned int val); +int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, + unsigned int size, unsigned int *val); + +int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *val); +int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, + const struct ad_sd_calib_data *cd, unsigned int n); +int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, + struct spi_device *spi, const struct ad_sigma_delta_info *info); + +int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev); +void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev); + +int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig); + +#define __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ + _storagebits, _shift, _extend_name, _type) \ + { \ + .type = (_type), \ + .differential = (_channel2 == -1 ? 0 : 1), \ + .indexed = 1, \ + .channel = (_channel1), \ + .channel2 = (_channel2), \ + .address = (_address), \ + .extend_name = (_extend_name), \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SHARED_BIT | \ + IIO_CHAN_INFO_OFFSET_SEPARATE_BIT, \ + .scan_index = (_si), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = (_bits), \ + .storagebits = (_storagebits), \ + .shift = (_shift), \ + .endianness = IIO_BE, \ + }, \ + } + +#define AD_SD_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ + _storagebits, _shift) \ + __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ + _storagebits, _shift, NULL, IIO_VOLTAGE) + +#define AD_SD_SHORTED_CHANNEL(_si, _channel, _address, _bits, \ + _storagebits, _shift) \ + __AD_SD_CHANNEL(_si, _channel, _channel, _address, _bits, \ + _storagebits, _shift, "shorted", IIO_VOLTAGE) + +#define AD_SD_CHANNEL(_si, _channel, _address, _bits, \ + _storagebits, _shift) \ + __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ + _storagebits, _shift, NULL, IIO_VOLTAGE) + +#define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \ + __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \ + _storagebits, _shift, NULL, IIO_TEMP) + +#define AD_SD_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \ + _shift) \ + __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ + _storagebits, _shift, "supply", IIO_VOLTAGE) + +#endif |