diff options
Diffstat (limited to 'include/linux/iio/adc/ad_sigma_delta.h')
| -rw-r--r-- | include/linux/iio/adc/ad_sigma_delta.h | 140 |
1 files changed, 140 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 000000000..7199280d8 --- /dev/null +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -0,0 +1,140 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Support code for Analog Devices Sigma-Delta ADCs + * + * Copyright 2012 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + */ +#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. + * @data_reg: Address of the data register, if 0 the default address of 0x3 will + * be used. + * @irq_flags: flags for the interrupt used by the triggered buffer + */ +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; + unsigned int data_reg; + unsigned long irq_flags; +}; + +/** + * 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; + bool keep_cs_asserted; + + 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. + * 'tx_buf' is up to 32 bits. + * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp, + * rounded to 16 bytes to take into account padding. + */ + uint8_t tx_buf[4] ____cacheline_aligned; + uint8_t rx_buf[16] __aligned(8); +}; + +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_sd_reset(struct ad_sigma_delta *sigma_delta, + unsigned int reset_length); + +int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *val); +int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, + unsigned int mode, unsigned int channel); +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); + +#endif |