name : ad_sigma_delta.h /* 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__ #include <linux/iio/iio.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 device; 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. * @append_status: Will be called to enable status append at the end of the sample, may be NULL. * @set_mode: Will be called to select the current mode, may be NULL. * @disable_all: Will be called to disable all channels, 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. * @status_ch_mask: Mask for the channel number stored in status register. * @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 * @num_slots: Number of sequencer slots */ struct ad_sigma_delta_info { int (*set_channel)(struct ad_sigma_delta *, unsigned int channel); int (*append_status)(struct ad_sigma_delta *, bool append); int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); int (*disable_all)(struct ad_sigma_delta *); int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); bool has_registers; unsigned int addr_shift; unsigned int read_mask; unsigned int status_ch_mask; unsigned int data_reg; unsigned long irq_flags; unsigned int num_slots; }; /** * 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; unsigned int active_slots; unsigned int current_slot; unsigned int num_slots; bool status_appended; /* map slots to channels in order to know what to expect from devices */ unsigned int *slots; uint8_t *samples_buf; /* * 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] __aligned(IIO_DMA_MINALIGN); 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_append_status(struct ad_sigma_delta *sd, bool append) { int ret; if (sd->info->append_status) { ret = sd->info->append_status(sd, append); if (ret < 0) return ret; sd->status_appended = append; } return 0; } static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd) { if (sd->info->disable_all) return sd->info->disable_all(sd); 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 devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev); int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig); #endif