path: root/drivers/iio/resolver/ad2s1210.c

// SPDX-License-Identifier: GPL-2.0
/*
 * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210
 *
 * Copyright (c) 2010-2010 Analog Devices Inc.
 * Copyright (c) 2023 BayLibre, SAS
 *
 * Device register to IIO ABI mapping:
 *
 * Register                    | Addr | IIO ABI (sysfs)
 * ----------------------------|------|-------------------------------------------
 * DOS Overrange Threshold     | 0x89 | events/in_altvoltage0_thresh_rising_value
 * DOS Mismatch Threshold      | 0x8A | events/in_altvoltage0_mag_rising_value
 * DOS Reset Maximum Threshold | 0x8B | events/in_altvoltage0_mag_rising_reset_max
 * DOS Reset Minimum Threshold | 0x8C | events/in_altvoltage0_mag_rising_reset_min
 * LOT High Threshold          | 0x8D | events/in_angl1_thresh_rising_value
 * LOT Low Threshold [1]       | 0x8E | events/in_angl1_thresh_rising_hysteresis
 * Excitation Frequency        | 0x91 | out_altvoltage0_frequency
 * Control                     | 0x92 | *as bit fields*
 *   Phase lock range          | D5   | events/in_phase0_mag_rising_value
 *   Hysteresis                | D4   | in_angl0_hysteresis
 *   Encoder resolution        | D3:2 | *not implemented*
 *   Resolution                | D1:0 | *device tree: assigned-resolution-bits*
 * Soft Reset                  | 0xF0 | [2]
 * Fault                       | 0xFF | *not implemented*
 *
 * [1]: The value written to the LOT low register is high value minus the
 * hysteresis.
 * [2]: Soft reset is performed when `out_altvoltage0_frequency` is written.
 *
 * Fault to event mapping:
 *
 * Fault                                   |    | Channel     | Type   | Direction
 * ----------------------------------------|----|---------------------------------
 * Sine/cosine inputs clipped [3]          | D7 | altvoltage1 | mag    | either
 * Si