diff options
Diffstat (limited to 'drivers/iio/resolver')
| -rw-r--r-- | drivers/iio/resolver/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/iio/resolver/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iio/resolver/ad2s1210.c | 1519 |
3 files changed, 1533 insertions, 0 deletions
diff --git a/drivers/iio/resolver/Kconfig b/drivers/iio/resolver/Kconfig index 47dbfead9b..424529d360 100644 --- a/drivers/iio/resolver/Kconfig +++ b/drivers/iio/resolver/Kconfig @@ -25,4 +25,17 @@ config AD2S1200 To compile this driver as a module, choose M here: the module will be called ad2s1200. + +config AD2S1210 + tristate "Analog Devices ad2s1210 driver" + depends on SPI + depends on COMMON_CLK + depends on GPIOLIB || COMPILE_TEST + help + Say yes here to build support for Analog Devices spi resolver + to digital converters, ad2s1210, provides direct access via sysfs. + + To compile this driver as a module, choose M here: the + module will be called ad2s1210. + endmenu diff --git a/drivers/iio/resolver/Makefile b/drivers/iio/resolver/Makefile index fa558138ce..7f6c876c35 100644 --- a/drivers/iio/resolver/Makefile +++ b/drivers/iio/resolver/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_AD2S90) += ad2s90.o obj-$(CONFIG_AD2S1200) += ad2s1200.o +obj-$(CONFIG_AD2S1210) += ad2s1210.o diff --git a/drivers/iio/resolver/ad2s1210.c b/drivers/iio/resolver/ad2s1210.c new file mode 100644 index 0000000000..1bd1b950e7 --- /dev/null +++ b/drivers/iio/resolver/ad2s1210.c @@ -0,0 +1,1519 @@ +// 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 + * Sine/cosine inputs below LOS | D6 | altvoltage0 | thresh | falling + * Sine/cosine inputs exceed DOS overrange | D5 | altvoltage0 | thresh | rising + * Sine/cosine inputs exceed DOS mismatch | D4 | altvoltage0 | mag | rising + * Tracking error exceeds LOT | D3 | angl1 | thresh | rising + * Velocity exceeds maximum tracking rate | D2 | anglvel0 | mag | rising + * Phase error exceeds phase lock range | D1 | phase0 | mag | rising + * Configuration parity error | D0 | *writes to kernel log* + * + * [3]: The chip does not differentiate between fault on sine vs. cosine so + * there will also be an event on the altvoltage2 channel. + */ + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/cleanup.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/sysfs.h> +#include <linux/types.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +/* control register flags */ +#define AD2S1210_ADDRESS_DATA BIT(7) +#define AD2S1210_PHASE_LOCK_RANGE_44 BIT(5) +#define AD2S1210_ENABLE_HYSTERESIS BIT(4) +#define AD2S1210_SET_ENRES GENMASK(3, 2) +#define AD2S1210_SET_RES GENMASK(1, 0) + +/* fault register flags */ +#define AD2S1210_FAULT_CLIP BIT(7) +#define AD2S1210_FAULT_LOS BIT(6) +#define AD2S1210_FAULT_DOS_OVR BIT(5) +#define AD2S1210_FAULT_DOS_MIS BIT(4) +#define AD2S1210_FAULT_LOT BIT(3) +#define AD2S1210_FAULT_VELOCITY BIT(2) +#define AD2S1210_FAULT_PHASE BIT(1) +#define AD2S1210_FAULT_CONFIG_PARITY BIT(0) + +#define AD2S1210_REG_POSITION_MSB 0x80 +#define AD2S1210_REG_POSITION_LSB 0x81 +#define AD2S1210_REG_VELOCITY_MSB 0x82 +#define AD2S1210_REG_VELOCITY_LSB 0x83 +#define AD2S1210_REG_LOS_THRD 0x88 +#define AD2S1210_REG_DOS_OVR_THRD 0x89 +#define AD2S1210_REG_DOS_MIS_THRD 0x8A +#define AD2S1210_REG_DOS_RST_MAX_THRD 0x8B +#define AD2S1210_REG_DOS_RST_MIN_THRD 0x8C +#define AD2S1210_REG_LOT_HIGH_THRD 0x8D +#define AD2S1210_REG_LOT_LOW_THRD 0x8E +#define AD2S1210_REG_EXCIT_FREQ 0x91 +#define AD2S1210_REG_CONTROL 0x92 +#define AD2S1210_REG_SOFT_RESET 0xF0 +#define AD2S1210_REG_FAULT 0xFF + +#define AD2S1210_MIN_CLKIN 6144000 +#define AD2S1210_MAX_CLKIN 10240000 +#define AD2S1210_MIN_EXCIT 2000 +#define AD2S1210_DEF_EXCIT 10000 +#define AD2S1210_MAX_EXCIT 20000 +#define AD2S1210_MIN_FCW 0x4 +#define AD2S1210_MAX_FCW 0x50 + +/* 44 degrees ~= 0.767945 radians */ +#define PHASE_44_DEG_TO_RAD_INT 0 +#define PHASE_44_DEG_TO_RAD_MICRO 767945 +/* 360 degrees ~= 6.283185 radians */ +#define PHASE_360_DEG_TO_RAD_INT 6 +#define PHASE_360_DEG_TO_RAD_MICRO 283185 + +/* Threshold voltage registers have 1 LSB == 38 mV */ +#define THRESHOLD_MILLIVOLT_PER_LSB 38 +/* max voltage for threshold registers is 0x7F * 38 mV */ +#define THRESHOLD_RANGE_STR "[0 38 4826]" + +#define FAULT_ONESHOT(bit, new, old) (new & bit && !(old & bit)) + +enum ad2s1210_mode { + MOD_POS = 0b00, + MOD_VEL = 0b01, + MOD_RESERVED = 0b10, + MOD_CONFIG = 0b11, +}; + +enum ad2s1210_resolution { + AD2S1210_RES_10 = 0b00, + AD2S1210_RES_12 = 0b01, + AD2S1210_RES_14 = 0b10, + AD2S1210_RES_16 = 0b11, +}; + +struct ad2s1210_state { + struct mutex lock; + struct spi_device *sdev; + /** GPIO pin connected to SAMPLE line. */ + struct gpio_desc *sample_gpio; + /** GPIO pins connected to A0 and A1 lines. */ + struct gpio_descs *mode_gpios; + /** Used to access config registers. */ + struct regmap *regmap; + /** The external oscillator frequency in Hz. */ + unsigned long clkin_hz; + /** Available raw hysteresis values based on resolution. */ + int hysteresis_available[2]; + /** The selected resolution */ + enum ad2s1210_resolution resolution; + /** Copy of fault register from the previous read. */ + u8 prev_fault_flags; + /** For reading raw sample value via SPI. */ + struct { + __be16 raw; + u8 fault; + } sample __aligned(IIO_DMA_MINALIGN); + /** Scan buffer */ + struct { + __be16 chan[2]; + /* Ensure timestamp is naturally aligned. */ + s64 timestamp __aligned(8); + } scan; + /** SPI transmit buffer. */ + u8 rx[2]; + /** SPI receive buffer. */ + u8 tx[2]; +}; + +static int ad2s1210_set_mode(struct ad2s1210_state *st, enum ad2s1210_mode mode) +{ + struct gpio_descs *gpios = st->mode_gpios; + DECLARE_BITMAP(bitmap, 2); + + bitmap[0] = mode; + + return gpiod_set_array_value(gpios->ndescs, gpios->desc, gpios->info, + bitmap); +} + +/* + * Writes the given data to the given register address. + * + * If the mode is configurable, the device will first be placed in + * configuration mode. + */ +static int ad2s1210_regmap_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + struct ad2s1210_state *st = context; + struct spi_transfer xfers[] = { + { + .len = 1, + .rx_buf = &st->rx[0], + .tx_buf = &st->tx[0], + .cs_change = 1, + }, { + .len = 1, + .rx_buf = &st->rx[1], + .tx_buf = &st->tx[1], + }, + }; + int ret; + + /* values can only be 7 bits, the MSB indicates an address */ + if (val & ~0x7F) + return -EINVAL; + + st->tx[0] = reg; + st->tx[1] = val; + + ret = ad2s1210_set_mode(st, MOD_CONFIG); + if (ret < 0) + return ret; + + ret = spi_sync_transfer(st->sdev, xfers, ARRAY_SIZE(xfers)); + if (ret < 0) + return ret; + + /* soft reset also clears the fault register */ + if (reg == AD2S1210_REG_SOFT_RESET) + st->prev_fault_flags = 0; + + return 0; +} + +/* + * Reads value from one of the registers. + * + * If the mode is configurable, the device will first be placed in + * configuration mode. + */ +static int ad2s1210_regmap_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + struct ad2s1210_state *st = context; + struct spi_transfer xfers[] = { + { + .len = 1, + .rx_buf = &st->rx[0], + .tx_buf = &st->tx[0], + .cs_change = 1, + }, { + .len = 1, + .rx_buf = &st->rx[1], + .tx_buf = &st->tx[1], + }, + }; + int ret; + + ret = ad2s1210_set_mode(st, MOD_CONFIG); + if (ret < 0) + return ret; + + st->tx[0] = reg; + /* + * Must be valid register address here otherwise this could write data. + * It doesn't matter which one as long as reading doesn't have side- + * effects. + */ + st->tx[1] = AD2S1210_REG_CONTROL; + + ret = spi_sync_transfer(st->sdev, xfers, ARRAY_SIZE(xfers)); + if (ret < 0) + return ret; + + /* reading the fault register also clears it */ + if (reg == AD2S1210_REG_FAULT) + st->prev_fault_flags = 0; + + /* + * If the D7 bit is set on any read/write register, it indicates a + * parity error. The fault register is read-only and the D7 bit means + * something else there. + */ + if (reg != AD2S1210_REG_FAULT && st->rx[1] & AD2S1210_ADDRESS_DATA) + return -EBADMSG; + + *val = st->rx[1]; + + return 0; +} + +/* + * Toggles the SAMPLE line on the AD2S1210 to latch in the current position, + * velocity, and faults. + * + * Must be called with lock held. + */ +static void ad2s1210_toggle_sample_line(struct ad2s1210_state *st) +{ + /* + * Datasheet specifies minimum hold time t16 = 2 * tck + 20 ns. So the + * longest time needed is when CLKIN is 6.144 MHz, in which case t16 + * ~= 350 ns. The same delay is also needed before re-asserting the + * SAMPLE line. + */ + gpiod_set_value(st->sample_gpio, 1); + ndelay(350); + gpiod_set_value(st->sample_gpio, 0); + ndelay(350); +} + +/* + * Sets the excitation frequency and performs software reset. + * + * Must be called with lock held. + */ +static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, + u16 fexcit) +{ + /* Map resolution to settle time in milliseconds. */ + static const int track_time_ms[] = { 10, 20, 25, 60 }; + unsigned int ignored; + int ret; + u8 fcw; + + fcw = fexcit * (1 << 15) / st->clkin_hz; + if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) + return -ERANGE; + + ret = regmap_write(st->regmap, AD2S1210_REG_EXCIT_FREQ, fcw); + if (ret < 0) + return ret; + + /* + * Software reset reinitializes the excitation frequency output. + * It does not reset any of the configuration registers. + */ + ret = regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); + if (ret < 0) + return ret; + + /* + * Soft reset always triggers some faults due the change in the output + * signal so clear the faults too. We need to delay for some time + * (what datasheet calls t[track]) to allow things to settle before + * clearing the faults. + */ + msleep(track_time_ms[st->resolution] * 8192000 / st->clkin_hz); + + /* Reading the fault register clears the faults. */ + ret = regmap_read(st->regmap, AD2S1210_REG_FAULT, &ignored); + if (ret < 0) + return ret; + + /* Have to toggle sample line to get fault output pins to reset. */ + ad2s1210_toggle_sample_line(st); + + return 0; +} + +static void ad2s1210_push_events(struct iio_dev *indio_dev, + u8 flags, s64 timestamp) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + /* Sine/cosine inputs clipped */ + if (FAULT_ONESHOT(AD2S1210_FAULT_CLIP, flags, st->prev_fault_flags)) { + /* + * The chip does not differentiate between fault on sine vs. + * cosine channel so we just send an event on both channels. + */ + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ALTVOLTAGE, 1, + IIO_EV_TYPE_MAG, + IIO_EV_DIR_EITHER), + timestamp); + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ALTVOLTAGE, 2, + IIO_EV_TYPE_MAG, + IIO_EV_DIR_EITHER), + timestamp); + } + + /* Sine/cosine inputs below LOS threshold */ + if (FAULT_ONESHOT(AD2S1210_FAULT_LOS, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ALTVOLTAGE, 0, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_FALLING), + timestamp); + + /* Sine/cosine inputs exceed DOS overrange threshold */ + if (FAULT_ONESHOT(AD2S1210_FAULT_DOS_OVR, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ALTVOLTAGE, 0, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + timestamp); + + /* Sine/cosine inputs exceed DOS mismatch threshold */ + if (FAULT_ONESHOT(AD2S1210_FAULT_DOS_MIS, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ALTVOLTAGE, 0, + IIO_EV_TYPE_MAG, + IIO_EV_DIR_RISING), + timestamp); + + /* Tracking error exceeds LOT threshold */ + if (FAULT_ONESHOT(AD2S1210_FAULT_LOT, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ANGL, 1, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + timestamp); + + /* Velocity exceeds maximum tracking rate */ + if (FAULT_ONESHOT(AD2S1210_FAULT_VELOCITY, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_ANGL_VEL, 0, + IIO_EV_TYPE_THRESH, + IIO_EV_DIR_RISING), + timestamp); + + /* Phase error exceeds phase lock range */ + if (FAULT_ONESHOT(AD2S1210_FAULT_PHASE, flags, st->prev_fault_flags)) + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_PHASE, 0, + IIO_EV_TYPE_MAG, + IIO_EV_DIR_RISING), + timestamp); + + /* Configuration parity error */ + if (FAULT_ONESHOT(AD2S1210_FAULT_CONFIG_PARITY, flags, + st->prev_fault_flags)) + /* + * Userspace should also get notified of this via error return + * when trying to write to any attribute that writes a register. + */ + dev_err_ratelimited(&indio_dev->dev, + "Configuration parity error\n"); + + st->prev_fault_flags = flags; +} + +static int ad2s1210_single_conversion(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + s64 timestamp; + int ret; + + guard(mutex)(&st->lock); + + ad2s1210_toggle_sample_line(st); + timestamp = iio_get_time_ns(indio_dev); + + switch (chan->type) { + case IIO_ANGL: + ret = ad2s1210_set_mode(st, MOD_POS); + break; + case IIO_ANGL_VEL: + ret = ad2s1210_set_mode(st, MOD_VEL); + break; + default: + return -EINVAL; + } + if (ret < 0) + return ret; + ret = spi_read(st->sdev, &st->sample, 3); + if (ret < 0) + return ret; + + switch (chan->type) { + case IIO_ANGL: + *val = be16_to_cpu(st->sample.raw); + ret = IIO_VAL_INT; + break; + case IIO_ANGL_VEL: + *val = (s16)be16_to_cpu(st->sample.raw); + ret = IIO_VAL_INT; + break; + default: + return -EINVAL; + } + + ad2s1210_push_events(indio_dev, st->sample.fault, timestamp); + + return ret; +} + +static int ad2s1210_get_hysteresis(struct ad2s1210_state *st, int *val) +{ + int ret; + + guard(mutex)(&st->lock); + ret = regmap_test_bits(st->regmap, AD2S1210_REG_CONTROL, + AD2S1210_ENABLE_HYSTERESIS); + if (ret < 0) + return ret; + + *val = ret << (2 * (AD2S1210_RES_16 - st->resolution)); + return IIO_VAL_INT; +} + +static int ad2s1210_set_hysteresis(struct ad2s1210_state *st, int val) +{ + guard(mutex)(&st->lock); + return regmap_update_bits(st->regmap, AD2S1210_REG_CONTROL, + AD2S1210_ENABLE_HYSTERESIS, + val ? AD2S1210_ENABLE_HYSTERESIS : 0); +} + +static int ad2s1210_get_phase_lock_range(struct ad2s1210_state *st, + int *val, int *val2) +{ + int ret; + + guard(mutex)(&st->lock); + ret = regmap_test_bits(st->regmap, AD2S1210_REG_CONTROL, + AD2S1210_PHASE_LOCK_RANGE_44); + if (ret < 0) + return ret; + + if (ret) { + /* 44 degrees as radians */ + *val = PHASE_44_DEG_TO_RAD_INT; + *val2 = PHASE_44_DEG_TO_RAD_MICRO; + } else { + /* 360 degrees as radians */ + *val = PHASE_360_DEG_TO_RAD_INT; + *val2 = PHASE_360_DEG_TO_RAD_MICRO; + } + + return IIO_VAL_INT_PLUS_MICRO; +} + +static int ad2s1210_set_phase_lock_range(struct ad2s1210_state *st, + int val, int val2) +{ + int deg; + + /* convert radians to degrees - only two allowable values */ + if (val == PHASE_44_DEG_TO_RAD_INT && val2 == PHASE_44_DEG_TO_RAD_MICRO) + deg = 44; + else if (val == PHASE_360_DEG_TO_RAD_INT && + val2 == PHASE_360_DEG_TO_RAD_MICRO) + deg = 360; + else + return -EINVAL; + + guard(mutex)(&st->lock); + return regmap_update_bits(st->regmap, AD2S1210_REG_CONTROL, + AD2S1210_PHASE_LOCK_RANGE_44, + deg == 44 ? AD2S1210_PHASE_LOCK_RANGE_44 : 0); +} + +/* map resolution to microradians/LSB for LOT registers */ +static const int ad2s1210_lot_threshold_urad_per_lsb[] = { + 6184, /* 10-bit: ~0.35 deg/LSB, 45 deg max */ + 2473, /* 12-bit: ~0.14 deg/LSB, 18 deg max */ + 1237, /* 14-bit: ~0.07 deg/LSB, 9 deg max */ + 1237, /* 16-bit: same as 14-bit */ +}; + +static int ad2s1210_get_voltage_threshold(struct ad2s1210_state *st, + unsigned int reg, int *val) +{ + unsigned int reg_val; + int ret; + + guard(mutex)(&st->lock); + ret = regmap_read(st->regmap, reg, ®_val); + if (ret < 0) + return ret; + + *val = reg_val * THRESHOLD_MILLIVOLT_PER_LSB; + return IIO_VAL_INT; +} + +static int ad2s1210_set_voltage_threshold(struct ad2s1210_state *st, + unsigned int reg, int val) +{ + unsigned int reg_val; + + reg_val = val / THRESHOLD_MILLIVOLT_PER_LSB; + + guard(mutex)(&st->lock); + return regmap_write(st->regmap, reg, reg_val); +} + +static int ad2s1210_get_lot_high_threshold(struct ad2s1210_state *st, + int *val, int *val2) +{ + unsigned int reg_val; + int ret; + + guard(mutex)(&st->lock); + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_HIGH_THRD, ®_val); + if (ret < 0) + return ret; + + *val = 0; + *val2 = reg_val * ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + return IIO_VAL_INT_PLUS_MICRO; +} + +static int ad2s1210_set_lot_high_threshold(struct ad2s1210_state *st, + int val, int val2) +{ + unsigned int high_reg_val, low_reg_val, hysteresis; + int ret; + + /* all valid values are between 0 and pi/4 radians */ + if (val != 0) + return -EINVAL; + + guard(mutex)(&st->lock); + /* + * We need to read both high and low registers first so we can preserve + * the hysteresis. + */ + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_HIGH_THRD, &high_reg_val); + if (ret < 0) + return ret; + + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_LOW_THRD, &low_reg_val); + if (ret < 0) + return ret; + + hysteresis = high_reg_val - low_reg_val; + high_reg_val = val2 / ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + low_reg_val = high_reg_val - hysteresis; + + ret = regmap_write(st->regmap, AD2S1210_REG_LOT_HIGH_THRD, high_reg_val); + if (ret < 0) + return ret; + + return regmap_write(st->regmap, AD2S1210_REG_LOT_LOW_THRD, low_reg_val); +} + +static int ad2s1210_get_lot_low_threshold(struct ad2s1210_state *st, + int *val, int *val2) +{ + unsigned int high_reg_val, low_reg_val; + int ret; + + guard(mutex)(&st->lock); + + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_HIGH_THRD, &high_reg_val); + if (ret < 0) + return ret; + + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_LOW_THRD, &low_reg_val); + if (ret < 0) + return ret; + + /* sysfs value is hysteresis rather than actual low value */ + *val = 0; + *val2 = (high_reg_val - low_reg_val) * + ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + return IIO_VAL_INT_PLUS_MICRO; +} + +static int ad2s1210_set_lot_low_threshold(struct ad2s1210_state *st, + int val, int val2) +{ + unsigned int reg_val, hysteresis; + int ret; + + /* all valid values are between 0 and pi/4 radians */ + if (val != 0) + return -EINVAL; + + hysteresis = val2 / ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + + guard(mutex)(&st->lock); + + ret = regmap_read(st->regmap, AD2S1210_REG_LOT_HIGH_THRD, ®_val); + if (ret < 0) + return ret; + + return regmap_write(st->regmap, AD2S1210_REG_LOT_LOW_THRD, + reg_val - hysteresis); +} + +static int ad2s1210_get_excitation_frequency(struct ad2s1210_state *st, int *val) +{ + unsigned int reg_val; + int ret; + + guard(mutex)(&st->lock); + + ret = regmap_read(st->regmap, AD2S1210_REG_EXCIT_FREQ, ®_val); + if (ret < 0) + return ret; + + *val = reg_val * st->clkin_hz / (1 << 15); + return IIO_VAL_INT; +} + +static int ad2s1210_set_excitation_frequency(struct ad2s1210_state *st, int val) +{ + if (val < AD2S1210_MIN_EXCIT || val > AD2S1210_MAX_EXCIT) + return -EINVAL; + + guard(mutex)(&st->lock); + return ad2s1210_reinit_excitation_frequency(st, val); +} + +static const int ad2s1210_velocity_scale[] = { + 17089132, /* 8.192MHz / (2*pi * 2500 / 2^15) */ + 42722830, /* 8.192MHz / (2*pi * 1000 / 2^15) */ + 85445659, /* 8.192MHz / (2*pi * 500 / 2^15) */ + 341782638, /* 8.192MHz / (2*pi * 125 / 2^15) */ +}; + +static int ad2s1210_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long mask) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return ad2s1210_single_conversion(indio_dev, chan, val); + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_ANGL: + /* approx 0.3 arc min converted to radians */ + *val = 0; + *val2 = 95874; + return IIO_VAL_INT_PLUS_NANO; + case IIO_ANGL_VEL: + *val = st->clkin_hz; + *val2 = ad2s1210_velocity_scale[st->resolution]; + return IIO_VAL_FRACTIONAL; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_FREQUENCY: + switch (chan->type) { + case IIO_ALTVOLTAGE: + return ad2s1210_get_excitation_frequency(st, val); + default: + return -EINVAL; + } + case IIO_CHAN_INFO_HYSTERESIS: + switch (chan->type) { + case IIO_ANGL: + return ad2s1210_get_hysteresis(st, val); + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static int ad2s1210_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, + int *length, long mask) +{ + static const int excitation_frequency_available[] = { + AD2S1210_MIN_EXCIT, + 250, /* step */ + AD2S1210_MAX_EXCIT, + }; + + struct ad2s1210_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_FREQUENCY: + switch (chan->type) { + case IIO_ALTVOLTAGE: + *type = IIO_VAL_INT; + *vals = excitation_frequency_available; + return IIO_AVAIL_RANGE; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_HYSTERESIS: + switch (chan->type) { + case IIO_ANGL: + *vals = st->hysteresis_available; + *type = IIO_VAL_INT; + *length = ARRAY_SIZE(st->hysteresis_available); + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static int ad2s1210_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_FREQUENCY: + switch (chan->type) { + case IIO_ALTVOLTAGE: + return ad2s1210_set_excitation_frequency(st, val); + default: + return -EINVAL; + } + case IIO_CHAN_INFO_HYSTERESIS: + switch (chan->type) { + case IIO_ANGL: + return ad2s1210_set_hysteresis(st, val); + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static const struct iio_event_spec ad2s1210_position_event_spec[] = { + { + /* Tracking error exceeds LOT threshold fault. */ + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = + /* Loss of tracking high threshold. */ + BIT(IIO_EV_INFO_VALUE) | + /* Loss of tracking low threshold. */ + BIT(IIO_EV_INFO_HYSTERESIS), + }, +}; + +static const struct iio_event_spec ad2s1210_velocity_event_spec[] = { + { + /* Velocity exceeds maximum tracking rate fault. */ + .type = IIO_EV_TYPE_MAG, + .dir = IIO_EV_DIR_RISING, + }, +}; + +static const struct iio_event_spec ad2s1210_phase_event_spec[] = { + { + /* Phase error fault. */ + .type = IIO_EV_TYPE_MAG, + .dir = IIO_EV_DIR_RISING, + /* Phase lock range. */ + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, +}; + +static const struct iio_event_spec ad2s1210_monitor_signal_event_spec[] = { + { + /* Sine/cosine below LOS threshold fault. */ + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + /* Loss of signal threshold. */ + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, + { + /* Sine/cosine DOS overrange fault.*/ + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + /* Degredation of signal overrange threshold. */ + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, + { + /* Sine/cosine DOS mismatch fault.*/ + .type = IIO_EV_TYPE_MAG, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE), + }, +}; + +static const struct iio_event_spec ad2s1210_sin_cos_event_spec[] = { + { + /* Sine/cosine clipping fault. */ + .type = IIO_EV_TYPE_MAG, + .dir = IIO_EV_DIR_EITHER, + }, +}; + +static const struct iio_chan_spec ad2s1210_channels[] = { + { + .type = IIO_ANGL, + .indexed = 1, + .channel = 0, + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_BE, + }, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_HYSTERESIS), + .info_mask_separate_available = + BIT(IIO_CHAN_INFO_HYSTERESIS), + }, { + .type = IIO_ANGL_VEL, + .indexed = 1, + .channel = 0, + .scan_index = 1, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_BE, + }, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .event_spec = ad2s1210_velocity_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_velocity_event_spec), + }, + IIO_CHAN_SOFT_TIMESTAMP(2), + { + /* used to configure LOT thresholds and get tracking error */ + .type = IIO_ANGL, + .indexed = 1, + .channel = 1, + .scan_index = -1, + .event_spec = ad2s1210_position_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_position_event_spec), + }, + { + /* used to configure phase lock range and get phase lock error */ + .type = IIO_PHASE, + .indexed = 1, + .channel = 0, + .scan_index = -1, + .event_spec = ad2s1210_phase_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_phase_event_spec), + }, { + /* excitation frequency output */ + .type = IIO_ALTVOLTAGE, + .indexed = 1, + .channel = 0, + .output = 1, + .scan_index = -1, + .info_mask_separate = BIT(IIO_CHAN_INFO_FREQUENCY), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_FREQUENCY), + }, { + /* monitor signal */ + .type = IIO_ALTVOLTAGE, + .indexed = 1, + .channel = 0, + .scan_index = -1, + .event_spec = ad2s1210_monitor_signal_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_monitor_signal_event_spec), + }, { + /* sine input */ + .type = IIO_ALTVOLTAGE, + .indexed = 1, + .channel = 1, + .scan_index = -1, + .event_spec = ad2s1210_sin_cos_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_sin_cos_event_spec), + }, { + /* cosine input */ + .type = IIO_ALTVOLTAGE, + .indexed = 1, + .channel = 2, + .scan_index = -1, + .event_spec = ad2s1210_sin_cos_event_spec, + .num_event_specs = ARRAY_SIZE(ad2s1210_sin_cos_event_spec), + }, +}; + +static ssize_t event_attr_voltage_reg_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); + struct iio_dev_attr *iattr = to_iio_dev_attr(attr); + unsigned int value; + int ret; + + guard(mutex)(&st->lock); + ret = regmap_read(st->regmap, iattr->address, &value); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", value * THRESHOLD_MILLIVOLT_PER_LSB); +} + +static ssize_t event_attr_voltage_reg_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); + struct iio_dev_attr *iattr = to_iio_dev_attr(attr); + u16 data; + int ret; + + ret = kstrtou16(buf, 10, &data); + if (ret) + return -EINVAL; + + guard(mutex)(&st->lock); + ret = regmap_write(st->regmap, iattr->address, + data / THRESHOLD_MILLIVOLT_PER_LSB); + if (ret < 0) + return ret; + + return len; +} + +static ssize_t +in_angl1_thresh_rising_value_available_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); + int step = ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + + return sysfs_emit(buf, "[0 0.%06d 0.%06d]\n", step, step * 0x7F); +} + +static ssize_t +in_angl1_thresh_rising_hysteresis_available_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev)); + int step = ad2s1210_lot_threshold_urad_per_lsb[st->resolution]; + + return sysfs_emit(buf, "[0 0.%06d 0.%06d]\n", step, step * 0x7F); +} + +static IIO_CONST_ATTR(in_phase0_mag_rising_value_available, + __stringify(PHASE_44_DEG_TO_RAD_INT) "." + __stringify(PHASE_44_DEG_TO_RAD_MICRO) " " + __stringify(PHASE_360_DEG_TO_RAD_INT) "." + __stringify(PHASE_360_DEG_TO_RAD_MICRO)); +static IIO_CONST_ATTR(in_altvoltage0_thresh_falling_value_available, + THRESHOLD_RANGE_STR); +static IIO_CONST_ATTR(in_altvoltage0_thresh_rising_value_available, + THRESHOLD_RANGE_STR); +static IIO_CONST_ATTR(in_altvoltage0_mag_rising_value_available, + THRESHOLD_RANGE_STR); +static IIO_DEVICE_ATTR(in_altvoltage0_mag_rising_reset_max, 0644, + event_attr_voltage_reg_show, event_attr_voltage_reg_store, + AD2S1210_REG_DOS_RST_MAX_THRD); +static IIO_CONST_ATTR(in_altvoltage0_mag_rising_reset_max_available, THRESHOLD_RANGE_STR); +static IIO_DEVICE_ATTR(in_altvoltage0_mag_rising_reset_min, 0644, + event_attr_voltage_reg_show, event_attr_voltage_reg_store, + AD2S1210_REG_DOS_RST_MIN_THRD); +static IIO_CONST_ATTR(in_altvoltage0_mag_rising_reset_min_available, THRESHOLD_RANGE_STR); +static IIO_DEVICE_ATTR_RO(in_angl1_thresh_rising_value_available, 0); +static IIO_DEVICE_ATTR_RO(in_angl1_thresh_rising_hysteresis_available, 0); + +static struct attribute *ad2s1210_event_attributes[] = { + &iio_const_attr_in_phase0_mag_rising_value_available.dev_attr.attr, + &iio_const_attr_in_altvoltage0_thresh_falling_value_available.dev_attr.attr, + &iio_const_attr_in_altvoltage0_thresh_rising_value_available.dev_attr.attr, + &iio_const_attr_in_altvoltage0_mag_rising_value_available.dev_attr.attr, + &iio_dev_attr_in_altvoltage0_mag_rising_reset_max.dev_attr.attr, + &iio_const_attr_in_altvoltage0_mag_rising_reset_max_available.dev_attr.attr, + &iio_dev_attr_in_altvoltage0_mag_rising_reset_min.dev_attr.attr, + &iio_const_attr_in_altvoltage0_mag_rising_reset_min_available.dev_attr.attr, + &iio_dev_attr_in_angl1_thresh_rising_value_available.dev_attr.attr, + &iio_dev_attr_in_angl1_thresh_rising_hysteresis_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad2s1210_event_attribute_group = { + .attrs = ad2s1210_event_attributes, +}; + +static int ad2s1210_initial(struct ad2s1210_state *st) +{ + unsigned int data; + int ret; + + guard(mutex)(&st->lock); + + /* Use default config register value plus resolution from devicetree. */ + data = FIELD_PREP(AD2S1210_PHASE_LOCK_RANGE_44, 1); + data |= FIELD_PREP(AD2S1210_ENABLE_HYSTERESIS, 1); + data |= FIELD_PREP(AD2S1210_SET_ENRES, 0x3); + data |= FIELD_PREP(AD2S1210_SET_RES, st->resolution); + + ret = regmap_write(st->regmap, AD2S1210_REG_CONTROL, data); + if (ret < 0) + return ret; + + return ad2s1210_reinit_excitation_frequency(st, AD2S1210_DEF_EXCIT); +} + +static int ad2s1210_read_label(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + char *label) +{ + if (chan->type == IIO_ANGL) { + if (chan->channel == 0) + return sprintf(label, "position\n"); + if (chan->channel == 1) + return sprintf(label, "tracking error\n"); + } + if (chan->type == IIO_ANGL_VEL) + return sprintf(label, "velocity\n"); + if (chan->type == IIO_PHASE) + return sprintf(label, "synthetic reference\n"); + if (chan->type == IIO_ALTVOLTAGE) { + if (chan->output) + return sprintf(label, "excitation\n"); + if (chan->channel == 0) + return sprintf(label, "monitor signal\n"); + if (chan->channel == 1) + return sprintf(label, "cosine\n"); + if (chan->channel == 2) + return sprintf(label, "sine\n"); + } + + return -EINVAL; +} + +static int ad2s1210_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int *val, int *val2) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + switch (chan->type) { + case IIO_ANGL: + switch (info) { + case IIO_EV_INFO_VALUE: + return ad2s1210_get_lot_high_threshold(st, val, val2); + case IIO_EV_INFO_HYSTERESIS: + return ad2s1210_get_lot_low_threshold(st, val, val2); + default: + return -EINVAL; + } + case IIO_ALTVOLTAGE: + if (chan->output) + return -EINVAL; + if (type == IIO_EV_TYPE_THRESH && dir == IIO_EV_DIR_FALLING) + return ad2s1210_get_voltage_threshold(st, + AD2S1210_REG_LOS_THRD, val); + if (type == IIO_EV_TYPE_THRESH && dir == IIO_EV_DIR_RISING) + return ad2s1210_get_voltage_threshold(st, + AD2S1210_REG_DOS_OVR_THRD, val); + if (type == IIO_EV_TYPE_MAG) + return ad2s1210_get_voltage_threshold(st, + AD2S1210_REG_DOS_MIS_THRD, val); + return -EINVAL; + case IIO_PHASE: + return ad2s1210_get_phase_lock_range(st, val, val2); + default: + return -EINVAL; + } +} + +static int ad2s1210_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int val, int val2) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + switch (chan->type) { + case IIO_ANGL: + switch (info) { + case IIO_EV_INFO_VALUE: + return ad2s1210_set_lot_high_threshold(st, val, val2); + case IIO_EV_INFO_HYSTERESIS: + return ad2s1210_set_lot_low_threshold(st, val, val2); + default: + return -EINVAL; + } + case IIO_ALTVOLTAGE: + if (chan->output) + return -EINVAL; + if (type == IIO_EV_TYPE_THRESH && dir == IIO_EV_DIR_FALLING) + return ad2s1210_set_voltage_threshold(st, + AD2S1210_REG_LOS_THRD, val); + if (type == IIO_EV_TYPE_THRESH && dir == IIO_EV_DIR_RISING) + return ad2s1210_set_voltage_threshold(st, + AD2S1210_REG_DOS_OVR_THRD, val); + if (type == IIO_EV_TYPE_MAG) + return ad2s1210_set_voltage_threshold(st, + AD2S1210_REG_DOS_MIS_THRD, val); + return -EINVAL; + case IIO_PHASE: + return ad2s1210_set_phase_lock_range(st, val, val2); + default: + return -EINVAL; + } +} + +static int ad2s1210_read_event_label(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + enum iio_event_type type, + enum iio_event_direction dir, + char *label) +{ + if (chan->type == IIO_ANGL) + return sprintf(label, "LOT\n"); + if (chan->type == IIO_ANGL_VEL) + return sprintf(label, "max tracking rate\n"); + if (chan->type == IIO_PHASE) + return sprintf(label, "phase lock\n"); + if (chan->type == IIO_ALTVOLTAGE) { + if (chan->channel == 0) { + if (type == IIO_EV_TYPE_THRESH && + dir == IIO_EV_DIR_FALLING) + return sprintf(label, "LOS\n"); + if (type == IIO_EV_TYPE_THRESH && + dir == IIO_EV_DIR_RISING) + return sprintf(label, "DOS overrange\n"); + if (type == IIO_EV_TYPE_MAG) + return sprintf(label, "DOS mismatch\n"); + } + if (chan->channel == 1 || chan->channel == 2) + return sprintf(label, "clipped\n"); + } + + return -EINVAL; +} + +static int ad2s1210_debugfs_reg_access(struct iio_dev *indio_dev, + unsigned int reg, unsigned int writeval, + unsigned int *readval) +{ + struct ad2s1210_state *st = iio_priv(indio_dev); + + guard(mutex)(&st->lock); + + if (readval) + return regmap_read(st->regmap, reg, readval); + + return regmap_write(st->regmap, reg, writeval); +} + +static irqreturn_t ad2s1210_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad2s1210_state *st = iio_priv(indio_dev); + size_t chan = 0; + int ret; + + guard(mutex)(&st->lock); + + memset(&st->scan, 0, sizeof(st->scan)); + ad2s1210_toggle_sample_line(st); + + if (test_bit(0, indio_dev->active_scan_mask)) { + ret = ad2s1210_set_mode(st, MOD_POS); + if (ret < 0) + goto error_ret; + + ret = spi_read(st->sdev, &st->sample, 3); + if (ret < 0) + goto error_ret; + + memcpy(&st->scan.chan[chan++], &st->sample.raw, 2); + } + + if (test_bit(1, indio_dev->active_scan_mask)) { + ret = ad2s1210_set_mode(st, MOD_VEL); + if (ret < 0) + goto error_ret; + + ret = spi_read(st->sdev, &st->sample, 3); + if (ret < 0) + goto error_ret; + + memcpy(&st->scan.chan[chan++], &st->sample.raw, 2); + } + + ad2s1210_push_events(indio_dev, st->sample.fault, pf->timestamp); + iio_push_to_buffers_with_timestamp(indio_dev, &st->scan, pf->timestamp); + +error_ret: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static const struct iio_info ad2s1210_info = { + .event_attrs = &ad2s1210_event_attribute_group, + .read_raw = ad2s1210_read_raw, + .read_avail = ad2s1210_read_avail, + .write_raw = ad2s1210_write_raw, + .read_label = ad2s1210_read_label, + .read_event_value = ad2s1210_read_event_value, + .write_event_value = ad2s1210_write_event_value, + .read_event_label = ad2s1210_read_event_label, + .debugfs_reg_access = &ad2s1210_debugfs_reg_access, +}; + +static int ad2s1210_setup_properties(struct ad2s1210_state *st) +{ + struct device *dev = &st->sdev->dev; + u32 val; + int ret; + + ret = device_property_read_u32(dev, "assigned-resolution-bits", &val); + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to read assigned-resolution-bits property\n"); + + if (val < 10 || val > 16) + return dev_err_probe(dev, -EINVAL, + "resolution out of range: %u\n", val); + + st->resolution = (val - 10) >> 1; + /* + * These are values that correlate to the hysteresis bit in the Control + * register. 0 = disabled, 1 = enabled. When enabled, the actual + * hysteresis is +/- 1 LSB of the raw position value. Which bit is the + * LSB depends on the specified resolution. + */ + st->hysteresis_available[0] = 0; + st->hysteresis_available[1] = 1 << (2 * (AD2S1210_RES_16 - + st->resolution)); + + return 0; +} + +static int ad2s1210_setup_clocks(struct ad2s1210_state *st) +{ + struct device *dev = &st->sdev->dev; + struct clk *clk; + + clk = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n"); + + st->clkin_hz = clk_get_rate(clk); + if (st->clkin_hz < AD2S1210_MIN_CLKIN || st->clkin_hz > AD2S1210_MAX_CLKIN) + return dev_err_probe(dev, -EINVAL, + "clock frequency out of range: %lu\n", + st->clkin_hz); + + return 0; +} + +static int ad2s1210_setup_gpios(struct ad2s1210_state *st) +{ + struct device *dev = &st->sdev->dev; + struct gpio_descs *resolution_gpios; + DECLARE_BITMAP(bitmap, 2); + int ret; + + /* should not be sampling on startup */ + st->sample_gpio = devm_gpiod_get(dev, "sample", GPIOD_OUT_LOW); + if (IS_ERR(st->sample_gpio)) + return dev_err_probe(dev, PTR_ERR(st->sample_gpio), + "failed to request sample GPIO\n"); + + /* both pins high means that we start in config mode */ + st->mode_gpios = devm_gpiod_get_array(dev, "mode", GPIOD_OUT_HIGH); + if (IS_ERR(st->mode_gpios)) + return dev_err_probe(dev, PTR_ERR(st->mode_gpios), + "failed to request mode GPIOs\n"); + + if (st->mode_gpios->ndescs != 2) + return dev_err_probe(dev, -EINVAL, + "requires exactly 2 mode-gpios\n"); + + /* + * If resolution gpios are provided, they get set to the required + * resolution, otherwise it is assumed the RES0 and RES1 pins are + * hard-wired to match the resolution indicated in the devicetree. + */ + resolution_gpios = devm_gpiod_get_array_optional(dev, "resolution", + GPIOD_ASIS); + if (IS_ERR(resolution_gpios)) + return dev_err_probe(dev, PTR_ERR(resolution_gpios), + "failed to request resolution GPIOs\n"); + + if (resolution_gpios) { + if (resolution_gpios->ndescs != 2) + return dev_err_probe(dev, -EINVAL, + "requires exactly 2 resolution-gpios\n"); + + bitmap[0] = st->resolution; + + ret = gpiod_set_array_value(resolution_gpios->ndescs, + resolution_gpios->desc, + resolution_gpios->info, + bitmap); + if (ret < 0) + return dev_err_probe(dev, ret, + "failed to set resolution gpios\n"); + } + + return 0; +} + +static const struct regmap_range ad2s1210_regmap_readable_ranges[] = { + regmap_reg_range(AD2S1210_REG_POSITION_MSB, AD2S1210_REG_VELOCITY_LSB), + regmap_reg_range(AD2S1210_REG_LOS_THRD, AD2S1210_REG_LOT_LOW_THRD), + regmap_reg_range(AD2S1210_REG_EXCIT_FREQ, AD2S1210_REG_CONTROL), + regmap_reg_range(AD2S1210_REG_FAULT, AD2S1210_REG_FAULT), +}; + +static const struct regmap_access_table ad2s1210_regmap_rd_table = { + .yes_ranges = ad2s1210_regmap_readable_ranges, + .n_yes_ranges = ARRAY_SIZE(ad2s1210_regmap_readable_ranges), +}; + +static const struct regmap_range ad2s1210_regmap_writeable_ranges[] = { + regmap_reg_range(AD2S1210_REG_LOS_THRD, AD2S1210_REG_LOT_LOW_THRD), + regmap_reg_range(AD2S1210_REG_EXCIT_FREQ, AD2S1210_REG_CONTROL), + regmap_reg_range(AD2S1210_REG_SOFT_RESET, AD2S1210_REG_SOFT_RESET), + regmap_reg_range(AD2S1210_REG_FAULT, AD2S1210_REG_FAULT), +}; + +static const struct regmap_access_table ad2s1210_regmap_wr_table = { + .yes_ranges = ad2s1210_regmap_writeable_ranges, + .n_yes_ranges = ARRAY_SIZE(ad2s1210_regmap_writeable_ranges), +}; + +static int ad2s1210_setup_regmap(struct ad2s1210_state *st) +{ + struct device *dev = &st->sdev->dev; + const struct regmap_config config = { + .reg_bits = 8, + .val_bits = 8, + .disable_locking = true, + .reg_read = ad2s1210_regmap_reg_read, + .reg_write = ad2s1210_regmap_reg_write, + .rd_table = &ad2s1210_regmap_rd_table, + .wr_table = &ad2s1210_regmap_wr_table, + .can_sleep = true, + }; + + st->regmap = devm_regmap_init(dev, NULL, st, &config); + if (IS_ERR(st->regmap)) + return dev_err_probe(dev, PTR_ERR(st->regmap), + "failed to allocate register map\n"); + + return 0; +} + +static int ad2s1210_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct ad2s1210_state *st; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + st = iio_priv(indio_dev); + + mutex_init(&st->lock); + st->sdev = spi; + + ret = ad2s1210_setup_properties(st); + if (ret < 0) + return ret; + + ret = ad2s1210_setup_clocks(st); + if (ret < 0) + return ret; + + ret = ad2s1210_setup_gpios(st); + if (ret < 0) + return ret; + + ret = ad2s1210_setup_regmap(st); + if (ret < 0) + return ret; + + ret = ad2s1210_initial(st); + if (ret < 0) + return ret; + + indio_dev->info = &ad2s1210_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ad2s1210_channels; + indio_dev->num_channels = ARRAY_SIZE(ad2s1210_channels); + indio_dev->name = spi_get_device_id(spi)->name; + + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, + &iio_pollfunc_store_time, + &ad2s1210_trigger_handler, NULL); + if (ret < 0) + return dev_err_probe(&spi->dev, ret, + "iio triggered buffer setup failed\n"); + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct of_device_id ad2s1210_of_match[] = { + { .compatible = "adi,ad2s1210", }, + { } +}; +MODULE_DEVICE_TABLE(of, ad2s1210_of_match); + +static const struct spi_device_id ad2s1210_id[] = { + { "ad2s1210" }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad2s1210_id); + +static struct spi_driver ad2s1210_driver = { + .driver = { + .name = "ad2s1210", + .of_match_table = ad2s1210_of_match, + }, + .probe = ad2s1210_probe, + .id_table = ad2s1210_id, +}; +module_spi_driver(ad2s1210_driver); + +MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>"); +MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver"); +MODULE_LICENSE("GPL v2"); |