diff options
Diffstat (limited to 'drivers/iio/dac/ad3552r-common.c')
| -rw-r--r-- | drivers/iio/dac/ad3552r-common.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad3552r-common.c b/drivers/iio/dac/ad3552r-common.c new file mode 100644 index 000000000000..2dfeca3656d2 --- /dev/null +++ b/drivers/iio/dac/ad3552r-common.c @@ -0,0 +1,249 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright (c) 2010-2024 Analog Devices Inc. +// Copyright (c) 2024 Baylibre, SAS + +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/regulator/consumer.h> + +#include "ad3552r.h" + +const s32 ad3552r_ch_ranges[AD3552R_MAX_RANGES][2] = { + [AD3552R_CH_OUTPUT_RANGE_0__2P5V] = { 0, 2500 }, + [AD3552R_CH_OUTPUT_RANGE_0__5V] = { 0, 5000 }, + [AD3552R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 }, + [AD3552R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 }, + [AD3552R_CH_OUTPUT_RANGE_NEG_10__10V] = { -10000, 10000 } +}; +EXPORT_SYMBOL_NS_GPL(ad3552r_ch_ranges, IIO_AD3552R); + +const s32 ad3542r_ch_ranges[AD3542R_MAX_RANGES][2] = { + [AD3542R_CH_OUTPUT_RANGE_0__2P5V] = { 0, 2500 }, + [AD3542R_CH_OUTPUT_RANGE_0__3V] = { 0, 3000 }, + [AD3542R_CH_OUTPUT_RANGE_0__5V] = { 0, 5000 }, + [AD3542R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 }, + [AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V] = { -2500, 7500 }, + [AD3542R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 } +}; +EXPORT_SYMBOL_NS_GPL(ad3542r_ch_ranges, IIO_AD3552R); + +/* Gain * AD3552R_GAIN_SCALE */ +static const s32 gains_scaling_table[] = { + [AD3552R_CH_GAIN_SCALING_1] = 1000, + [AD3552R_CH_GAIN_SCALING_0_5] = 500, + [AD3552R_CH_GAIN_SCALING_0_25] = 250, + [AD3552R_CH_GAIN_SCALING_0_125] = 125 +}; + +u16 ad3552r_calc_custom_gain(u8 p, u8 n, s16 goffs) +{ + return FIELD_PREP(AD3552R_MASK_CH_RANGE_OVERRIDE, 1) | + FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_P, p) | + FIELD_PREP(AD3552R_MASK_CH_GAIN_SCALING_N, n) | + FIELD_PREP(AD3552R_MASK_CH_OFFSET_BIT_8, abs(goffs)) | + FIELD_PREP(AD3552R_MASK_CH_OFFSET_POLARITY, goffs < 0); +} +EXPORT_SYMBOL_NS_GPL(ad3552r_calc_custom_gain, IIO_AD3552R); + +static void ad3552r_get_custom_range(struct ad3552r_ch_data *ch_data, + s32 *v_min, s32 *v_max) +{ + s64 vref, tmp, common, offset, gn, gp; + /* + * From datasheet formula (In Volts): + * Vmin = 2.5 + [(GainN + Offset / 1024) * 2.5 * Rfb * 1.03] + * Vmax = 2.5 - [(GainP + Offset / 1024) * 2.5 * Rfb * 1.03] + * Calculus are converted to milivolts + */ + vref = 2500; + /* 2.5 * 1.03 * 1000 (To mV) */ + common = 2575 * ch_data->rfb; + offset = ch_data->gain_offset; + + gn = gains_scaling_table[ch_data->n]; + tmp = (1024 * gn + AD3552R_GAIN_SCALE * offset) * common; + tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE); + *v_max = vref + tmp; + + gp = gains_scaling_table[ch_data->p]; + tmp = (1024 * gp - AD3552R_GAIN_SCALE * offset) * common; + tmp = div_s64(tmp, 1024 * AD3552R_GAIN_SCALE); + *v_min = vref - tmp; +} + +void ad3552r_calc_gain_and_offset(struct ad3552r_ch_data *ch_data, + const struct ad3552r_model_data *model_data) +{ + s32 idx, v_max, v_min, span, rem; + s64 tmp; + + if (ch_data->range_override) { + ad3552r_get_custom_range(ch_data, &v_min, &v_max); + } else { + /* Normal range */ + idx = ch_data->range; + v_min = model_data->ranges_table[idx][0]; + v_max = model_data->ranges_table[idx][1]; + } + + /* + * From datasheet formula: + * Vout = Span * (D / 65536) + Vmin + * Converted to scale and offset: + * Scale = Span / 65536 + * Offset = 65536 * Vmin / Span + * + * Reminders are in micros in order to be printed as + * IIO_VAL_INT_PLUS_MICRO + */ + span = v_max - v_min; + ch_data->scale_int = div_s64_rem(span, 65536, &rem); + /* Do operations in microvolts */ + ch_data->scale_dec = DIV_ROUND_CLOSEST((s64)rem * 1000000, 65536); + + ch_data->offset_int = div_s64_rem(v_min * 65536, span, &rem); + tmp = (s64)rem * 1000000; + ch_data->offset_dec = div_s64(tmp, span); +} +EXPORT_SYMBOL_NS_GPL(ad3552r_calc_gain_and_offset, IIO_AD3552R); + +int ad3552r_get_ref_voltage(struct device *dev, u32 *val) +{ + int voltage; + int delta = 100000; + + voltage = devm_regulator_get_enable_read_voltage(dev, "vref"); + if (voltage < 0 && voltage != -ENODEV) + return dev_err_probe(dev, voltage, + "Error getting vref voltage\n"); + + if (voltage == -ENODEV) { + if (device_property_read_bool(dev, "adi,vref-out-en")) + *val = AD3552R_INTERNAL_VREF_PIN_2P5V; + else + *val = AD3552R_INTERNAL_VREF_PIN_FLOATING; + + return 0; + } + + if (voltage > 2500000 + delta || voltage < 2500000 - delta) { + dev_warn(dev, "vref-supply must be 2.5V"); + return -EINVAL; + } + + *val = AD3552R_EXTERNAL_VREF_PIN_INPUT; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(ad3552r_get_ref_voltage, IIO_AD3552R); + +int ad3552r_get_drive_strength(struct device *dev, u32 *val) +{ + int err; + u32 drive_strength; + + err = device_property_read_u32(dev, "adi,sdo-drive-strength", + &drive_strength); + if (err) + return err; + + if (drive_strength > 3) { + dev_err_probe(dev, -EINVAL, + "adi,sdo-drive-strength must be less than 4\n"); + return -EINVAL; + } + + *val = drive_strength; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(ad3552r_get_drive_strength, IIO_AD3552R); + +int ad3552r_get_custom_gain(struct device *dev, struct fwnode_handle *child, + u8 *gs_p, u8 *gs_n, u16 *rfb, s16 *goffs) +{ + int err; + u32 val; + struct fwnode_handle *gain_child __free(fwnode_handle) = + fwnode_get_named_child_node(child, + "custom-output-range-config"); + + if (!gain_child) + return dev_err_probe(dev, -EINVAL, + "custom-output-range-config mandatory\n"); + + err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-p", &val); + if (err) + return dev_err_probe(dev, err, + "adi,gain-scaling-p mandatory\n"); + *gs_p = val; + + err = fwnode_property_read_u32(gain_child, "adi,gain-scaling-n", &val); + if (err) + return dev_err_probe(dev, err, + "adi,gain-scaling-n property mandatory\n"); + *gs_n = val; + + err = fwnode_property_read_u32(gain_child, "adi,rfb-ohms", &val); + if (err) + return dev_err_probe(dev, err, + "adi,rfb-ohms mandatory\n"); + *rfb = val; + + err = fwnode_property_read_u32(gain_child, "adi,gain-offset", &val); + if (err) + return dev_err_probe(dev, err, + "adi,gain-offset mandatory\n"); + *goffs = val; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(ad3552r_get_custom_gain, IIO_AD3552R); + +static int ad3552r_find_range(const struct ad3552r_model_data *model_info, + s32 *vals) +{ + int i; + + for (i = 0; i < model_info->num_ranges; i++) + if (vals[0] == model_info->ranges_table[i][0] * 1000 && + vals[1] == model_info->ranges_table[i][1] * 1000) + return i; + + return -EINVAL; +} + +int ad3552r_get_output_range(struct device *dev, + const struct ad3552r_model_data *model_info, + struct fwnode_handle *child, u32 *val) +{ + int ret; + s32 vals[2]; + + /* This property is optional, so returning -ENOENT if missing */ + if (!fwnode_property_present(child, "adi,output-range-microvolt")) + return -ENOENT; + + ret = fwnode_property_read_u32_array(child, + "adi,output-range-microvolt", + vals, 2); + if (ret) + return dev_err_probe(dev, ret, + "invalid adi,output-range-microvolt\n"); + + ret = ad3552r_find_range(model_info, vals); + if (ret < 0) + return dev_err_probe(dev, ret, + "invalid adi,output-range-microvolt value\n"); + + *val = ret; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(ad3552r_get_output_range, IIO_AD3552R); + +MODULE_DESCRIPTION("ad3552r common functions"); +MODULE_LICENSE("GPL"); |