linux-stable/drivers/iio/dac/ad3552r-common.c
Angelo Dureghello f665d7d33d iio: dac: ad3552r: extract common code (no changes in behavior intended)
Extracting common code, to share common code to be used later
by the AXI driver version (ad3552r-axi.c).

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20241028-wip-bl-ad3552r-axi-v0-iio-testing-v9-6-f6960b4f9719@kernel-space.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-11-01 14:54:48 +00:00

250 lines
6.9 KiB
C

// 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");