iio: dac: ad3552r: extract common code (no changes in behavior intended)

[ Upstream commit f665d7d ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: spectrum70

drivers/iio/dac/Makefile

@@ -4,7 +4,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
-obj-$(CONFIG_AD3552R) += ad3552r.o
+obj-$(CONFIG_AD3552R) += ad3552r.o ad3552r-common.o
 obj-$(CONFIG_AD5360) += ad5360.o
 obj-$(CONFIG_AD5380) += ad5380.o
 obj-$(CONFIG_AD5421) += ad5421.o

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");