linux/drivers/iio/dac/ad3552r-hs.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Analog Devices AD3552R
 * Digital to Analog converter driver, High Speed version
 *
 * Copyright 2024 Analog Devices Inc.
 */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/backend.h>
#include <linux/iio/buffer.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/units.h>

#include "ad3552r.h"
#include "ad3552r-hs.h"

struct ad3552r_hs_state {
	const struct ad3552r_model_data *model_data;
	struct gpio_desc *reset_gpio;
	struct device *dev;
	struct iio_backend *back;
	bool single_channel;
	struct ad3552r_ch_data ch_data[AD3552R_MAX_CH];
	struct ad3552r_hs_platform_data *data;
};

static int ad3552r_qspi_update_reg_bits(struct ad3552r_hs_state *st,
					u32 reg, u32 mask, u32 val,
					size_t xfer_size)
{
	u32 rval;
	int ret;

	ret = st->data->bus_reg_read(st->back, reg, &rval, xfer_size);
	if (ret)
		return ret;

	rval = (rval & ~mask) | val;

	return st->data->bus_reg_write(st->back, reg, rval, xfer_size);
}

static int ad3552r_hs_read_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan,
			       int *val, int *val2, long mask)
{
	struct ad3552r_hs_state *st = iio_priv(indio_dev);
	int ret;
	int ch = chan->channel;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		/*
		 * Using 4 lanes (QSPI), then using 2 as DDR mode is
		 * considered always on (considering buffering mode always).
		 */
		*val = DIV_ROUND_CLOSEST(st->data->bus_sample_data_clock_hz *
					 4 * 2, chan->scan_type.realbits);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_RAW:
		ret = st->data->bus_reg_read(st->back,
				AD3552R_REG_ADDR_CH_DAC_16B(chan->channel),
				val, 2);
		if (ret)
			return ret;

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = st->ch_data[ch].scale_int;
		*val2 = st->ch_data[ch].scale_dec;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_OFFSET:
		*val = st->ch_data[ch].offset_int;
		*val2 = st->ch_data[ch].offset_dec;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static int ad3552r_hs_write_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int val, int val2, long mask)
{
	struct ad3552r_hs_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
			return st->data->bus_reg_write(st->back,
				    AD3552R_REG_ADDR_CH_DAC_16B(chan->channel),
				    val, 2);
		}
		unreachable();
	default:
		return -EINVAL;
	}
}

static int ad3552r_hs_buffer_postenable(struct iio_dev *indio_dev)
{
	struct ad3552r_hs_state *st = iio_priv(indio_dev);
	struct iio_backend_data_fmt fmt = {
		.type = IIO_BACKEND_DATA_UNSIGNED
	};
	int loop_len, val, ret;

	switch (*indio_dev->active_scan_mask) {
	case AD3552R_CH0_ACTIVE:
		st->single_channel = true;
		loop_len = 2;
		val = AD3552R_REG_ADDR_CH_DAC_16B(0);
		break;
	case AD3552R_CH1_ACTIVE:
		st->single_channel = true;
		loop_len = 2;
		val = AD3552R_REG_ADDR_CH_DAC_16B(1);
		break;
	case AD3552R_CH0_ACTIVE | AD3552R_CH1_ACTIVE:
		st->single_channel = false;
		loop_len = 4;
		val = AD3552R_REG_ADDR_CH_DAC_16B(1);
		break;
	default:
		return -EINVAL;
	}

	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_STREAM_MODE,
				      loop_len, 1);
	if (ret)
		return ret;

	/* Inform DAC chip to switch into DDR mode */
	ret = ad3552r_qspi_update_reg_bits(st,
					   AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
					   AD3552R_MASK_SPI_CONFIG_DDR,
					   AD3552R_MASK_SPI_CONFIG_DDR, 1);
	if (ret)
		return ret;

	/* Inform DAC IP to go for DDR mode from now on */
	ret = iio_backend_ddr_enable(st->back);
	if (ret) {
		dev_err(st->dev, "could not set DDR mode, not streaming");
		goto exit_err;
	}

	ret = iio_backend_data_transfer_addr(st->back, val);
	if (ret)
		goto exit_err;

	ret = iio_backend_data_format_set(st->back, 0, &fmt);
	if (ret)
		goto exit_err;

	ret = iio_backend_data_stream_enable(st->back);
	if (ret)
		goto exit_err;

	return 0;

exit_err:
	ad3552r_qspi_update_reg_bits(st,
				     AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
				     AD3552R_MASK_SPI_CONFIG_DDR,
				     0, 1);

	iio_backend_ddr_disable(st->back);

	return ret;
}

static int ad3552r_hs_buffer_predisable(struct iio_dev *indio_dev)
{
	struct ad3552r_hs_state *st = iio_priv(indio_dev);
	int ret;

	ret = iio_backend_data_stream_disable(st->back);
	if (ret)
		return ret;

	/* Inform DAC to set in SDR mode */
	ret = ad3552r_qspi_update_reg_bits(st,
					   AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
					   AD3552R_MASK_SPI_CONFIG_DDR,
					   0, 1);
	if (ret)
		return ret;

	ret = iio_backend_ddr_disable(st->back);
	if (ret)
		return ret;

	return 0;
}

static inline int ad3552r_hs_set_output_range(struct ad3552r_hs_state *st,
					      int ch, unsigned int mode)
{
	int val;

	if (ch == 0)
		val = FIELD_PREP(AD3552R_MASK_CH0_RANGE, mode);
	else
		val = FIELD_PREP(AD3552R_MASK_CH1_RANGE, mode);

	return ad3552r_qspi_update_reg_bits(st,
					AD3552R_REG_ADDR_CH0_CH1_OUTPUT_RANGE,
					AD3552R_MASK_CH_OUTPUT_RANGE_SEL(ch),
					val, 1);
}

static int ad3552r_hs_reset(struct ad3552r_hs_state *st)
{
	int ret;

	st->reset_gpio = devm_gpiod_get_optional(st->dev,
						 "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(st->reset_gpio))
		return PTR_ERR(st->reset_gpio);

	if (st->reset_gpio) {
		fsleep(10);
		gpiod_set_value_cansleep(st->reset_gpio, 0);
	} else {
		ret = ad3552r_qspi_update_reg_bits(st,
					AD3552R_REG_ADDR_INTERFACE_CONFIG_A,
					AD3552R_MASK_SOFTWARE_RESET,
					AD3552R_MASK_SOFTWARE_RESET, 1);
		if (ret)
			return ret;
	}
	msleep(100);

	return 0;
}

static int ad3552r_hs_scratch_pad_test(struct ad3552r_hs_state *st)
{
	int ret, val;

	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
				      AD3552R_SCRATCH_PAD_TEST_VAL1, 1);
	if (ret)
		return ret;

	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
				     &val, 1);
	if (ret)
		return ret;

	if (val != AD3552R_SCRATCH_PAD_TEST_VAL1)
		return dev_err_probe(st->dev, -EIO,
			"SCRATCH_PAD_TEST mismatch. Expected 0x%x, Read 0x%x\n",
			AD3552R_SCRATCH_PAD_TEST_VAL1, val);

	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
				      AD3552R_SCRATCH_PAD_TEST_VAL2, 1);
	if (ret)
		return ret;

	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_SCRATCH_PAD,
				     &val, 1);
	if (ret)
		return ret;

	if (val != AD3552R_SCRATCH_PAD_TEST_VAL2)
		return dev_err_probe(st->dev, -EIO,
			"SCRATCH_PAD_TEST mismatch. Expected 0x%x, Read 0x%x\n",
			AD3552R_SCRATCH_PAD_TEST_VAL2, val);

	return 0;
}

static int ad3552r_hs_setup_custom_gain(struct ad3552r_hs_state *st,
					int ch, u16 gain, u16 offset)
{
	int ret;

	ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_CH_OFFSET(ch),
				      offset, 1);
	if (ret)
		return ret;

	return st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_CH_GAIN(ch),
				      gain, 1);
}

static int ad3552r_hs_setup(struct ad3552r_hs_state *st)
{
	u16 id;
	u16 gain = 0, offset = 0;
	u32 ch, val, range;
	int ret;

	ret = ad3552r_hs_reset(st);
	if (ret)
		return ret;

	ret = iio_backend_ddr_disable(st->back);
	if (ret)
		return ret;

	ret = ad3552r_hs_scratch_pad_test(st);
	if (ret)
		return ret;

	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_PRODUCT_ID_L,
				     &val, 1);
	if (ret)
		return ret;

	id = val;

	ret = st->data->bus_reg_read(st->back, AD3552R_REG_ADDR_PRODUCT_ID_H,
				     &val, 1);
	if (ret)
		return ret;

	id |= val << 8;
	if (id != st->model_data->chip_id)
		dev_info(st->dev, "Chip ID error. Expected 0x%x, Read 0x%x\n",
			 AD3552R_ID, id);

	ret = st->data->bus_reg_write(st->back,
				      AD3552R_REG_ADDR_SH_REFERENCE_CONFIG,
				      0, 1);
	if (ret)
		return ret;

	ret = st->data->bus_reg_write(st->back,
				AD3552R_REG_ADDR_TRANSFER_REGISTER,
				FIELD_PREP(AD3552R_MASK_MULTI_IO_MODE,
					   AD3552R_QUAD_SPI) |
				AD3552R_MASK_STREAM_LENGTH_KEEP_VALUE, 1);
	if (ret)
		return ret;

	ret = iio_backend_data_source_set(st->back, 0, IIO_BACKEND_EXTERNAL);
	if (ret)
		return ret;

	ret = iio_backend_data_source_set(st->back, 1, IIO_BACKEND_EXTERNAL);
	if (ret)
		return ret;

	ret = ad3552r_get_ref_voltage(st->dev, &val);
	if (ret < 0)
		return ret;

	val = ret;

	ret = ad3552r_qspi_update_reg_bits(st,
				AD3552R_REG_ADDR_SH_REFERENCE_CONFIG,
				AD3552R_MASK_REFERENCE_VOLTAGE_SEL,
				val, 1);
	if (ret)
		return ret;

	ret = ad3552r_get_drive_strength(st->dev, &val);
	if (!ret) {
		ret = ad3552r_qspi_update_reg_bits(st,
					AD3552R_REG_ADDR_INTERFACE_CONFIG_D,
					AD3552R_MASK_SDO_DRIVE_STRENGTH,
					val, 1);
		if (ret)
			return ret;
	}

	device_for_each_child_node_scoped(st->dev, child) {
		ret = fwnode_property_read_u32(child, "reg", &ch);
		if (ret)
			return dev_err_probe(st->dev, ret,
					     "reg property missing\n");

		ret = ad3552r_get_output_range(st->dev, st->model_data, child,
					       &range);
		if (ret && ret != -ENOENT)
			return ret;
		if (ret == -ENOENT) {
			ret = ad3552r_get_custom_gain(st->dev, child,
						&st->ch_data[ch].p,
						&st->ch_data[ch].n,
						&st->ch_data[ch].rfb,
						&st->ch_data[ch].gain_offset);
			if (ret)
				return ret;

			gain = ad3552r_calc_custom_gain(st->ch_data[ch].p,
						st->ch_data[ch].n,
						st->ch_data[ch].gain_offset);
			offset = abs(st->ch_data[ch].gain_offset);

			st->ch_data[ch].range_override = 1;

			ret = ad3552r_hs_setup_custom_gain(st, ch, gain,
							   offset);
			if (ret)
				return ret;
		} else {
			st->ch_data[ch].range = range;

			ret = ad3552r_hs_set_output_range(st, ch, range);
			if (ret)
				return ret;
		}

		ad3552r_calc_gain_and_offset(&st->ch_data[ch], st->model_data);
	}

	return 0;
}

static const struct iio_buffer_setup_ops ad3552r_hs_buffer_setup_ops = {
	.postenable = ad3552r_hs_buffer_postenable,
	.predisable = ad3552r_hs_buffer_predisable,
};

#define AD3552R_CHANNEL(ch) { \
	.type = IIO_VOLTAGE, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
			      BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
			      BIT(IIO_CHAN_INFO_SCALE) | \
			      BIT(IIO_CHAN_INFO_OFFSET), \
	.output = 1, \
	.indexed = 1, \
	.channel = (ch), \
	.scan_index = (ch), \
	.scan_type = { \
		.sign = 'u', \
		.realbits = 16, \
		.storagebits = 16, \
		.endianness = IIO_BE, \
	} \
}

static const struct iio_chan_spec ad3552r_hs_channels[] = {
	AD3552R_CHANNEL(0),
	AD3552R_CHANNEL(1),
};

static const struct iio_info ad3552r_hs_info = {
	.read_raw = &ad3552r_hs_read_raw,
	.write_raw = &ad3552r_hs_write_raw,
};

static int ad3552r_hs_probe(struct platform_device *pdev)
{
	struct ad3552r_hs_state *st;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	st->dev = &pdev->dev;

	st->data = dev_get_platdata(st->dev);
	if (!st->data)
		return dev_err_probe(st->dev, -ENODEV, "No platform data !");

	st->back = devm_iio_backend_get(&pdev->dev, NULL);
	if (IS_ERR(st->back))
		return PTR_ERR(st->back);

	ret = devm_iio_backend_enable(&pdev->dev, st->back);
	if (ret)
		return ret;

	st->model_data = device_get_match_data(&pdev->dev);
	if (!st->model_data)
		return -ENODEV;

	indio_dev->name = "ad3552r";
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->setup_ops = &ad3552r_hs_buffer_setup_ops;
	indio_dev->channels = ad3552r_hs_channels;
	indio_dev->num_channels = ARRAY_SIZE(ad3552r_hs_channels);
	indio_dev->info = &ad3552r_hs_info;

	ret = devm_iio_backend_request_buffer(&pdev->dev, st->back, indio_dev);
	if (ret)
		return ret;

	ret = ad3552r_hs_setup(st);
	if (ret)
		return ret;

	return devm_iio_device_register(&pdev->dev, indio_dev);
}

static const struct ad3552r_model_data ad3552r_model_data = {
	.model_name = "ad3552r",
	.chip_id = AD3552R_ID,
	.num_hw_channels = 2,
	.ranges_table = ad3552r_ch_ranges,
	.num_ranges = ARRAY_SIZE(ad3552r_ch_ranges),
};

static const struct of_device_id ad3552r_hs_of_id[] = {
	{ .compatible = "adi,ad3552r", .data = &ad3552r_model_data },
	{ }
};
MODULE_DEVICE_TABLE(of, ad3552r_hs_of_id);

static struct platform_driver ad3552r_hs_driver = {
	.driver = {
		.name = "ad3552r-hs",
		.of_match_table = ad3552r_hs_of_id,
	},
	.probe = ad3552r_hs_probe,
};
module_platform_driver(ad3552r_hs_driver);

MODULE_AUTHOR("Dragos Bogdan <dragos.bogdan@analog.com>");
MODULE_AUTHOR("Angelo Dureghello <adueghello@baylibre.com>");
MODULE_DESCRIPTION("AD3552R Driver - High Speed version");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_BACKEND");
MODULE_IMPORT_NS("IIO_AD3552R");