drivers/iio/dac/ad5686-spi.c

Source file repositories/reference/linux-study-clean/drivers/iio/dac/ad5686-spi.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/dac/ad5686-spi.c
Extension
.c
Size
3017 bytes
Lines
133
Domain
Driver Families
Bucket
drivers/iio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * AD5672R, AD5674R, AD5676, AD5676R, AD5679R,
 * AD5681R, AD5682R, AD5683, AD5683R, AD5684,
 * AD5684R, AD5685R, AD5686, AD5686R
 * Digital to analog converters driver
 *
 * Copyright 2018 Analog Devices Inc.
 */

#include "ad5686.h"

#include <linux/module.h>
#include <linux/spi/spi.h>

static int ad5686_spi_write(struct ad5686_state *st,
			    u8 cmd, u8 addr, u16 val)
{
	struct spi_device *spi = to_spi_device(st->dev);
	u8 tx_len, *buf;

	switch (st->chip_info->regmap_type) {
	case AD5310_REGMAP:
		st->data[0].d16 = cpu_to_be16(AD5310_CMD(cmd) |
					      val);
		buf = &st->data[0].d8[0];
		tx_len = 2;
		break;
	case AD5683_REGMAP:
		st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
					      AD5683_DATA(val));
		buf = &st->data[0].d8[1];
		tx_len = 3;
		break;
	case AD5686_REGMAP:
		st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
					      AD5686_ADDR(addr) |
					      val);
		buf = &st->data[0].d8[1];
		tx_len = 3;
		break;
	default:
		return -EINVAL;
	}

	return spi_write(spi, buf, tx_len);
}

static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
{
	struct spi_transfer t[] = {
		{
			.tx_buf = &st->data[0].d8[1],
			.len = 3,
			.cs_change = 1,
		}, {
			.tx_buf = &st->data[1].d8[1],
			.rx_buf = &st->data[2].d8[1],
			.len = 3,
		},
	};
	struct spi_device *spi = to_spi_device(st->dev);
	u8 cmd = 0;
	int ret;

	switch (st->chip_info->regmap_type) {
	case AD5310_REGMAP:
		return -ENOTSUPP;
	case AD5683_REGMAP:
		cmd = AD5686_CMD_READBACK_ENABLE_V2;
		break;
	case AD5686_REGMAP:
		cmd = AD5686_CMD_READBACK_ENABLE;
		break;
	default:
		return -EINVAL;
	}

	st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
				      AD5686_ADDR(addr));
	st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));

	ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
	if (ret < 0)
		return ret;

	return be32_to_cpu(st->data[2].d32);
}

static int ad5686_spi_probe(struct spi_device *spi)

Annotation

Implementation Notes