drivers/iio/pressure/mprls0025pa_spi.c

Source file repositories/reference/linux-study-clean/drivers/iio/pressure/mprls0025pa_spi.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/pressure/mprls0025pa_spi.c
Extension
.c
Size
2213 bytes
Lines
82
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-only
/*
 * MPRLS0025PA - Honeywell MicroPressure MPR series SPI sensor driver
 *
 * Copyright (c) 2024 Petre Rodan <petre.rodan@subdimension.ro>
 *
 * Data sheet:
 *  https://prod-edam.honeywell.com/content/dam/honeywell-edam/sps/siot/en-us/products/sensors/pressure-sensors/board-mount-pressure-sensors/micropressure-mpr-series/documents/sps-siot-mpr-series-datasheet-32332628-ciid-172626.pdf
 */

#include <linux/array_size.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/stddef.h>
#include <linux/types.h>

#include "mprls0025pa.h"

static int mpr_spi_xfer(struct mpr_data *data, const u8 cmd, const u8 pkt_len)
{
	struct spi_device *spi = to_spi_device(data->dev);
	struct spi_transfer xfers[2] = { };

	if (pkt_len > MPR_MEASUREMENT_RD_SIZE)
		return -EOVERFLOW;

	data->tx_buf[0] = cmd;

	/*
	 * Dummy transfer with no data, just cause a 2.5us+ delay between the CS assert
	 * and the first clock edge as per the datasheet tHDSS timing requirement.
	 */
	xfers[0].delay.value = 2500;
	xfers[0].delay.unit = SPI_DELAY_UNIT_NSECS;

	xfers[1].tx_buf = data->tx_buf;
	xfers[1].rx_buf = data->rx_buf;
	xfers[1].len = pkt_len;

	return spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
}

static const struct mpr_ops mpr_spi_ops = {
	.read = mpr_spi_xfer,
	.write = mpr_spi_xfer,
};

static int mpr_spi_probe(struct spi_device *spi)
{
	return mpr_common_probe(&spi->dev, &mpr_spi_ops, spi->irq);
}

static const struct of_device_id mpr_spi_match[] = {
	{ .compatible = "honeywell,mprls0025pa" },
	{ }
};
MODULE_DEVICE_TABLE(of, mpr_spi_match);

static const struct spi_device_id mpr_spi_id[] = {
	{ "mprls0025pa" },
	{ }
};
MODULE_DEVICE_TABLE(spi, mpr_spi_id);

static struct spi_driver mpr_spi_driver = {
	.driver = {
		.name = "mprls0025pa",
		.of_match_table = mpr_spi_match,
	},
	.probe = mpr_spi_probe,
	.id_table = mpr_spi_id,
};
module_spi_driver(mpr_spi_driver);

MODULE_AUTHOR("Petre Rodan <petre.rodan@subdimension.ro>");
MODULE_DESCRIPTION("Honeywell MPR pressure sensor spi driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_HONEYWELL_MPRLS0025PA");

Annotation

Implementation Notes