drivers/comedi/drivers/aio_iiro_16.c

Source file repositories/reference/linux-study-clean/drivers/comedi/drivers/aio_iiro_16.c

File Facts

System
Linux kernel
Corpus path
drivers/comedi/drivers/aio_iiro_16.c
Extension
.c
Size
6153 bytes
Lines
237
Domain
Driver Families
Bucket
drivers/comedi
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+
/*
 * aio_iiro_16.c
 * Comedi driver for ACCES I/O Products 104-IIRO-16 board
 * Copyright (C) 2006 C&C Technologies, Inc.
 */

/*
 * Driver: aio_iiro_16
 * Description: ACCES I/O Products PC/104 Isolated Input/Relay Output Board
 * Author: Zachary Ware <zach.ware@cctechnol.com>
 * Devices: [ACCES I/O] 104-IIRO-16 (aio_iiro_16)
 * Status: experimental
 *
 * Configuration Options:
 *   [0] - I/O port base address
 *   [1] - IRQ (optional)
 *
 * The board supports interrupts on change of state of the digital inputs.
 * The sample data returned by the async command indicates which inputs
 * changed state and the current state of the inputs:
 *
 *	Bit 23 - IRQ Enable (1) / Disable (0)
 *	Bit 17 - Input 8-15 Changed State (1 = Changed, 0 = No Change)
 *	Bit 16 - Input 0-7 Changed State (1 = Changed, 0 = No Change)
 *	Bit 15 - Digital input 15
 *	...
 *	Bit 0  - Digital input 0
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/comedi/comedidev.h>

#define AIO_IIRO_16_RELAY_0_7		0x00
#define AIO_IIRO_16_INPUT_0_7		0x01
#define AIO_IIRO_16_IRQ			0x02
#define AIO_IIRO_16_RELAY_8_15		0x04
#define AIO_IIRO_16_INPUT_8_15		0x05
#define AIO_IIRO_16_STATUS		0x07
#define AIO_IIRO_16_STATUS_IRQE		BIT(7)
#define AIO_IIRO_16_STATUS_INPUT_8_15	BIT(1)
#define AIO_IIRO_16_STATUS_INPUT_0_7	BIT(0)

static unsigned int aio_iiro_16_read_inputs(struct comedi_device *dev)
{
	unsigned int val;

	val = inb(dev->iobase + AIO_IIRO_16_INPUT_0_7);
	val |= inb(dev->iobase + AIO_IIRO_16_INPUT_8_15) << 8;

	return val;
}

static irqreturn_t aio_iiro_16_cos(int irq, void *d)
{
	struct comedi_device *dev = d;
	struct comedi_subdevice *s = dev->read_subdev;
	unsigned int status;
	unsigned int val;

	status = inb(dev->iobase + AIO_IIRO_16_STATUS);
	if (!(status & AIO_IIRO_16_STATUS_IRQE))
		return IRQ_NONE;

	val = aio_iiro_16_read_inputs(dev);
	val |= (status << 16);

	comedi_buf_write_samples(s, &val, 1);
	comedi_handle_events(dev, s);

	return IRQ_HANDLED;
}

static void aio_iiro_enable_irq(struct comedi_device *dev, bool enable)
{
	if (enable)
		inb(dev->iobase + AIO_IIRO_16_IRQ);
	else
		outb(0, dev->iobase + AIO_IIRO_16_IRQ);
}

static int aio_iiro_16_cos_cancel(struct comedi_device *dev,
				  struct comedi_subdevice *s)
{
	aio_iiro_enable_irq(dev, false);

	return 0;
}

Annotation

Implementation Notes