drivers/comedi/drivers/amplc_pc236_common.c

Source file repositories/reference/linux-study-clean/drivers/comedi/drivers/amplc_pc236_common.c

File Facts

System
Linux kernel
Corpus path
drivers/comedi/drivers/amplc_pc236_common.c
Extension
.c
Size
4668 bytes
Lines
182
Domain
Driver Families
Bucket
drivers/comedi
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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+
/*
 * comedi/drivers/amplc_pc236_common.c
 * Common support code for "amplc_pc236" and "amplc_pci236".
 *
 * Copyright (C) 2002-2014 MEV Ltd. <https://www.mev.co.uk/>
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/comedi/comedidev.h>
#include <linux/comedi/comedi_8255.h>

#include "amplc_pc236.h"

static void pc236_intr_update(struct comedi_device *dev, bool enable)
{
	const struct pc236_board *board = dev->board_ptr;
	struct pc236_private *devpriv = dev->private;
	unsigned long flags;

	spin_lock_irqsave(&dev->spinlock, flags);
	devpriv->enable_irq = enable;
	if (board->intr_update_cb)
		board->intr_update_cb(dev, enable);
	spin_unlock_irqrestore(&dev->spinlock, flags);
}

/*
 * This function is called when an interrupt occurs to check whether
 * the interrupt has been marked as enabled and was generated by the
 * board.  If so, the function prepares the hardware for the next
 * interrupt.
 * Returns false if the interrupt should be ignored.
 */
static bool pc236_intr_check(struct comedi_device *dev)
{
	const struct pc236_board *board = dev->board_ptr;
	struct pc236_private *devpriv = dev->private;
	bool retval = false;
	unsigned long flags;

	spin_lock_irqsave(&dev->spinlock, flags);
	if (devpriv->enable_irq) {
		if (board->intr_chk_clr_cb)
			retval = board->intr_chk_clr_cb(dev);
		else
			retval = true;
	}
	spin_unlock_irqrestore(&dev->spinlock, flags);

	return retval;
}

static int pc236_intr_insn(struct comedi_device *dev,
			   struct comedi_subdevice *s, struct comedi_insn *insn,
			   unsigned int *data)
{
	data[1] = 0;
	return insn->n;
}

static int pc236_intr_cmdtest(struct comedi_device *dev,
			      struct comedi_subdevice *s,
			      struct comedi_cmd *cmd)
{
	int err = 0;

	/* Step 1 : check if triggers are trivially valid */

	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
	err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_NONE);

	if (err)
		return 1;

	/* Step 2a : make sure trigger sources are unique */
	/* Step 2b : and mutually compatible */

	/* Step 3: check it arguments are trivially valid */

	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
	err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
	err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);

Annotation

Implementation Notes