drivers/comedi/drivers/ssv_dnp.c

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

File Facts

System
Linux kernel
Corpus path
drivers/comedi/drivers/ssv_dnp.c
Extension
.c
Size
4969 bytes
Lines
181
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+
/*
 * ssv_dnp.c
 * generic comedi driver for SSV Embedded Systems' DIL/Net-PCs
 * Copyright (C) 2001 Robert Schwebel <robert@schwebel.de>
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
 */

/*
 * Driver: ssv_dnp
 * Description: SSV Embedded Systems DIL/Net-PC
 * Author: Robert Schwebel <robert@schwebel.de>
 * Devices: [SSV Embedded Systems] DIL/Net-PC 1486 (dnp-1486)
 * Status: unknown
 */

/* include files ----------------------------------------------------------- */

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

/* Some global definitions: the registers of the DNP ----------------------- */
/*                                                                           */
/* For port A and B the mode register has bits corresponding to the output   */
/* pins, where Bit-N = 0 -> input, Bit-N = 1 -> output. Note that bits       */
/* 4 to 7 correspond to pin 0..3 for port C data register. Ensure that bits  */
/* 0..3 remain unchanged! For details about Port C Mode Register see         */
/* the remarks in dnp_insn_config() below.                                   */

#define CSCIR 0x22		/* Chip Setup and Control Index Register     */
#define CSCDR 0x23		/* Chip Setup and Control Data Register      */
#define PAMR  0xa5		/* Port A Mode Register                      */
#define PADR  0xa9		/* Port A Data Register                      */
#define PBMR  0xa4		/* Port B Mode Register                      */
#define PBDR  0xa8		/* Port B Data Register                      */
#define PCMR  0xa3		/* Port C Mode Register                      */
#define PCDR  0xa7		/* Port C Data Register                      */

static int dnp_dio_insn_bits(struct comedi_device *dev,
			     struct comedi_subdevice *s,
			     struct comedi_insn *insn,
			     unsigned int *data)
{
	unsigned int mask;
	unsigned int val;

	/*
	 * Ports A and B are straight forward: each bit corresponds to an
	 * output pin with the same order. Port C is different: bits 0...3
	 * correspond to bits 4...7 of the output register (PCDR).
	 */

	mask = comedi_dio_update_state(s, data);
	if (mask) {
		outb(PADR, CSCIR);
		outb(s->state & 0xff, CSCDR);

		outb(PBDR, CSCIR);
		outb((s->state >> 8) & 0xff, CSCDR);

		outb(PCDR, CSCIR);
		val = inb(CSCDR) & 0x0f;
		outb(((s->state >> 12) & 0xf0) | val, CSCDR);
	}

	outb(PADR, CSCIR);
	val = inb(CSCDR);
	outb(PBDR, CSCIR);
	val |= (inb(CSCDR) << 8);
	outb(PCDR, CSCIR);
	val |= ((inb(CSCDR) & 0xf0) << 12);

	data[1] = val;

	return insn->n;
}

static int dnp_dio_insn_config(struct comedi_device *dev,
			       struct comedi_subdevice *s,
			       struct comedi_insn *insn,
			       unsigned int *data)
{
	unsigned int chan = CR_CHAN(insn->chanspec);
	unsigned int mask;
	unsigned int val;
	int ret;

	ret = comedi_dio_insn_config(dev, s, insn, data, 0);

Annotation

Implementation Notes