drivers/ata/pata_parport/aten.c

Source file repositories/reference/linux-study-clean/drivers/ata/pata_parport/aten.c

File Facts

System
Linux kernel
Corpus path
drivers/ata/pata_parport/aten.c
Extension
.c
Size
3158 bytes
Lines
145
Domain
Driver Families
Bucket
drivers/ata
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-or-later
/*
 * (c) 1997-8  Grant R. Guenther <grant@torque.net>
 *
 * aten.c is a low-level protocol driver for the ATEN EH-100
 * parallel port adapter.  The EH-100 supports 4-bit and 8-bit
 * modes only.  There is also an EH-132 which supports EPP mode
 * transfers.  The EH-132 is not yet supported.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <asm/io.h>
#include "pata_parport.h"

#define j44(a,b)                ((((a>>4)&0x0f)|(b&0xf0))^0x88)

/*
 * cont = 0 - access the IDE register file
 * cont = 1 - access the IDE command set
 */
static int  cont_map[2] = { 0x08, 0x20 };

static void aten_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
{
	int r = regr + cont_map[cont] + 0x80;

	w0(r); w2(0xe); w2(6); w0(val); w2(7); w2(6); w2(0xc);
}

static int aten_read_regr(struct pi_adapter *pi, int cont, int regr)
{
	int  a, b, r;

	r = regr + cont_map[cont] + 0x40;

	switch (pi->mode) {

	case 0:
		w0(r); w2(0xe); w2(6);
		w2(7); w2(6); w2(0);
		a = r1(); w0(0x10); b = r1(); w2(0xc);
		return j44(a,b);

	case 1:
		r |= 0x10;
		w0(r); w2(0xe); w2(6); w0(0xff);
		w2(0x27); w2(0x26); w2(0x20);
		a = r0();
		w2(0x26); w2(0xc);
		return a;
	}
	return -1;
}

static void aten_read_block(struct pi_adapter *pi, char *buf, int count)
{
	int  k, a, b, c, d;

	switch (pi->mode) {

	case 0:
		w0(0x48); w2(0xe); w2(6);
		for (k = 0; k < count / 2; k++) {
			w2(7); w2(6); w2(2);
			a = r1(); w0(0x58); b = r1();
			w2(0); d = r1(); w0(0x48); c = r1();
			buf[2 * k] = j44(c, d);
			buf[2 * k + 1] = j44(a, b);
		}
		w2(0xc);
		break;

	case 1:
		w0(0x58); w2(0xe); w2(6);
		for (k = 0; k < count / 2; k++) {
			w2(0x27); w2(0x26); w2(0x22);
			a = r0(); w2(0x20); b = r0();
			buf[2 * k] = b;
			buf[2 * k + 1] = a;
		}
		w2(0x26); w2(0xc);
		break;
	}
}

Annotation

Implementation Notes