drivers/net/dsa/mv88e6xxx/global2_avb.c

Source file repositories/reference/linux-study-clean/drivers/net/dsa/mv88e6xxx/global2_avb.c

File Facts

System
Linux kernel
Corpus path
drivers/net/dsa/mv88e6xxx/global2_avb.c
Extension
.c
Size
6545 bytes
Lines
240
Domain
Driver Families
Bucket
drivers/net
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
/*
 * Marvell 88E6xxx Switch Global 2 Registers support
 *
 * Copyright (c) 2008 Marvell Semiconductor
 *
 * Copyright (c) 2016-2017 Savoir-faire Linux Inc.
 *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 *
 * Copyright (c) 2017 National Instruments
 *	Brandon Streiff <brandon.streiff@ni.com>
 */

#include <linux/bitfield.h>

#include "global2.h"

/* Offset 0x16: AVB Command Register
 * Offset 0x17: AVB Data Register
 *
 * There are two different versions of this register interface:
 *    "6352": 3-bit "op" field, 4-bit "port" field.
 *    "6390": 2-bit "op" field, 5-bit "port" field.
 *
 * The "op" codes are different between the two, as well as the special
 * port fields for global PTP and TAI configuration.
 */

/* mv88e6xxx_g2_avb_read -- Read one or multiple 16-bit words.
 * The hardware supports snapshotting up to four contiguous registers.
 */
static int mv88e6xxx_g2_avb_wait(struct mv88e6xxx_chip *chip)
{
	int bit = __bf_shf(MV88E6352_G2_AVB_CMD_BUSY);

	return mv88e6xxx_g2_wait_bit(chip, MV88E6352_G2_AVB_CMD, bit, 0);
}

static int mv88e6xxx_g2_avb_read(struct mv88e6xxx_chip *chip, u16 readop,
				 u16 *data, int len)
{
	int err;
	int i;

	err = mv88e6xxx_g2_avb_wait(chip);
	if (err)
		return err;

	/* Hardware can only snapshot four words. */
	if (len > 4)
		return -E2BIG;

	err = mv88e6xxx_g2_write(chip, MV88E6352_G2_AVB_CMD,
				 MV88E6352_G2_AVB_CMD_BUSY | readop);
	if (err)
		return err;

	err = mv88e6xxx_g2_avb_wait(chip);
	if (err)
		return err;

	for (i = 0; i < len; ++i) {
		err = mv88e6xxx_g2_read(chip, MV88E6352_G2_AVB_DATA,
					&data[i]);
		if (err)
			return err;
	}

	return 0;
}

/* mv88e6xxx_g2_avb_write -- Write one 16-bit word. */
static int mv88e6xxx_g2_avb_write(struct mv88e6xxx_chip *chip, u16 writeop,
				  u16 data)
{
	int err;

	err = mv88e6xxx_g2_avb_wait(chip);
	if (err)
		return err;

	err = mv88e6xxx_g2_write(chip, MV88E6352_G2_AVB_DATA, data);
	if (err)
		return err;

	err = mv88e6xxx_g2_write(chip, MV88E6352_G2_AVB_CMD,
				 MV88E6352_G2_AVB_CMD_BUSY | writeop);

	return mv88e6xxx_g2_avb_wait(chip);
}

Annotation

Implementation Notes