linux/drivers/net/dsa/mv88e6xxx/smi.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Marvell 88E6xxx System Management Interface (SMI) support
 *
 * Copyright (c) 2008 Marvell Semiconductor
 *
 * Copyright (c) 2019 Vivien Didelot <[email protected]>
 */

#include "chip.h"
#include "smi.h"

/* The switch ADDR[4:1] configuration pins define the chip SMI device address
 * (ADDR[0] is always zero, thus only even SMI addresses can be strapped).
 *
 * When ADDR is all zero, the chip uses Single-chip Addressing Mode, assuming it
 * is the only device connected to the SMI master. In this mode it responds to
 * all 32 possible SMI addresses, and thus maps directly the internal devices.
 *
 * When ADDR is non-zero, the chip uses Multi-chip Addressing Mode, allowing
 * multiple devices to share the SMI interface. In this mode it responds to only
 * 2 registers, used to indirectly access the internal SMI devices.
 *
 * Some chips use a different scheme: Only the ADDR4 pin is used for
 * configuration, and the device responds to 16 of the 32 SMI
 * addresses, allowing two to coexist on the same SMI interface.
 */

static int mv88e6xxx_smi_direct_read(struct mv88e6xxx_chip *chip,
				     int dev, int reg, u16 *data)
{ … }

static int mv88e6xxx_smi_direct_write(struct mv88e6xxx_chip *chip,
				      int dev, int reg, u16 data)
{ … }

static int mv88e6xxx_smi_direct_wait(struct mv88e6xxx_chip *chip,
				     int dev, int reg, int bit, int val)
{ … }

static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_direct_ops = …;

static int mv88e6xxx_smi_dual_direct_read(struct mv88e6xxx_chip *chip,
					  int dev, int reg, u16 *data)
{ … }

static int mv88e6xxx_smi_dual_direct_write(struct mv88e6xxx_chip *chip,
					   int dev, int reg, u16 data)
{ … }

static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_dual_direct_ops = …;

/* Offset 0x00: SMI Command Register
 * Offset 0x01: SMI Data Register
 */

static int mv88e6xxx_smi_indirect_read(struct mv88e6xxx_chip *chip,
				       int dev, int reg, u16 *data)
{ … }

static int mv88e6xxx_smi_indirect_write(struct mv88e6xxx_chip *chip,
					int dev, int reg, u16 data)
{ … }

static int mv88e6xxx_smi_indirect_init(struct mv88e6xxx_chip *chip)
{ … }

static const struct mv88e6xxx_bus_ops mv88e6xxx_smi_indirect_ops = …;

int mv88e6xxx_smi_init(struct mv88e6xxx_chip *chip,
		       struct mii_bus *bus, int sw_addr)
{ … }