linux/include/linux/mdio-bitbang.h
Andrew Lunn 800fcab823 net: phy: Add support for microchip SMI0 MDIO bus
SMI0 is a mangled version of MDIO. The main low level difference is
the MDIO C22 OP code is always 0, not 0x2 or 0x1 for Read/Write. The
read/write information is instead encoded in the PHY address.

Extend the bit-bang code to allow the op code to be overridden, but
default to normal C22 values. Add an extra compatible to the mdio-gpio
driver, and when this compatible is present, set the op codes to 0.

A higher level driver, sitting on top of the basic MDIO bus driver can
then implement the rest of the microchip SMI0 odderties.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 14:13:24 -07:00

51 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_MDIO_BITBANG_H
#define __LINUX_MDIO_BITBANG_H
#include <linux/phy.h>
struct module;
struct mdiobb_ctrl;
struct mdiobb_ops {
struct module *owner;
/* Set the Management Data Clock high if level is one,
* low if level is zero.
*/
void (*set_mdc)(struct mdiobb_ctrl *ctrl, int level);
/* Configure the Management Data I/O pin as an input if
* "output" is zero, or an output if "output" is one.
*/
void (*set_mdio_dir)(struct mdiobb_ctrl *ctrl, int output);
/* Set the Management Data I/O pin high if value is one,
* low if "value" is zero. This may only be called
* when the MDIO pin is configured as an output.
*/
void (*set_mdio_data)(struct mdiobb_ctrl *ctrl, int value);
/* Retrieve the state Management Data I/O pin. */
int (*get_mdio_data)(struct mdiobb_ctrl *ctrl);
};
struct mdiobb_ctrl {
const struct mdiobb_ops *ops;
unsigned int override_op_c22;
u8 op_c22_read;
u8 op_c22_write;
};
int mdiobb_read(struct mii_bus *bus, int phy, int reg);
int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val);
/* The returned bus is not yet registered with the phy layer. */
struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl);
/* The bus must already have been unregistered. */
void free_mdio_bitbang(struct mii_bus *bus);
#endif