u-boot/include/generic-phy.h
Jean-Jacques Hiblot 4e18429883 drivers: phy: Handle gracefully NULL pointers
For some controllers PHYs can be optional. Handling NULL pointers without
crashing nor failing, makes it easy to handle optional PHYs.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
2019-10-31 07:22:53 -04:00

277 lines
7.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com/
* Written by Jean-Jacques Hiblot <jjhiblot@ti.com>
*/
#ifndef __GENERIC_PHY_H
#define __GENERIC_PHY_H
struct ofnode_phandle_args;
/**
* struct phy - A handle to (allowing control of) a single phy port.
*
* Clients provide storage for phy handles. The content of the structure is
* managed solely by the PHY API and PHY drivers. A phy struct is
* initialized by "get"ing the phy struct. The phy struct is passed to all
* other phy APIs to identify which PHY port to operate upon.
*
* @dev: The device which implements the PHY port.
* @id: The PHY ID within the provider.
*
*/
struct phy {
struct udevice *dev;
unsigned long id;
};
/*
* struct udevice_ops - set of function pointers for phy operations
* @init: operation to be performed for initializing phy (optional)
* @exit: operation to be performed while exiting (optional)
* @reset: reset the phy (optional).
* @power_on: powering on the phy (optional)
* @power_off: powering off the phy (optional)
*/
struct phy_ops {
/**
* of_xlate - Translate a client's device-tree (OF) phy specifier.
*
* The PHY core calls this function as the first step in implementing
* a client's generic_phy_get_by_*() call.
*
* If this function pointer is set to NULL, the PHY core will use a
* default implementation, which assumes #phy-cells = <0> or
* #phy-cells = <1>, and in the later case that the DT cell
* contains a simple integer PHY port ID.
*
* @phy: The phy struct to hold the translation result.
* @args: The phy specifier values from device tree.
* @return 0 if OK, or a negative error code.
*/
int (*of_xlate)(struct phy *phy, struct ofnode_phandle_args *args);
/**
* init - initialize the hardware.
*
* Hardware intialization should not be done in during probe() but
* should be implemented in this init() function. It could be starting
* PLL, taking a controller out of reset, routing, etc. This function
* is typically called only once per PHY port.
* If power_on() is not implemented, it must power up the phy.
*
* @phy: the PHY port to initialize
* @return 0 if OK, or a negative error code.
*/
int (*init)(struct phy *phy);
/**
* exit - de-initialize the PHY device
*
* Hardware de-intialization should be done here. Every step done in
* init() should be undone here.
* This could be used to suspend the phy to reduce power consumption or
* to put the phy in a known condition before booting the OS (though it
* is NOT called automatically before booting the OS)
* If power_off() is not implemented, it must power down the phy.
*
* @phy: PHY port to be de-initialized
* @return 0 if OK, or a negative error code
*/
int (*exit)(struct phy *phy);
/**
* reset - resets a PHY device without shutting down
*
* @phy: PHY port to be reset
*
* During runtime, the PHY may need to be reset in order to
* re-establish connection etc without being shut down or exit.
*
* @return 0 if OK, or a negative error code
*/
int (*reset)(struct phy *phy);
/**
* power_on - power on a PHY device
*
* @phy: PHY port to be powered on
*
* During runtime, the PHY may need to be powered on or off several
* times. This function is used to power on the PHY. It relies on the
* setup done in init(). If init() is not implemented, it must take care
* of setting up the context (PLLs, ...)
*
* @return 0 if OK, or a negative error code
*/
int (*power_on)(struct phy *phy);
/**
* power_off - power off a PHY device
*
* @phy: PHY port to be powered off
*
* During runtime, the PHY may need to be powered on or off several
* times. This function is used to power off the PHY. Except if
* init()/deinit() are not implemented, it must not de-initialize
* everything.
*
* @return 0 if OK, or a negative error code
*/
int (*power_off)(struct phy *phy);
};
#ifdef CONFIG_PHY
/**
* generic_phy_init() - initialize the PHY port
*
* @phy: the PHY port to initialize
* @return 0 if OK, or a negative error code
*/
int generic_phy_init(struct phy *phy);
/**
* generic_phy_init() - de-initialize the PHY device
*
* @phy: PHY port to be de-initialized
* @return 0 if OK, or a negative error code
*/
int generic_phy_exit(struct phy *phy);
/**
* generic_phy_reset() - resets a PHY device without shutting down
*
* @phy: PHY port to be reset
*@return 0 if OK, or a negative error code
*/
int generic_phy_reset(struct phy *phy);
/**
* generic_phy_power_on() - power on a PHY device
*
* @phy: PHY port to be powered on
* @return 0 if OK, or a negative error code
*/
int generic_phy_power_on(struct phy *phy);
/**
* generic_phy_power_off() - power off a PHY device
*
* @phy: PHY port to be powered off
* @return 0 if OK, or a negative error code
*/
int generic_phy_power_off(struct phy *phy);
/**
* generic_phy_get_by_index() - Get a PHY device by integer index.
*
* @user: the client device
* @index: The index in the list of available PHYs
* @phy: A pointer to the PHY port
*
* This looks up a PHY device for a client device based on its position in the
* list of the possible PHYs.
*
* example:
* usb1: usb_otg_ss@xxx {
* compatible = "xxx";
* reg = <xxx>;
* .
* .
* phys = <&usb2_phy>, <&usb3_phy>;
* .
* .
* };
* the USB2 phy can be accessed by passing index '0' and the USB3 phy can
* be accessed by passing index '1'
*
* @return 0 if OK, or a negative error code
*/
int generic_phy_get_by_index(struct udevice *user, int index,
struct phy *phy);
/**
* generic_phy_get_by_name() - Get a PHY device by its name.
*
* @user: the client device
* @phy_name: The name of the PHY in the list of possible PHYs
* @phy: A pointer to the PHY port
*
* This looks up a PHY device for a client device in the
* list of the possible PHYs based on its name.
*
* example:
* usb1: usb_otg_ss@xxx {
* compatible = "xxx";
* reg = <xxx>;
* .
* .
* phys = <&usb2_phy>, <&usb3_phy>;
* phy-names = "usb2phy", "usb3phy";
* .
* .
* };
* the USB3 phy can be accessed using "usb3phy", and USB2 by using "usb2phy"
*
* @return 0 if OK, or a negative error code
*/
int generic_phy_get_by_name(struct udevice *user, const char *phy_name,
struct phy *phy);
#else /* CONFIG_PHY */
static inline int generic_phy_init(struct phy *phy)
{
return 0;
}
static inline int generic_phy_exit(struct phy *phy)
{
return 0;
}
static inline int generic_phy_reset(struct phy *phy)
{
return 0;
}
static inline int generic_phy_power_on(struct phy *phy)
{
return 0;
}
static inline int generic_phy_power_off(struct phy *phy)
{
return 0;
}
static inline int generic_phy_get_by_index(struct udevice *user, int index,
struct phy *phy)
{
return 0;
}
static inline int generic_phy_get_by_name(struct udevice *user, const char *phy_name,
struct phy *phy)
{
return 0;
}
#endif /* CONFIG_PHY */
/**
* generic_phy_valid() - check if PHY port is valid
*
* @phy: the PHY port to check
* @return TRUE if valid, or FALSE
*/
static inline bool generic_phy_valid(struct phy *phy)
{
return phy && phy->dev;
}
#endif /*__GENERIC_PHY_H */