u-boot/include/sysreset.h
Harald Seiler 35b65dd8ef reset: Remove addr parameter from reset_cpu()
Historically, the reset_cpu() function had an `addr` parameter which was
meant to pass in an address of the reset vector location, where the CPU
should reset to.  This feature is no longer used anywhere in U-Boot as
all reset_cpu() implementations now ignore the passed value.  Generic
code has been added which always calls reset_cpu() with `0` which means
this feature can no longer be used easily anyway.

Over time, many implementations seem to have "misunderstood" the
existence of this parameter as a way to customize/parameterize the reset
(e.g.  COLD vs WARM resets).  As this is not properly supported, the
code will almost always not do what it is intended to (because all
call-sites just call reset_cpu() with 0).

To avoid confusion and to clean up the codebase from unused left-overs
of the past, remove the `addr` parameter entirely.  Code which intends
to support different kinds of resets should be rewritten as a sysreset
driver instead.

This transformation was done with the following coccinelle patch:

    @@
    expression argvalue;
    @@
    - reset_cpu(argvalue)
    + reset_cpu()

    @@
    identifier argname;
    type argtype;
    @@
    - reset_cpu(argtype argname)
    + reset_cpu(void)
    { ... }

Signed-off-by: Harald Seiler <hws@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-03-02 14:03:02 -05:00

121 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#ifndef __SYSRESET_H
#define __SYSRESET_H
struct udevice;
enum sysreset_t {
SYSRESET_WARM, /* Reset CPU, keep GPIOs active */
SYSRESET_COLD, /* Reset CPU and GPIOs */
SYSRESET_POWER, /* Reset PMIC (remove and restore power) */
SYSRESET_POWER_OFF, /* Turn off power */
SYSRESET_COUNT,
};
struct sysreset_ops {
/**
* request() - request a sysreset of the given type
*
* Note that this function may return before the reset takes effect.
*
* @type: Reset type to request
* @return -EINPROGRESS if the reset has been started and
* will complete soon, -EPROTONOSUPPORT if not supported
* by this device, 0 if the reset has already happened
* (in which case this method will not actually return)
*/
int (*request)(struct udevice *dev, enum sysreset_t type);
/**
* get_status() - get printable reset status information
*
* @dev: Device to check
* @buf: Buffer to receive the textual reset information
* @size: Size of the passed buffer
* @return 0 if OK, -ve on error
*/
int (*get_status)(struct udevice *dev, char *buf, int size);
/**
* get_last() - get information on the last reset
*
* @dev: Device to check
* @return last reset state (enum sysreset_t) or -ve error
*/
int (*get_last)(struct udevice *dev);
};
#define sysreset_get_ops(dev) ((struct sysreset_ops *)(dev)->driver->ops)
/**
* sysreset_request() - request a sysreset
*
* @type: Reset type to request
* @return 0 if OK, -EPROTONOSUPPORT if not supported by this device
*/
int sysreset_request(struct udevice *dev, enum sysreset_t type);
/**
* sysreset_get_status() - get printable reset status information
*
* @dev: Device to check
* @buf: Buffer to receive the textual reset information
* @size: Size of the passed buffer
* @return 0 if OK, -ve on error
*/
int sysreset_get_status(struct udevice *dev, char *buf, int size);
/**
* sysreset_get_last() - get information on the last reset
*
* @dev: Device to check
* @return last reset state (enum sysreset_t) or -ve error
*/
int sysreset_get_last(struct udevice *dev);
/**
* sysreset_walk() - cause a system reset
*
* This works through the available sysreset devices until it finds one that can
* perform a reset. If the provided sysreset type is not available, the next one
* will be tried.
*
* If this function fails to reset, it will display a message and halt
*
* @type: Reset type to request
* @return -EINPROGRESS if a reset is in progress, -ENOSYS if not available
*/
int sysreset_walk(enum sysreset_t type);
/**
* sysreset_get_last_walk() - get information on the last reset
*
* This works through the available sysreset devices until it finds one that can
* perform a reset. If the provided sysreset type is not available, the next one
* will be tried.
*
* If no device prives the information, this function returns -ENOENT
*
* @return last reset state (enum sysreset_t) or -ve error
*/
int sysreset_get_last_walk(void);
/**
* sysreset_walk_halt() - try to reset, otherwise halt
*
* This calls sysreset_walk(). If it returns, indicating that reset is not
* supported, it prints a message and halts.
*/
void sysreset_walk_halt(enum sysreset_t type);
/**
* reset_cpu() - calls sysreset_walk(SYSRESET_WARM)
*/
void reset_cpu(void);
#endif