mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-03 08:43:45 +09:00
f9917454d5
It is common for system reset to be available at multiple levels in modern hardware. For example, an SoC may provide a reset option, and a board may provide its own reset for reasons of security or thoroughness. It is useful to be able to model this hardware without hard-coding the behaviour in the SoC or board. Also there is a distinction sometimes between resetting just the CPU (leaving GPIO state alone) and resetting all the PMICs, just cutting power. To achieve this, add a simple system reset uclass. It allows multiple devices to provide reset functionality and provides a way to walk through them, requesting a particular reset type until is it provided. Signed-off-by: Simon Glass <sjg@chromium.org>
63 lines
1.5 KiB
C
63 lines
1.5 KiB
C
/*
|
|
* Copyright (c) 2015 Google, Inc
|
|
* Written by Simon Glass <sjg@chromium.org>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#ifndef __RESET_H
|
|
#define __RESET_H
|
|
|
|
enum reset_t {
|
|
RESET_WARM, /* Reset CPU, keep GPIOs active */
|
|
RESET_COLD, /* Reset CPU and GPIOs */
|
|
RESET_POWER, /* Reset PMIC (remove and restore power) */
|
|
|
|
RESET_COUNT,
|
|
};
|
|
|
|
struct reset_ops {
|
|
/**
|
|
* request() - request a reset 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 reset_t type);
|
|
};
|
|
|
|
#define reset_get_ops(dev) ((struct reset_ops *)(dev)->driver->ops)
|
|
|
|
/**
|
|
* reset_request() - request a reset
|
|
*
|
|
* @type: Reset type to request
|
|
* @return 0 if OK, -EPROTONOSUPPORT if not supported by this device
|
|
*/
|
|
int reset_request(struct udevice *dev, enum reset_t type);
|
|
|
|
/**
|
|
* reset_walk() - cause a reset
|
|
*
|
|
* This works through the available reset devices until it finds one that can
|
|
* perform a reset. If the provided reset 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
|
|
*/
|
|
void reset_walk(enum reset_t type);
|
|
|
|
/**
|
|
* reset_cpu() - calls reset_walk(RESET_WARM)
|
|
*/
|
|
void reset_cpu(ulong addr);
|
|
|
|
#endif
|