u-boot/drivers/reset/reset-raspberrypi.c
Nicolas Saenz Julienne f676eb217b reset: Add Raspberry Pi 4 firmware reset controller
Raspberry Pi 4's co-processor controls some of the board's HW
initialization process, but it's up to Linux to trigger it when
relevant. Introduce a reset controller capable of interfacing with
RPi4's co-processor that models these firmware initialization routines as
reset lines.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
2020-07-10 11:49:28 +02:00

60 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Raspberry Pi 4 firmware reset driver
*
* Copyright (C) 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
*/
#include <common.h>
#include <dm.h>
#include <reset-uclass.h>
#include <asm/arch/msg.h>
#include <dt-bindings/reset/raspberrypi,firmware-reset.h>
static int raspberrypi_reset_request(struct reset_ctl *reset_ctl)
{
if (reset_ctl->id >= RASPBERRYPI_FIRMWARE_RESET_NUM_IDS)
return -EINVAL;
return 0;
}
static int raspberrypi_reset_free(struct reset_ctl *reset_ctl)
{
return 0;
}
static int raspberrypi_reset_assert(struct reset_ctl *reset_ctl)
{
switch (reset_ctl->id) {
case RASPBERRYPI_FIRMWARE_RESET_ID_USB:
bcm2711_notify_vl805_reset();
return 0;
default:
return -EINVAL;
}
}
static int raspberrypi_reset_deassert(struct reset_ctl *reset_ctl)
{
return 0;
}
struct reset_ops raspberrypi_reset_ops = {
.request = raspberrypi_reset_request,
.rfree = raspberrypi_reset_free,
.rst_assert = raspberrypi_reset_assert,
.rst_deassert = raspberrypi_reset_deassert,
};
static const struct udevice_id raspberrypi_reset_ids[] = {
{ .compatible = "raspberrypi,firmware-reset" },
{ }
};
U_BOOT_DRIVER(raspberrypi_reset) = {
.name = "raspberrypi-reset",
.id = UCLASS_RESET,
.of_match = raspberrypi_reset_ids,
.ops = &raspberrypi_reset_ops,
};