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 --- drivers/reset/Kconfig | 10 ++++ drivers/reset/Makefile | 1 + drivers/reset/reset-raspberrypi.c | 60 +++++++++++++++++++ .../reset/raspberrypi,firmware-reset.h | 13 ++++ 4 files changed, 84 insertions(+) create mode 100644 drivers/reset/reset-raspberrypi.c create mode 100644 include/dt-bindings/reset/raspberrypi,firmware-reset.h
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 88d3be1593..d02c1522e5 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -148,4 +148,14 @@ config RESET_IMX7 help Support for reset controller on i.MX7/8 SoCs.
+config RESET_RASPBERRYPI + bool "Raspberry Pi 4 Firmware Reset Controller Driver" + depends on DM_RESET && ARCH_BCM283X + default USB_XHCI_PCI + help + 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. This driver provides a reset controller capable of + interfacing with RPi4's co-processor and model these firmware + initialization routines as reset lines. endmenu diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 0a044d5d8c..be54dae725 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -23,3 +23,4 @@ obj-$(CONFIG_RESET_MTMIPS) += reset-mtmips.o obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o obj-$(CONFIG_RESET_HISILICON) += reset-hisilicon.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.o +obj-$(CONFIG_RESET_RASPBERRYPI) += reset-raspberrypi.o diff --git a/drivers/reset/reset-raspberrypi.c b/drivers/reset/reset-raspberrypi.c new file mode 100644 index 0000000000..e2d284e5ac --- /dev/null +++ b/drivers/reset/reset-raspberrypi.c @@ -0,0 +1,60 @@ +// 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, +}; + diff --git a/include/dt-bindings/reset/raspberrypi,firmware-reset.h b/include/dt-bindings/reset/raspberrypi,firmware-reset.h new file mode 100644 index 0000000000..1a4f4c7927 --- /dev/null +++ b/include/dt-bindings/reset/raspberrypi,firmware-reset.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2020 Nicolas Saenz Julienne + * Author: Nicolas Saenz Julienne nsaenzjulienne@suse.com + */ + +#ifndef _DT_BINDINGS_RASPBERRYPI_FIRMWARE_RESET_H +#define _DT_BINDINGS_RASPBERRYPI_FIRMWARE_RESET_H + +#define RASPBERRYPI_FIRMWARE_RESET_ID_USB 0 +#define RASPBERRYPI_FIRMWARE_RESET_NUM_IDS 1 + +#endif