u-boot/drivers/firmware/psci.c
Masahiro Yamada 573a3811ed sysreset: psci: support system reset in a generic way with PSCI
If the system is running PSCI firmware, the System Reset function
(func ID: 0x80000009) is supposed to be handled by PSCI, that is,
the SoC/board specific reset implementation should be moved to PSCI.
U-Boot should call the PSCI service according to the arm-smccc
manner.

The arm-smccc is supported on ARMv7 or later.  Especially, ARMv8
generation SoCs are likely to run ARM Trusted Firmware BL31.  In
this case, U-Boot is a non-secure world boot loader, so it should
not be able to reset the system directly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-04-18 10:29:19 -04:00

94 lines
2.1 KiB
C

/*
* Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
*
* Based on drivers/firmware/psci.c from Linux:
* Copyright (C) 2015 ARM Limited
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm/device.h>
#include <dm/lists.h>
#include <libfdt.h>
#include <linux/arm-smccc.h>
#include <linux/errno.h>
#include <linux/psci.h>
psci_fn *invoke_psci_fn;
static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
unsigned long arg0, unsigned long arg1,
unsigned long arg2)
{
struct arm_smccc_res res;
arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
return res.a0;
}
static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
unsigned long arg0, unsigned long arg1,
unsigned long arg2)
{
struct arm_smccc_res res;
arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
return res.a0;
}
static int psci_bind(struct udevice *dev)
{
/* No SYSTEM_RESET support for PSCI 0.1 */
if (of_device_is_compatible(dev, "arm,psci-0.2") ||
of_device_is_compatible(dev, "arm,psci-1.0")) {
int ret;
/* bind psci-sysreset optionally */
ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
NULL);
if (ret)
debug("PSCI System Reset was not bound.\n");
}
return 0;
}
static int psci_probe(struct udevice *dev)
{
DECLARE_GLOBAL_DATA_PTR;
const char *method;
method = fdt_stringlist_get(gd->fdt_blob, dev->of_offset, "method", 0,
NULL);
if (!method) {
printf("missing \"method\" property\n");
return -ENXIO;
}
if (!strcmp("hvc", method)) {
invoke_psci_fn = __invoke_psci_fn_hvc;
} else if (!strcmp("smc", method)) {
invoke_psci_fn = __invoke_psci_fn_smc;
} else {
printf("invalid \"method\" property: %s\n", method);
return -EINVAL;
}
return 0;
}
static const struct udevice_id psci_of_match[] = {
{ .compatible = "arm,psci" },
{ .compatible = "arm,psci-0.2" },
{ .compatible = "arm,psci-1.0" },
{},
};
U_BOOT_DRIVER(psci) = {
.name = "psci",
.id = UCLASS_FIRMWARE,
.of_match = psci_of_match,
.bind = psci_bind,
.probe = psci_probe,
};