[PATCH v2 1/2] sysreset: Implement PSCI based reset to EDL mode for QCOM SoCs
neil.armstrong at linaro.org
neil.armstrong at linaro.org
Wed Apr 30 11:05:59 CEST 2025
On 30/04/2025 10:54, Varadarajan Narayanan wrote:
> The SYSRESET_PSCI interface presently available doesn't support booting
> into Emergency DownLoad (EDL) mode. The EDL mode is used to flash the
> board with different firmware.
>
> Since EDL is Qcom specific, implement a Qcom specific SYSRESET_PSCI
> handler that handles resetting to EDL in addition to the usual cold/warm
> reset and poweroff.
>
> Signed-off-by: Varadarajan Narayanan <quic_varada at quicinc.com>
> ---
> v2: * Update commit message
> * Elaborate Kconfig help text
> * Use '-edl' instead of 'edl' for consistency with other arguments of reset
> command
> * Remove 'weak' for qcom_psci_sysreset_get_status() and make it static
> * Mention 'SYSRESET_EDL' is Qcom specific in the enum's comments
> ---
> drivers/firmware/psci.c | 4 +++
> drivers/sysreset/Kconfig | 7 ++++
> drivers/sysreset/Makefile | 1 +
> drivers/sysreset/sysreset-uclass.c | 7 ++--
> drivers/sysreset/sysreset_qcom-psci.c | 48 +++++++++++++++++++++++++++
> include/sysreset.h | 7 ++++
> 6 files changed, 72 insertions(+), 2 deletions(-)
> create mode 100644 drivers/sysreset/sysreset_qcom-psci.c
>
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 2e3223e1c32..b6838a244d2 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -186,6 +186,10 @@ static int psci_bind(struct udevice *dev)
> NULL);
> if (ret)
> pr_debug("PSCI System Reset was not bound.\n");
> + if (IS_ENABLED(CONFIG_SYSRESET_QCOM_PSCI) &&
> + device_bind_driver(dev, "qcom_psci-sysreset",
> + "qcom_psci-sysreset", NULL))
> + pr_debug("QCOM PSCI System Reset was not bound.\n");
> }
>
> /* From PSCI v1.0 onward we can discover services through ARM_SMCCC_FEATURE */
> diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> index 4972905482a..d407c322bdb 100644
> --- a/drivers/sysreset/Kconfig
> +++ b/drivers/sysreset/Kconfig
> @@ -285,6 +285,13 @@ config SYSRESET_RAA215300
> help
> Add support for the system reboot via the Renesas RAA215300 PMIC.
>
> +config SYSRESET_QCOM_PSCI
> + bool "Support sysreset for Qualcomm SoCs via PSCI"
> + help
> + Add support for the system reboot on Qualcomm SoCs via PSCI.
> + This allows warm/cold reset, poweroff and reset to EDL (Emergency
> + Download)
> +
> config SYSRESET_QCOM_PSHOLD
> bool "Support sysreset for Qualcomm SoCs via PSHOLD"
> help
> diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
> index ded91a4d325..58eb0e356e1 100644
> --- a/drivers/sysreset/Makefile
> +++ b/drivers/sysreset/Makefile
> @@ -29,5 +29,6 @@ obj-$(CONFIG_SYSRESET_RESETCTL) += sysreset_resetctl.o
> obj-$(CONFIG_$(PHASE_)SYSRESET_AT91) += sysreset_at91.o
> obj-$(CONFIG_$(PHASE_)SYSRESET_X86) += sysreset_x86.o
> obj-$(CONFIG_SYSRESET_RAA215300) += sysreset_raa215300.o
> +obj-$(CONFIG_SYSRESET_QCOM_PSCI) += sysreset_qcom-psci.o
> obj-$(CONFIG_SYSRESET_QCOM_PSHOLD) += sysreset_qcom-pshold.o
> obj-$(CONFIG_TARGET_XTFPGA) += sysreset_xtfpga.o
> diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
> index 536ac727142..ff9bc962ec0 100644
> --- a/drivers/sysreset/sysreset-uclass.c
> +++ b/drivers/sysreset/sysreset-uclass.c
> @@ -125,8 +125,11 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> if (argc > 2)
> return CMD_RET_USAGE;
>
> - if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'w') {
> - reset_type = SYSRESET_WARM;
> + if (argc == 2) {
> + if (argv[1][0] == '-' && argv[1][1] == 'w')
> + reset_type = SYSRESET_WARM;
> + else if (!strncmp("-edl", argv[1], 4))
> + reset_type = SYSRESET_EDL;
> }
>
> printf("resetting ...\n");
> diff --git a/drivers/sysreset/sysreset_qcom-psci.c b/drivers/sysreset/sysreset_qcom-psci.c
> new file mode 100644
> index 00000000000..9d0606c059b
> --- /dev/null
> +++ b/drivers/sysreset/sysreset_qcom-psci.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro at socionext.com>
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#include <dm.h>
> +#include <sysreset.h>
> +#include <asm/system.h>
> +#include <linux/errno.h>
> +#include <linux/psci.h>
> +
> +static int qcom_psci_sysreset_get_status(struct udevice *dev, char *buf, int size)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static int qcom_psci_sysreset_request(struct udevice *dev, enum sysreset_t type)
> +{
> + switch (type) {
> + case SYSRESET_WARM:
> + case SYSRESET_COLD:
> + psci_sys_reset(type);
> + break;
> + case SYSRESET_POWER_OFF:
> + psci_sys_poweroff();
> + break;
> + case SYSRESET_EDL:
> + psci_system_reset2(0, 1);
Can you explicit which platforms do support this new psci_system_reset2() ?
> + break;
> + default:
> + return -EPROTONOSUPPORT;
> + }
> +
> + return -EINPROGRESS;
> +}
> +
> +static struct sysreset_ops qcom_psci_sysreset_ops = {
> + .request = qcom_psci_sysreset_request,
> + .get_status = qcom_psci_sysreset_get_status,
> +};
> +
> +U_BOOT_DRIVER(qcom_psci_sysreset) = {
> + .name = "qcom_psci-sysreset",
> + .id = UCLASS_SYSRESET,
> + .ops = &qcom_psci_sysreset_ops,
> + .flags = DM_FLAG_PRE_RELOC,
> +};
> diff --git a/include/sysreset.h b/include/sysreset.h
> index ff20abdeed3..d0f60ed2456 100644
> --- a/include/sysreset.h
> +++ b/include/sysreset.h
> @@ -21,6 +21,13 @@ enum sysreset_t {
> SYSRESET_POWER,
> /** @SYSRESET_POWER_OFF: turn off power */
> SYSRESET_POWER_OFF,
> +#if IS_ENABLED(CONFIG_SYSRESET_QCOM_PSCI)
> + /**
> + * @SYSRESET_EDL: Reset and boot into Emergency DownLoader.
> + * This is supported only in recent Qcom SoCs.
> + */
> + SYSRESET_EDL,
> +#endif
> /** @SYSRESET_COUNT: number of available reset types */
> SYSRESET_COUNT,
> };
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