sysreset: Implement PSCI based reset to EDL mode for QCOM SoCs

Implement request_arg() sysreset_op for QCOM SoCs that use
PSCI to reset to EDL (Emergency Download) mode.

Reviewed-by: Casey Connolly <[email protected]>
Reviewed-by: Sumit Garg <[email protected]>
Signed-off-by: Varadarajan Narayanan <[email protected]>
Link: https://patch.msgid.link/[email protected]
[casey: add missing ARM_SMCCC depends to kconfig to fix CI allyesconfig]
Signed-off-by: Casey Connolly <[email protected]>

4 files changed, 57 insertions, 0 deletions

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 f589ad15418..90f740f51d4 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -301,6 +301,13 @@ config SYSRESET_RAA215300
 	help
 	  Add support for the system reboot via the Renesas RAA215300 PMIC.
 
+config SYSRESET_QCOM_PSCI
+	bool "Support reset to EDL for Qualcomm SoCs via PSCI"
+	depends on ARM_SMCCC
+	help
+	  Add support for the reset to EDL (Emergency Download) on Qualcomm
+	  SoCs via PSCI.
+
 config SYSRESET_QCOM_PSHOLD
 	bool "Support sysreset for Qualcomm SoCs via PSHOLD"
 	help
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index d18a5d52360..b5b99235b6e 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -30,6 +30,7 @@ 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-$(CONFIG_TARGET_XTFPGA) += sysreset_xtfpga.o
 obj-$(CONFIG_SYSRESET_QEMU_VIRT_CTRL) += sysreset_qemu_virt_ctrl.o
diff --git a/drivers/sysreset/sysreset_qcom-psci.c b/drivers/sysreset/sysreset_qcom-psci.c
new file mode 100644
index 00000000000..3627bbf5c82
--- /dev/null
+++ b/drivers/sysreset/sysreset_qcom-psci.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Masahiro Yamada <[email protected]>
+ * 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>
+#include <asm/psci.h>
+
+static int qcom_psci_sysreset_get_status(struct udevice *dev, char *buf, int size)
+{
+	return -EOPNOTSUPP;
+}
+
+static int qcom_psci_sysreset_request_arg(struct udevice *dev, int argc,
+					  char * const argv[])
+{
+	if (!strncasecmp(argv[1], "-edl", 4)) {
+		/* Supported in qcs9100, qcs8300, sc7280, qcs615 */
+		if (psci_features(ARM_PSCI_1_1_FN64_SYSTEM_RESET2) ==
+							ARM_PSCI_RET_SUCCESS) {
+			psci_system_reset2(0, 1);
+			return -EINPROGRESS;
+		}
+		printf("PSCI SYSTEM_RESET2 not supported\n");
+	}
+
+	return -EPROTONOSUPPORT;
+}
+
+static struct sysreset_ops qcom_psci_sysreset_ops = {
+	.request_arg = qcom_psci_sysreset_request_arg,
+	.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,
+};