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>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 16578b8..7812f21 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -177,6 +177,7 @@ config SYS_CACHELINE_SIZE
 config ARM_SMCCC
        bool "Support for ARM SMC Calling Convention (SMCCC)"
        depends on CPU_V7 || ARM64
+       select ARM_PSCI_FW
        help
          Say Y here if you want to enable ARM SMC Calling Convention.
          This should be enabled if U-Boot needs to communicate with system

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 3e6bbac..a096dad 100644 (file)
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -24,6 +24,8 @@ source "drivers/dfu/Kconfig"
 
 source "drivers/dma/Kconfig"
 
+source "drivers/firmware/Kconfig"
+
 source "drivers/fpga/Kconfig"
 
 source "drivers/gpio/Kconfig"

diff --git a/drivers/Makefile b/drivers/Makefile
index 5d8baa5..4a4b237 100644 (file)
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -23,7 +23,7 @@ obj-$(CONFIG_SPL_SERIAL_SUPPORT) += serial/
 obj-$(CONFIG_SPL_SPI_SUPPORT) += spi/
 obj-$(CONFIG_SPL_POWER_SUPPORT) += power/ power/pmic/
 obj-$(CONFIG_SPL_POWER_SUPPORT) += power/regulator/
-obj-$(CONFIG_SPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/
+obj-$(CONFIG_SPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/ firmware/
 obj-$(CONFIG_SPL_MTD_SUPPORT) += mtd/
 obj-$(CONFIG_SPL_NAND_SUPPORT) += mtd/nand/
 obj-$(CONFIG_SPL_ONENAND_SUPPORT) += mtd/onenand/
@@ -52,7 +52,7 @@ endif
 ifdef CONFIG_TPL_BUILD
 
 obj-$(CONFIG_TPL_I2C_SUPPORT) += i2c/
-obj-$(CONFIG_TPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/
+obj-$(CONFIG_TPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/ firmware/
 obj-$(CONFIG_TPL_MMC_SUPPORT) += mmc/
 obj-$(CONFIG_TPL_MPC8XXX_INIT_DDR_SUPPORT) += ddr/fsl/
 obj-$(CONFIG_TPL_NAND_SUPPORT) += mtd/nand/
@@ -71,6 +71,7 @@ obj-y += block/
 obj-$(CONFIG_BOOTCOUNT_LIMIT) += bootcount/
 obj-$(CONFIG_CPU) += cpu/
 obj-y += crypto/
+obj-y += firmware/
 obj-$(CONFIG_FPGA) += fpga/
 obj-y += hwmon/
 obj-y += misc/

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
new file mode 100644 (file)
index 0000000..4c32426
--- /dev/null
+++ b/drivers/firmware/Kconfig
@@ -0,0 +1,6 @@
+config FIRMWARE
+       bool
+
+config ARM_PSCI_FW
+       bool
+       select FIRMWARE

diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
new file mode 100644 (file)
index 0000000..b208255
--- /dev/null
+++ b/drivers/firmware/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_FIRMWARE)         += firmware-uclass.o
+obj-$(CONFIG_ARM_PSCI_FW)      += psci.o

diff --git a/drivers/firmware/firmware-uclass.c b/drivers/firmware/firmware-uclass.c
new file mode 100644 (file)
index 0000000..01b6a44
--- /dev/null
+++ b/drivers/firmware/firmware-uclass.c
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <dm/uclass.h>
+
+/* Firmware access is platform-dependent.  No generic code in uclass */
+UCLASS_DRIVER(firmware) = {
+       .id             = UCLASS_FIRMWARE,
+       .name           = "firmware",
+};

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
new file mode 100644 (file)
index 0000000..40fba64
--- /dev/null
+++ b/drivers/firmware/psci.c
@@ -0,0 +1,94 @@
+/*
+ * 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,
+};

diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 05a37b9..9664630 100644 (file)
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -13,4 +13,14 @@ config SYSRESET
          to effect a reset. The uclass will try all available drivers when
          reset_walk() is called.
 
+if SYSRESET
+
+config SYSRESET_PSCI
+       bool "Enable support for PSCI System Reset"
+       depends on ARM_PSCI_FW
+       help
+         Enable PSCI SYSTEM_RESET function call.  To use this, PSCI firmware
+         must be running on your system.
+
+endif
 endmenu

diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index 49b8bb6..7bb8406 100644 (file)
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -5,6 +5,7 @@
 #
 
 obj-$(CONFIG_SYSRESET) += sysreset-uclass.o
+obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o
 
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_ROCKCHIP_RK3036) += sysreset_rk3036.o

diff --git a/drivers/sysreset/sysreset_psci.c b/drivers/sysreset/sysreset_psci.c
new file mode 100644 (file)
index 0000000..a4911b7
--- /dev/null
+++ b/drivers/sysreset/sysreset_psci.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <dm/device.h>
+#include <sysreset.h>
+#include <linux/errno.h>
+#include <linux/psci.h>
+
+static int psci_sysreset_request(struct udevice *dev, enum sysreset_t type)
+{
+       unsigned long function_id;
+
+       switch (type) {
+       case SYSRESET_WARM:
+       case SYSRESET_COLD:
+               function_id = PSCI_0_2_FN_SYSTEM_RESET;
+               break;
+       case SYSRESET_POWER:
+               function_id = PSCI_0_2_FN_SYSTEM_OFF;
+               break;
+       default:
+               return -ENOSYS;
+       }
+
+       invoke_psci_fn(function_id, 0, 0, 0);
+
+       return -EINPROGRESS;
+}
+
+static struct sysreset_ops psci_sysreset_ops = {
+       .request = psci_sysreset_request,
+};
+
+U_BOOT_DRIVER(psci_sysreset) = {
+       .name = "psci-sysreset",
+       .id = UCLASS_SYSRESET,
+       .ops = &psci_sysreset_ops,
+};

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 8c92d0b..1b635e4 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -35,6 +35,7 @@ enum uclass_id {
        UCLASS_DMA,             /* Direct Memory Access */
        UCLASS_ETH,             /* Ethernet device */
        UCLASS_GPIO,            /* Bank of general-purpose I/O pins */
+       UCLASS_FIRMWARE,        /* Firmware */
        UCLASS_I2C,             /* I2C bus */
        UCLASS_I2C_EEPROM,      /* I2C EEPROM device */
        UCLASS_I2C_GENERIC,     /* Generic I2C device */

diff --git a/include/linux/psci.h b/include/linux/psci.h
index 310d83e..8d13bd2 100644 (file)
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -87,4 +87,17 @@
 #define PSCI_RET_NOT_PRESENT                   -7
 #define PSCI_RET_DISABLED                      -8
 
+#ifdef CONFIG_ARM_PSCI_FW
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+                               unsigned long, unsigned long);
+
+extern psci_fn *invoke_psci_fn;
+#else
+unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
+                            unsigned long a2, unsigned long a3)
+{
+       return PSCI_RET_DISABLED;
+}
+#endif
+
 #endif /* _UAPI_LINUX_PSCI_H */