sysreset: Add TI System Control Interface (TI SCI) sysreset driver

Devices from the TI K3 family of SoCs like the AM654x contain a Device
Management and Security Controller (SYSFW) that manages the low-level
device control (like clocks, resets etc) for the various hardware
modules present on the SoC. These device control operations are provided
to the host processor OS through a communication protocol called the TI
System Control Interface (TI SCI) protocol.

This patch adds a system reset driver that communicates to the system
controller over the TI SCI protocol for allowing to perform a system-
wide SoC reset.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

diff --git a/doc/device-tree-bindings/sysreset/ti,sci-sysreset.txt b/doc/device-tree-bindings/sysreset/ti,sci-sysreset.txt
new file mode 100644 (file)
index 0000000..02704c6
--- /dev/null
+++ b/doc/device-tree-bindings/sysreset/ti,sci-sysreset.txt
@@ -0,0 +1,29 @@
+Texas Instruments TI SCI System Reset Controller
+================================================
+
+Some TI SoCs contain a system controller (like the SYSFW, etc...) that is
+responsible for controlling the state of the IPs that are present.
+Communication between the host processor running an OS and the system
+controller happens through a protocol known as TI SCI [1].
+
+[1] http://processors.wiki.ti.com/index.php/TISCI
+
+System Reset Controller Node
+============================
+The sysreset controller node represents the reset for the overall SoC
+which is managed by the SYSFW. Because this relies on the TI SCI protocol
+to communicate with the SYSFW it must be a child of the sysfw node.
+
+Required Properties:
+--------------------
+ - compatible: Must be "ti,sci-sysreset"
+
+Example (AM65x):
+----------------
+       sysfw: sysfw {
+               compatible = "ti,am654-system-controller";
+               ...
+               k3_sysreset: sysreset-controller {
+                       compatible = "ti,sci-sysreset";
+               };
+       };

diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 9b2fda4..ed1d437 100644 (file)
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -36,6 +36,13 @@ config SYSRESET_PSCI
          Enable PSCI SYSTEM_RESET function call.  To use this, PSCI firmware
          must be running on your system.
 
+config SYSRESET_TI_SCI
+       bool "TI System Control Interface (TI SCI) system reset driver"
+       depends on TI_SCI_PROTOCOL
+       help
+         This enables the system reset driver support over TI System Control
+         Interface available on some new TI's SoCs.
+
 endif
 
 config SYSRESET_SYSCON

diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index 707f1d7..02ee1df 100644 (file)
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_SYSRESET) += sysreset-uclass.o
 obj-$(CONFIG_SYSRESET_GPIO) += sysreset_gpio.o
 obj-$(CONFIG_SYSRESET_MICROBLAZE) += sysreset_microblaze.o
 obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o
+obj-$(CONFIG_SYSRESET_TI_SCI) += sysreset-ti-sci.o
 obj-$(CONFIG_SYSRESET_SYSCON) += sysreset_syscon.o
 obj-$(CONFIG_SYSRESET_WATCHDOG) += sysreset_watchdog.o
 obj-$(CONFIG_SYSRESET_X86) += sysreset_x86.o

diff --git a/drivers/sysreset/sysreset-ti-sci.c b/drivers/sysreset/sysreset-ti-sci.c
new file mode 100644 (file)
index 0000000..890a607
--- /dev/null
+++ b/drivers/sysreset/sysreset-ti-sci.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments System Control Interface (TI SCI) system reset driver
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *     Andreas Dannenberg <dannenberg@ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <sysreset.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+/**
+ * struct ti_sci_sysreset_data - sysreset controller information structure
+ * @sci: TI SCI handle used for communication with system controller
+ */
+struct ti_sci_sysreset_data {
+       const struct ti_sci_handle *sci;
+};
+
+static int ti_sci_sysreset_probe(struct udevice *dev)
+{
+       struct ti_sci_sysreset_data *data = dev_get_priv(dev);
+
+       debug("%s(dev=%p)\n", __func__, dev);
+
+       if (!data)
+               return -ENOMEM;
+
+       /* Store handle for communication with the system controller */
+       data->sci = ti_sci_get_handle(dev);
+       if (IS_ERR(data->sci))
+               return PTR_ERR(data->sci);
+
+       return 0;
+}
+
+static int ti_sci_sysreset_request(struct udevice *dev, enum sysreset_t type)
+{
+       struct ti_sci_sysreset_data *data = dev_get_priv(dev);
+       const struct ti_sci_handle *sci = data->sci;
+       const struct ti_sci_core_ops *cops = &sci->ops.core_ops;
+       int ret;
+
+       debug("%s(dev=%p, type=%d)\n", __func__, dev, type);
+
+       ret = cops->reboot_device(sci);
+       if (ret)
+               dev_err(rst->dev, "%s: reboot_device failed (%d)\n",
+                       __func__, ret);
+
+       return ret;
+}
+
+static struct sysreset_ops ti_sci_sysreset_ops = {
+       .request = ti_sci_sysreset_request,
+};
+
+static const struct udevice_id ti_sci_sysreset_of_match[] = {
+       { .compatible = "ti,sci-sysreset", },
+       { /* sentinel */ },
+};
+
+U_BOOT_DRIVER(ti_sci_sysreset) = {
+       .name = "ti-sci-sysreset",
+       .id = UCLASS_SYSRESET,
+       .of_match = ti_sci_sysreset_of_match,
+       .probe = ti_sci_sysreset_probe,
+       .priv_auto_alloc_size = sizeof(struct ti_sci_sysreset_data),
+       .ops = &ti_sci_sysreset_ops,
+};