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>

1 files changed, 73 insertions, 0 deletions

diff --git a/drivers/sysreset/sysreset-ti-sci.c b/drivers/sysreset/sysreset-ti-sci.c
new file mode 100644
index 0000000000..890a607c4b
--- /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,
+};