[PATCH v1 0/2] firmware: Add MediaTek TinySYS SCMI Protocol

[PATCH v1 0/2] firmware: Add MediaTek TinySYS SCMI Protocol

[AngeloGioacchino Del Regno]

This series adds basic support for the MediaTek TinySYS SCMI Protocol,
found on the MediaTek Dimensity 9200, 9300 and 9400, other than on the
MT8196 Chromebook SoC.

This is used to communicate with the CM_MGR and other MCUs for power
management purposes.

AngeloGioacchino Del Regno (2):
  dt-bindings: firmware: Add MediaTek TinySYS SCMI Extension protocol
  firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

 .../firmware/mediatek,mt6895-scmi.yaml        |  22 ++
 drivers/firmware/arm_scmi/Kconfig             |   1 +
 drivers/firmware/arm_scmi/Makefile            |   1 +
 .../arm_scmi/vendors/mediatek/Kconfig         |  16 +
 .../arm_scmi/vendors/mediatek/Makefile        |   2 +
 .../arm_scmi/vendors/mediatek/mtk-tinysys.c   | 344 ++++++++++++++++++
 include/linux/scmi_mtk_protocol.h             |  62 ++++
 7 files changed, 448 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Makefile
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
 create mode 100644 include/linux/scmi_mtk_protocol.h

-- 
2.49.0

[PATCH v1 1/2] dt-bindings: firmware: Add MediaTek TinySYS SCMI Extension protocol

[AngeloGioacchino Del Regno]

Add the MediaTek TinySYS SCMI Extension protocol as found on a
number of SoCs, including MT6895 and MT8196.

This includes controls and power state notifications for the GPU,
CPU Memory latency Manager (cm_mgr), SLBC, SSPM and others.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 .../firmware/mediatek,mt6895-scmi.yaml        | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml

diff --git a/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
new file mode 100644
index 000000000000..98a5b81983b1
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2025 Collabora Ltd
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/mediatek,mt6895-scmi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek System Control and Management Interface(SCMI) Vendor Protocols Extension
+
+maintainers:
+  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+
+properties:
+  protocol@80:
+    $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        const: 0x80
+
+additionalProperties: true
-- 
2.49.0

[PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

[AngeloGioacchino Del Regno]

Add a driver for the SCMI protocol extensions for MediaTek TinySYS.
This is used to communicate with various remote processors in some
MediaTek SoCs, which mainly handle power management related tasks.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/firmware/arm_scmi/Kconfig             |   1 +
 drivers/firmware/arm_scmi/Makefile            |   1 +
 .../arm_scmi/vendors/mediatek/Kconfig         |  16 +
 .../arm_scmi/vendors/mediatek/Makefile        |   2 +
 .../arm_scmi/vendors/mediatek/mtk-tinysys.c   | 344 ++++++++++++++++++
 include/linux/scmi_mtk_protocol.h             |  62 ++++
 6 files changed, 426 insertions(+)
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Makefile
 create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
 create mode 100644 include/linux/scmi_mtk_protocol.h

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index e3fb36825978..baadf4f7fef6 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -84,6 +84,7 @@ config ARM_SCMI_QUIRKS
 
 source "drivers/firmware/arm_scmi/transports/Kconfig"
 source "drivers/firmware/arm_scmi/vendors/imx/Kconfig"
+source "drivers/firmware/arm_scmi/vendors/mediatek/Kconfig"
 
 endif #ARM_SCMI_PROTOCOL
 
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 780cd62b2f78..d1b4ec16b8bc 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -13,6 +13,7 @@ scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
 
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += transports/
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/imx/
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/mediatek/
 
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
new file mode 100644
index 000000000000..8facdcd3819f
--- /dev/null
+++ b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "ARM SCMI MediaTek Vendor Protocols"
+
+config MTK_SCMI_TINYSYS
+	tristate "MediaTek SCMI TinySYS Extension"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	default y if ARCH_MEDIATEK
+	help
+	  This enables communication with the MediaTek TinySYS MCU
+	  to control the power status of various SoC sub-devices
+	  other than passing other messages for initialization.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mtk-tinysys.
+
+endmenu
diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Makefile b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
new file mode 100644
index 000000000000..dc1ff63c3b69
--- /dev/null
+++ b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_MTK_SCMI_TINYSYS) += mtk-tinysys.o
diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
new file mode 100644
index 000000000000..baeb36493952
--- /dev/null
+++ b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) MediaTek TinySYS Protocol
+ *
+ * Copyright (c) 2021 MediaTek Inc.
+ * Copyright (c) 2025 Collabora Ltd
+ *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications TinySYS - " fmt
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_mtk_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_MTK_CMD_SSPM_QUERY_ALIVE		0xdead
+
+enum scmi_mtk_tinysys_protocol_cmd {
+	MTK_TINYSYS_COMMON_SET = 0x3,
+	MTK_TINYSYS_COMMON_GET = 0x4,
+	MTK_TINYSYS_POWER_STATE_NOTIFY = 0x5,
+	MTK_TINYSYS_SLBC_CTRL = 0x6,
+};
+
+struct scmi_mtk_tinysys_common_get_payld {
+	__le32 rsvd;
+	__le32 param[SCMI_MTK_MSG_COMMON_REPLY_BYTES];
+};
+
+struct scmi_mtk_tinysys_common_set_payld {
+	__le32 rsvd;
+	__le32 ctrl_id;
+	__le32 param[SCMI_MTK_MSG_COMMON_PARAM_BYTES];
+};
+
+struct scmi_mtk_tinysys_slbc_payld {
+	__le32 rsvd;
+	__le32 cmd;
+	__le32 arg[SCMI_MTK_MSG_SLBC_PARAM_BYTES];
+};
+
+struct scmi_mtk_tinysys_pwrst_notify {
+	__le32 rsvd;
+	__le32 fid;
+	__le32 enable;
+};
+
+struct scmi_mtk_tinysys_notify_payld {
+	__le32 fid;
+	__le32 param[SCMI_MTK_MSG_NOTIF_ST_BYTES];
+};
+
+struct scmi_mtk_tinysys_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_mtk_tinysys_info {
+	int num_domains;
+};
+
+static int scmi_mtk_tinysys_attributes_get(const struct scmi_protocol_handle *ph,
+					   struct scmi_mtk_tinysys_info *tinfo)
+{
+	struct scmi_mtk_tinysys_protocol_attributes *attr;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		attr->attributes = get_unaligned_le32(t->rx.buf);
+		tinfo->num_domains = attr->attributes;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_mtk_tinysys_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_mtk_tinysys_info *tinfo = ph->get_priv(ph);
+
+	if (!tinfo)
+		return -EINVAL;
+
+	return tinfo->num_domains;
+}
+
+static int scmi_mtk_tinysys_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					       u8 evt_id, u32 src_id, bool enable)
+{
+	struct scmi_mtk_tinysys_pwrst_notify *pwrst_notify;
+	struct scmi_xfer *t;
+	int ret;
+
+	/* There's only one possible event for now */
+	if (evt_id != 0)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_POWER_STATE_NOTIFY,
+				      sizeof(*pwrst_notify), 0, &t);
+	if (ret)
+		return ret;
+
+	pwrst_notify = t->tx.buf;
+	pwrst_notify->fid = src_id;
+	pwrst_notify->enable = cpu_to_le32(enable);
+
+	ret = ph->xops->do_xfer(ph, t);
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static void *scmi_mtk_tinysys_fill_custom_report(const struct scmi_protocol_handle *ph,
+						 u8 evt_id, ktime_t timestamp,
+						 const void *payld, size_t payld_sz,
+						 void *report, u32 *src_id)
+{
+	const struct scmi_mtk_tinysys_notify_payld *p = payld;
+	struct scmi_mtk_tinysys_notif_report *r = report;
+	int i;
+
+	if (sizeof(*p) != payld_sz)
+		return NULL;
+
+	if (evt_id == SCMI_EVENT_MTK_TINYSYS_NOTIFIER) {
+		r->timestamp = timestamp;
+		r->fid = le32_to_cpu(p->fid);
+		for (i = 0; i < SCMI_MTK_MSG_NOTIF_ST_BYTES; i++)
+			r->status[i] = le32_to_cpu(p->param[i]);
+		if (src_id)
+			*src_id = p->fid;
+	} else {
+		WARN_ON_ONCE(1);
+		return NULL;
+	}
+
+	return r;
+}
+
+static const struct scmi_event scmi_mtk_tinysys_events[] = {
+	{
+		.id = SCMI_EVENT_MTK_TINYSYS_NOTIFIER,
+		.max_payld_sz =	sizeof(struct scmi_mtk_tinysys_notify_payld),
+		.max_report_sz = sizeof(struct scmi_mtk_tinysys_notif_report),
+	},
+};
+
+static int scmi_mtk_tinysys_common_get(const struct scmi_protocol_handle *ph,
+				       u32 ctrl_id, u32 cmd,
+				       struct scmi_mtk_tinysys_status *retval)
+{
+	struct scmi_mtk_tinysys_common_get_payld *p;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_COMMON_GET,
+				      sizeof(*p), sizeof(*retval), &t);
+	if (ret)
+		return ret;
+
+	p = t->tx.buf;
+	p->param[0] = ctrl_id;
+	p->param[1] = cmd;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		if (t->rx.len == sizeof(*retval))
+			memcpy(retval, t->rx.buf, sizeof(*retval));
+		else
+			ret = -EINVAL;
+	}
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_mtk_tinysys_common_set(const struct scmi_protocol_handle *ph,
+				       u32 ctrl_id, const u32 *params,
+				       const u8 num_params)
+{
+	struct scmi_mtk_tinysys_common_set_payld *p;
+	struct scmi_xfer *t;
+	int i, ret;
+
+	if (!params || num_params > SCMI_MTK_MSG_COMMON_PARAM_BYTES)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_COMMON_SET, sizeof(*p), 0, &t);
+	if (ret)
+		return ret;
+
+	p = t->tx.buf;
+	p->ctrl_id = cpu_to_le32(ctrl_id);
+	for (i = 0; i < num_params; i++)
+		p->param[i] = cpu_to_le32(params[i]);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_mtk_tinysys_cm_mgr_set(const struct scmi_protocol_handle *ph,
+				       u32 ctrl_id, u32 cmd, u32 arg)
+{
+	const u32 params[2] = { cmd, arg };
+
+	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
+}
+
+static int scmi_mtk_tinysys_gpu_pwr_set(const struct scmi_protocol_handle *ph,
+				       u32 ctrl_id, u8 pwr_indication, bool enable)
+{
+	const u32 params[2] = { pwr_indication, enable };
+
+	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
+}
+
+static int scmi_mtk_tinysys_slbc_req(const struct scmi_protocol_handle *ph,
+				     const struct scmi_mtk_tinysys_slbc *req,
+				     struct scmi_mtk_tinysys_slbc *retval)
+{
+	struct scmi_mtk_tinysys_slbc_payld *p;
+	struct scmi_xfer *t;
+	int i, ret;
+
+	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_SLBC_CTRL,
+				      sizeof(*p), sizeof(*p), &t);
+	if (ret)
+		return ret;
+
+	p = t->tx.buf;
+	p->cmd = cpu_to_le32(req->cmd);
+	for (i = 0; i < SCMI_MTK_MSG_SLBC_PARAM_BYTES; i++)
+		p->arg[i] = cpu_to_le32(req->arg[i]);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret && retval) {
+		if (t->rx.len == sizeof(*retval))
+			memcpy(retval, t->rx.buf, sizeof(*retval));
+		else
+			ret = -EINVAL;
+	}
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_mtk_tinysys_sspm_mem_set(const struct scmi_protocol_handle *ph,
+					 u32 ctrl_id, u32 pa, u32 mem_sz)
+{
+	const u32 params[2] = { pa, mem_sz };
+
+	if (mem_sz < SZ_1M)
+		return -EINVAL;
+
+	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
+}
+
+static bool scmi_mtk_tinysys_sspm_is_alive(const struct scmi_protocol_handle *ph,
+					   u32 ctrl_id)
+{
+	const u32 param = SCMI_MTK_CMD_SSPM_QUERY_ALIVE;
+	int ret;
+
+	ret = scmi_mtk_tinysys_common_set(ph, ctrl_id, &param, 1);
+
+	return ret ? false : true;
+}
+
+static const struct scmi_mtk_tinysys_proto_ops mtk_tinysys_proto_ops = {
+	.common_get = scmi_mtk_tinysys_common_get,
+	.cm_mgr_set = scmi_mtk_tinysys_cm_mgr_set,
+	.gpu_pwr_set = scmi_mtk_tinysys_gpu_pwr_set,
+	.slbc_req = scmi_mtk_tinysys_slbc_req,
+	.sspm_is_alive = scmi_mtk_tinysys_sspm_is_alive,
+	.sspm_mem_set = scmi_mtk_tinysys_sspm_mem_set,
+};
+
+static const struct scmi_event_ops scmi_mtk_tinysys_event_ops = {
+	.get_num_sources = scmi_mtk_tinysys_get_num_sources,
+	.set_notify_enabled = scmi_mtk_tinysys_set_notify_enabled,
+	.fill_custom_report = scmi_mtk_tinysys_fill_custom_report,
+};
+
+static const struct scmi_protocol_events scmi_mtk_tinysys_protocol_events = {
+	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
+	.ops = &scmi_mtk_tinysys_event_ops,
+	.evts = scmi_mtk_tinysys_events,
+	.num_events = ARRAY_SIZE(scmi_mtk_tinysys_events),
+};
+
+static int scmi_mtk_tinysys_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_mtk_tinysys_info *tinfo;
+	u32 version;
+	int ret;
+
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
+
+	dev_info(ph->dev, "MediaTek TinySYS Protocol Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	tinfo = devm_kzalloc(ph->dev, sizeof(*tinfo), GFP_KERNEL);
+	if (!tinfo)
+		return -ENOMEM;
+
+	ret = scmi_mtk_tinysys_attributes_get(ph, tinfo);
+	if (ret)
+		return ret;
+
+	return ph->set_priv(ph, tinfo, version);
+}
+
+static const struct scmi_protocol scmi_mtk_tinysys = {
+	.id = SCMI_PROTOCOL_MTK_TINYSYS,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_mtk_tinysys_protocol_init,
+	.ops = &mtk_tinysys_proto_ops,
+	.events = &scmi_mtk_tinysys_protocol_events,
+	.vendor_id = SCMI_MTK_VENDOR,
+};
+module_scmi_protocol(scmi_mtk_tinysys);
+
+MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_MTK_TINYSYS) "-" SCMI_MTK_VENDOR);
+MODULE_DESCRIPTION("MediaTek SCMI TinySYS driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/scmi_mtk_protocol.h b/include/linux/scmi_mtk_protocol.h
new file mode 100644
index 000000000000..51ad0cb4b72d
--- /dev/null
+++ b/include/linux/scmi_mtk_protocol.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * SCMI Message Protocol driver MediaTek extension header
+ *
+ * Copyright (c) 2021 MediaTek Inc.
+ * Copyright (c) 2025 Collabora Ltd
+ *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+ */
+
+#ifndef _LINUX_SCMI_MTK_PROTOCOL_H
+#define _LINUX_SCMI_MTK_PROTOCOL_H
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/types.h>
+
+#define SCMI_PROTOCOL_MTK_TINYSYS	0x80
+#define SCMI_MTK_VENDOR			"MediaTek"
+
+#define SCMI_MTK_MSG_COMMON_PARAM_BYTES	5
+#define SCMI_MTK_MSG_COMMON_REPLY_BYTES	2
+#define SCMI_MTK_MSG_NOTIF_ST_BYTES	4
+#define SCMI_MTK_MSG_SLBC_PARAM_BYTES	4
+
+struct scmi_mtk_tinysys_status {
+	u32 rsvd;
+	u32 reply[SCMI_MTK_MSG_COMMON_REPLY_BYTES];
+};
+
+struct scmi_mtk_tinysys_slbc {
+	u32 cmd;
+	u32 arg[SCMI_MTK_MSG_SLBC_PARAM_BYTES];
+};
+
+struct scmi_mtk_tinysys_proto_ops {
+	int (*common_get)(const struct scmi_protocol_handle *ph,
+			  u32 ctrl_id, u32 cmd,
+			  struct scmi_mtk_tinysys_status *retval);
+	int (*cm_mgr_set)(const struct scmi_protocol_handle *ph,
+			  u32 ctrl_id, u32 cmd, u32 arg);
+	int (*gpu_pwr_set)(const struct scmi_protocol_handle *ph,
+			   u32 ctrl_id, u8 pwr_indication, bool enable);
+	int (*slbc_req)(const struct scmi_protocol_handle *ph,
+			const struct scmi_mtk_tinysys_slbc *req,
+			struct scmi_mtk_tinysys_slbc *retval);
+	bool (*sspm_is_alive)(const struct scmi_protocol_handle *ph,
+			      u32 ctrl_id);
+	int (*sspm_mem_set)(const struct scmi_protocol_handle *ph,
+			    u32 ctrl_id, u32 pa, u32 mem_sz);
+};
+
+enum scmi_mtk_tinysys_notification_events {
+	SCMI_EVENT_MTK_TINYSYS_NOTIFIER = 0x0,
+};
+
+struct scmi_mtk_tinysys_notif_report {
+	ktime_t timestamp;
+	unsigned int fid;
+	unsigned int status[SCMI_MTK_MSG_NOTIF_ST_BYTES];
+};
+#endif
-- 
2.49.0

Re: [PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

[Sudeep Holla]

On Mon, Jun 23, 2025 at 02:01:36PM +0200, AngeloGioacchino Del Regno wrote:
> Add a driver for the SCMI protocol extensions for MediaTek TinySYS.
> This is used to communicate with various remote processors in some
> MediaTek SoCs, which mainly handle power management related tasks.
> 

Please provide the detailed documentation for this vendor protocol/extension.
Refer drivers/firmware/arm_scmi/vendors/imx/imx95.rst for example.
It is hard to do any useful review without the detailed documentation.

-- 
Regards,
Sudeep

Re: [PATCH v1 0/2] firmware: Add MediaTek TinySYS SCMI Protocol

[Cristian Marussi]

On Mon, Jun 23, 2025 at 02:01:34PM +0200, AngeloGioacchino Del Regno wrote:
> This series adds basic support for the MediaTek TinySYS SCMI Protocol,
> found on the MediaTek Dimensity 9200, 9300 and 9400, other than on the
> MT8196 Chromebook SoC.
> 
> This is used to communicate with the CM_MGR and other MCUs for power
> management purposes.

Hi Angelo,

thanks for this.

I will do a proper review in the coming days of this series anyway, but
upfront for future V2:

- you should provide some sort of documentation for this new
  vendor protocol and its messages, as an example from IMX:

	drivers/firmware/arm_scmi/vendors/imx/imx95.rst

- where is the SCMI driver that will call all the new vendor ops
  defined in: scmi_mtk_protocol.h ?

Thanks,
Cristian

Re: [PATCH v1 0/2] firmware: Add MediaTek TinySYS SCMI Protocol

[AngeloGioacchino Del Regno]

Il 23/06/25 14:17, Cristian Marussi ha scritto:
> On Mon, Jun 23, 2025 at 02:01:34PM +0200, AngeloGioacchino Del Regno wrote:
>> This series adds basic support for the MediaTek TinySYS SCMI Protocol,
>> found on the MediaTek Dimensity 9200, 9300 and 9400, other than on the
>> MT8196 Chromebook SoC.
>>
>> This is used to communicate with the CM_MGR and other MCUs for power
>> management purposes.
> 
> Hi Angelo,
> 
> thanks for this.
> 
> I will do a proper review in the coming days of this series anyway, but
> upfront for future V2:
> 
> - you should provide some sort of documentation for this new
>    vendor protocol and its messages, as an example from IMX:
> 
> 	drivers/firmware/arm_scmi/vendors/imx/imx95.rst

Noted.

> 
> - where is the SCMI driver that will call all the new vendor ops
>    defined in: scmi_mtk_protocol.h ?

This was tested with code that is not clean at all (hence I can't push it upstream)
and well... I didn't think about the fact that, effectively, without an user, this
code ends up being unused.

I can't promise to send a clean user in this cycle, but I would really appreciate
if you could still check the protocol code, so that if there's anything that you
can spot I can fix it while the rest gets done :-)

Thank you,
Angelo

> 
> Thanks,
> Cristian

Re: [PATCH v1 0/2] firmware: Add MediaTek TinySYS SCMI Protocol

[Cristian Marussi]

On Mon, Jun 23, 2025 at 02:32:24PM +0200, AngeloGioacchino Del Regno wrote:
> Il 23/06/25 14:17, Cristian Marussi ha scritto:
> > On Mon, Jun 23, 2025 at 02:01:34PM +0200, AngeloGioacchino Del Regno wrote:
> > > This series adds basic support for the MediaTek TinySYS SCMI Protocol,
> > > found on the MediaTek Dimensity 9200, 9300 and 9400, other than on the
> > > MT8196 Chromebook SoC.
> > > 
> > > This is used to communicate with the CM_MGR and other MCUs for power
> > > management purposes.
> > 
> > Hi Angelo,
> > 
> > thanks for this.
> > 
> > I will do a proper review in the coming days of this series anyway, but
> > upfront for future V2:
> > 
> > - you should provide some sort of documentation for this new
> >    vendor protocol and its messages, as an example from IMX:
> > 
> > 	drivers/firmware/arm_scmi/vendors/imx/imx95.rst
> 
> Noted.
> 
> > 
> > - where is the SCMI driver that will call all the new vendor ops
> >    defined in: scmi_mtk_protocol.h ?
> 
> This was tested with code that is not clean at all (hence I can't push it upstream)
> and well... I didn't think about the fact that, effectively, without an user, this
> code ends up being unused.
> 
> I can't promise to send a clean user in this cycle, but I would really appreciate
> if you could still check the protocol code, so that if there's anything that you
> can spot I can fix it while the rest gets done :-)

Sure, I will anyway review, but a driver user exampe would be useful, maybe
posting it at the end of the series as a NOT-FOR-UPSTREAM/RFC (something like that)
so that we can have an iddea of the usage patterns while being aware that it is
still not clean for upstream.

Thanks,
Cristian

Re: [PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

[Peng Fan]

On Mon, Jun 23, 2025 at 02:01:36PM +0200, AngeloGioacchino Del Regno wrote:
>Add a driver for the SCMI protocol extensions for MediaTek TinySYS.
>This is used to communicate with various remote processors in some
>MediaTek SoCs, which mainly handle power management related tasks.
>
>Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>---
> drivers/firmware/arm_scmi/Kconfig             |   1 +
> drivers/firmware/arm_scmi/Makefile            |   1 +
> .../arm_scmi/vendors/mediatek/Kconfig         |  16 +
> .../arm_scmi/vendors/mediatek/Makefile        |   2 +
> .../arm_scmi/vendors/mediatek/mtk-tinysys.c   | 344 ++++++++++++++++++
> include/linux/scmi_mtk_protocol.h             |  62 ++++
> 6 files changed, 426 insertions(+)
> create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
> create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Makefile
> create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
> create mode 100644 include/linux/scmi_mtk_protocol.h
>
>diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
>index e3fb36825978..baadf4f7fef6 100644
>--- a/drivers/firmware/arm_scmi/Kconfig
>+++ b/drivers/firmware/arm_scmi/Kconfig
>@@ -84,6 +84,7 @@ config ARM_SCMI_QUIRKS
> 
> source "drivers/firmware/arm_scmi/transports/Kconfig"
> source "drivers/firmware/arm_scmi/vendors/imx/Kconfig"
>+source "drivers/firmware/arm_scmi/vendors/mediatek/Kconfig"
> 
> endif #ARM_SCMI_PROTOCOL
> 
>diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
>index 780cd62b2f78..d1b4ec16b8bc 100644
>--- a/drivers/firmware/arm_scmi/Makefile
>+++ b/drivers/firmware/arm_scmi/Makefile
>@@ -13,6 +13,7 @@ scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
> 
> obj-$(CONFIG_ARM_SCMI_PROTOCOL) += transports/
> obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/imx/
>+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/mediatek/
> 
> obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
> obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
>diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
>new file mode 100644
>index 000000000000..8facdcd3819f
>--- /dev/null
>+++ b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
>@@ -0,0 +1,16 @@
>+# SPDX-License-Identifier: GPL-2.0-only
>+menu "ARM SCMI MediaTek Vendor Protocols"
>+
>+config MTK_SCMI_TINYSYS
>+	tristate "MediaTek SCMI TinySYS Extension"
>+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)

Should dependency to ARCH_MEDIATEK be added, as below
ARM_SCMI_PROTOCOL & ARCH_MEDIATEK ?

>+	default y if ARCH_MEDIATEK
>+	help
>+	  This enables communication with the MediaTek TinySYS MCU
>+	  to control the power status of various SoC sub-devices
>+	  other than passing other messages for initialization.
>+
>+	  To compile this driver as a module, choose M here: the
>+	  module will be called mtk-tinysys.
>+
>+endmenu
>diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Makefile b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
>new file mode 100644
>index 000000000000..dc1ff63c3b69
>--- /dev/null
>+++ b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
>@@ -0,0 +1,2 @@
>+# SPDX-License-Identifier: GPL-2.0-only
>+obj-$(CONFIG_MTK_SCMI_TINYSYS) += mtk-tinysys.o
>diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
>new file mode 100644
>index 000000000000..baeb36493952
>--- /dev/null
>+++ b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
>@@ -0,0 +1,344 @@
>+// SPDX-License-Identifier: GPL-2.0
>+/*
>+ * System Control and Management Interface (SCMI) MediaTek TinySYS Protocol
>+ *
>+ * Copyright (c) 2021 MediaTek Inc.
>+ * Copyright (c) 2025 Collabora Ltd
>+ *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>+ */
>+
>+#define pr_fmt(fmt) "SCMI Notifications TinySYS - " fmt
>+
>+#include <linux/bits.h>
>+#include <linux/io.h>
>+#include <linux/module.h>
>+#include <linux/of.h>
>+#include <linux/platform_device.h>

This header is not needed, since no user here.
I just see i.MX also includes this header, but could be dropped.

>+#include <linux/scmi_protocol.h>
>+#include <linux/scmi_mtk_protocol.h>
>+
>+#include "../../protocols.h"
>+#include "../../notify.h"
>+
>+#define SCMI_MTK_CMD_SSPM_QUERY_ALIVE		0xdead
>+
>+enum scmi_mtk_tinysys_protocol_cmd {
>+	MTK_TINYSYS_COMMON_SET = 0x3,
>+	MTK_TINYSYS_COMMON_GET = 0x4,
>+	MTK_TINYSYS_POWER_STATE_NOTIFY = 0x5,
>+	MTK_TINYSYS_SLBC_CTRL = 0x6,
>+};
>+
>+struct scmi_mtk_tinysys_common_get_payld {
>+	__le32 rsvd;
>+	__le32 param[SCMI_MTK_MSG_COMMON_REPLY_BYTES];
>+};
>+
>+struct scmi_mtk_tinysys_common_set_payld {
>+	__le32 rsvd;
>+	__le32 ctrl_id;
>+	__le32 param[SCMI_MTK_MSG_COMMON_PARAM_BYTES];
>+};
>+
>+struct scmi_mtk_tinysys_slbc_payld {
>+	__le32 rsvd;
>+	__le32 cmd;
>+	__le32 arg[SCMI_MTK_MSG_SLBC_PARAM_BYTES];
>+};
>+
>+struct scmi_mtk_tinysys_pwrst_notify {
>+	__le32 rsvd;

Not sure why all upper structure has 'rsvd', meaning reserved?

>+	__le32 fid;
>+	__le32 enable;
>+};
>+
>+struct scmi_mtk_tinysys_notify_payld {
>+	__le32 fid;
>+	__le32 param[SCMI_MTK_MSG_NOTIF_ST_BYTES];
>+};
>+
>+struct scmi_mtk_tinysys_protocol_attributes {
>+	__le32 attributes;
>+};
>+
>+struct scmi_mtk_tinysys_info {
>+	int num_domains;
>+};
>+
>+static int scmi_mtk_tinysys_attributes_get(const struct scmi_protocol_handle *ph,
>+					   struct scmi_mtk_tinysys_info *tinfo)
>+{
>+	struct scmi_mtk_tinysys_protocol_attributes *attr;
>+	struct scmi_xfer *t;
>+	int ret;
>+
>+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
>+	if (ret)
>+		return ret;
>+
>+	attr = t->rx.buf;
>+
>+	ret = ph->xops->do_xfer(ph, t);
>+	if (!ret) {
>+		attr->attributes = get_unaligned_le32(t->rx.buf);
>+		tinfo->num_domains = attr->attributes;

Not sure the spec use whole 32bits for num_domains, if not, better
use le32_get_bits to the expect fields

>+	}
>+
>+	ph->xops->xfer_put(ph, t);
>+
>+	return ret;
>+}
>+
>+static int scmi_mtk_tinysys_get_num_sources(const struct scmi_protocol_handle *ph)
>+{
>+	struct scmi_mtk_tinysys_info *tinfo = ph->get_priv(ph);
>+
>+	if (!tinfo)
>+		return -EINVAL;
>+
>+	return tinfo->num_domains;
>+}
>+
>+static int scmi_mtk_tinysys_set_notify_enabled(const struct scmi_protocol_handle *ph,
>+					       u8 evt_id, u32 src_id, bool enable)
>+{
>+	struct scmi_mtk_tinysys_pwrst_notify *pwrst_notify;
>+	struct scmi_xfer *t;
>+	int ret;
>+
>+	/* There's only one possible event for now */
>+	if (evt_id != 0)

Use 'evt_id != SCMI_EVENT_MTK_TINYSYS_NOTIFIER' ?

>+		return -EINVAL;
>+
...
>+#endif
>-- 
>2.49.0
>

Regards,
Peng

Re: [PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

[kernel test robot]

Hi AngeloGioacchino,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.16-rc3 next-20250626]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/AngeloGioacchino-Del-Regno/dt-bindings-firmware-Add-MediaTek-TinySYS-SCMI-Extension-protocol/20250623-201014
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20250623120136.109311-3-angelogioacchino.delregno%40collabora.com
patch subject: [PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support
config: csky-randconfig-r111-20250627 (https://download.01.org/0day-ci/archive/20250627/202506271642.aFdjzjw7-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 15.1.0
reproduce: (https://download.01.org/0day-ci/archive/20250627/202506271642.aFdjzjw7-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202506271642.aFdjzjw7-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:83:34: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 [usertype] attributes @@     got unsigned int @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:83:34: sparse:     expected restricted __le32 [usertype] attributes
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:83:34: sparse:     got unsigned int
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:84:36: sparse: sparse: incorrect type in assignment (different base types) @@     expected int num_domains @@     got restricted __le32 [usertype] attributes @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:84:36: sparse:     expected int num_domains
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:84:36: sparse:     got restricted __le32 [usertype] attributes
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:119:27: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 [usertype] fid @@     got unsigned int [usertype] src_id @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:119:27: sparse:     expected restricted __le32 [usertype] fid
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:119:27: sparse:     got unsigned int [usertype] src_id
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:145:33: sparse: sparse: incorrect type in assignment (different base types) @@     expected unsigned int [usertype] @@     got restricted __le32 const [usertype] fid @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:145:33: sparse:     expected unsigned int [usertype]
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:145:33: sparse:     got restricted __le32 const [usertype] fid
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:176:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 @@     got unsigned int [usertype] ctrl_id @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:176:21: sparse:     expected restricted __le32
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:176:21: sparse:     got unsigned int [usertype] ctrl_id
>> drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:177:21: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __le32 @@     got unsigned int [usertype] cmd @@
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:177:21: sparse:     expected restricted __le32
   drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c:177:21: sparse:     got unsigned int [usertype] cmd

vim +83 drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c

    67	
    68	static int scmi_mtk_tinysys_attributes_get(const struct scmi_protocol_handle *ph,
    69						   struct scmi_mtk_tinysys_info *tinfo)
    70	{
    71		struct scmi_mtk_tinysys_protocol_attributes *attr;
    72		struct scmi_xfer *t;
    73		int ret;
    74	
    75		ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
    76		if (ret)
    77			return ret;
    78	
    79		attr = t->rx.buf;
    80	
    81		ret = ph->xops->do_xfer(ph, t);
    82		if (!ret) {
  > 83			attr->attributes = get_unaligned_le32(t->rx.buf);
  > 84			tinfo->num_domains = attr->attributes;
    85		}
    86	
    87		ph->xops->xfer_put(ph, t);
    88	
    89		return ret;
    90	}
    91	
    92	static int scmi_mtk_tinysys_get_num_sources(const struct scmi_protocol_handle *ph)
    93	{
    94		struct scmi_mtk_tinysys_info *tinfo = ph->get_priv(ph);
    95	
    96		if (!tinfo)
    97			return -EINVAL;
    98	
    99		return tinfo->num_domains;
   100	}
   101	
   102	static int scmi_mtk_tinysys_set_notify_enabled(const struct scmi_protocol_handle *ph,
   103						       u8 evt_id, u32 src_id, bool enable)
   104	{
   105		struct scmi_mtk_tinysys_pwrst_notify *pwrst_notify;
   106		struct scmi_xfer *t;
   107		int ret;
   108	
   109		/* There's only one possible event for now */
   110		if (evt_id != 0)
   111			return -EINVAL;
   112	
   113		ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_POWER_STATE_NOTIFY,
   114					      sizeof(*pwrst_notify), 0, &t);
   115		if (ret)
   116			return ret;
   117	
   118		pwrst_notify = t->tx.buf;
 > 119		pwrst_notify->fid = src_id;
   120		pwrst_notify->enable = cpu_to_le32(enable);
   121	
   122		ret = ph->xops->do_xfer(ph, t);
   123		ph->xops->xfer_put(ph, t);
   124		return ret;
   125	}
   126	
   127	static void *scmi_mtk_tinysys_fill_custom_report(const struct scmi_protocol_handle *ph,
   128							 u8 evt_id, ktime_t timestamp,
   129							 const void *payld, size_t payld_sz,
   130							 void *report, u32 *src_id)
   131	{
   132		const struct scmi_mtk_tinysys_notify_payld *p = payld;
   133		struct scmi_mtk_tinysys_notif_report *r = report;
   134		int i;
   135	
   136		if (sizeof(*p) != payld_sz)
   137			return NULL;
   138	
   139		if (evt_id == SCMI_EVENT_MTK_TINYSYS_NOTIFIER) {
   140			r->timestamp = timestamp;
   141			r->fid = le32_to_cpu(p->fid);
   142			for (i = 0; i < SCMI_MTK_MSG_NOTIF_ST_BYTES; i++)
   143				r->status[i] = le32_to_cpu(p->param[i]);
   144			if (src_id)
 > 145				*src_id = p->fid;
   146		} else {
   147			WARN_ON_ONCE(1);
   148			return NULL;
   149		}
   150	
   151		return r;
   152	}
   153	
   154	static const struct scmi_event scmi_mtk_tinysys_events[] = {
   155		{
   156			.id = SCMI_EVENT_MTK_TINYSYS_NOTIFIER,
   157			.max_payld_sz =	sizeof(struct scmi_mtk_tinysys_notify_payld),
   158			.max_report_sz = sizeof(struct scmi_mtk_tinysys_notif_report),
   159		},
   160	};
   161	
   162	static int scmi_mtk_tinysys_common_get(const struct scmi_protocol_handle *ph,
   163					       u32 ctrl_id, u32 cmd,
   164					       struct scmi_mtk_tinysys_status *retval)
   165	{
   166		struct scmi_mtk_tinysys_common_get_payld *p;
   167		struct scmi_xfer *t;
   168		int ret;
   169	
   170		ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_COMMON_GET,
   171					      sizeof(*p), sizeof(*retval), &t);
   172		if (ret)
   173			return ret;
   174	
   175		p = t->tx.buf;
 > 176		p->param[0] = ctrl_id;
 > 177		p->param[1] = cmd;
   178	
   179		ret = ph->xops->do_xfer(ph, t);
   180		if (!ret) {
   181			if (t->rx.len == sizeof(*retval))
   182				memcpy(retval, t->rx.buf, sizeof(*retval));
   183			else
   184				ret = -EINVAL;
   185		}
   186	
   187		ph->xops->xfer_put(ph, t);
   188		return ret;
   189	}
   190	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v1 1/2] dt-bindings: firmware: Add MediaTek TinySYS SCMI Extension protocol

[Cristian Marussi]

On Mon, Jun 23, 2025 at 02:01:35PM +0200, AngeloGioacchino Del Regno wrote:
> Add the MediaTek TinySYS SCMI Extension protocol as found on a
> number of SoCs, including MT6895 and MT8196.
> 
> This includes controls and power state notifications for the GPU,
> CPU Memory latency Manager (cm_mgr), SLBC, SSPM and others.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  .../firmware/mediatek,mt6895-scmi.yaml        | 22 +++++++++++++++++++
>  1 file changed, 22 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> new file mode 100644
> index 000000000000..98a5b81983b1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> @@ -0,0 +1,22 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2025 Collabora Ltd
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/firmware/mediatek,mt6895-scmi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek System Control and Management Interface(SCMI) Vendor Protocols Extension
> +
> +maintainers:
> +  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> +
> +properties:

Can we add some general description too.

Thanks,
Cristian

Re: [PATCH v1 2/2] firmware: arm_scmi: Add MediaTek TinySYS SCMI Protocol support

[Cristian Marussi]

On Mon, Jun 23, 2025 at 02:01:36PM +0200, AngeloGioacchino Del Regno wrote:
> Add a driver for the SCMI protocol extensions for MediaTek TinySYS.
> This is used to communicate with various remote processors in some
> MediaTek SoCs, which mainly handle power management related tasks.
> 

Hi,

> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  drivers/firmware/arm_scmi/Kconfig             |   1 +
>  drivers/firmware/arm_scmi/Makefile            |   1 +
>  .../arm_scmi/vendors/mediatek/Kconfig         |  16 +
>  .../arm_scmi/vendors/mediatek/Makefile        |   2 +
>  .../arm_scmi/vendors/mediatek/mtk-tinysys.c   | 344 ++++++++++++++++++
>  include/linux/scmi_mtk_protocol.h             |  62 ++++
>  6 files changed, 426 insertions(+)
>  create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
>  create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/Makefile
>  create mode 100644 drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
>  create mode 100644 include/linux/scmi_mtk_protocol.h
> 
> diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
> index e3fb36825978..baadf4f7fef6 100644
> --- a/drivers/firmware/arm_scmi/Kconfig
> +++ b/drivers/firmware/arm_scmi/Kconfig
> @@ -84,6 +84,7 @@ config ARM_SCMI_QUIRKS
>  
>  source "drivers/firmware/arm_scmi/transports/Kconfig"
>  source "drivers/firmware/arm_scmi/vendors/imx/Kconfig"
> +source "drivers/firmware/arm_scmi/vendors/mediatek/Kconfig"
>  
>  endif #ARM_SCMI_PROTOCOL
>  
> diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
> index 780cd62b2f78..d1b4ec16b8bc 100644
> --- a/drivers/firmware/arm_scmi/Makefile
> +++ b/drivers/firmware/arm_scmi/Makefile
> @@ -13,6 +13,7 @@ scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
>  
>  obj-$(CONFIG_ARM_SCMI_PROTOCOL) += transports/
>  obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/imx/
> +obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/mediatek/
>  
>  obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
>  obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
> diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
> new file mode 100644
> index 000000000000..8facdcd3819f
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/vendors/mediatek/Kconfig
> @@ -0,0 +1,16 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +menu "ARM SCMI MediaTek Vendor Protocols"
> +
> +config MTK_SCMI_TINYSYS
> +	tristate "MediaTek SCMI TinySYS Extension"
> +	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
> +	default y if ARCH_MEDIATEK
> +	help
> +	  This enables communication with the MediaTek TinySYS MCU
> +	  to control the power status of various SoC sub-devices
> +	  other than passing other messages for initialization.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called mtk-tinysys.
> +
> +endmenu
> diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/Makefile b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
> new file mode 100644
> index 000000000000..dc1ff63c3b69
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/vendors/mediatek/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_MTK_SCMI_TINYSYS) += mtk-tinysys.o
> diff --git a/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
> new file mode 100644
> index 000000000000..baeb36493952
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/vendors/mediatek/mtk-tinysys.c
> @@ -0,0 +1,344 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * System Control and Management Interface (SCMI) MediaTek TinySYS Protocol
> + *
> + * Copyright (c) 2021 MediaTek Inc.
> + * Copyright (c) 2025 Collabora Ltd
> + *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> + */
> +
> +#define pr_fmt(fmt) "SCMI Notifications TinySYS - " fmt
> +
> +#include <linux/bits.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/scmi_protocol.h>
> +#include <linux/scmi_mtk_protocol.h>
> +
> +#include "../../protocols.h"
> +#include "../../notify.h"
> +
> +#define SCMI_MTK_CMD_SSPM_QUERY_ALIVE		0xdead
> +
> +enum scmi_mtk_tinysys_protocol_cmd {
> +	MTK_TINYSYS_COMMON_SET = 0x3,
> +	MTK_TINYSYS_COMMON_GET = 0x4,
> +	MTK_TINYSYS_POWER_STATE_NOTIFY = 0x5,
> +	MTK_TINYSYS_SLBC_CTRL = 0x6,
> +};
> +
> +struct scmi_mtk_tinysys_common_get_payld {
> +	__le32 rsvd;
> +	__le32 param[SCMI_MTK_MSG_COMMON_REPLY_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_common_set_payld {
> +	__le32 rsvd;
> +	__le32 ctrl_id;
> +	__le32 param[SCMI_MTK_MSG_COMMON_PARAM_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_slbc_payld {
> +	__le32 rsvd;
> +	__le32 cmd;
> +	__le32 arg[SCMI_MTK_MSG_SLBC_PARAM_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_pwrst_notify {
> +	__le32 rsvd;
> +	__le32 fid;
> +	__le32 enable;
> +};
> +
> +struct scmi_mtk_tinysys_notify_payld {
> +	__le32 fid;
> +	__le32 param[SCMI_MTK_MSG_NOTIF_ST_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_protocol_attributes {
> +	__le32 attributes;

...this is a clear example where would be benificial to have a
doc describing the protocol fields (as mentioned already previously) so
that you can at least know here what is the nature of attributes: is it
completely made up of bitfield? has any subfield wider than one-bute
that has to be interpreted as a quantity (so le32_to_cpu and friends...)

..I see all of this is apparent by the code below but a bit of protocol
description would be better...you get my point...

...anyway...you can avoid single field structures in message descriptors...

> +};
> +
> +struct scmi_mtk_tinysys_info {
> +	int num_domains;
> +};
> +
> +static int scmi_mtk_tinysys_attributes_get(const struct scmi_protocol_handle *ph,
> +					   struct scmi_mtk_tinysys_info *tinfo)
> +{
> +	struct scmi_mtk_tinysys_protocol_attributes *attr;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
> +	if (ret)
> +		return ret;
> +
> +	attr = t->rx.buf;

...especially if you are gonna use down below the get_unaligned_le32()
directly on the buffer at the end....

> +
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret) {
> +		attr->attributes = get_unaligned_le32(t->rx.buf);

..also I think this will make smatch/sparse static analyzers screams
since yiu defined attr_attributes as __le32 BUT here you then assign to
it the u32 which you get out of get_unaligned_le32()

> +		tinfo->num_domains = attr->attributes;

...so what about dropping attr struct definitions and declararion and just:

		tinfo->num_domains = get_unaligned_le32(t->rx.buf);

> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static int scmi_mtk_tinysys_get_num_sources(const struct scmi_protocol_handle *ph)
> +{
> +	struct scmi_mtk_tinysys_info *tinfo = ph->get_priv(ph);
> +
> +	if (!tinfo)
> +		return -EINVAL;
> +
> +	return tinfo->num_domains;
> +}
> +
> +static int scmi_mtk_tinysys_set_notify_enabled(const struct scmi_protocol_handle *ph,
> +					       u8 evt_id, u32 src_id, bool enable)
> +{
> +	struct scmi_mtk_tinysys_pwrst_notify *pwrst_notify;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	/* There's only one possible event for now */
> +	if (evt_id != 0)

As also Peng pointed out...

	if (evt != SCMI_EVENT_MTK_TINYSYS_NOTIFIER)

> +		return -EINVAL;
> +
> +	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_POWER_STATE_NOTIFY,
> +				      sizeof(*pwrst_notify), 0, &t);
> +	if (ret)
> +		return ret;
> +
> +	pwrst_notify = t->tx.buf;
> +	pwrst_notify->fid = src_id;

 	... = cpu_to_le32(src_id)

> +	pwrst_notify->enable = cpu_to_le32(enable);

...I suppose (since no doc) that this is mant to simply set BIT_0 if
enable....so maybe simply

	pwrst_notify->enable = enable ? BIT(0) : 0;

... endianityshould not matter and you risk to set the wrong bit by
using  cpu_to_le32()

> +
> +	ret = ph->xops->do_xfer(ph, t);
> +	ph->xops->xfer_put(ph, t);
> +	return ret;
> +}
> +
> +static void *scmi_mtk_tinysys_fill_custom_report(const struct scmi_protocol_handle *ph,
> +						 u8 evt_id, ktime_t timestamp,
> +						 const void *payld, size_t payld_sz,
> +						 void *report, u32 *src_id)
> +{
> +	const struct scmi_mtk_tinysys_notify_payld *p = payld;
> +	struct scmi_mtk_tinysys_notif_report *r = report;
> +	int i;
> +
> +	if (sizeof(*p) != payld_sz)
> +		return NULL;
> +
> +	if (evt_id == SCMI_EVENT_MTK_TINYSYS_NOTIFIER) {
> +		r->timestamp = timestamp;
> +		r->fid = le32_to_cpu(p->fid);
> +		for (i = 0; i < SCMI_MTK_MSG_NOTIF_ST_BYTES; i++)
> +			r->status[i] = le32_to_cpu(p->param[i]);
> +		if (src_id)
> +			*src_id = p->fid;

			*src_id = le32_to_cpu(p->fid);

			or better

			*src_id = r->fid;

> +	} else {
> +		WARN_ON_ONCE(1);
> +		return NULL;
> +	}
> +
> +	return r;
> +}
> +
> +static const struct scmi_event scmi_mtk_tinysys_events[] = {
> +	{
> +		.id = SCMI_EVENT_MTK_TINYSYS_NOTIFIER,
> +		.max_payld_sz =	sizeof(struct scmi_mtk_tinysys_notify_payld),
> +		.max_report_sz = sizeof(struct scmi_mtk_tinysys_notif_report),
> +	},
> +};
> +
> +static int scmi_mtk_tinysys_common_get(const struct scmi_protocol_handle *ph,
> +				       u32 ctrl_id, u32 cmd,
> +				       struct scmi_mtk_tinysys_status *retval)
> +{
> +	struct scmi_mtk_tinysys_common_get_payld *p;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_COMMON_GET,
> +				      sizeof(*p), sizeof(*retval), &t);
> +	if (ret)
> +		return ret;
> +
> +	p = t->tx.buf;
> +	p->param[0] = ctrl_id;

	cpu_to_le32(ctrl_id);


> +	p->param[1] = cmd;

	cpu_to_le32(ctrl_id);

...you should run smatch() or any other Kenel static analyzer ... it
would have screamed a lot around endianity...trivial errors really but
posshbly painful bugs if this ever get run on a BigEndian thing...

> +
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret) {
> +		if (t->rx.len == sizeof(*retval))
> +			memcpy(retval, t->rx.buf, sizeof(*retval));

mmmm...so you suddenly have stuff in a reply that is NON-littleEndian
defined in the protocol message fields so that you can brutally memcpy
to a u32 ?

..this would go against basic SCMI (all message fields are LE) and could be
painful since it is really NOT properly defined anywhere what is the expectation
here from the payload received from the server...and again...no docs...

....it would be clearer and safer to define a reply msg as _le32 fields and
just loop and le32_to_cpu() the single __le32 words

> +		else
> +			ret = -EINVAL;
> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +	return ret;
> +}
> +
> +static int scmi_mtk_tinysys_common_set(const struct scmi_protocol_handle *ph,
> +				       u32 ctrl_id, const u32 *params,
> +				       const u8 num_params)
> +{
> +	struct scmi_mtk_tinysys_common_set_payld *p;
> +	struct scmi_xfer *t;
> +	int i, ret;
> +
> +	if (!params || num_params > SCMI_MTK_MSG_COMMON_PARAM_BYTES)
> +		return -EINVAL;
> +
> +	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_COMMON_SET, sizeof(*p), 0, &t);
> +	if (ret)
> +		return ret;
> +
> +	p = t->tx.buf;
> +	p->ctrl_id = cpu_to_le32(ctrl_id);
> +	for (i = 0; i < num_params; i++)
> +		p->param[i] = cpu_to_le32(params[i]);
> +
> +	ret = ph->xops->do_xfer(ph, t);
> +
> +	ph->xops->xfer_put(ph, t);
> +	return ret;
> +}
> +
> +static int scmi_mtk_tinysys_cm_mgr_set(const struct scmi_protocol_handle *ph,
> +				       u32 ctrl_id, u32 cmd, u32 arg)
> +{
> +	const u32 params[2] = { cmd, arg };
> +
> +	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
> +}
> +
> +static int scmi_mtk_tinysys_gpu_pwr_set(const struct scmi_protocol_handle *ph,
> +				       u32 ctrl_id, u8 pwr_indication, bool enable)
> +{
> +	const u32 params[2] = { pwr_indication, enable };
> +
> +	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
> +}
> +
> +static int scmi_mtk_tinysys_slbc_req(const struct scmi_protocol_handle *ph,
> +				     const struct scmi_mtk_tinysys_slbc *req,
> +				     struct scmi_mtk_tinysys_slbc *retval)
> +{
> +	struct scmi_mtk_tinysys_slbc_payld *p;
> +	struct scmi_xfer *t;
> +	int i, ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, MTK_TINYSYS_SLBC_CTRL,
> +				      sizeof(*p), sizeof(*p), &t);
> +	if (ret)
> +		return ret;
> +
> +	p = t->tx.buf;
> +	p->cmd = cpu_to_le32(req->cmd);
> +	for (i = 0; i < SCMI_MTK_MSG_SLBC_PARAM_BYTES; i++)

	for (int i = 0;

> +		p->arg[i] = cpu_to_le32(req->arg[i]);
> +
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret && retval) {
> +		if (t->rx.len == sizeof(*retval))
> +			memcpy(retval, t->rx.buf, sizeof(*retval));

...same as above on endianess of reply payload...did I miss somethinng ?

> +		else
> +			ret = -EINVAL;
> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +	return ret;
> +}
> +
> +static int scmi_mtk_tinysys_sspm_mem_set(const struct scmi_protocol_handle *ph,
> +					 u32 ctrl_id, u32 pa, u32 mem_sz)
> +{
> +	const u32 params[2] = { pa, mem_sz };
> +
> +	if (mem_sz < SZ_1M)
> +		return -EINVAL;
> +
> +	return scmi_mtk_tinysys_common_set(ph, ctrl_id, params, 2);
> +}
> +
> +static bool scmi_mtk_tinysys_sspm_is_alive(const struct scmi_protocol_handle *ph,
> +					   u32 ctrl_id)
> +{
> +	const u32 param = SCMI_MTK_CMD_SSPM_QUERY_ALIVE;
> +	int ret;
> +
> +	ret = scmi_mtk_tinysys_common_set(ph, ctrl_id, &param, 1);
> +
> +	return ret ? false : true;
> +}
> +
> +static const struct scmi_mtk_tinysys_proto_ops mtk_tinysys_proto_ops = {
> +	.common_get = scmi_mtk_tinysys_common_get,
> +	.cm_mgr_set = scmi_mtk_tinysys_cm_mgr_set,
> +	.gpu_pwr_set = scmi_mtk_tinysys_gpu_pwr_set,
> +	.slbc_req = scmi_mtk_tinysys_slbc_req,
> +	.sspm_is_alive = scmi_mtk_tinysys_sspm_is_alive,
> +	.sspm_mem_set = scmi_mtk_tinysys_sspm_mem_set,
> +};
> +
> +static const struct scmi_event_ops scmi_mtk_tinysys_event_ops = {
> +	.get_num_sources = scmi_mtk_tinysys_get_num_sources,
> +	.set_notify_enabled = scmi_mtk_tinysys_set_notify_enabled,
> +	.fill_custom_report = scmi_mtk_tinysys_fill_custom_report,
> +};

I would keep this....

> +
> +static const struct scmi_protocol_events scmi_mtk_tinysys_protocol_events = {
> +	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
> +	.ops = &scmi_mtk_tinysys_event_ops,
> +	.evts = scmi_mtk_tinysys_eventsSCMI_EVENT_MTK_TINYSYS_NOTIFIER,
> +	.num_events = ARRAY_SIZE(scmi_mtk_tinysys_events),
> +};
> +

..and all all of these events related stuff above... near where the
protocol events and defs are defined...

> +static int scmi_mtk_tinysys_protocol_init(const struct scmi_protocol_handle *ph)
> +{
> +	struct scmi_mtk_tinysys_info *tinfo;
> +	u32 version;
> +	int ret;
> +
> +	ret = ph->xops->version_get(ph, &version);
> +	if (ret)
> +		return ret;
> +
> +	dev_info(ph->dev, "MediaTek TinySYS Protocol Version %d.%d\n",
> +		 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
> +
> +	tinfo = devm_kzalloc(ph->dev, sizeof(*tinfo), GFP_KERNEL);
> +	if (!tinfo)
> +		return -ENOMEM;
> +
> +	ret = scmi_mtk_tinysys_attributes_get(ph, tinfo);
> +	if (ret)
> +		return ret;
> +
> +	return ph->set_priv(ph, tinfo, version);
> +}
> +
> +static const struct scmi_protocol scmi_mtk_tinysys = {
> +	.id = SCMI_PROTOCOL_MTK_TINYSYS,
> +	.owner = THIS_MODULE,
> +	.instance_init = &scmi_mtk_tinysys_protocol_init,
> +	.ops = &mtk_tinysys_proto_ops,
> +	.events = &scmi_mtk_tinysys_protocol_events,
> +	.vendor_id = SCMI_MTK_VENDOR,
> +};
> +module_scmi_protocol(scmi_mtk_tinysys);
> +
> +MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
> +MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_MTK_TINYSYS) "-" SCMI_MTK_VENDOR);
> +MODULE_DESCRIPTION("MediaTek SCMI TinySYS driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/scmi_mtk_protocol.h b/include/linux/scmi_mtk_protocol.h
> new file mode 100644
> index 000000000000..51ad0cb4b72d
> --- /dev/null
> +++ b/include/linux/scmi_mtk_protocol.h
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * SCMI Message Protocol driver MediaTek extension header
> + *
> + * Copyright (c) 2021 MediaTek Inc.
> + * Copyright (c) 2025 Collabora Ltd
> + *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> + */
> +
> +#ifndef _LINUX_SCMI_MTK_PROTOCOL_H
> +#define _LINUX_SCMI_MTK_PROTOCOL_H
> +
> +#include <linux/bitfield.h>
> +#include <linux/device.h>
> +#include <linux/notifier.h>
> +#include <linux/types.h>
> +
> +#define SCMI_PROTOCOL_MTK_TINYSYS	0x80
> +#define SCMI_MTK_VENDOR			"MediaTek"
> +
> +#define SCMI_MTK_MSG_COMMON_PARAM_BYTES	5

This definition can go into the protocol compilation unit, since it is
NOT used by the SCMI drivers using the ops below, right ? ... I mean
it's an internal define so no need to expose it here..

> +#define SCMI_MTK_MSG_COMMON_REPLY_BYTES	2
> +#define SCMI_MTK_MSG_NOTIF_ST_BYTES	4
> +#define SCMI_MTK_MSG_SLBC_PARAM_BYTES	4
> +
> +struct scmi_mtk_tinysys_status {
> +	u32 rsvd;
> +	u32 reply[SCMI_MTK_MSG_COMMON_REPLY_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_slbc {
> +	u32 cmd;
> +	u32 arg[SCMI_MTK_MSG_SLBC_PARAM_BYTES];
> +};
> +
> +struct scmi_mtk_tinysys_proto_ops {
> +	int (*common_get)(const struct scmi_protocol_handle *ph,
> +			  u32 ctrl_id, u32 cmd,
> +			  struct scmi_mtk_tinysys_status *retval);
> +	int (*cm_mgr_set)(const struct scmi_protocol_handle *ph,
> +			  u32 ctrl_id, u32 cmd, u32 arg);
> +	int (*gpu_pwr_set)(const struct scmi_protocol_handle *ph,
> +			   u32 ctrl_id, u8 pwr_indication, bool enable);
> +	int (*slbc_req)(const struct scmi_protocol_handle *ph,
> +			const struct scmi_mtk_tinysys_slbc *req,
> +			struct scmi_mtk_tinysys_slbc *retval);
> +	bool (*sspm_is_alive)(const struct scmi_protocol_handle *ph,
> +			      u32 ctrl_id);
> +	int (*sspm_mem_set)(const struct scmi_protocol_handle *ph,
> +			    u32 ctrl_id, u32 pa, u32 mem_sz);
> +};

You could add some Doxy-style comments for these ops...NO strong
opinion here, though, since other vendor protos do NOT have it...
...much more important is to add the the protocol .rst docs detailing
the message format (...you may have guessed at this point that I would
have reiterated this :P)

Thanks,
Cristian

Re: [PATCH v1 1/2] dt-bindings: firmware: Add MediaTek TinySYS SCMI Extension protocol

[Rob Herring]

On Mon, Jun 23, 2025 at 02:01:35PM +0200, AngeloGioacchino Del Regno wrote:
> Add the MediaTek TinySYS SCMI Extension protocol as found on a
> number of SoCs, including MT6895 and MT8196.
> 
> This includes controls and power state notifications for the GPU,
> CPU Memory latency Manager (cm_mgr), SLBC, SSPM and others.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  .../firmware/mediatek,mt6895-scmi.yaml        | 22 +++++++++++++++++++
>  1 file changed, 22 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> new file mode 100644
> index 000000000000..98a5b81983b1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/firmware/mediatek,mt6895-scmi.yaml
> @@ -0,0 +1,22 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2025 Collabora Ltd
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/firmware/mediatek,mt6895-scmi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek System Control and Management Interface(SCMI) Vendor Protocols Extension
> +
> +maintainers:
> +  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> +

This schema will never be applied.

> +properties:
> +  protocol@80:
> +    $ref: '/schemas/firmware/arm,scmi.yaml#/$defs/protocol-node'
> +    unevaluatedProperties: false
> +
> +    properties:
> +      reg:
> +        const: 0x80
> +
> +additionalProperties: true
> -- 
> 2.49.0
>