diff mbox series

[v4,3/8] firmware: scmi: support Arm SMCCC transport

Message ID 20200909164407.14327-3-etienne.carriere@linaro.org
State Accepted
Commit 1e35913a2677b1d0511769425a53cd9ae113c238
Headers show
Series [v4,1/8] firmware: add SCMI agent uclass | expand

Commit Message

Etienne Carriere Sept. 9, 2020, 4:44 p.m. UTC
This change implements a SMCCC transport for SCMI exchanges. This
implementation follows the Linux kernel as references implementation
for SCMI message processing, using the SMT format for communication
channel meta-data.

Use of SMCCC transport in SCMI FDT bindings are defined in the Linux
kernel DT bindings since v5.8. SMCCC with SMT is implemented in OP-TEE
from tag 3.9.0 [2].

Links: [2] https://github.com/OP-TEE/optee_os/commit/a58c4d706d23
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

Cc: Simon Glass <sjg@chromium.org>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
---

Changes in v4:
- Update CONFIG_SCMI_FIRMWARE dependencies regarding CONFIG_ARM_SMCCC.
- Remove useless cast hence remove helper dev2agent() to get dev private.
- Fix header file inclusion ordering.

Changes in v3:
- This is a followup of the SCMI agent patches posted in
  https://patchwork.ozlabs.org/project/uboot/list/?series=196253
  The v3 splits commits and introduces a new uclass as requested.
- This patch implements the same Arm SMCCC SCMI agent as presented
  in v2 but in its own source file smccc_agent.c, and based in smt.h.
---
 drivers/firmware/scmi/Kconfig       |  6 +-
 drivers/firmware/scmi/Makefile      |  1 +
 drivers/firmware/scmi/smccc_agent.c | 89 +++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+), 3 deletions(-)
 create mode 100644 drivers/firmware/scmi/smccc_agent.c

-- 
2.17.1

Comments

Simon Glass Sept. 10, 2020, 1:38 p.m. UTC | #1
On Wed, 9 Sep 2020 at 10:44, Etienne Carriere
<etienne.carriere@linaro.org> wrote:
>

> This change implements a SMCCC transport for SCMI exchanges. This

> implementation follows the Linux kernel as references implementation

> for SCMI message processing, using the SMT format for communication

> channel meta-data.

>

> Use of SMCCC transport in SCMI FDT bindings are defined in the Linux

> kernel DT bindings since v5.8. SMCCC with SMT is implemented in OP-TEE

> from tag 3.9.0 [2].

>

> Links: [2] https://github.com/OP-TEE/optee_os/commit/a58c4d706d23

> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

> Cc: Simon Glass <sjg@chromium.org>

> Cc: Peng Fan <peng.fan@nxp.com>

> Cc: Sudeep Holla <sudeep.holla@arm.com>

> ---

>

> Changes in v4:

> - Update CONFIG_SCMI_FIRMWARE dependencies regarding CONFIG_ARM_SMCCC.

> - Remove useless cast hence remove helper dev2agent() to get dev private.

> - Fix header file inclusion ordering.

>

> Changes in v3:

> - This is a followup of the SCMI agent patches posted in

>   https://patchwork.ozlabs.org/project/uboot/list/?series=196253

>   The v3 splits commits and introduces a new uclass as requested.

> - This patch implements the same Arm SMCCC SCMI agent as presented

>   in v2 but in its own source file smccc_agent.c, and based in smt.h.

> ---

>  drivers/firmware/scmi/Kconfig       |  6 +-

>  drivers/firmware/scmi/Makefile      |  1 +

>  drivers/firmware/scmi/smccc_agent.c | 89 +++++++++++++++++++++++++++++

>  3 files changed, 93 insertions(+), 3 deletions(-)

>  create mode 100644 drivers/firmware/scmi/smccc_agent.c


Reviewed-by: Simon Glass <sjg@chromium.org>
Tom Rini Oct. 1, 2020, 2:07 p.m. UTC | #2
On Wed, Sep 09, 2020 at 06:44:02PM +0200, Etienne Carriere wrote:

> This change implements a SMCCC transport for SCMI exchanges. This

> implementation follows the Linux kernel as references implementation

> for SCMI message processing, using the SMT format for communication

> channel meta-data.

> 

> Use of SMCCC transport in SCMI FDT bindings are defined in the Linux

> kernel DT bindings since v5.8. SMCCC with SMT is implemented in OP-TEE

> from tag 3.9.0 [2].

> 

> Links: [2] https://github.com/OP-TEE/optee_os/commit/a58c4d706d23

> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

> Cc: Simon Glass <sjg@chromium.org>

> Cc: Peng Fan <peng.fan@nxp.com>

> Cc: Sudeep Holla <sudeep.holla@arm.com>

> Reviewed-by: Simon Glass <sjg@chromium.org>


Applied to u-boot/next, thanks!

-- 
Tom
diff mbox series

Patch

diff --git a/drivers/firmware/scmi/Kconfig b/drivers/firmware/scmi/Kconfig
index c501bf4943..c3a109beac 100644
--- a/drivers/firmware/scmi/Kconfig
+++ b/drivers/firmware/scmi/Kconfig
@@ -2,7 +2,7 @@  config SCMI_FIRMWARE
 	bool "Enable SCMI support"
 	select FIRMWARE
 	select OF_TRANSLATE
-	depends on SANDBOX || DM_MAILBOX
+	depends on SANDBOX || DM_MAILBOX || ARM_SMCCC
 	help
 	  System Control and Management Interface (SCMI) is a communication
 	  protocol that defines standard interfaces for power, performance
@@ -15,5 +15,5 @@  config SCMI_FIRMWARE
 
 	  Communications between agent (client) and the SCMI server are
 	  based on message exchange. Messages can be exchange over tranport
-	  channels as a mailbox device with some piece of identified shared
-	  memory.
+	  channels as a mailbox device or an Arm SMCCC service with some
+	  piece of identified shared memory.
diff --git a/drivers/firmware/scmi/Makefile b/drivers/firmware/scmi/Makefile
index d22f53efe7..2f782bbd55 100644
--- a/drivers/firmware/scmi/Makefile
+++ b/drivers/firmware/scmi/Makefile
@@ -1,4 +1,5 @@ 
 obj-y	+= scmi_agent-uclass.o
 obj-y	+= smt.o
+obj-$(CONFIG_ARM_SMCCC) 	+= smccc_agent.o
 obj-$(CONFIG_DM_MAILBOX)	+= mailbox_agent.o
 obj-$(CONFIG_SANDBOX)		+= sandbox-scmi_agent.o
diff --git a/drivers/firmware/scmi/smccc_agent.c b/drivers/firmware/scmi/smccc_agent.c
new file mode 100644
index 0000000000..85dbf9195e
--- /dev/null
+++ b/drivers/firmware/scmi/smccc_agent.c
@@ -0,0 +1,89 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Linaro Limited.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <scmi_agent.h>
+#include <scmi_agent-uclass.h>
+#include <dm/devres.h>
+#include <dm/device-internal.h>
+#include <linux/arm-smccc.h>
+#include <linux/compat.h>
+
+#include "smt.h"
+
+#define SMCCC_RET_NOT_SUPPORTED         ((unsigned long)-1)
+
+/**
+ * struct scmi_smccc_channel - Description of an SCMI SMCCC transport
+ * @func_id:	SMCCC function ID used by the SCMI transport
+ * @smt:	Shared memory buffer
+ */
+struct scmi_smccc_channel {
+	ulong func_id;
+	struct scmi_smt smt;
+};
+
+static int scmi_smccc_process_msg(struct udevice *dev, struct scmi_msg *msg)
+{
+	struct scmi_smccc_channel *chan = dev_get_priv(dev);
+	struct arm_smccc_res res;
+	int ret;
+
+	ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
+	if (ret)
+		return ret;
+
+	arm_smccc_smc(chan->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		ret = -ENXIO;
+	else
+		ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
+
+	scmi_clear_smt_channel(&chan->smt);
+
+	return ret;
+}
+
+static int scmi_smccc_probe(struct udevice *dev)
+{
+	struct scmi_smccc_channel *chan = dev_get_priv(dev);
+	u32 func_id;
+	int ret;
+
+	if (dev_read_u32(dev, "arm,smc-id", &func_id)) {
+		dev_err(dev, "Missing property func-id\n");
+		return -EINVAL;
+	}
+
+	chan->func_id = func_id;
+
+	ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
+	if (ret) {
+		dev_err(dev, "Failed to get smt resources: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id scmi_smccc_ids[] = {
+	{ .compatible = "arm,scmi-smc" },
+	{ }
+};
+
+static const struct scmi_agent_ops scmi_smccc_ops = {
+	.process_msg = scmi_smccc_process_msg,
+};
+
+U_BOOT_DRIVER(scmi_smccc) = {
+	.name		= "scmi-over-smccc",
+	.id		= UCLASS_SCMI_AGENT,
+	.of_match	= scmi_smccc_ids,
+	.priv_auto_alloc_size = sizeof(struct scmi_smccc_channel),
+	.probe		= scmi_smccc_probe,
+	.ops		= &scmi_smccc_ops,
+};