[PATCH v2 5/8] firmware: arm_scmi: Make SMC transport a standalone driver

Cristian Marussi
2024-07-10T17:32:32Z

Make SCMI SMC transport a standalone driver that can be optionally
loaded as a module.

CC: Peng Fan <peng.fan@nxp.com>
CC: Nikunj Kela <quic_nkela@quicinc.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- make scmi_smc_desc static
---
drivers/firmware/arm_scmi/Kconfig | 4 ++-
drivers/firmware/arm_scmi/Makefile | 2 +-
drivers/firmware/arm_scmi/common.h | 3 --
drivers/firmware/arm_scmi/driver.c | 5 ---
.../arm_scmi/{smc.c => scmi_transport_smc.c} | 33 +++++++++++++++----
5 files changed, 30 insertions(+), 17 deletions(-)
rename drivers/firmware/arm_scmi/{smc.c => scmi_transport_smc.c} (89%)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index 135e34aefd70..a4d44ef8bf45 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -102,7 +102,7 @@ config ARM_SCMI_TRANSPORT_OPTEE
transport based on OP-TEE SCMI service, answer Y.

config ARM_SCMI_TRANSPORT_SMC
- bool "SCMI transport based on SMC"
+ tristate "SCMI transport based on SMC"
depends on HAVE_ARM_SMCCC_DISCOVERY
select ARM_SCMI_HAVE_TRANSPORT
select ARM_SCMI_HAVE_SHMEM
@@ -112,6 +112,8 @@ config ARM_SCMI_TRANSPORT_SMC

If you want the ARM SCMI PROTOCOL stack to include support for a
transport based on SMC, answer Y.
+ This driver can also be built as a module. If so, the module
+ will be called scmi_transport_smc.

config ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE
bool "Enable atomic mode support for SCMI SMC transport"
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 121612d75f0b..6868a47fa4ab 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -5,7 +5,6 @@ scmi-core-objs := $(scmi-bus-y)
scmi-driver-y = driver.o notify.o
scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
-scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o
scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o
scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += virtio.o
scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) += optee.o
@@ -13,6 +12,7 @@ scmi-protocols-y := base.o clock.o perf.o power.o reset.o sensors.o system.o vol
scmi-protocols-y += pinctrl.o
scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)

+obj-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += scmi_transport_smc.o
obj-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += scmi_transport_mailbox.o

obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 0f2256a61622..edb786cde25c 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -286,9 +286,6 @@ int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer,
unsigned int timeout_ms);
-#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
-extern const struct scmi_desc scmi_smc_desc;
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
extern const struct scmi_desc scmi_virtio_desc;
#endif
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 96cf8ab4421e..b14c5326930a 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -3254,11 +3254,6 @@ static const struct of_device_id scmi_of_match[] = {
#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
{ .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc },
#endif
-#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
- { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
- { .compatible = "arm,scmi-smc-param", .data = &scmi_smc_desc},
- { .compatible = "qcom,scmi-smc", .data = &scmi_smc_desc},
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
{ .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc},
#endif
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/scmi_transport_smc.c
similarity index 89%
rename from drivers/firmware/arm_scmi/smc.c
rename to drivers/firmware/arm_scmi/scmi_transport_smc.c
index 4cb86386c490..291e33207536 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/scmi_transport_smc.c
@@ -3,7 +3,7 @@
* System Control and Management Interface (SCMI) Message SMC/HVC
* Transport driver
*
- * Copyright 2020 NXP
+ * Copyright 2020-2024 NXP
*/

#include <linux/arm-smccc.h>
@@ -16,6 +16,7 @@
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/limits.h>
+#include <linux/platform_device.h>
#include <linux/processor.h>
#include <linux/slab.h>

@@ -69,12 +70,14 @@ struct scmi_smc {
unsigned long cap_id;
};

+static struct scmi_transport_core_operations *core;
+
static irqreturn_t smc_msg_done_isr(int irq, void *data)
{
struct scmi_smc *scmi_info = data;

- scmi_rx_callback(scmi_info->cinfo,
- scmi_shmem_ops.read_header(scmi_info->shmem), NULL);
+ core->rx_callback(scmi_info->cinfo,
+ core->shmem->read_header(scmi_info->shmem), NULL);

return IRQ_HANDLED;
}
@@ -141,7 +144,7 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
if (!scmi_info)
return -ENOMEM;

- scmi_info->shmem = scmi_shmem_ops.setup_iomap(cinfo, dev, tx, &res);
+ scmi_info->shmem = core->shmem->setup_iomap(cinfo, dev, tx, &res);
if (IS_ERR(scmi_info->shmem))
return PTR_ERR(scmi_info->shmem);

@@ -226,7 +229,7 @@ static int smc_send_message(struct scmi_chan_info *cinfo,
*/
smc_channel_lock_acquire(scmi_info, xfer);

- scmi_shmem_ops.tx_prepare(scmi_info->shmem, xfer, cinfo);
+ core->shmem->tx_prepare(scmi_info->shmem, xfer, cinfo);

if (scmi_info->cap_id != ULONG_MAX)
arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->cap_id, 0,
@@ -250,7 +253,7 @@ static void smc_fetch_response(struct scmi_chan_info *cinfo,
{
struct scmi_smc *scmi_info = cinfo->transport_info;

- scmi_shmem_ops.fetch_response(scmi_info->shmem, xfer);
+ core->shmem->fetch_response(scmi_info->shmem, xfer);
}

static void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret,
@@ -270,7 +273,7 @@ static const struct scmi_transport_ops scmi_smc_ops = {
.fetch_response = smc_fetch_response,
};

-const struct scmi_desc scmi_smc_desc = {
+static const struct scmi_desc scmi_smc_desc = {
.ops = &scmi_smc_ops,
.max_rx_timeout_ms = 30,
.max_msg = 20,
@@ -286,3 +289,19 @@ const struct scmi_desc scmi_smc_desc = {
.sync_cmds_completed_on_ret = true,
.atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE),
};
+
+static const struct of_device_id scmi_of_match[] = {
+ { .compatible = "arm,scmi-smc" },
+ { .compatible = "arm,scmi-smc-param" },
+ { .compatible = "qcom,scmi-smc" },
+ { /* Sentinel */ },
+};
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_smc, scmi_of_match, &core);
+module_platform_driver(scmi_smc_driver);
+
+MODULE_ALIAS("scmi-transport-smc");
+MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
+MODULE_AUTHOR("Nikunj Kela <quic_nkela@quicinc.com>");
+MODULE_DESCRIPTION("SCMI SMC Transport driver");
+MODULE_LICENSE("GPL");
--
2.45.2