[PATCH v2 4/8] firmware: arm_scmi: Make MBOX transport a standalone driver

Cristian Marussi
2024-07-10T17:32:29Z

Make SCMI mailbox transport a standalne driver that can be optionally
loaded as a module.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
drivers/firmware/arm_scmi/Kconfig | 4 +-
drivers/firmware/arm_scmi/Makefile | 3 +-
drivers/firmware/arm_scmi/common.h | 3 --
drivers/firmware/arm_scmi/driver.c | 3 --
.../{mailbox.c => scmi_transport_mailbox.c} | 44 +++++++++++++------
5 files changed, 36 insertions(+), 21 deletions(-)
rename drivers/firmware/arm_scmi/{mailbox.c => scmi_transport_mailbox.c} (88%)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index aa5842be19b2..135e34aefd70 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -75,7 +75,7 @@ config ARM_SCMI_HAVE_MSG
available.

config ARM_SCMI_TRANSPORT_MAILBOX
- bool "SCMI transport based on Mailbox"
+ tristate "SCMI transport based on Mailbox"
depends on MAILBOX
select ARM_SCMI_HAVE_TRANSPORT
select ARM_SCMI_HAVE_SHMEM
@@ -85,6 +85,8 @@ config ARM_SCMI_TRANSPORT_MAILBOX

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

config ARM_SCMI_TRANSPORT_OPTEE
bool "SCMI transport based on OP-TEE service"
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index fd59f58ce8a2..121612d75f0b 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_MAILBOX) += mailbox.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
@@ -14,6 +13,8 @@ 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-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += scmi_transport_mailbox.o
+
obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 4af06810eb39..0f2256a61622 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_MAILBOX
-extern const struct scmi_desc scmi_mailbox_desc;
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
extern const struct scmi_desc scmi_smc_desc;
#endif
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index a1892d4d8c69..96cf8ab4421e 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -3251,9 +3251,6 @@ ATTRIBUTE_GROUPS(versions);

/* Each compatible listed below must have descriptor associated with it */
static const struct of_device_id scmi_of_match[] = {
-#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
- { .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
{ .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc },
#endif
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/scmi_transport_mailbox.c
similarity index 88%
rename from drivers/firmware/arm_scmi/mailbox.c
rename to drivers/firmware/arm_scmi/scmi_transport_mailbox.c
index 60698efe8442..c19513e6dbdf 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/scmi_transport_mailbox.c
@@ -11,6 +11,7 @@
#include <linux/mailbox_client.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/platform_device.h>
#include <linux/slab.h>

#include "common.h"
@@ -36,11 +37,13 @@ struct scmi_mailbox {

#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)

+static struct scmi_transport_core_operations *core;
+
static void tx_prepare(struct mbox_client *cl, void *m)
{
struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);

- scmi_shmem_ops.tx_prepare(smbox->shmem, m, smbox->cinfo);
+ core->shmem->tx_prepare(smbox->shmem, m, smbox->cinfo);
}

static void rx_callback(struct mbox_client *cl, void *m)
@@ -56,15 +59,17 @@ static void rx_callback(struct mbox_client *cl, void *m)
* a previous timed-out reply which arrived late could be wrongly
* associated with the next pending transaction.
*/
- if (cl->knows_txdone && !scmi_shmem_ops.channel_free(smbox->shmem)) {
+ if (cl->knows_txdone &&
+ !core->shmem->channel_free(smbox->shmem)) {
dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
- scmi_bad_message_trace(smbox->cinfo,
- scmi_shmem_ops.read_header(smbox->shmem),
- MSG_MBOX_SPURIOUS);
+ core->bad_message_trace(smbox->cinfo,
+ core->shmem->read_header(smbox->shmem),
+ MSG_MBOX_SPURIOUS);
return;
}

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

static bool mailbox_chan_available(struct device_node *of_node, int idx)
@@ -192,7 +197,7 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
if (!smbox)
return -ENOMEM;

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

@@ -293,7 +298,7 @@ static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
{
struct scmi_mailbox *smbox = cinfo->transport_info;

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

static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
@@ -301,7 +306,7 @@ static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
{
struct scmi_mailbox *smbox = cinfo->transport_info;

- scmi_shmem_ops.fetch_notification(smbox->shmem, max_len, xfer);
+ core->shmem->fetch_notification(smbox->shmem, max_len, xfer);
}

static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
@@ -310,9 +315,9 @@ static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
struct mbox_chan *intr_chan;
int ret;

- scmi_shmem_ops.clear_channel(smbox->shmem);
+ core->shmem->clear_channel(smbox->shmem);

- if (!scmi_shmem_ops.channel_intr_enabled(smbox->shmem))
+ if (!core->shmem->channel_intr_enabled(smbox->shmem))
return;

if (smbox->chan_platform_receiver)
@@ -335,7 +340,7 @@ mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
{
struct scmi_mailbox *smbox = cinfo->transport_info;

- return scmi_shmem_ops.poll_done(smbox->shmem, xfer);
+ return core->shmem->poll_done(smbox->shmem, xfer);
}

static const struct scmi_transport_ops scmi_mailbox_ops = {
@@ -350,9 +355,22 @@ static const struct scmi_transport_ops scmi_mailbox_ops = {
.poll_done = mailbox_poll_done,
};

-const struct scmi_desc scmi_mailbox_desc = {
+static const struct scmi_desc scmi_mailbox_desc = {
.ops = &scmi_mailbox_ops,
.max_rx_timeout_ms = 30, /* We may increase this if required */
.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
.max_msg_size = 128,
};
+
+static const struct of_device_id scmi_of_match[] = {
+ { .compatible = "arm,scmi" },
+ { /* Sentinel */ },
+};
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_mailbox, scmi_of_match, &core);
+module_platform_driver(scmi_mailbox_driver);
+
+MODULE_ALIAS("scmi-transport-mailbox");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("SCMI Mailbox Transport driver");
+MODULE_LICENSE("GPL");
--
2.45.2