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

From: Nikunj Kela
Date: Wed Jul 10 2024 - 17:04:49 EST


On 7/10/2024 10:31 AM, Cristian Marussi wrote:
> Make SCMI SMC transport a standalone driver that can be optionally
> loaded as a module.
>
> CC: Peng Fan <peng.fan@xxxxxxx>
> CC: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---

Tested-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>

Tested this series on SA8775p Qualcomm platform that uses Qualcomm SMC
transport.

> 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@xxxxxxx>");
> +MODULE_AUTHOR("Nikunj Kela <quic_nkela@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("SCMI SMC Transport driver");
> +MODULE_LICENSE("GPL");