Re: [PATCH v6 01/37] firmware: arm_scmi: review protocol registration interface

Sudeep Holla
2021-03-08T04:39:34Z

On Tue, Feb 02, 2021 at 10:15:19PM +0000, Cristian Marussi wrote:
> Extend common protocol registration routines and provide some new generic
> protocols get/put helpers that can track protocols usage and automatically
> perform the proper initialization and de-initialization on demand when
> required.
>
> Convert all standard protocols to use this new registration scheme while
> keeping them all still using the usual initialization logic bound to SCMI
> devices probing.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
> v2 --> v3
> - removed new Base protocol initialization, it will be re-introduced
> later with all other protocols
> ---
> drivers/firmware/arm_scmi/base.c | 8 ++
> drivers/firmware/arm_scmi/bus.c | 61 ++++++++---
> drivers/firmware/arm_scmi/clock.c | 10 +-
> drivers/firmware/arm_scmi/common.h | 30 +++++-
> drivers/firmware/arm_scmi/driver.c | 159 +++++++++++++++++++++++++++-
> drivers/firmware/arm_scmi/perf.c | 10 +-
> drivers/firmware/arm_scmi/power.c | 10 +-
> drivers/firmware/arm_scmi/reset.c | 10 +-
> drivers/firmware/arm_scmi/sensors.c | 8 +-
> drivers/firmware/arm_scmi/system.c | 8 +-
> drivers/firmware/arm_scmi/voltage.c | 8 +-
> include/linux/scmi_protocol.h | 6 +-
> 12 files changed, 296 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
> index 1377ec76a45d..044aa9e3ebb0 100644
> --- a/drivers/firmware/arm_scmi/bus.c
> +++ b/drivers/firmware/arm_scmi/bus.c
> @@ -16,7 +16,7 @@
> #include "common.h"
>
> static DEFINE_IDA(scmi_bus_id);
> -static DEFINE_IDR(scmi_protocols);
> +static DEFINE_IDR(scmi_available_protocols);

[nit] Any particular reason for this name change ? Does it hold refer to
something different from before ? IIRC, this is list of registered protocols ?
Available might refer to the ones advertised to be present by the platform
firmware ?

> static DEFINE_SPINLOCK(protocol_lock);
>
> static const struct scmi_device_id *
> @@ -51,13 +51,29 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv)
> return 0;
> }
>
> +const struct scmi_protocol *scmi_get_protocol(int protocol_id)
> +{
> + const struct scmi_protocol *proto;
> +
> + proto = idr_find(&scmi_available_protocols, protocol_id);
> + if (!proto) {
> + pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
> + return NULL;
> + }
> +
> + pr_debug("GOT SCMI Protocol 0x%x\n", protocol_id);
> +

[nit] For sake of consistency, s/GOT/Found/

[..]

> @@ -194,26 +210,45 @@ void scmi_set_handle(struct scmi_device *scmi_dev)
> scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
> }
>
> -int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
> +int scmi_protocol_register(const struct scmi_protocol *proto)
> {
> int ret;
>
> + if (!proto) {
> + pr_err("invalid protocol\n");
> + return -EINVAL;
> + }
> +
> + if (!proto->init && !proto->init_instance) {
> + pr_err("missing .init() for protocol 0x%x\n", proto->id);

s/.init()/init as it can be init_instance too ?

> diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
> index 4645677d86f1..e8c84cff9922 100644
> --- a/drivers/firmware/arm_scmi/clock.c
> +++ b/drivers/firmware/arm_scmi/clock.c
> @@ -2,7 +2,7 @@
> /*
> * System Control and Management Interface (SCMI) Clock Protocol
> *
> - * Copyright (C) 2018 ARM Ltd.
> + * Copyright (C) 2018-2020 ARM Ltd.

2021 perhaps ? Few instances are not updated, I prefer to be consistent
across all modified scmi firmware driver files.

Other than these minor comments, the other changes looks good to me.

--
Regards,
Sudeep