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

[Sudeep Holla]

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@xxxxxxx>
> ---
> 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