Re: [PATCH 08/15] firmware: arm_scmi: Add and initialise protocol version to scmi_device structure

[Cristian Marussi]

On 10/12/2019 14:53, Sudeep Holla wrote:
> It's useful to keep track of scmi protocol version in the scmi device
> structure along with the protocol id. These can be used to expose the
> information to the userspace via bus dev_groups attributes as well.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> ---
>  drivers/firmware/arm_scmi/clock.c   | 6 +++++-
>  drivers/firmware/arm_scmi/perf.c    | 6 +++++-
>  drivers/firmware/arm_scmi/power.c   | 6 +++++-
>  drivers/firmware/arm_scmi/reset.c   | 6 +++++-
>  drivers/firmware/arm_scmi/sensors.c | 6 +++++-
>  include/linux/scmi_protocol.h       | 1 +
>  6 files changed, 26 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
> index b567ec03f711..b68736ae7f88 100644
> --- a/drivers/firmware/arm_scmi/clock.c
> +++ b/drivers/firmware/arm_scmi/clock.c
> @@ -318,8 +318,11 @@ static int scmi_clock_protocol_init(struct scmi_device *dev)
>  	struct clock_info *cinfo;
>  	struct scmi_handle *handle = dev->handle;
> 
> -	if (handle->clk_ops && handle->clk_priv)
> +	if (handle->clk_ops && handle->clk_priv) {
> +		cinfo = handle->clk_priv;
> +		dev->version = cinfo->version;
>  		return 0; /* initialised already for the first device */
> +	}
> 

This is the device specific init stuff which I would remove from this proto initialization,
which is the reason for this proto_init to be invoked for all devices defined for such proto.

I'd say to move dev->version initialization into the specific scmi_drv->probe
which is called after scmi_protocol_init inside bus:scmi_dev_probe, after having
disabled the proto_init after the first invocation, once the protocol is initialized,
BUT this would result anyway in duplication since you'll have to fill dev->version
from the custom protocol info in each of the related scmi drivers, and that would also mean
delegating to a possible user scmi driver .probe an initialization which is then needed by
the sysfs attribute exposed by the SCMI framework code.

So not a solution.

Cristian


>  	scmi_version_get(handle, SCMI_PROTOCOL_CLOCK, &version);
> 
> @@ -345,6 +348,7 @@ static int scmi_clock_protocol_init(struct scmi_device *dev)
>  			scmi_clock_describe_rates_get(handle, clkid, clk);
>  	}
> 
> +	dev->version = version;
>  	cinfo->version = version;
>  	handle->clk_ops = &clk_ops;
>  	handle->clk_priv = cinfo;
> diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
> index b1de6197f61c..8a02dc453894 100644
> --- a/drivers/firmware/arm_scmi/perf.c
> +++ b/drivers/firmware/arm_scmi/perf.c
> @@ -712,8 +712,11 @@ static int scmi_perf_protocol_init(struct scmi_device *dev)
>  	struct scmi_perf_info *pinfo;
>  	struct scmi_handle *handle = dev->handle;
> 
> -	if (handle->perf_ops && handle->perf_priv)
> +	if (handle->perf_ops && handle->perf_priv) {
> +		pinfo = handle->perf_priv;
> +		dev->version = pinfo->version;
>  		return 0; /* initialised already for the first device */
> +	}
> 
>  	scmi_version_get(handle, SCMI_PROTOCOL_PERF, &version);
> 
> @@ -741,6 +744,7 @@ static int scmi_perf_protocol_init(struct scmi_device *dev)
>  			scmi_perf_domain_init_fc(handle, domain, &dom->fc_info);
>  	}
> 
> +	dev->version = version;
>  	pinfo->version = version;
>  	handle->perf_ops = &perf_ops;
>  	handle->perf_priv = pinfo;
> diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
> index d11c6cd6bbab..6267111e38e6 100644
> --- a/drivers/firmware/arm_scmi/power.c
> +++ b/drivers/firmware/arm_scmi/power.c
> @@ -187,8 +187,11 @@ static int scmi_power_protocol_init(struct scmi_device *dev)
>  	struct scmi_power_info *pinfo;
>  	struct scmi_handle *handle = dev->handle;
> 
> -	if (handle->power_ops && handle->power_priv)
> +	if (handle->power_ops && handle->power_priv) {
> +		pinfo = handle->power_priv;
> +		dev->version = pinfo->version;
>  		return 0; /* initialised already for the first device */
> +	}
> 
>  	scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
> 
> @@ -212,6 +215,7 @@ static int scmi_power_protocol_init(struct scmi_device *dev)
>  		scmi_power_domain_attributes_get(handle, domain, dom);
>  	}
> 
> +	dev->version = version;
>  	pinfo->version = version;
>  	handle->power_ops = &power_ops;
>  	handle->power_priv = pinfo;
> diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
> index dce103781b3f..76f1cee85a06 100644
> --- a/drivers/firmware/arm_scmi/reset.c
> +++ b/drivers/firmware/arm_scmi/reset.c
> @@ -197,8 +197,11 @@ static int scmi_reset_protocol_init(struct scmi_device *dev)
>  	struct scmi_reset_info *pinfo;
>  	struct scmi_handle *handle = dev->handle;
> 
> -	if (handle->reset_ops && handle->reset_priv)
> +	if (handle->reset_ops && handle->reset_priv) {
> +		pinfo = handle->reset_priv;
> +		dev->version = pinfo->version;
>  		return 0; /* initialised already for the first device */
> +	}
> 
>  	scmi_version_get(handle, SCMI_PROTOCOL_RESET, &version);
> 
> @@ -222,6 +225,7 @@ static int scmi_reset_protocol_init(struct scmi_device *dev)
>  		scmi_reset_domain_attributes_get(handle, domain, dom);
>  	}
> 
> +	dev->version = version;
>  	pinfo->version = version;
>  	handle->reset_ops = &reset_ops;
>  	handle->reset_priv = pinfo;
> diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
> index aac0243e2880..fb3bed4cb171 100644
> --- a/drivers/firmware/arm_scmi/sensors.c
> +++ b/drivers/firmware/arm_scmi/sensors.c
> @@ -278,8 +278,11 @@ static int scmi_sensors_protocol_init(struct scmi_device *dev)
>  	struct sensors_info *sinfo;
>  	struct scmi_handle *handle = dev->handle;
> 
> -	if (handle->sensor_ops && handle->sensor_priv)
> +	if (handle->sensor_ops && handle->sensor_priv) {
> +		sinfo = handle->sensor_priv;
> +		dev->version = sinfo->version;
>  		return 0; /* initialised already for the first device */
> +	}
> 
>  	scmi_version_get(handle, SCMI_PROTOCOL_SENSOR, &version);
> 
> @@ -299,6 +302,7 @@ static int scmi_sensors_protocol_init(struct scmi_device *dev)
> 
>  	scmi_sensor_description_get(handle, sinfo);
> 
> +	dev->version = version;
>  	sinfo->version = version;
>  	handle->sensor_ops = &sensor_ops;
>  	handle->sensor_priv = sinfo;
> diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> index b676825e6eb0..a863bc0cdf28 100644
> --- a/include/linux/scmi_protocol.h
> +++ b/include/linux/scmi_protocol.h
> @@ -256,6 +256,7 @@ enum scmi_std_protocol {
> 
>  struct scmi_device {
>  	u32 id;
> +	u32 version;
>  	u8 protocol_id;
>  	const char *name;
>  	struct device dev;
> --
> 2.17.1
>