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

From: Cristian Marussi
Date: Wed Dec 11 2019 - 13:06:55 EST


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
>