[PATCH 14/15] hwmon: (scmi-hwmon) Match scmi device by both name and protocol id

[PATCH 14/15] hwmon: (scmi-hwmon) Match scmi device by both name and protocol id

[Sudeep Holla]

The scmi bus now has support to match the driver with devices not only
based on their protocol id but also based on their device name if one is
available. This was added to cater the need to support multiple devices
and drivers for the same protocol.

Let us add the name "hwmon" to scmi_device_id table in the driver so
that in matches only with device with the same name and protocol id
SCMI_PROTOCOL_SENSOR. This will help to add IIO support in parallel if
needed.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/hwmon/scmi-hwmon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index 8a7732c0bef3..286d3cfda7de 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -259,7 +259,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 }

 static const struct scmi_device_id scmi_id_table[] = {
-	{ SCMI_PROTOCOL_SENSOR },
+	{ SCMI_PROTOCOL_SENSOR, "hwmon" },
 	{ },
 };
 MODULE_DEVICE_TABLE(scmi, scmi_id_table);
--
2.17.1

Re: [PATCH 14/15] hwmon: (scmi-hwmon) Match scmi device by both name and protocol id

[Guenter Roeck]

On Tue, Dec 10, 2019 at 02:53:44PM +0000, Sudeep Holla wrote:
> The scmi bus now has support to match the driver with devices not only
> based on their protocol id but also based on their device name if one is
> available. This was added to cater the need to support multiple devices
> and drivers for the same protocol.
> 
> Let us add the name "hwmon" to scmi_device_id table in the driver so
> that in matches only with device with the same name and protocol id
> SCMI_PROTOCOL_SENSOR. This will help to add IIO support in parallel if
> needed.

If you are planning to re-implement the driver as iio driver, it would
make more sense to drop the hwmon driver entirely and use the iio->hwmon
bridge to access the sensors as hwmon devices if needed.

Guenter

> 
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: linux-hwmon@vger.kernel.org
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  drivers/hwmon/scmi-hwmon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
> index 8a7732c0bef3..286d3cfda7de 100644
> --- a/drivers/hwmon/scmi-hwmon.c
> +++ b/drivers/hwmon/scmi-hwmon.c
> @@ -259,7 +259,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>  }
> 
>  static const struct scmi_device_id scmi_id_table[] = {
> -	{ SCMI_PROTOCOL_SENSOR },
> +	{ SCMI_PROTOCOL_SENSOR, "hwmon" },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(scmi, scmi_id_table);
> --
> 2.17.1
> 

Re: [PATCH 14/15] hwmon: (scmi-hwmon) Match scmi device by both name and protocol id

[Sudeep Holla]

On Tue, Dec 10, 2019 at 10:06:43AM -0800, Guenter Roeck wrote:
> On Tue, Dec 10, 2019 at 02:53:44PM +0000, Sudeep Holla wrote:
> > The scmi bus now has support to match the driver with devices not only
> > based on their protocol id but also based on their device name if one is
> > available. This was added to cater the need to support multiple devices
> > and drivers for the same protocol.
> >
> > Let us add the name "hwmon" to scmi_device_id table in the driver so
> > that in matches only with device with the same name and protocol id
> > SCMI_PROTOCOL_SENSOR. This will help to add IIO support in parallel if
> > needed.
>
> If you are planning to re-implement the driver as iio driver, it would
> make more sense to drop the hwmon driver entirely and use the iio->hwmon
> bridge to access the sensors as hwmon devices if needed.
>

Ah, does it provides the same interface as hwmon to userspace ? Sorry but
I haven't spent much time looking at IIO yet, but since there are similar
needs to share protocol between subsystems in the kernel, this was just
an example that I listed as recently some requirement to add IIO SCMI
support had come up. If we can achieve hwmon kind of interface with iio->hwmon,
we should do that. We have other examples like devfreq and cpufreq, genpd
and regulators.

This patch is optional at least as of now (but good to have for completeness),
if the driver provides no name, we just match on protocol id only.

--
Regards,
Sudeep