Re: [PATCH v2 2/2] cpufreq: ti: Add cpufreq driver to determine available OPPs at runtime

[Viresh Kumar <viresh.kumar@linaro.org>]

On 31-08-16, 21:53, Dave Gerlach wrote:
> Some TI SoCs, like those in the AM335x, AM437x, DRA7x, and AM57x families,
> have different OPPs available for the MPU depending on which specific
> variant of the SoC is in use. This can be determined through use of the
> revision and an eFuse register present in the silicon. Introduce a
> ti-cpufreq driver that can read the aformentioned values and provide
> them as version matching data to the opp framework. Through this the
> opp-supported-hw dt binding that is part of the operating-points-v2
> table can be used to indicate availability of OPPs for each device.
> 
> This driver also creates the "cpufreq-dt" platform_device after passing
> the version matching data to the OPP framework so that the cpufreq-dt
> handles the actual cpufreq implementation. Even without the necessary
> data to pass the version matching data the driver will still create this
> device to maintain backwards compatibility with operating-points v1
> tables.
> 
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> ---
> v1->v2:
> 	- Convert to module_platform_driver to match against new compatibles
> 	  in patch 1
> 	- Cleaned up some bit shifts
> 	- of_property_read_u32_array used rather than reading values individually
> 
>  drivers/cpufreq/Kconfig.arm  |  11 ++
>  drivers/cpufreq/Makefile     |   1 +
>  drivers/cpufreq/ti-cpufreq.c | 308 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 320 insertions(+)
>  create mode 100644 drivers/cpufreq/ti-cpufreq.c

I am wondering if we should start writing OPP drivers instead. As this
patch doesn't have anything to do with cpufreq really :)

But its fine for now..

> +static const struct of_device_id ti_cpufreq_of_match[] = {
> +	{ .compatible = "operating-points-v2-ti-am3352-cpu",
> +	  .data = &am3x_soc_data, },
> +	{ .compatible = "operating-points-v2-ti-am4372-cpu",
> +	  .data = &am4x_soc_data, },
> +	{ .compatible = "operating-points-v2-ti-dra7-cpu",
> +	  .data = &dra7_soc_data },

You should be using your SoC compatible strings here. OPP compatible
property isn't supposed to be (mis)used for this purpose.

-- 
viresh