[PATCH v6 04/11] firmware: xilinx: Add query data API

[Jolly Shah]

HI Sudeep,

> -----Original Message-----
> From: Sudeep Holla [mailto:sudeep.holla at arm.com]
> Sent: Thursday, May 10, 2018 7:12 AM
> To: Jolly Shah <JOLLYS at xilinx.com>; ard.biesheuvel at linaro.org;
> mingo at kernel.org; gregkh at linuxfoundation.org; matt at codeblueprint.co.uk;
> hkallweit1 at gmail.com; keescook at chromium.org;
> dmitry.torokhov at gmail.com; mturquette at baylibre.com;
> sboyd at codeaurora.org; michal.simek at xilinx.com; robh+dt at kernel.org;
> mark.rutland at arm.com; linux-clk at vger.kernel.org
> Cc: Sudeep Holla <sudeep.holla at arm.com>; Rajan Vaja <RAJANV at xilinx.com>;
> linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org;
> devicetree at vger.kernel.org; Jolly Shah <JOLLYS at xilinx.com>
> Subject: Re: [PATCH v6 04/11] firmware: xilinx: Add query data API
> 
> 
> 
> On 10/04/18 20:38, Jolly Shah wrote:
> > From: Rajan Vaja <rajanv at xilinx.com>
> >
> > Add ZynqMP firmware query data API to query platform specific
> > information(clocks, pins) from firmware.
> >
> > Signed-off-by: Rajan Vaja <rajanv at xilinx.com>
> > Signed-off-by: Jolly Shah <jollys at xilinx.com>
> > ---
> >  drivers/firmware/xilinx/zynqmp.c     | 14 ++++++++++++++
> >  include/linux/firmware/xlnx-zynqmp.h | 20 ++++++++++++++++++++
> >  2 files changed, 34 insertions(+)
> >
> > diff --git a/drivers/firmware/xilinx/zynqmp.c
> > b/drivers/firmware/xilinx/zynqmp.c
> > index 44b43fa..ef09c44 100644
> > --- a/drivers/firmware/xilinx/zynqmp.c
> > +++ b/drivers/firmware/xilinx/zynqmp.c
> > @@ -258,9 +258,23 @@ static int zynqmp_pm_ioctl(u32 node_id, u32
> ioctl_id, u32 arg1, u32 arg2,
> >  				   arg1, arg2, out);
> >  }
> >
> > +/**
> > + * zynqmp_pm_query_data() - Get query data from firmware
> > + * @qdata:	Variable to the zynqmp_pm_query_data structure
> > + * @out:	Returned output value
> > + *
> > + * Return: Returns status, either success or error+reason  */ static
> > +int zynqmp_pm_query_data(struct zynqmp_pm_query_data qdata, u32 *out)
> > +{
> > +	return zynqmp_pm_invoke_fn(PM_QUERY_DATA, qdata.qid,
> qdata.arg1,
> > +				   qdata.arg2, qdata.arg3, out);
> > +}
> > +
> >  static const struct zynqmp_eemi_ops eemi_ops = {
> >  	.get_api_version = zynqmp_pm_get_api_version,
> >  	.ioctl = zynqmp_pm_ioctl,
> > +	.query_data = zynqmp_pm_query_data,
> 
> Can you give more insight into this ? How will be this used ?
> How this aligns with data we get from DT ? I am just trying to understand how is
> this information split between this API and DT for example.
> 
> --
> Regards,
> Sudeep

This API is used to get clock information from firmware and register clocks accordingly in driver. In our case, firmware maintains database of all clocks available on chip. DT will provide information for off chip reference clocks only.
This is to avoid duplication of clocks data in DT and firmware both as firmware anyways need clock data to manage them.

Thanks,
Jolly Shah