RE: [RFC PATCH v3 1/3] firmware: xilinx: Add reset API's

From: Nava kishore Manne
Date: Mon Sep 10 2018 - 00:47:19 EST


Hi Philipp

Thanks for the quick response...
Please find my response inline.

> -----Original Message-----
> From: Philipp Zabel [mailto:p.zabel@xxxxxxxxxxxxxx]
> Sent: Wednesday, September 5, 2018 4:00 PM
> To: Nava kishore Manne <navam@xxxxxxxxxx>; robh+dt@xxxxxxxxxx;
> mark.rutland@xxxxxxx; Michal Simek <michals@xxxxxxxxxx>; Rajan Vaja
> <RAJANV@xxxxxxxxxx>; Jolly Shah <JOLLYS@xxxxxxxxxx>;
> devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [RFC PATCH v3 1/3] firmware: xilinx: Add reset API's
>
> Hi,
>
> On Wed, 2018-09-05 at 12:39 +0530, Nava kishore Manne wrote:
> > This Patch Adds reset API's to support release, assert and status
> > functionalities by using firmware interface.
> >
> > Signed-off-by: Nava kishore Manne <nava.manne@xxxxxxxxxx>
> > ---
> > Changes for v3:
> > -None.
> > Changes for v2:
> > -New Patch.
> >
> > drivers/firmware/xilinx/zynqmp.c | 40 +++++++++++
> > include/linux/firmware/xlnx-zynqmp.h | 136
> > +++++++++++++++++++++++++++++++++++
> > 2 files changed, 176 insertions(+)
> >
> > diff --git a/drivers/firmware/xilinx/zynqmp.c
> > b/drivers/firmware/xilinx/zynqmp.c
> > index 7ccedf0..639c72f 100644
> > --- a/drivers/firmware/xilinx/zynqmp.c
> > +++ b/drivers/firmware/xilinx/zynqmp.c
> > @@ -447,6 +447,44 @@ static int zynqmp_pm_clock_getparent(u32
> clock_id, u32 *parent_id)
> > return ret;
> > }
> >
> > +/**
> > + * zynqmp_pm_reset_assert - Request setting of reset (1 - assert, 0 - release)
> > + * @reset: Reset to be configured
> > + * @assert_flag: Flag stating should reset be asserted (1) or
> > + * released (0)
> > + *
> > + * Return: Returns status, either success or error+reason */ static
> > +int zynqmp_pm_reset_assert(const enum zynqmp_pm_reset reset,
> > + const enum zynqmp_pm_reset_action
> assert_flag) {
> > + return zynqmp_pm_invoke_fn(PM_RESET_ASSERT, reset, assert_flag,
> > + 0, 0, NULL);
> > +}
> > +
> > +/**
> > + * zynqmp_pm_reset_get_status - Get status of the reset
> > + * @reset: Reset whose status should be returned
> > + * @status: Returned status
> > + *
> > + * Return: Returns status, either success or error+reason */ static
> > +int zynqmp_pm_reset_get_status(const enum zynqmp_pm_reset reset,
> > + u32 *status)
> > +{
> > + u32 ret_payload[PAYLOAD_ARG_CNT];
> > + int ret;
> > +
> > + if (!status)
> > + return -EINVAL;
> > +
> > + ret = zynqmp_pm_invoke_fn(PM_RESET_GET_STATUS, reset, 0,
> > + 0, 0, ret_payload);
> > + *status = ret_payload[1];
>
> It doesn't really matter here, but in general I'd skip writing output arguments in
> case of error.
> For all I know, the result returned in ret_payload could be undefined.
>

Will fix in the next version.

Regards,
Navakishore.