[PATCH 2/2] reset: reset-zynqmp: Added support for Versal platform

Sai Krishna Potthuri lakshmis at xilinx.com
Mon Jul 20 09:58:25 EDT 2020


Hi Philipp,

Thanks for the review.

> -----Original Message-----
> From: Philipp Zabel <p.zabel at pengutronix.de>
> Sent: Monday, July 20, 2020 3:18 PM
> To: Sai Krishna Potthuri <lakshmis at xilinx.com>; Rob Herring
> <robh+dt at kernel.org>; Michal Simek <michals at xilinx.com>
> Cc: devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-
> kernel at vger.kernel.org; git <git at xilinx.com>; saikrishna12468 at gmail.com
> Subject: Re: [PATCH 2/2] reset: reset-zynqmp: Added support for Versal
> platform
> 
> On Tue, 2020-07-14 at 11:59 +0530, Sai Krishna Potthuri wrote:
> > Updated the reset driver to support Versal platform.
> > As part of adding Versal support
> > - Added Versal specific compatible string.
> > - Reset Id and number of resets are different for Versal and ZynqMP,
> > hence taken care of these two based on compatible string.
> >
> > Signed-off-by: Sai Krishna Potthuri
> > <lakshmi.sai.krishna.potthuri at xilinx.com>
> > ---
> >  drivers/reset/reset-zynqmp.c | 24 ++++++++++++++++++++----
> >  1 file changed, 20 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/reset/reset-zynqmp.c
> > b/drivers/reset/reset-zynqmp.c index 373ea8d4f7a1..17aa4532ec5e
> 100644
> > --- a/drivers/reset/reset-zynqmp.c
> > +++ b/drivers/reset/reset-zynqmp.c
> > @@ -12,9 +12,11 @@
> >
> >  #define ZYNQMP_NR_RESETS (ZYNQMP_PM_RESET_END -
> > ZYNQMP_PM_RESET_START)  #define ZYNQMP_RESET_ID
> ZYNQMP_PM_RESET_START
> > +#define VERSAL_NR_RESETS	95
> >
> >  struct zynqmp_reset_data {
> >  	struct reset_controller_dev rcdev;
> > +	u32 reset_id;
> >  };
> >
> >  static inline struct zynqmp_reset_data * @@ -26,23 +28,28 @@
> > to_zynqmp_reset_data(struct reset_controller_dev *rcdev)  static int
> > zynqmp_reset_assert(struct reset_controller_dev *rcdev,
> >  			       unsigned long id)
> >  {
> > -	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
> > +	struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
> > +
> > +	return zynqmp_pm_reset_assert(priv->reset_id + id,
> >  				      PM_RESET_ACTION_ASSERT);
> >  }
> >
> >  static int zynqmp_reset_deassert(struct reset_controller_dev *rcdev,
> >  				 unsigned long id)
> >  {
> > -	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
> > +	struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
> > +
> > +	return zynqmp_pm_reset_assert(priv->reset_id + id,
> >  				      PM_RESET_ACTION_RELEASE);
> >  }
> >
> >  static int zynqmp_reset_status(struct reset_controller_dev *rcdev,
> >  			       unsigned long id)
> >  {
> > +	struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
> >  	int val, err;
> >
> > -	err = zynqmp_pm_reset_get_status(ZYNQMP_RESET_ID + id, &val);
> > +	err = zynqmp_pm_reset_get_status(priv->reset_id + id, &val);
> >  	if (err)
> >  		return err;
> >
> > @@ -52,7 +59,9 @@ static int zynqmp_reset_status(struct
> > reset_controller_dev *rcdev,  static int zynqmp_reset_reset(struct
> reset_controller_dev *rcdev,
> >  			      unsigned long id)
> >  {
> > -	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
> > +	struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
> > +
> > +	return zynqmp_pm_reset_assert(priv->reset_id + id,
> >  				      PM_RESET_ACTION_PULSE);
> >  }
> >
> > @@ -76,13 +85,20 @@ static int zynqmp_reset_probe(struct
> platform_device *pdev)
> >  	priv->rcdev.ops = &zynqmp_reset_ops;
> >  	priv->rcdev.owner = THIS_MODULE;
> >  	priv->rcdev.of_node = pdev->dev.of_node;
> > +	priv->reset_id = ZYNQMP_RESET_ID;
> >  	priv->rcdev.nr_resets = ZYNQMP_NR_RESETS;
> > +	if (of_device_is_compatible(pdev->dev.of_node,
> > +				    "xlnx,versal-reset")) {
> 
> It would be better to use of_match_device and static const initalization data
> for this.
Will create soc specific initialization data structure and assign based on
of_device_get_match_data().

> 
> > +		priv->reset_id = 0;
> > +		priv->rcdev.nr_resets = VERSAL_NR_RESETS;
> 
> This won't work. All your reset ids are greater than 95, and this driver is using
> the default of_xlate callback, so of_reset_simple_xlate will fail all reset
> control requests with -EINVAL.
Will create of_xlate callback that will simply return the reset line number
without any checks. We have underlying secure library which will validate
the reset line number.

Regards
Sai Krishna
> 
> regards
> Philipp


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