[PATCH 05/20] i3c: dw: switch to array-based exclusive reset control

[Jisheng Zhang]

On Mon, Oct 19, 2026 at 02:55:21PM +0200, Philipp Zabel wrote:
> On Di, 2026-09-29 at 14:14 +0800, Jisheng Zhang wrote:
> > The Synopsys DesignWare I3C master controller can have multiple reset
> > lines, such as a core reset and APB reset.
> > 
> > Refactor the driver to use devm_reset_control_array_get_exclusive()
> > instead of a single named reset handle. This automatically manages all
> > resets allocated to the device node sequentially.
> 
> Note that this does not guarantee any particular order. Are you sure
> that this is good enough for all implementations of the DW I3C core?

Per my understanding of the doc, it only requires the resets are
asserted and de-asserted, didn't mention the order. And per my tests
on syna SL2610 platforms, the DW I3C works perfectly no matter I
reset apb reset or core reset firstly.
> 
> Otherwise it may be wise to at least specify the names in binding, to
> be able to switch to the bulk API or individual control later, if
> needed.
> 
> > Signed-off-by: Jisheng Zhang <jszhang at kernel.org>
> > ---
> >  drivers/i3c/master/dw-i3c-master.c | 24 ++++++++++++++++++------
> >  drivers/i3c/master/dw-i3c-master.h |  2 +-
> >  2 files changed, 19 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> > index 4563d8761ba0..1c6c870f5bb3 100644
> > --- a/drivers/i3c/master/dw-i3c-master.c
> > +++ b/drivers/i3c/master/dw-i3c-master.c
> > @@ -1657,6 +1657,11 @@ static const struct dw_i3c_platform_ops dw_i3c_platform_ops_default = {
> >  	.set_dat_ibi = dw_i3c_platform_set_dat_ibi_nop,
> >  };
> >  
> > +static void dw_i3c_resets_assert(void *data)
> > +{
> > +	reset_control_assert(data);
> > +}
> > +
> >  int dw_i3c_common_probe(struct dw_i3c_master *master,
> >  			struct platform_device *pdev)
> >  {
> > @@ -1696,10 +1701,17 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
> >  	if (IS_ERR(master->pclk))
> >  		return PTR_ERR(master->pclk);
> >  
> > -	master->core_rst = devm_reset_control_get_optional_exclusive_deasserted(&pdev->dev,
> > -										NULL);
> > -	if (IS_ERR(master->core_rst))
> > -		return PTR_ERR(master->core_rst);
> > +	master->resets = devm_reset_control_array_get_optional_exclusive(&pdev->dev);
> > +	if (IS_ERR(master->resets))
> > +		return PTR_ERR(master->resets);
> > +
> > +	ret = reset_control_deassert(master->resets);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = devm_add_action_or_reset(&pdev->dev, dw_i3c_resets_assert, master->resets);
> > +	if (ret)
> > +		return ret;
> 
> This looks like we are missing
> devm_reset_control_array_get_optional_exclusive_deasserted().
> 
> regards
> Philipp