Re: [Patch v4 3/4] memory: tegra: Add memory controller channels support

[Jon Hunter]

On 02/03/2022 19:35, Krzysztof Kozlowski wrote:
> On 02/03/2022 09:43, Ashish Mhetre wrote:
> >  From tegra186 onwards, memory controller support multiple channels.
> > Add support for mapping address spaces of these channels.
> > During error interrupts from memory controller, appropriate registers
> > from these channels need to be accessed for logging error info.
> >
> > Signed-off-by: Ashish Mhetre <amhetre@xxxxxxxxxx>
> > ---
> >   drivers/memory/tegra/mc.c       |  6 ++++++
> >   drivers/memory/tegra/tegra186.c | 21 +++++++++++++++++++++
> >   drivers/memory/tegra/tegra194.c |  1 +
> >   drivers/memory/tegra/tegra234.c |  1 +
> >   include/soc/tegra/mc.h          |  7 +++++++
> >   5 files changed, 36 insertions(+)
> >
> > diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
> > index bf3abb6..3cda1d9 100644
> > --- a/drivers/memory/tegra/mc.c
> > +++ b/drivers/memory/tegra/mc.c
> > @@ -749,6 +749,12 @@ static int tegra_mc_probe(struct platform_device *pdev)
> >   	if (IS_ERR(mc->regs))
> >   		return PTR_ERR(mc->regs);
> >   
> > +	if (mc->soc->ops && mc->soc->ops->map_regs) {
> > +		err = mc->soc->ops->map_regs(mc, pdev);
> > +		if (err < 0)
> > +			return err;
> > +	}
> > +
> >   	mc->debugfs.root = debugfs_create_dir("mc", NULL);
> >   
> >   	if (mc->soc->ops && mc->soc->ops->probe) {
> > diff --git a/drivers/memory/tegra/tegra186.c b/drivers/memory/tegra/tegra186.c
> > index 3d15388..59a4425 100644
> > --- a/drivers/memory/tegra/tegra186.c
> > +++ b/drivers/memory/tegra/tegra186.c
> > @@ -139,11 +139,31 @@ static int tegra186_mc_probe_device(struct tegra_mc *mc, struct device *dev)
> >   	return 0;
> >   }
> >   
> > +static int tegra186_mc_map_regs(struct tegra_mc *mc,
> > +				struct platform_device *pdev)
> > +{
> > +	struct resource *res;
> > +	int i;
> > +
> > +	mc->mcb_regs = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
> > +	if (IS_ERR(mc->mcb_regs))
> > +		return PTR_ERR(mc->mcb_regs);
> > +
> > +	for (i = 0; i < mc->soc->num_channels; i++) {
> > +		mc->mc_regs[i] = devm_platform_get_and_ioremap_resource(pdev, i + 2, &res);
> > +		if (IS_ERR(mc->mc_regs[i]))
> > +			return PTR_ERR(mc->mc_regs[i]);
>
> This breaks the ABI, so I need Thierry's ack that such ABI break is
> perfectly ok.


We should not break the DT ABI and so if all the reg entries it should 
still be able to work.

Jon

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