Hi Herve, On Thu, 2024-10-03 at 10:16 +0200, Herve Codina wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you > know the content is safe > > In the LAN966x PCI device use case, the syscon API cannot be used as > it does not support device removal [1]. A syscon device is a core > "system" device and not a device available in some addon boards and > so, > it is not supposed to be removed. The syscon API follows this > assumption > but this assumption is no longer valid in the LAN966x use case. > > In order to avoid the use of the syscon API and so, support for > removal, > use a local mapping of the syscon device. > > Link: > https://lore.kernel.org/all/20240923100741.11277439@xxxxxxxxxxx/ [1] > Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx> > --- > drivers/reset/reset-microchip-sparx5.c | 35 > +++++++++++++++++++++++++- > 1 file changed, 34 insertions(+), 1 deletion(-) > > diff --git a/drivers/reset/reset-microchip-sparx5.c > b/drivers/reset/reset-microchip-sparx5.c > index 636e85c388b0..48a62d5da78d 100644 > --- a/drivers/reset/reset-microchip-sparx5.c > +++ b/drivers/reset/reset-microchip-sparx5.c > @@ -62,6 +62,28 @@ static const struct reset_control_ops > sparx5_reset_ops = { > .reset = sparx5_reset_noop, > }; > > +static const struct regmap_config mchp_lan966x_syscon_regmap_config > = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +static struct regmap *mchp_lan966x_syscon_to_regmap(struct device > *dev, > + struct > device_node *syscon_np) > +{ > + struct regmap_config regmap_config = > mchp_lan966x_syscon_regmap_config; > + resource_size_t size; > + void __iomem *base; > + > + base = devm_of_iomap(dev, syscon_np, 0, &size); > + if (IS_ERR(base)) > + return ERR_CAST(base); > + > + regmap_config.max_register = size - 4; > + > + return devm_regmap_init_mmio(dev, base, ®map_config); > +} > + > static int mchp_sparx5_map_syscon(struct platform_device *pdev, char > *name, > struct regmap **target) > { > @@ -72,7 +94,18 @@ static int mchp_sparx5_map_syscon(struct > platform_device *pdev, char *name, > syscon_np = of_parse_phandle(pdev->dev.of_node, name, 0); > if (!syscon_np) > return -ENODEV; > - regmap = syscon_node_to_regmap(syscon_np); > + > + /* > + * The syscon API doesn't support syscon device removal. > + * When used in LAN966x PCI device, the cpu-syscon device > needs to be > + * removed when the PCI device is removed. > + * In case of LAN966x, map the syscon device locally to > support the > + * device removal. > + */ > + if (of_device_is_compatible(pdev->dev.of_node, > "microchip,lan966x-switch-reset")) > + regmap = mchp_lan966x_syscon_to_regmap(&pdev->dev, > syscon_np); > + else > + regmap = syscon_node_to_regmap(syscon_np); > of_node_put(syscon_np); > if (IS_ERR(regmap)) { > err = PTR_ERR(regmap); > -- > 2.46.1 > This looks good to me. Reviewed-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx> BR Steen
