Messages in this thread | | | Subject | Re: [RFC PATCH 2/2] HISI LPC: Add PNP device support | From | John Garry <> | Date | Fri, 20 Apr 2018 14:09:58 +0100 |
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On 20/04/2018 13:50, Andy Shevchenko wrote: > On Fri, 2018-04-20 at 18:07 +0800, John Garry wrote: >> Currently the driver creates an per-ACPI device mfd_cell >> for child devices. This does not suit devices which are >> PNP-compatible, as we expect PNP-compatible devices to >> derive PNP devices. >> >> To add PNP device support, we continue to allow the PNP >> scan code to create the PNP device (which have the >> enumeration_by_parent flag set), but expect the PNP >> scan to defer adding the device to allow the host probe >> code to do this. In addition, no longer do we create an >> mfd_cell (platform_device) for PNP-compatible devices. >> >> We take this approach so that host probe code can >> translate the IO resources of the PNP device prior >> to adding the device. >
Hi Andy,
Thanks for checking this.
>> + list_for_each_entry(child, &adev->children, node) { >> + if (acpi_is_pnp_device(child)) >> + continue; > > This is good candidate for a separate helper macro > > #define for_each_acpi_non_pnp_device(child, adev) \ > ...
Right, I did consider this, but was holding off refining until I get past RFC stage. In fact, we could also process each child entry in one loop, like this:
list_for_each_entry(child, &adev->children, node) { if (acpi_is_pnp_device(child)) { /* Do PNP compatible device work */
} else { /* otherwise, make an MFD cell ... */ }
> > (see, for example, for_each_pci_bridge() implementation as an example) > > >> + list_for_each_entry(child, &adev->children, node) { > >> + if (!acpi_is_pnp_device(child)) >> + continue; > > Ditto. >
ok
>> + /* >> + * Prior to adding the device, we need to translate >> the >> + * resources to logical PIO addresses. >> + */ >> + list_for_each_entry(pnp_res, &pnp_dev->resources, >> list) { >> + struct resource *res = &pnp_res->res; >> + > >> + if (res->flags | IORESOURCE_IO) > > What does this mean?
Here we check the resource flag for each resource for this PNP device - for IO resources we must translate the resource value from the bus address to the logical PIO address.
> >> + hisi_lpc_acpi_xlat_io_res(child, >> adev, res); >> + } >
Regards, John
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