Re: [RFC PATCH 0/2] add support for CDX bus MSI domain

[Robin Murphy]

On 2022-08-03 13:26, Nipun Gupta wrote:
> Devices in FPGA can be added/modified dynamically on run-time.
> These devices are exposed on system bus to embedded CPUs.
>
> CDX is an upcoming bus, that caters to the requirement for
> dynamically discovered FPGA devices. These devices are added
> as platform devices where fwnode is created using 'software
> nodes' in Linux framework.
>
> This RFC targets to solves 2 issues when adding devices
> dynamically using platform_device_register API.
>
> 1. It creates a MSI domain for CDX bus devices, which can
>     discover device ID used by GIC ITS without depending
>     on of_node.
> 2. Since these devices are not present in device tree, it
>     creates a sysfs entry to expose the compatible string.

Isn't this pretty much what CONFIG_OF_DYNAMIC is for? From the look of 
these patches this thing is still completely tied to devicetree, so why 
reinvent that wheel?

Robin.

> Nipun Gupta (2):
>    irqchip: cdx-bus: add cdx-MSI domain with gic-its domain as parent
>    driver core: add compatible string in sysfs for platform devices
>
>   drivers/base/platform.c                  |  15 +++
>   drivers/irqchip/Makefile                 |   1 +
>   drivers/irqchip/irq-gic-v3-its-cdx-msi.c | 114 +++++++++++++++++++++++
>   include/linux/cdx/cdx.h                  |  15 +++
>   4 files changed, 145 insertions(+)
>   create mode 100644 drivers/irqchip/irq-gic-v3-its-cdx-msi.c
>   create mode 100644 include/linux/cdx/cdx.h