This patchset adds support for creating PNP devices for devices attached to the HiSilicon LPC host bus. Currently an mfd-cell (platform device) is created per device on the bus for using ACPI-based firmware. As such, we need require a platform driver for these devices. However for PNP-compatible devices, it would be better to create a PNP device so that we may use the existing PNP driver. The PNP-compatible device we are interested in is the 8250-compatible UART on the Huawei D03 development board. This uart has the following profile: - IO space iotype - no interrupt, so polling mode required - 16550 compatible Currently no platform driver exists for this. I did send an RFC to add support to the 8250_dw driver, but Andy Shevchenko suggested adding PNP support to the host driver instead so we may use the appropriate PNP driver (8250_pnp) without modification, see here: https://lkml.org/lkml/2018/2/26/354 As for the implementation in this patchset, to avoid the PNP scan from creating and adding the device, we reuse the "enumeration_by_parent" flag to hold off adding the PNP device, so the parent driver can modify the IO resources to translate from the bus address to the logical PIO address, and then add the device for probing. This solution is not good - hence the RFC. But I am looking for suggestions on how to solve this. Any opinions or ideas? Thanks! John Garry (2): ACPI / PNP: Don't add "enumeration_by_parent" devices HISI LPC: Add PNP device support drivers/bus/hisi_lpc.c | 38 +++++++++++++++++++++++++++++++++++++- drivers/pnp/pnpacpi/core.c | 12 ++++++++---- 2 files changed, 45 insertions(+), 5 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
