linux-stable/drivers/usb/chipidea/Kconfig
Lukas Bulwahn d818320ea2 usb: chipidea: make configs for glue drivers visible with EXPERT
Commit 6a108a14fa ("kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT")
introduces CONFIG_EXPERT to carry the previous intent of CONFIG_EMBEDDED
and just gives that intent a much better name. That has been clearly a good
and long overdue renaming, and it is clearly an improvement to the kernel
build configuration that has shown to help managing the kernel build
configuration in the last decade.

However, rather than bravely and radically just deleting CONFIG_EMBEDDED,
this commit gives CONFIG_EMBEDDED a new intended semantics, but keeps it
open for future contributors to implement that intended semantics:

    A new CONFIG_EMBEDDED option is added that automatically selects
    CONFIG_EXPERT when enabled and can be used in the future to isolate
    options that should only be considered for embedded systems (RISC
    architectures, SLOB, etc).

Since then, this CONFIG_EMBEDDED implicitly had two purposes:

  - It can make even more options visible beyond what CONFIG_EXPERT makes
    visible. In other words, it may introduce another level of enabling the
    visibility of configuration options: always visible, visible with
    CONFIG_EXPERT and visible with CONFIG_EMBEDDED.

  - Set certain default values of some configurations differently,
    following the assumption that configuring a kernel build for an
    embedded system generally starts with a different set of default values
    compared to kernel builds for all other kind of systems.

Considering the first purpose, at the point in time where CONFIG_EMBEDDED
was renamed to CONFIG_EXPERT, CONFIG_EXPERT already made 130 more options
become visible throughout all different menus for the kernel configuration.
Over the last decade, this has gradually increased, so that currently, with
CONFIG_EXPERT, roughly 170 more options become visible throughout all
different menus for the kernel configuration. In comparison, currently with
CONFIG_EMBEDDED enabled, just seven more options are visible, one in x86,
one in arm, and five for the ChipIdea Highspeed Dual Role Controller.

As the numbers suggest, these two levels of enabling the visibility of even
more configuration options---beyond what CONFIG_EXPERT enables---never
evolved to a good solution in the last decade. In other words, this
additional level of visibility of configuration option with CONFIG_EMBEDDED
compared to CONFIG_EXPERT has since its introduction never become really
valuable. It requires quite some investigation to actually understand what
is additionally visible and it does not differ significantly in complexity
compared to just enabling CONFIG_EXPERT. This CONFIG_EMBEDDED---or any
other config to show more detailed options beyond CONFIG_EXPERT---is
unlikely to be valuable unless somebody puts significant effort in
identifying how such visibility options can be properly split and creating
clear criteria, when some config option is visible with CONFIG_EXPERT and
when some config option is visible only with some further option enabled
beyond CONFIG_EXPERT, such as CONFIG_EMBEDDED attempted to do. For now, it
is much more reasonable to simply make those additional seven options that
visible with CONFIG_EMBEDDED, visible with CONFIG_EXPERT, and then remove
CONFIG_EMBEDDED. If anyone spends significant effort in structuring the
visibility of config options, they may re-introduce suitable new config
options simply as they see fit.

Make the configs for usb chipidea glue drivers visible when CONFIG_EXPERT
is enabled.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220908104337.11940-5-lukas.bulwahn@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-08 13:32:50 +02:00

60 lines
1.5 KiB
Text

# SPDX-License-Identifier: GPL-2.0
config USB_CHIPIDEA
tristate "ChipIdea Highspeed Dual Role Controller"
depends on ((USB_EHCI_HCD && USB_GADGET) || (USB_EHCI_HCD && !USB_GADGET) || (!USB_EHCI_HCD && USB_GADGET)) && HAS_DMA
select EXTCON
select RESET_CONTROLLER
select USB_ULPI_BUS
select USB_ROLE_SWITCH
select USB_TEGRA_PHY if ARCH_TEGRA
help
Say Y here if your system has a dual role high speed USB
controller based on ChipIdea silicon IP. It supports:
Dual-role switch (ID, OTG FSM, sysfs), Host-only, and
Peripheral-only.
When compiled dynamically, the module will be called ci_hdrc.ko.
if USB_CHIPIDEA
config USB_CHIPIDEA_UDC
bool "ChipIdea device controller"
depends on USB_GADGET
help
Say Y here to enable device controller functionality of the
ChipIdea driver.
config USB_CHIPIDEA_HOST
bool "ChipIdea host controller"
depends on USB_EHCI_HCD
select USB_EHCI_ROOT_HUB_TT
help
Say Y here to enable host controller functionality of the
ChipIdea driver.
config USB_CHIPIDEA_PCI
tristate "Enable PCI glue driver" if EXPERT
depends on USB_PCI
depends on NOP_USB_XCEIV
default USB_CHIPIDEA
config USB_CHIPIDEA_MSM
tristate "Enable MSM hsusb glue driver" if EXPERT
default USB_CHIPIDEA
config USB_CHIPIDEA_IMX
tristate "Enable i.MX USB glue driver" if EXPERT
depends on OF
default USB_CHIPIDEA
config USB_CHIPIDEA_GENERIC
tristate "Enable generic USB2 glue driver" if EXPERT
default USB_CHIPIDEA
config USB_CHIPIDEA_TEGRA
tristate "Enable Tegra USB glue driver" if EXPERT
depends on OF
default USB_CHIPIDEA
endif