![Lee Jones](/assets/img/avatar_default.png)
Traditionally, any System-on-Chip based platform creates a flat list of platform_devices directly under /sys/devices/platform. In order to give these some better structure, this introduces a new bus type for soc_devices that are registered with the new soc_device_register() function. All devices that are on the same chip should then be registered as child devices of the soc device. The soc bus also exports a few standardised device attributes which allow user space to query the specific type of soc. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
196 lines
7.3 KiB
Plaintext
196 lines
7.3 KiB
Plaintext
menu "Generic Driver Options"
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config UEVENT_HELPER_PATH
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string "path to uevent helper"
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depends on HOTPLUG
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default ""
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help
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Path to uevent helper program forked by the kernel for
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every uevent.
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Before the switch to the netlink-based uevent source, this was
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used to hook hotplug scripts into kernel device events. It
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usually pointed to a shell script at /sbin/hotplug.
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This should not be used today, because usual systems create
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many events at bootup or device discovery in a very short time
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frame. One forked process per event can create so many processes
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that it creates a high system load, or on smaller systems
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it is known to create out-of-memory situations during bootup.
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To disable user space helper program execution at early boot
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time specify an empty string here. This setting can be altered
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via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
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later at runtime.
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config DEVTMPFS
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bool "Maintain a devtmpfs filesystem to mount at /dev"
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depends on HOTPLUG
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help
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This creates a tmpfs/ramfs filesystem instance early at bootup.
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In this filesystem, the kernel driver core maintains device
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nodes with their default names and permissions for all
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registered devices with an assigned major/minor number.
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Userspace can modify the filesystem content as needed, add
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symlinks, and apply needed permissions.
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It provides a fully functional /dev directory, where usually
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udev runs on top, managing permissions and adding meaningful
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symlinks.
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In very limited environments, it may provide a sufficient
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functional /dev without any further help. It also allows simple
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rescue systems, and reliably handles dynamic major/minor numbers.
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Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
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file system will be used instead.
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config DEVTMPFS_MOUNT
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bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
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depends on DEVTMPFS
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help
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This will instruct the kernel to automatically mount the
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devtmpfs filesystem at /dev, directly after the kernel has
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mounted the root filesystem. The behavior can be overridden
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with the commandline parameter: devtmpfs.mount=0|1.
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This option does not affect initramfs based booting, here
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the devtmpfs filesystem always needs to be mounted manually
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after the roots is mounted.
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With this option enabled, it allows to bring up a system in
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rescue mode with init=/bin/sh, even when the /dev directory
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on the rootfs is completely empty.
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config STANDALONE
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bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
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default y
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help
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Select this option if you don't have magic firmware for drivers that
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need it.
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If unsure, say Y.
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config PREVENT_FIRMWARE_BUILD
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bool "Prevent firmware from being built"
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default y
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help
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Say yes to avoid building firmware. Firmware is usually shipped
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with the driver and only when updating the firmware should a
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rebuild be made.
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If unsure, say Y here.
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config FW_LOADER
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tristate "Userspace firmware loading support" if EXPERT
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default y
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---help---
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This option is provided for the case where none of the in-tree modules
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require userspace firmware loading support, but a module built
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out-of-tree does.
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config FIRMWARE_IN_KERNEL
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bool "Include in-kernel firmware blobs in kernel binary"
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depends on FW_LOADER
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default y
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help
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The kernel source tree includes a number of firmware 'blobs'
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that are used by various drivers. The recommended way to
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use these is to run "make firmware_install", which, after
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converting ihex files to binary, copies all of the needed
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binary files in firmware/ to /lib/firmware/ on your system so
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that they can be loaded by userspace helpers on request.
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Enabling this option will build each required firmware blob
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into the kernel directly, where request_firmware() will find
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them without having to call out to userspace. This may be
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useful if your root file system requires a device that uses
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such firmware and do not wish to use an initrd.
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This single option controls the inclusion of firmware for
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every driver that uses request_firmware() and ships its
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firmware in the kernel source tree, which avoids a
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proliferation of 'Include firmware for xxx device' options.
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Say 'N' and let firmware be loaded from userspace.
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config EXTRA_FIRMWARE
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string "External firmware blobs to build into the kernel binary"
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depends on FW_LOADER
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help
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This option allows firmware to be built into the kernel for the case
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where the user either cannot or doesn't want to provide it from
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userspace at runtime (for example, when the firmware in question is
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required for accessing the boot device, and the user doesn't want to
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use an initrd).
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This option is a string and takes the (space-separated) names of the
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firmware files -- the same names that appear in MODULE_FIRMWARE()
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and request_firmware() in the source. These files should exist under
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the directory specified by the EXTRA_FIRMWARE_DIR option, which is
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by default the firmware subdirectory of the kernel source tree.
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For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
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the usb8388.bin file into the firmware directory, and build the kernel.
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Then any request_firmware("usb8388.bin") will be satisfied internally
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without needing to call out to userspace.
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WARNING: If you include additional firmware files into your binary
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kernel image that are not available under the terms of the GPL,
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then it may be a violation of the GPL to distribute the resulting
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image since it combines both GPL and non-GPL work. You should
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consult a lawyer of your own before distributing such an image.
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config EXTRA_FIRMWARE_DIR
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string "Firmware blobs root directory"
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depends on EXTRA_FIRMWARE != ""
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default "firmware"
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help
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This option controls the directory in which the kernel build system
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looks for the firmware files listed in the EXTRA_FIRMWARE option.
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The default is firmware/ in the kernel source tree, but by changing
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this option you can point it elsewhere, such as /lib/firmware/ or
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some other directory containing the firmware files.
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config DEBUG_DRIVER
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bool "Driver Core verbose debug messages"
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depends on DEBUG_KERNEL
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help
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Say Y here if you want the Driver core to produce a bunch of
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debug messages to the system log. Select this if you are having a
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problem with the driver core and want to see more of what is
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going on.
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If you are unsure about this, say N here.
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config DEBUG_DEVRES
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bool "Managed device resources verbose debug messages"
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depends on DEBUG_KERNEL
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help
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This option enables kernel parameter devres.log. If set to
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non-zero, devres debug messages are printed. Select this if
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you are having a problem with devres or want to debug
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resource management for a managed device. devres.log can be
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switched on and off from sysfs node.
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If you are unsure about this, Say N here.
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config SYS_HYPERVISOR
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bool
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default n
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config GENERIC_CPU_DEVICES
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bool
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default n
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config SOC_BUS
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bool
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source "drivers/base/regmap/Kconfig"
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config DMA_SHARED_BUFFER
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bool
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default n
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select ANON_INODES
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depends on EXPERIMENTAL
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help
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This option enables the framework for buffer-sharing between
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multiple drivers. A buffer is associated with a file using driver
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APIs extension; the file's descriptor can then be passed on to other
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driver.
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endmenu
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