You've already forked linux-apfs
mirror of
https://github.com/linux-apfs/linux-apfs.git
synced 2026-05-01 15:00:59 -07:00
Serge Semin
cfad642538
This driver provides an access to EEPROM of IDT PCIe-switches. IDT PCIe-
switches expose a simple SMBus interface to perform IO-operations from/to
EEPROM, which is located at private (so called Master) SMBus. The driver
creates a simple binary sysfs-file to have an access to the EEPROM using
the SMBus-slave interface in the i2c-device susfs-directory:
/sys/bus/i2c/devices/<bus>-<devaddr>/eeprom
In case if read-only flag is specified at dts-node of the device, User-space
applications won't be able to write to the EEPROM sysfs-node.
Additionally IDT 89HPESx SMBus interface has an ability to read/write
values of device CSRs. This driver exposes debugfs-file to perform simple
IO-operations using that ability for just basic debug purpose. Particularly
the next file is created in the specific debugfs-directory:
/sys/kernel/debug/idt_csr/
Format of the debugfs-file value is:
$ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
<CSR address>:<CSR value>
So reading the content of the file gives current CSR address and it value.
If User-space application wishes to change current CSR address, it can just
write a proper value to the sysfs-file:
$ echo "<CSR address>" >
/sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
If it wants to change the CSR value as well, the format of the write
operation is:
$ echo "<CSR address>:<CSR value>" > \
/sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
CSR address and value can be any of hexadecimal, decimal or octal format.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.