The link to the I2C specification is broken. Although
"https://www.nxp.com" hosts Rev 7 (2021) of this specification, it is
behind a login-wall. Thus, an additional link has been added (which
doesn't require a login) and the NXP official docs link has been
updated.
Signed-off-by: Deep Majumder <deep@fastmail.in>
[wsa: minor updates to text and commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Sr is a repeated start, it is used in both I2C and SMBus protocols.
Provide its description and replace start ("S") conditions with repeated
start ("Sr") conditions when relevant. This allows the documentation to
match the SMBus specification available at [1].
[1] http://www.smbus.org/specs/SMBus_3_1_20180319.pdf
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Append i2c-sysfs to toctree in order to get rid of building warnings.
Fixes: 31df7195b1 ("Documentation: i2c: Add doc for I2C sysfs")
Signed-off-by: Hu Haowen <src.res@email.cn>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Pull i2c updates from Wolfram Sang:
- core supports now bus regulators controlling power for SCL/SDA
- quite some DT binding conversions to YAML
- added a seperate DT binding for the optional SMBus Alert feature
- documentation with examples how to deal with I2C sysfs files
- some bigger rework for the i801 driver
- and a few usual driver updates
* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (42 commits)
i2c: ali1535: mention that the device should not be disabled
i2c: mpc: Restore reread of I2C status register
i2c: core-smbus: Expose PEC calculate function for generic use
Documentation: i2c: Add doc for I2C sysfs
i2c: core: Disable client irq on reboot/shutdown
dt-bindings: i2c: update bindings for MT8195 SoC
i2c: imx: Fix some checkpatch warnings
i2c: davinci: Simplify with dev_err_probe()
i2c: cadence: Simplify with dev_err_probe()
i2c: xiic: Simplify with dev_err_probe()
i2c: cadence: Clear HOLD bit before xfer_size register rolls over
dt-bindings: i2c: ce4100: Replace "ti,pcf8575" by "nxp,pcf8575"
i2c: i801: Improve i801_setup_hstcfg
i2c: i801: Use driver name constant instead of function dev_driver_string
i2c: i801: Simplify initialization of i2c_board_info in i801_probe_optional_slaves
i2c: i801: Improve status polling
i2c: cht-wc: Replace of_node by NULL
i2c: riic: Add RZ/G2L support
dt-bindings: i2c: renesas,riic: Document RZ/G2L I2C controller
dt-bindings: i2c: renesas,iic: Convert to json-schema
...
This doc helps Linux users navigate through I2C sysfs and learn
the system I2C topology.
Signed-off-by: Alex Qiu <xqiu@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Devices offering SMBus block process calls are rare, so add it to the
testunit. This is also a good test case for testing proper
I2C_M_RECV_LEN flag handling of I2C bus masters emulating SMBus.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Mention that new CMDs will be NACKed while the old one is still
on-going, that the I2C address parameter of READ_BYTES is 7 bit only,
and reword one paragraph to be more precise.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Add PCI ID of SMBus controller on Intel Alder Lake PCH-S
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Here is an I2C slave backend driver which allows to test some uncommon
functionalities of the I2C and SMBus world. Usually, you need specific
devices to test e.g. SMBus Host Notify and such. With this driver you
just need the slave interface of another I2C controller.
This initial version has testcases for multi-master and SMBus Host
Notify. Already planned but not yet implemented are SMBus Alert and
messages with I2C_M_RECV_LEN.
Please read the documentation for further details.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Pull i2c updates from Wolfram Sang:
- bus recovery can now be given a pinctrl handle and the I2C core will
do all the steps to switch to/from GPIO which can save quite some
boilerplate code from drivers
- "fallthrough" conversion
- driver updates, mostly ID additions
* 'i2c/for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (32 commits)
i2c: iproc: fix race between client unreg and isr
i2c: eg20t: use generic power management
i2c: eg20t: Drop PCI wakeup calls from .suspend/.resume
i2c: mediatek: Fix i2c_spec_values description
i2c: mediatek: Add i2c compatible for MediaTek MT8192
dt-bindings: i2c: update bindings for MT8192 SoC
i2c: mediatek: Add access to more than 8GB dram in i2c driver
i2c: mediatek: Add apdma sync in i2c driver
i2c: i801: Add support for Intel Tiger Lake PCH-H
i2c: i801: Add support for Intel Emmitsburg PCH
i2c: bcm2835: Replace HTTP links with HTTPS ones
Documentation: i2c: dev: 'block process call' is supported
i2c: at91: Move to generic GPIO bus recovery
i2c: core: treat EPROBE_DEFER when acquiring SCL/SDA GPIOs
i2c: core: add generic I2C GPIO recovery
dt-bindings: i2c: add generic properties for GPIO bus recovery
i2c: rcar: avoid race when unregistering slave
i2c: tegra: Avoid tegra_i2c_init_dma() for Tegra210 vi i2c
i2c: tegra: Fix runtime resume to re-init VI I2C
i2c: tegra: Fix the error path in tegra_i2c_runtime_resume
...
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Merge tag 'docs-5.9-2' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"A handful of obvious fixes that wandered in during the merge window"
* tag 'docs-5.9-2' of git://git.lwn.net/linux:
Documentation/locking/locktypes: fix the typo
doc/zh_CN: resolve undefined label warning in admin-guide index
doc/zh_CN: fix title heading markup in admin-guide cpu-load
docs: remove the 2.6 "Upgrading I2C Drivers" guide
docs: Correct the release date of 5.2 stable
mailmap: Update comments for with format and more detalis
docs: cdrom: Fix a typo and rst markup
Doc: admin-guide: use correct legends in kernel-parameters.txt
Documentation/features: refresh RISC-V arch support files
documentation: coccinelle: Improve command example for make C={1,2}
Core-api: Documentation: Replace deprecated :c:func: Usage
Dev-tools: Documentation: Replace deprecated :c:func: Usage
Filesystems: Documentation: Replace deprecated :c:func: Usage
docs: trace: fix a typo
All the drivers have long since been upgraded, and all the important
information here is also included in the "Implementing I2C device
drivers" guide.
Signed-off-by: Stephen Kitt <steve@sk2.org>
Reviewed-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20200806161456.8680-1-steve@sk2.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add support for SMBus controller on Intel Emmitsburg PCH. This is the
same IP as used in Cannon Lake and derivatives.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
And it has been for a while (since 2012 at least), only it was not
documented. Add it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again for a
while. Unless we decide to switch to asciidoc or something...:)
- Lots of typo fixes, warning fixes, and more.
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Merge tag 'docs-5.9' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It's been a busy cycle for documentation - hopefully the busiest for a
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS
URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again
for a while. Unless we decide to switch to asciidoc or
something...:)
- Lots of typo fixes, warning fixes, and more"
* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
scripts/kernel-doc: optionally treat warnings as errors
docs: ia64: correct typo
mailmap: add entry for <alobakin@marvell.com>
doc/zh_CN: add cpu-load Chinese version
Documentation/admin-guide: tainted-kernels: fix spelling mistake
MAINTAINERS: adjust kprobes.rst entry to new location
devices.txt: document rfkill allocation
PCI: correct flag name
docs: filesystems: vfs: correct flag name
docs: filesystems: vfs: correct sync_mode flag names
docs: path-lookup: markup fixes for emphasis
docs: path-lookup: more markup fixes
docs: path-lookup: fix HTML entity mojibake
CREDITS: Replace HTTP links with HTTPS ones
docs: process: Add an example for creating a fixes tag
doc/zh_CN: add Chinese translation prefer section
doc/zh_CN: add clearing-warn-once Chinese version
doc/zh_CN: add admin-guide index
doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
futex: MAINTAINERS: Re-add selftests directory
...
Add more details which have either been missing ever since or describe
recent additions.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Just like all other I2C/SMBus commands, the start signal for the SMBus
Quick Command is S, not A.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Daniel Schaefer <git@danielschaefer.me>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
When generating the PDF output, the Documentation/i2c dir
will generate an i2c.pdf. The same happens with i2c.svg:
it will also produce a file with the same name, at the same dir.
This causes errors when building the PDF output. So, rename the
image to i2c_bus.svg.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Link: https://lore.kernel.org/r/ecf3d51909ce46b3e84a1df4b36f07d76989e5da.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Only few drivers use this call, so drivers and I2C core are converted at
once with this patch. By simply using i2c_new_client_device() instead of
i2c_new_device(), we easily can return an ERRPTR for this function as
well. To make out of tree users aware that something changed, the
function is renamed to i2c_new_smbus_alert_device().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In I2C there is no such thing as a "stop bit". Use the proper naming: "stop
condition".
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reported-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In smbus-protocol.rst we use the text "Implemented by" for the same meaning
as "This corresponds to". Change everything to "Implemented by" for
coherency.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reported-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some of the section names are not very clear. Reading those names in the
index.rst page does not help much in grasping what the content is supposed
to be.
Rename those sections to clarify their content, especially when reading
the index page.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Acked-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use a monospace (literal) formatting for better readability of sysfs
attributes and the "dummy" client name. This looks much more readable in
ReST-generated output.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This section applies only to code for very old kernels. Avoid people
reading this unnecessarily.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use ReST syntax so that a proper hyperlink is generated.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use a monospace (literal) formatting for better readability of sysfs
attributes.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Among the "static" instantiation methods the "board file" method is
described first. Move it as last, since it is being replaced by the other
methods.
Also fix subsubsection heading syntax and remove the "Method 1[abc]"
prefix as the subsubsection structure clarifies the logical hierarchy.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use ReST syntax so that a proper hyperlink is generated.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Clarify from the beginning what these transactions are, and specifically
how they differ from the SMBus counterparts, i.e. the lack of a Count byte.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The subject is plural, fix the verb.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This clarifies these are functions (and would/will adds a hyperlink to the
function documentation if/when documented).
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Hyperlinks from function names are not generated in headings. Move them in
the plain text so they are rendered as clickable hyperlinks.
While there also remove an unneeded colon in a heading.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use the proper ACK and NACK naming from the I2C specification instead of
"accept" and "reverse accept".
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
These colons are not needed: the columns already nicely separate the
symbols from their description. They are also inconsistently preceded by
whitespace.
Remove the colons completely to simplify and clean up.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In I2C there is no such thing as a "start bit" or a "stop bit". Use the
proper naming: "start condition" and "stop condition".
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use the proper ReST syntax to generate a valid hyperlink.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use the proper ACK and NACK naming from the I2C specification instead of
"accept" and "reverse accept".
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
These colons are not needed: the columns already nicely separate the
symbols from their description. They are also inconsistently preceded by
whitespace.
Remove the colons completely to simplify and clean up.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In I2C there is no such thing as a "start bit" or a "stop bit". Use the
proper naming: "start condition" and "stop condition".
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This clarifies these are functions and adds a hyperlink to the function
documentation.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
"I2C transfer" is a legitimate english sentence, no need for a hyphen
between the two words, as as such it is used in most of the
documentation. Remove the hyphen in the few places where it is present.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Acked-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Uppercase "I2C" is used almost everywhere in the docs, but the lowercase
version "i2c" is used somewhere. Use the uppercase form consistently.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Acked-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This section, partly dating back to the pre-git era, is somewhat
unclear and partly incorrect. Rewrite it almost completely including a
reference figure, concise but precise definition of each term and the
paths where drivers are found. Particular care has been put in clarifying
the relation between adapter and algorithm, which has no correspondence
in the I2C spec terminology.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
- state the "official" name (I²C, not I2C, according to the spec) at
the beginning but keep using the more practical I2C elsewhere
- mention some known different names
- add link to the specification document
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The index page currently lists sections in alphabetical file order without
caring about their content. Sort sections based on their content logically,
according to the following structure:
* Intro to I2C/SMBus and their usage in Linux: summary, i2c-protocol,
smbus-protocol, instantiating-devices, busses/index, i2c-topology,
muxes/i2c-mux-gpio
* Implementing drivers: writing-clients, dev-interface,
dma-considerations, fault-codes, functionality
* Debugging: gpio-fault-injection, i2c-stub
* Slave I2C: slave-interface, slave-eeprom-backend
* Advanced: ten-bit-addresses
* Obsolete info: upgrading-clients, old-module-parameters
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Deep Majumder