Commit Graph

9 Commits

Author SHA1 Message Date
Linus Torvalds f18e345dd1 I3C for 5.18
Subsystem:
  - support dynamic addition of i2c devices
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEBqsFVZXh8s/0O5JiY6TcMGxwOjIFAmJDhx4ACgkQY6TcMGxw
 OjIP+A//euxqZUwhTY9ayUuuvguecajhALFeiMw7Z6yJhGMob/9dy+rrAJUUYm84
 wHGRRj7lgkW6v1TwK5WlxZF/zecxQCjKy71UPV7OPgYM84DdMQvqwkjRcNJB5k1/
 kZap3Xro7SFtooalG3QVf8kK69AGYJ+7JqM4rYWT/h1rXJPfiypWSc5lYKGnAdHG
 lFCPhPr/tX1JE+RRKin4bmWnE93bZw0XzhanlNf6YI3SZmdjnhVo8Kf7wn8AYBZ+
 wR5TjmfAhwrAUq6hkc/XHMOrkZFAYfAwzrUS6EPfxawDMJkYXwyYruF8okjESCT+
 uoYDKtWo8PjsZ5CB/qm8JInlnCLFvUr3+kIedvv3SXJdeZQHsPHQ7LOdzTP3pqLH
 F/mzlyoipNIkKW6p519hd2q1XpLtEEr2DLCErF+BkUECWoaLRYJ9An9bdTUD9Mnp
 1cVbRfEc9LxNQHhzHl/0RMxHCHQZum2r04TBCaFqGbt8MRJjwv75mpPahrvf65jP
 eFyCUCpGsvkN+JAQzmtDSzMKN3TJEWdKD8SuTr1LvzXTZPPVEVZlRDz0ivRldQbj
 WrMrmKQqCR494EYwbNC4xMjVHZwOkBC/JvSvV9uwD18x09BLj1TvGCE8Z+yr/S8h
 50Onxj9gC3Xdx24CYzHSDTo4NXgTw7WagNv4lDtA3DQwINrx9Yk=
 =PU3X
 -----END PGP SIGNATURE-----

Merge tag 'i3c/for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux

Pull i3c updates from Alexandre Belloni:

 - support dynamic addition of i2c devices

* tag 'i3c/for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: fix uninitialized variable use in i2c setup
  i3c: support dynamically added i2c devices
  i3c: remove i2c board info from i2c_dev_desc
2022-03-30 10:36:41 -07:00
Jamie Iles 31b9887c72 i3c: remove i2c board info from i2c_dev_desc
I2C board info is only required during adapter setup so there is no
requirement to keeping a pointer to it once running.  To support dynamic
device addition we can't rely on board info - user-space creation
through sysfs won't have a boardinfo.

Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Jamie Iles <quic_jiles@quicinc.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220117174816.1963463-2-quic_jiles@quicinc.com
2022-03-04 11:39:03 +01:00
Gustavo A. R. Silva 5224f79096 treewide: Replace zero-length arrays with flexible-array members
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

UAPI and wireless changes were intentionally excluded from this patch
and will be sent out separately.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-02-17 07:00:39 -06:00
Uwe Kleine-König dd9267034c i3c: Make remove callback return void
The driver core ignores the return value of struct bus_type::remove()
because there is only little that can be done. To simplify the quest to
make this function return void, let struct i3c_driver::remove() return
void, too. This makes it obvious that returning an error code is
a bad idea and future driver authors cannot get that wrong.

Up to now there are no drivers with a remove callback, so there is no
need to adapt drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210128091048.17006-2-u.kleine-koenig@pengutronix.de
2021-02-02 00:16:57 +01:00
Przemyslaw Gaj b1ac3a4b9a i3c: add addr and lvr to i2c_dev_desc structure
I need to store address and lvr value for I2C devices without static definition
in DT. This allows secondary master to transmit DEFSLVS command properly.

Main changes between v4 and v5:
- Change in defslvs to use addr and lvr from i2c_dev_desc structure
- Change in CDNS and DW drivers to use addr and lvr from i2c_dev_desc structure

Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-08-11 10:48:28 +02:00
Vitor Soares 934d24a5e1 i3c: move i3c_device_match_id to device.c and export it
Some I3C device drivers need to know which entry matches the
i3c_device object passed to the probe function

Let's move i3c_device_match_id() to device.c and export it so it can be
used by drivers.

Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-07-27 11:22:19 +02:00
Vitor Soares cbf4f7325a i3c: add mixed limited bus mode
The i3c bus spec defines a bus configuration where i2c devices don't
have a 50ns filter but support SCL running at SDR max rate (12.5MHz).

This patch introduces the limited bus mode so that users can use
a higher speed in presence of i2c devices index 1.

Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-06-20 09:23:22 +02:00
Przemyslaw Gaj 88c5032244 i3c: Drop support for I2C 10 bit addresing
This patch drops support for I2C devices with 10 bit addressing. When I2C
device with 10 bit address is defined in DT, I3C master registration fails.

Address space for I2C devices has been reduced and ->i2c_funcs() hook has been
removed.

Because this patch series dropped support for 10 bit I2C devices, support is
also dropped in Cadence I3C master driver and Synopsys DesignWare I3C master
driver.

Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-05-28 09:39:53 +02:00
Boris Brezillon 3a379bbcea i3c: Add core I3C infrastructure
Add core infrastructure to support I3C in Linux and document it.

This infrastructure adds basic I3C support. Advanced features will be
added afterwards.

There are a few design choices that are worth mentioning because they
impact the way I3C device drivers can interact with their devices:

- all functions used to send I3C/I2C frames must be called in
  non-atomic context. Mainly done this way to ease implementation, but
  this is not set in stone, and if anyone needs async support, new
  functions can be added later on.
- the bus element is a separate object, but it's tightly coupled with
  the master object. We thus have a 1:1 relationship between i3c_bus
  and i3c_master_controller objects, and if 2 master controllers are
  connected to the same bus and both exposed to the same Linux instance
  they will appear as two distinct busses, and devices on this bus will
  be exposed twice.
- I2C backward compatibility has been designed to be transparent to I2C
  drivers and the I2C subsystem. The I3C master just registers an I2C
  adapter which creates a new I2C bus. I'd say that, from a
  representation PoV it's not ideal because what should appear as a
  single I3C bus exposing I3C and I2C devices here appears as 2
  different buses connected to each other through the parenting (the
  I3C master is the parent of the I2C and I3C busses).
  On the other hand, I don't see a better solution if we want something
  that is not invasive.

Missing features:
- I3C HDR modes are not supported
- no support for multi-master and the associated concepts (mastership
  handover, support for secondary masters, ...)
- I2C devices can only be described using DT because this is the only
  use case I have. However, the framework can easily be extended with
  ACPI and board info support
- I3C slave framework. This has been completely omitted, but shouldn't
  have a huge impact on the I3C framework because I3C slaves don't see
  the whole bus, it's only about handling master requests and generating
  IBIs. Some of the struct, constant and enum definitions could be
  shared, but most of the I3C slave framework logic will be different

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-12 10:33:49 +01:00