linux-stable.git/drivers/i3c, branch v5.12.2

Merge tag 'i3c/for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux

2021-02-22T17:52:55+00:00

Pull i3c update from Alexandre Belloni:
 "Subsystem:
   - Handle drivers without probe or remove callback
   - Remove callback now returns void
   - DT documentation is now in yaml

  New driver:
   - Silvaco I3C master"

* tag 'i3c/for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: master: dw: Drop redundant disec call
  MAINTAINERS: Add Silvaco I3C master
  i3c: master: svc: Add Silvaco I3C master driver
  dt-bindings: i3c: Describe Silvaco master binding
  dt-bindings: Add vendor prefix for Silvaco
  dt-bindings: i3c: mipi-hci: Include the bus binding
  dt-bindings: i3c: Convert the bus description to yaml
  i3c: Make remove callback return void
  i3c: Handle drivers without probe or remove callback
  i3c/master/mipi-i3c-hci: Specify HAS_IOMEM dependency

i3c: master: dw: Drop redundant disec call

2021-02-05T23:44:15+00:00

Disabling all event calls is already handled by the core right before
starting the DAA process. Do not do it again when the DAA process
completes, it is redundant.

Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP")
Signed-off-by: Miquel Raynal 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20201228105501.6104-1-miquel.raynal@bootlin.com

i3c: master: svc: Add Silvaco I3C master driver

2021-02-05T23:43:29+00:00

Add support for Silvaco I3C dual-role IP. The master role is supported
in SDR mode only. I2C transfers have not been tested but are shared
because they are very close to the I3C transfers in terms of register
configuration.

The IBI processing follows this logic:
- When a slave advertizes an interrupt (SDA pulled low) an interrupt
  gets generated by the master. This time is unbounded and may be
  deferred.
- The IRQ handler itself does not process anything: it only queues a
  work that will be run in non-atomic context. This is needed because
  short wait periods must be experienced.
- The IBI job is divided in two parts: the first one is "critical" in
  the sense that it may not support getting interrupted. If this
  happens, after this first section the driver checks the master error
  register and depending on its content either flushes everything and
  errors out, or ends the processing (this second section may be
  interrupted).
- If the critical section got interrupted, the slave will
  automatically respin it's IBI request when it will be allowed to.

Signed-off-by: Miquel Raynal 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210121101808.14654-6-miquel.raynal@bootlin.com

i3c: Make remove callback return void

2021-02-01T23:16:57+00:00

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 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210128091048.17006-2-u.kleine-koenig@pengutronix.de

i3c: Handle drivers without probe or remove callback

2021-02-01T23:16:57+00:00

A registered driver without a probe callback doesn't make sense, so
refuse to register such a driver. (Otherwise i3c_device_probe() yields a
NULL pointer exception.)

A driver without remove is possible, e.g. when all resources are freed
using devm callbacks. So guard the call to driver->remove by a check
for being non-NULL.

Note that the only in-tree i3c driver
(drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c) doesn't have a remove
callback.

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210128091048.17006-1-u.kleine-koenig@pengutronix.de

i3c/master/mipi-i3c-hci: Specify HAS_IOMEM dependency

2021-02-01T22:39:17+00:00

The MIPI i3c HCI driver makes use of IOMEM functions like
devm_platform_ioremap_resource(), which are only available if
CONFIG_HAS_IOMEM is defined.

This causes the driver to be enabled under make ARCH=um allyesconfig,
even though it won't build.

By adding a dependency on HAS_IOMEM, the driver will not be enabled on
architectures which don't support it.

Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver")
Signed-off-by: David Gow 
Acked-by: Nicolas Pitre 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20210127040636.1535722-1-davidgow@google.com

i3c/master/mipi-i3c-hci: Fix position of __maybe_unused in i3c_hci_of_match

2020-12-31T17:41:37+00:00

Clang warns:

 ../drivers/i3c/master/mipi-i3c-hci/core.c:780:21: warning: attribute
 declaration must precede definition [-Wignored-attributes]
 static const struct __maybe_unused of_device_id i3c_hci_of_match[] = {
                     ^
 ../include/linux/compiler_attributes.h:267:56: note: expanded from macro
 '__maybe_unused'
 #define __maybe_unused                  __attribute__((__unused__))
                                                        ^
 ../include/linux/mod_devicetable.h:262:8: note: previous definition is
 here
 struct of_device_id {
        ^
1 warning generated.

'struct of_device_id' should not be split, as it is a type. Move the
__maybe_unused attribute after the static and const qualifiers so that
there are no warnings about this variable, period.

Fixes: 95393f3e07ab ("i3c/master/mipi-i3c-hci: quiet maybe-unused variable warning")
Link: https://github.com/ClangBuiltLinux/linux/issues/1221
Signed-off-by: Nathan Chancellor 
Acked-by: Nicolas Pitre 
Signed-off-by: Alexandre Belloni 
Link: https://lore.kernel.org/r/20201222025931.3043480-1-natechancellor@gmail.com

i3c/master/mipi-i3c-hci: quiet maybe-unused variable warning

2020-12-17T09:31:30+00:00

If CONFIG_OF is disabled then the matching table is notreferenced.

Reported-by: kernel test robot 
Signed-off-by: Nicolas Pitre 
Signed-off-by: Boris Brezillon

i3c/master: Fix uninitialized variable next_addr

2020-11-25T10:02:43+00:00

The variable next_addr is not initialized and is being used in a call
to i3c_master_get_free_addr as a starting point to find the next address.
Fix this by initializing next_addr to 0 to avoid an uninitialized garbage
starting address from being used.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver")
Signed-off-by: Colin Ian King 
Acked-by: Nicolas Pitre 
Signed-off-by: Boris Brezillon 
Link: https://lore.kernel.org/linux-i3c/20201124123504.396249-1-colin.king@canonical.com

i3c/master: introduce the mipi-i3c-hci driver

2020-11-23T09:22:18+00:00

This adds basic support for hardware implementing the MIPI I3C HCI
specification. This driver is currently limited by the capabilities
of the I3C subsystem, meaning things like scheduled commands,
auto-commands and NCM mode are not yet supported.

This supports version 1.0 of the MIPI I3C HCI spec, as well as the
imminent release of version 1.1. Support for draft version 2.0 of the
spec is also largely included with the caveat that future adjustments
to this code are likely as the spec is still a work in progress.

This is also lightly tested as actual hardware is still very scarce,
even for HCI v1.0. Hence the EXPERIMENTAL tag. Further contributions
to this driver are expected once vendor implementations and new I3C
devices become available.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Boris Brezillon 
Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net