Convert the I2C subsystem to drop using the 'master_'-prefixed callbacks
in favor of the simplified ones. Fix alignment of '=' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Some I2C ATRs can have other I2C ATRs as children. The I2C messages of
the child ATRs need to be forwarded as-is if the parent I2C ATR can
only do static mapping.
In the case of GMSL, the deserializer I2C ATR actually doesn't have I2C
address remapping hardware capabilities, but it is able to select which
GMSL link to talk to, allowing it to change the address of the
serializer.
The child ATRs need to have their alias pools defined in such a way to
prevent overlapping addresses between them, but there's no way around
this without orchestration between multiple ATR instances.
To allow for this use-case, add a flag that allows unmapped addresses
to be passed through, since they are already remapped by the child ATRs.
There's no case where an address that has not been remapped by the child
ATR will hit the parent ATR.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Some I2C ATRs do not support dynamic remapping, only static mapping
of direct children.
Mappings will only be added or removed as a result of devices being
added or removed from a child bus.
The ATR pool will have to be big enough to accommodate all devices
expected to be added to the child buses.
Add a new flag that prevents old mappings to be replaced or new mappings
to be created in the alias finding code paths. That mens adding a flags
parameter to i2c_atr_new() and an i2c_atr_flags enum.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
It is possible for aliases to be exhausted while we are still attaching
children.
Allow replacing mapping on attach by calling
i2c_atr_replace_mapping_by_addr() if i2c_atr_create_mapping_by_addr()
fails.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
This is the same logic as in i2c_atr_create_mapping_by_addr().
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
It is useless to create a new mapping just to detach it immediately.
Use the newly added i2c_atr_find_mapping_by_addr() function to avoid it,
and exit without logging an error if not found.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The i2c_atr_get_mapping_by_addr() function handles three separate
usecases: finding an existing mapping, creating a new mapping, or
replacing an existing mapping if a new mapping cannot be created
because there aren't enough aliases available.
Split up the function into three different functions handling its
individual usecases to prepare for better usage of each one.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
A find operation implies that a null result is not an error.
Use get naming to clarify things and to prepare for splitting up the
logic inside this function.
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
When we have an ATR, and another ATR as a subdevice of the first ATR,
we get lockdep warnings for the i2c_atr.lock and
i2c_atr_chan.orig_addrs_lock. This is because lockdep uses a static key
for the locks, and doesn't see the locks of the separate ATR instances
as separate.
Fix this by generating a dynamic lock key per lock instance.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
When the list_for_each_entry_reverse() exits without hitting a break
then the list cursor points to invalid memory. So this check for
if (c2a->fixed) is checking bogus memory. Fix it by using a "found"
variable to track if we found what we were looking for or not.
The list head (i2c_atr_chan.alias_pairs) is not a full entry, it's just
a struct list_head. When the for loop runs to completion, c2a doesn't
point to a struct i2c_atr_alias_pair, so you can't access c2a->fixed.
Fixes: c3f5524188 ("i2c: Support dynamic address translation")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The i2c-atr module keeps a list of associations between I2C client aliases
and I2C addresses. This represents the address translation table which is
programmed into an ATR channel at any given time. This list is only updated
when a new client is bound to the channel.
However in some cases, an ATR channel can have more downstream clients than
available aliases. One example of this is an SFP module that is bound to an
FPC202 port. The FPC202 port can only access up to two logical I2C
addresses. However, the SFP module may expose up to three logical I2C
addresses: its EEPROM on 7-bit addresses 0x50 and 0x51, and a PHY
transceiver on address 0x56.
In cases like these, it is necessary to reconfigure the channel's
translation table on the fly, so that all three I2C addresses can be
accessed when needed.
As there are currently no known ATR's which do not support dynamic address
translation, this feature can be enabled by default without breaking
existing use cases.
Modify the i2c-atr module to provide on-the-fly address translation. This
is achieved by modifying an ATR channel's translation table whenever an I2C
transaction with unmapped clients is requested.
Add a mutex to protect alias_list. This prevents
i2c_atr_dynamic_attach/detach_addr from racing with the bus notifier
handler to modify alias_list.
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Some I2C address translators (ATRs) assign each of their remote peripheral
aliases to a specific channel. To properly handle these devices, add
support for having separate alias pools for each ATR channel.
This is achieved by allowing callers of i2c_atr_add_adapter to pass an
optional alias list. If present, this list will be used to populate the
channel's alias pool. Otherwise, the common alias pool will be used.
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The "alias_list" field of struct i2c_atr_chan describes translation table
entries programmed in the ATR channel. This terminology will become more
confusing when per-channel alias pool support is introduced, as struct
i2c_atr_chan will gain a new field called "alias_pool", which will describe
aliases which are available to the ATR channel.
Rename the "alias_list" field to "alias_pairs" to clearly distinguish it
from the future "alias_pool" field.
No functional change is intended.
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Each I2C address translator (ATR) has a pool of client aliases which can be
used as translation targets. Some ATRs have a single alias pool shared by
all downstream channels, while others have a separate alias pool for each
channel. Currently, this alias pool is represented by the "aliases",
"num_aliases", and "use_mask" fields of struct i2c_atr.
In preparation for adding per-channel alias pool support, move the
"aliases", "num_aliases", "use_mask" and associated lock to a new struct
called "struct alias_pool".
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The I2C Address Translator (ATR) module defines mappings from i2c_client
structs to aliases. However, only the physical address of each i2c_client
struct is actually relevant to the workings of the ATR module. Moreover,
some drivers require address translation functionality but do not allocate
i2c_client structs, accessing the adapter directly instead. The SFP
subsystem is an example of this.
Replace the "i2c_client" field of the i2c_atr_alias_pair struct with a u16
"addr" field. Rewrite helper functions and callbacks as needed.
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
The fwnode.h is not supposed to be used by the drivers as it
has the definitions for the core parts for different device
property provider implementations. Drop it.
Note, that fwnode API for drivers is provided in property.h
which is included here.
Fixes: a076a860ac ("media: i2c: add I2C Address Translator (ATR) support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
[wsa: reworded subject]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
i2c-atr catches the BUS_NOTIFY_DEL_DEVICE event on the bus and removes
the translation by calling i2c_atr_detach_client().
However, BUS_NOTIFY_DEL_DEVICE happens when the device is about to be
removed from this bus, i.e. before removal, and thus before calling
.remove() on the driver. If the driver happens to do any i2c
transactions in its remove(), they will fail.
Fix this by catching BUS_NOTIFY_REMOVED_DEVICE instead, thus removing
the translation only after the device is actually removed.
Fixes: a076a860ac ("media: i2c: add I2C Address Translator (ATR) support")
Cc: stable@vger.kernel.org
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Tested-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
As found with Coccinelle[1], add __counted_by for struct i2c_atr.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
An ATR is a device that looks similar to an i2c-mux: it has an I2C
slave "upstream" port and N master "downstream" ports, and forwards
transactions from upstream to the appropriate downstream port. But it
is different in that the forwarded transaction has a different slave
address. The address used on the upstream bus is called the "alias"
and is (potentially) different from the physical slave address of the
downstream chip.
Add a helper file (just like i2c-mux.c for a mux or switch) to allow
implementing ATR features in a device driver. The helper takes care of
adapter creation/destruction and translates addresses at each transaction.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
