Commit Graph

9 Commits

Author SHA1 Message Date
Jeff LaBundy 381932cf61 Input: iqs7222 - remove support for RF filter
The vendor has marked the RF filter enable control as reserved in
the datasheet; remove it from the driver.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-7-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:58 -07:00
Jeff LaBundy 8635c68891 Input: iqs7222 - handle reset during ATI
If the device suffers a spurious reset during ATI, there is no point
in enduring any further retries. Instead, simply return successfully
from the polling loop.

In this case, the interrupt handler will intervene and recognize the
device has been reset. It then proceeds to initialize the device and
trigger ATI once more.

As part of this change, swap the order of status field evaluation to
match that of the interrupt handler, and correct a nearby off-by-one
error that causes an error message to suggest the final attempt will
be retried.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-6-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:57 -07:00
Jeff LaBundy 2e70ef525b Input: iqs7222 - acknowledge reset before writing registers
If the device suffers a spurious reset while reacting to a previous
spurious reset, the second reset interrupt is preempted because the
ACK_RESET bit is written last.

To solve this problem, write the ACK_RESET bit prior to writing any
other registers. This ensures that any registers written before the
second spurious reset will be rewritten.

Last but not least, the order in which the ACK_RESET bit is written
relative to the second filter beta register is important for select
variants of silicon. Enforce the correct order so as to not clobber
the system status register.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-5-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:55 -07:00
Jeff LaBundy 1e4189d8af Input: iqs7222 - protect volatile registers
Select variants of silicon silently mirror part of the event mask
register to the system setup register (0xD0), and vice versa. For
the following sequence:

1. Read registers 0xD0 onward and store their contents.
2. Modify the contents, including event mask fields.
3. Write registers 0xD0 onward with the modified contents.
4. Write register 0xD0 on its own again later, using the contents
   from step 1 to populate any reserved fields.

...the event mask register (e.g. address 0xDA) has been corrupted
by writing register 0xD0 with contents that were made stale after
step 3.

To solve this problem, read register 0xD0 once more between steps
3 and 4. When register 0xD0 is written during step 4, the portion
which is mirrored to the event mask register already matches what
was written in step 3.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-4-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:54 -07:00
Jeff LaBundy 95215d3d19 Input: iqs7222 - fortify slider event reporting
The release cycle of any key mapped to a slider gesture relies upon
trailing interrupts generated by other unmasked sources, the timing
and presence of which are inconsistent.

To solve this problem, explicitly report a release cycle to emulate
a full keystroke. Also, unmask touch interrupts if the slider press
event is defined; this ensures the device reports a final interrupt
with coordinate = 0xFFFF once the finger is lifted.

As a result of how the logic has been refactored, the press/release
event can now be mapped to a GPIO. This is more convenient than the
previous solution, which required each channel within the slider to
specify the same GPIO.

As part of this change, use the device's resolution rather than its
number of interrupt status registers to more safely determine if it
is capable of reporting gestures.

Last but not least, make the code a bit simpler by eliminating some
unnecessarily complex conditional statements and a macro that could
be derived using information that is already available.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-3-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:52 -07:00
Jeff LaBundy 56a0c54c4c Input: iqs7222 - correct slider event disable logic
If a positive swipe/flick gesture is defined but the corresponding
negative gesture is not, the former is inadvertently disabled. Fix
this by gently refactoring the logic responsible for disabling all
gestures by default.

As part of this change, make the code a bit simpler by eliminating
a superfluous conditional check. If a slider event does not define
an enable control, the second term of the bitwise AND operation is
simply 0xFFFF.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220626072412.475211-2-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-06-27 15:25:50 -07:00
Jeff LaBundy 66ab05c756 Input: iqs7222 - avoid dereferencing a NULL pointer
Select callers of iqs7222_parse_props() do not expect a child node
to be derived and returned via pointer. As such, these callers set
**child_node to NULL. However, this pointer is dereferenced in all
cases.

To solve this problem, dereference the pointer only for cases that
expect a child node in the first place. In these cases, the caller
provides a valid pointer.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220417214132.497487-1-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-04-17 16:08:58 -07:00
Dan Carpenter eba697b3c3 Input: iqs7222 - propagate some error codes correctly
If fwnode_property_count_u32() returns a negative error code then,
because of type promotion, the "count > ARRAY_SIZE(pins)" condition
will be true.  The negative "count" is type promoted to a high unsigned
size_t value.

That means the "else if (count < 0)" condition will always be false and
we don't print that error message or propagate the error code from
fwnode_property_count_u32() as intended.

Fix this by re-ordering the checks so that we check for negative first.

Fixes: e505edaedc ("Input: add support for Azoteq IQS7222A/B/C")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220412153954.GA15406@kili
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-04-17 13:14:29 -07:00
Jeff LaBundy e505edaedc Input: add support for Azoteq IQS7222A/B/C
This patch adds support for the Azoteq IQS7222A/B/C family of
capacitive touch controllers.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20220403221659.865997-3-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-04-08 19:28:12 -07:00