Some device may need to be put up on CS high logic. The active low logic
is the default as usual, but it is now possible to request the active
high logic.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Adding Kconfig options to set supported modes by the controller
(master, slave or both)
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Instead of using CONFIG_POLL, which is not directly related to SPI and
is a kernel option, let's have SPI_ASYNC instead. When enabled, it will
select POLL automatically.
Fixes#5839
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
tx_bufs/tx_count and rx_bufs/rx_count can be hold in another dedicated
structure, thus reducing the number of parameters to transceive. This
permits to avoid using the stack when calling transceive.
Since we saved parameters, we can expose back the struct device pointer,
to stay consistent with other device driver APIs.
Fixes#5839
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
As the content of this struct will not be modified by drivers, it's
better to pass it as constant. Also, if someday struct device can be
made contant too, this change will make spi ready for registering the
spi_config into ROM directly.
Fixes#5839
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Current buffers might be configured to skip data, thus only len will be
set, buf will be NULL. Buffer should be used if only len is > 0 and
buffer is valid as well.
tx/rx are "on" if len is > 0
tx/rx buf should be touched if only len is > 0 _and_ buf != NULL.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Previous approach allowed only single word update for single
function call. Updating context in ISR was inefficient for
controllers supporting automatic multiple data packets transaction.
Signed-off-by: Michał Kruszewski <michal.kruszewski@nordicsemi.no>
Added function helps setting the longest possible rx and tx buffers for
single SPI transfer. Each of these buffers is a continuous memory
region. It is useful for example when peripheral supports easyDMA.
Signed-off-by: Michał Kruszewski <michal.kruszewski@nordicsemi.no>
The SPI API allows waiters to block until SPI I/O has completed. The
asynchronous subset of the API allows waiters to learn a status value
for the result of the I/O. However, the synchronous API does not allow
this.
Due to this limitation, synchronous API users cannot learn when
interrupt-driven I/O fails, which precludes proper error handling.
Resolve this limitation by adding a sync_status field to struct
spi_context, and using it to return operation results to the waiter.
Since there is only one status field, reduce the maximum number of
supported waiters from UINT_MAX to 1. This is not a problem for
current users, which all wait with the entire context locked.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Void pointer arithmetic is undefined behavior (UB).
It's OK for struct spi_buf to contain a void *, because those values
are only ever stored, read, and compared. However, pointer arithmetic
is done on the tx_buf and rx_buf fields in struct spi_context, so
those need to be u8_t * to avoid UB.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Upcoming memory protection features will be placing some additional
constraints on kernel objects:
- They need to reside in memory owned by the kernel and not the
application
- Certain kernel object validation schemes will require some run-time
initialization of all kernel objects before they can be used.
Per Ben these initializer macros were never intended to be public. It is
not forbidden to use them, but doing so requires care: the memory being
initialized must reside in kernel space, and extra runtime
initialization steps may need to be peformed before they are fully
usable as kernel objects. In particular, kernel subsystems or drivers
whose objects are already in kernel memory may still need to use these
macros if they define kernel objects as members of a larger data
structure.
It is intended that application developers instead use the
K_<object>_DEFINE macros, which will automatically put the object in the
right memory and add them to a section which can be iterated over at
boot to complete initiailization.
There was no K_WORK_DEFINE() macro for creating struct k_work objects,
this is now added.
k_poll_event and k_poll_signal are intended to be instatiated from
application memory and have not been changed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Instead of NULL terminated buffer arrays, let's add a parameter for each
that tells the number of spi_buf in it.
It adds a little bit more complexity in driver's side (spi_context.h)
but not on user side (bufer one has to take care of providing the NULL
pointer at the end of the array, now he requires to give the count).
This will saves a significant amount of bytes in more complex setup than
the current dumb spi driver sample.
Fix and Use size_t everywhere (spi_context.h was using u32_t).
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
If CS is controlled over GPIO, it will be possible to keep the slave up
and running (though no transaction will be going on) using this
configuration bit.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
All is done through the generic spi_context driver's API as it will be
generic to all SPI drivers.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
All SPI drivers have this same way to handle synchronous call, thus
let's generalize it in struct spi_context, with a relevant API and apply
the change into SPI DW driver.
spi_context API will prove to be useful once asynchronous call will be
handled as well, through the same completion functions used now only for
synchronous call. It will be transparent for the driver.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Let's improve common SPI driver context by adding a lock and generic
function to get/release it.
It's statically initialized to save a bit of ROM.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Introducing as well a generic driver helper for CS gpio control and
buffer management.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Tomasz Bursztyka