When the header file is located in the same directory as the source
file it is better to use a relative quote-include, e.g.
than a system include like
Avoiding the use of system includes in these cases is beneficial
because;
* The source code will be easier to build because there will be fewer
system include paths.
* It is easier for a user to determine where a quote-include header
file is located than where a system include is located.
* You are less likely to encounter aliasing issues if the list of
system include paths is minimized.
Authors:
Anas Nashif
Sebastian Bøe
Signed-off-by: Sebastian Boe <sebastian.boe@nordicsemi.no>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The current prescaler calculation incorrectly fails to configure the
desired frequency when it is possible to match it exactly. Fix this.
Without this patch, if the user requests frequency N Hz, and there is
a SPI prescaler that can match this frequency exactly, the actual
frequency chosen by spi_stm32_configure() will be N/2 Hz.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
If CS (Chip Select, known also as Slave Select...) is managed externaly
of the stm32_ll SPI controller, just config NSS line management
accordingly.
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>
The transmit and receive procedure used in the STM32 SPI driver is not
correct.
On STM32F4, this is causing OVR errors (per the logged error mask) and
transmission of undesired 0x00 bytes (verified with a logic analyzer).
The root cause is that the receive register is not read (via DR, when
RXNE is set) each time the transmit register is written (also via DR,
when TXE is set). This clearly causes OVR errors when there is no
FIFO, as the receive register needs to be read each time a frame is
transceived, or the IP block has no way of knowing that the
overwritten data were not important.
Adapt the I/O procedure so that every DR write is matched by a DR
read, blocking until the relevant flags are set if necessary.
This behavior is suboptimal for targets such as STM32L4, where there
is a SPI FIFO. However, SPI I/O is broken on those targets, and this
patch fixes them as well. Further optimizations for targets with FIFOs
is left to future work.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
With some other issues in polled mode now resolved, add error handling
and report a valid error status when releasing the context.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Byte access is always naturally aligned; there's no need to use
UNALIGNED_GET or UNALIGNED_PUT. Those would only be needed when
supporting 16-bit data frames.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
The current implementation unconditionally enables the SPI (sets
SPI_CR1_SPE) in transceive(), but disables it only in master mode.
The peripheral should only be enabled while the user has specifically
requested I/O. Fix this by always disabling the peripheral when I/O is
complete.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Polled and IRQ-driven SPI I/O share code for cleanup and completion,
which can now be factored into its own routine.
This keeps a single point of truth for common paths, which will allow
a subsequent bug fix to happen in one place, and help avoid future
regressions.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
In polled mode, the STM32 SPI driver is signaling completion when
there are no waiters:
- the only spi_context_wait_for_completion() caller in this driver is
in the IRQ-driven portion of transceive() itself, which isn't
compiled in polled mode.
- the "asynchronous completion + polled I/O" combination is not
supported by the driver, so there are no other threads polling on
this I/O we need to signal completion to.
What should be happening instead of signaling completion is releasing
the chip select pin, which polled I/O currently doesn't do.
Fix these issues.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
The LL_SPI_NSS_* macros used in spi_stm32_configure() when
hardware-based NSS management is requested are incorrect; fix them.
In master mode, this seems like a copy/paste error. The slave mode
case is likely due to following incorrect documentation in the ST LL
headers.
Note that in my testing on STM32F4, NSS appears to be open drain when
managed by hardware, making that configuration harder to test (and
probably less useful).
Details for the curious:
The ST LL headers (for example stm32f4xx_ll_spi.h) claim
LL_SPI_NSS_HARD_INPUT is to be used only in master mode, and
LL_SPI_NSS_HARD_OUTPUT is to be used in slave mode.
The opposite is true: when NSS is not handled by software, the SPI
peripheral is responsible for driving NSS as an output, and the
slave peripheral is responsible for reading it as an input.
This is an error in the LL header files; the reference manuals and
the other LL code make this clear.
- The ST reference manuals specify that LL_SPI_HARD_OUTPUT (which
corresponds to SSM unset, SSOE set) is a master-only
configuration. For example, STM32 RM0368 says:
"NSS output enabled (SSM = 0, SSOE = 1)
This configuration is used only when the device operates in
master mode."
- LL_SPI_HARD_INPUT (SSM unset, SSOE unset) is either a master or
a slave configuration; in the slave case (which is what we're
interested in here), it corresponds to the "usual" NSS
input. RM0368, again:
"NSS output disabled (SSM = 0, SSOE = 0)
This configuration allows multimaster capability for devices
operating in master mode. For devices set as slave, the NSS
pin acts as a classical NSS input: the slave is selected when
NSS is low and deselected when NSS high."
The LL_SPI_StructInit() implementations similarly combine
LL_SPI_MODE_SLAVE with LL_SPI_NSS_HARD_INPUT.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Now that struct spi_context supports passing errors from
interrupt-driven I/O handlers to waiting threads, we can enable error
interrupts and propagate errors to spi_transceive() callers.
To make it easier for users to debug SPI-related issues, log any error
bits set in SR when failures occur.
A subsequent patch will add error checking to polled mode as well, but
other cleanups and fixes will go in first to make this easier.
Note that this breaks the spi_loopback test on some targets, but it's
not a regression, as it wasn't working properly anyway. Subsequent
patches the bugs that this error checking has exposed.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
It is incorrect to call spi_context_release() on an STM32
spi_stm32_data object's ctx field before data->ctx->config is first
set in spi_stm32_configure(). This is because spi_context_release()
reads ctx->config->operation. In particular, during spi_stm32_init(),
calling spi_context_release() reads the uninitialized memory in
data->ctx->config->operation.
Call spi_context_unlock_unconditionally() instead to properly increase
the semaphore count.
Without this patch, the first call to spi_transceive() can block
forever depending on the value of the uninitialized memory holding
data->ctx->config->operation.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
Add a SPI master and slave driver for the L4, F4 and F3 STM32
SoCs families.
Change-Id: I1faf5c97f992c91eba852fd126e7d3b83158993d
Origin: Original
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Tested-by: Lee Jones <lee.jones@linaro.org>
