If CONFIG_SPI_STATS is enabled, the device state for all SPI controller
drivers must contain the SPI stats. This space is allocated by calling
Z_SPI_INIT_FN as part of the device definition; this is done automatically
when using SPI_DEVICE_DT_DEFINE instead of DEVICE_DT_DEFINE. If space for
statistics is not properly allocated but CONFIG_SPI_STATS is enabled, an
unexpected write to memory outside of the stats region may occur on a SPI
transfer. This commit uses SPI_DEVICE_DT_DEFINE or
SPI_DEVICE_DT_INST_DEFINE for all in-tree SPI controller drivers.
Signed-off-by: Dane Wagner <dane.wagner@gmail.com>
Use minimized PIO code for 3-wire operation.
Input and output buffers are conventionally stored in bus byte order.
For 16 and 32 bit transfers, this is effectively big-endian, so
txbuf and rxbuf need to be read as such. Those pointers also need
to be declared uint8_t * instead of void *.
In addition, tx_count and rx_count are based on dts, and refer to
whole transfers (8, 16, or 32 bits), not bytes.
Added rpi_pico.overlay to samples/sensor/magn_polling to demonstrate
32-bit word size, and updated the README.rst to make it independent
of the specific sensor.
Clean up compliance check failures.
Fix typos.
Synchronize 3-wire TX and RX cycles.
Simplify state machine synchronization
Minimize SPI bus delay time in 3-wire mode
Move clock delay to PIO code and remove k_sleep
Signed-off-by: Steve Boylan <stephen.boylan@beechwoods.com>
Add support for half-duplex (3-wire) SPI operation using the Raspberry
Pi Pico PIO. To allow control of the size of the driver, including
half-duplex support is optional, under the control of Kconfig options.
The original PIO source code is also included as a reference.
Corrected 3-wire tx/rx counts.
Enable half-duplex code based on DTS configuration
Replace runtime checks with static BUILD_ASSERT()
Remove too-fussy Kconfig options
Removed PIO source per review request
Signed-off-by: Steve Boylan <stephen.boylan@beechwoods.com>
This change marks each instance of the 'spi_driver_api' as 'static const'.
The rationale is that 'spi_driver_api' is used for declaring internal
module interfaces and is not intended to be modified at runtime.
By using 'static const', we ensure immutability, leading to usage of only
.rodata and a reduction in the .data area.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
Add fundamental feature support for RP2040 PIO SPI peripherals.
This commit implements synchronous transfer with 8-bit MSB
format. Using PIO allows any GPIO pins to be assigned the roles
of CS, CLK, MOSI, and MISO.
Optional features not implemented yet:
- Interrupt based transfer
- DMA transfer
- Slave mode
- Varying word size
- 3-wire SPI support
- LSB-first
Updated in response to review comments.
Further updates from second round of review.
Rename spi_pico_pio.c source to match zephyr/MAINTAINERS.yml
Remove unnecessary initialization code.
Resolve merge conflicts
Signed-off-by: Steve Boylan <stephen.boylan@beechwoods.com>
