Hi Amelie, On Mon, 2018-12-10 at 12:37 +0000, Amelie DELAUNAY wrote: > Hi Cezary, > > On 12/9/18 2:53 PM, cezary.gapin...@gmail.com wrote: > > > > From: Cezary Gapinski <cezary.gapin...@gmail.com> > > > > This series of patches adds support for first generation of SPI > > interface > > for STM32F4 family. > > > First of all, thanks for adding STM32F4 SPI support.
Thanks for your answer and hints for correct approach to this driver. > > > > This version of driver is mostly different to STM32H7 one. Based on > > linux > > kernel I2C drivers for STM32 where drivers were splited into > > STM32F4 and > > STM32F7 family the same approach seems to be sufficient for SPI > > STM32 > > drivers. Therefore STM32H7 driver was moved to spi-stm32h7.c file > > and > > register and functions were renamed to be more specific to STM32H7. > > > You're right, STM32F4 SPI is slightly different from STM32H7 one: > register map/bits offsets are different and STM32H7 has an RX and TX > FIFO. > But if you have a look on STM32F7 SPI [1], you'll see that STM32F7 > SPI > is based on STM32F4 SPI with new features (data frames & FIFOs) also > available on STM32H7 SPI. > > That's why STM32H7 SPI driver was called spi-stm32. The goal was to > use > compatible & match data to differentiate each STM32Fx specificities. > > You can have a look on how it is managed in drivers/rtc/rtc-stm32.c > (the > same driver covers 2 HW version of STM32 RTC), or in > drivers/iio/dac/stm32-dac-core.c and stm32-dac.c (the same driver > also > covers 2 HW version of STM32 DAC). > As your spi-stm32f4.c file is highly based on the existing spi- > stm32.c > file, I think that common code could be factored and specificities > could > be handled with compatible and match data. I have seen these drivers before. I have been trying to do this for my previous approach and it is still on my second branch. There was not too much common parts and I have stuck with complex compatible data configurations. I thought that was too verbose, therefore I resigned for it and have gone into idea with two totally different files. I think I need to get down again to idea you proposed. It seems to be more difficult approach and it is gonna take a while before I send second version of these patches. Regards, Cezary > Regards, > Amelie > [1] > https://www.st.com/content/ccc/resource/technical/document/reference_ > manual/c5/cf/ef/52/c0/f1/4b/fa/DM00124865.pdf/files/DM00124865.pdf/jc > r:content/translations/en.DM00124865.pdf > > > > > For current version master mode with full-duplex and 8/16 bit data > > frame > > format are supported. There is no TX and RX FIFOs like in STM32H7. > > DMA capabilility is supported for messages longer than arbitrary > > number > > of bytes (that is set already to 16 bytes) when TX and RX channels > > are > > set at the same time. > > > > Cezary Gapinski (5): > > spi: stm32: rename STM32 SPI registers and functions to STM32H7 > > spi: stm32: rename spi-stm32 to spi-stm32h7 > > spi: stm32: add driver for STM32F4 controller > > ARM: dts: stm32: add SPI support on STM32F429 SoC > > spi: stm32: add description about STM32F4 bindings > > > > .../devicetree/bindings/spi/spi-stm32.txt | 9 +- > > arch/arm/boot/dts/stm32f429.dtsi | 60 + > > drivers/spi/Kconfig | 18 +- > > drivers/spi/Makefile | 3 +- > > drivers/spi/spi-stm32.c | 1322 ----- > > -------------- > > drivers/spi/spi-stm32f4.c | 1002 > > +++++++++++++++ > > drivers/spi/spi-stm32h7.c | 1340 > > ++++++++++++++++++++ > > 7 files changed, 2424 insertions(+), 1330 deletions(-) > > delete mode 100644 drivers/spi/spi-stm32.c > > create mode 100644 drivers/spi/spi-stm32f4.c > > create mode 100644 drivers/spi/spi-stm32h7.c
