MAX3421 host adapter on STM32H7, concept question

[rondlh]

I'm trying to get a MAX3421 host adapter to work with a STM32H723. My goal is to read a file from a FAT formatted USB key that is directly connected to the MAX3421 (no hub). The STM32H723 USB device is not available on my board.
I'm trying my luck with example host\cdc_msc_hid and host\msc_file_explorer but cannot make any progress.

Probably I don't fully understand what needs to be done.

I did the following:

1. In tusb_config.h I set "#define CFG_TUH_MAX3421 1" and "#define CFG_TUH_ENABLED 1", and raised the debug level to 3.
2. In board.h I defined the pins/ports (MISO, MOSI, SCK, Chip Select, interrupt)
3. In family.c I added the required SPI2 clock initialization/selection and SPI2 pins configuration (all taken from CubeIDE).
4. In family.c I implemented the required APIs:
   void tuh_max3421_int_api(uint8_t rhport, bool enabled); --> Setup interrupt line and interrupt handler which forwards the interrupt to tuh_int_handler(0, true); Interrupt on falling edge.
   void tuh_max3421_spi_cs_api(uint8_t rhport, bool active); --> Set the CS pin as required (active on low)
   bool tuh_max3421_spi_xfer_api(uint8_t rhport, const uint8_t * tx_buf, uint8_t* rx_buf, size_t xfer_bytes); --> Handle the SPI transfer depending on the provided buffers.

I can see that the MAX3421 code in src\portable\analog\max3421\hcd_max3421 is not included in the code.
Anyway, when I run the bin-file I get some serial feedback, but the MAX3421 does not seem to be doing anything.

Do I need to define "MAX3421_HOST = 1" in the makefile?

Any feedback would be greatly appreciated.

[rondlh]

The board I'm talking about is a 3D printer board, the Mellow Fly D8 Pro:
https://mellow.klipper.cn/en/docs/ProductDoc/MainBoard/fly-d/fly-d8-h723/?persistLocale=true
I created a custom board config for it, and even had to adjust the family.c. The board doesn't have Vbus sensing or Vbus control. There is a 4 port hub on the board, but unfortunately the upstream side of the hub is pointed outwards to the USB type-c port.
I want to make a bootloader to update the board firmware, which currently can only be done by DFU-mode. The board does not have a sd-card slot.
Does anybody know how to get the Max3421 running on a STM32H7? I will share the setup here so it can be useful for other STM32 users.

[hathach]

yeah, if you use the example makefile, you need to have make BOARD=yourboard MAX3421_HOST=1 all to include hcd_max3421.c in the compiling sources, it will also add define for CFG_TUH_MAX3421=1 as well https://github.com/hathach/tinyusb/blob/master/examples/build_system/make/make.mk#L117

[rondlh]

Thanks, that's very helpful.

Here my progress:
When I compile an example (host\msc_file_explorer) with "make BOARD=yourboard MAX3421_HOST=1 all", then I also need to add:
$(ST_HAL_DRIVER)/Src/${ST_PREFIX}_hal_spi.c in the board family.mk
I got a lot of compiler errors for function that are defined multiple times, like "hcd_configure" and "hcd_init" (in hcd_dwc2.c).
I solved this by changing the function names in hcd_dwc2.c.
Now I can compile the example and things are starting to work. I can see the MAX3421 code is being executed and commands are being send to the MAX3421, here some debug info I captured:
Time: 3 SPI: Write REG:17 VAL:0x10 READ:0x00 (Set full duplex mode)
Time: 5 SPI: Read REG:18 VAL:0x00 READ:0x01 (Read version number)
Time: 6 SPI: Write REG:15 VAL:0x20 READ:0x00 (Chip reset)
Time: 8 SPI: Write REG:15 VAL:0x00 READ:0x00 (End chip reset)
Time:10 SPI: Read REG:13 VAL:0x00 READ:0x00 (Check oscillator)
Time:12 SPI: Read REG:13 VAL:0x00 READ:0x01 (Check oscillator --> OK)
Time:14 SPI: Write REG:27 VAL:0xC1 READ:0x00 (Host mode with pullups)
Time:16 SPI: Write REG:29 VAL:0x03 READ:0x00 (Host control bus reset, frame reset)
Time:18 SPI: Write REG:25 VAL:0xFF READ:0x00 (HIRQ, clear all interrupt flags)
Time:20 SPI: Write REG:26 VAL:0xE4 READ:0x00 (HIEN, enable several interrupts)
Time:22 SPI: Write REG:16 VAL:0x01 READ:0x00 (Enable interrupts)

It seems to be working :D
It reports:
General USB Flash Disk rev 0.00
Disk Size: 3853 MB

I will cleanup the code a bit and post it here soon.

[hathach]

great to hear that you got it working. Right dwc2 also has host mode. Please make an PR, you can add hal_spi.c to makefile + max3421 API implementation in family.c for h7. I will help to update PR to switch off native host driver when MAX3421 is in use

[rondlh]

I'm not sure what to do, because the board I use (Mellow Fly D8 Pro V1.1 3D printer motherboard) does not fit into the STM32H7xx family, it doesn't have Vbus control and doesn't use the USB ID pin, it only connects the USB D+ and D- pins, and there is a hub on the board with the upstream port at the external type-C connector. This means that the STM32H723 can only be used as a device. I tried the dual port CDC example, which works fine on the board.

Here the board configuration I made for this board:
stm32h723flyd8pro.zip

Probably the most interesting part is the MAX3421 API implementation for the STM32H7 platform.
family.zip

Compile it with: make BOARD=stm32h723flyd8pro MAX3421_HOST=1 all

Some conclusions:

1. The MAX3421 works in SPI mode 0 (CPOL = 0, CPHA = 0) and mode 3 (CPOL = 1, CPHA = 1) according to the spec. I only tried mode 0.

2. The MAX3421 code does not support workarounds for the bugs in chip revision 1 and 2, it only supports revision 3. But how to know which revision the board is? Perhaps the examples could report the chip revision and provide a warning if revision 1 or 2 are detected. My project does not work on the revision 1 boards (I don't have any revision 2 boards).

3. The STM32H723 supports handling the Chip Select in hardware, but I could not get that to work (I tried the CS delay capabilities). When debugging I can see that the SPI communication is working and in the beginning the SPI reads and writes are identical (for about 15 commands). In the end I used software handling of Chip Select which works fine.

4. Currently when compiling this there will be many errors that are defined multiple times. Solve it by renaming the functions in hcd_dwc2.c. I added a "2" to the end of the function name. This will probably be fixed in the future.

5. The maximum SPI speed I could get working was 24 MHz, 25Mhz didn't work (spec says 26MHz is the limit).

6. I could achieve a transfer rate of about 300kb/s. That doesn't sound like much, but is enough for my purpose.

7. To be able to mount larger (>4GB I guess) flash drives I had to enable FF_LBA64 in ffconfig.h (FatFS file).

8. I found the Tinyusb build environment (make) doesn't detect all file changes, so cleaning the project is required if you are making changes outside of the main application files (e.g. ffconfig.h).

9. CubeIDE and CubeMX are your friends to find clock and device configuration settings. I used CubeIDE extensively to get the SPI parameters and clock configuration.

10. I setup the project in CubeIDE, which works quite well together with TinyUSB

11. I transferred my project to CubeIDE for further development, and will post the result on my github soon. I made a USB bootloader to flash the firmware of a MKS Monster8 V1/V2 3D printer motherboard. This works so fast that at first I thought nothing had happened and the program just exited, but actually the firmware was flashed. For the Mellow Fly D8 I also made a USB bootloader, but I had to resort to using a MAX3421. I will also publish this project.

UPDATE: 2 more items

12. After a cold start the first SPI command for the MAX might fail because of some noise on the lines during startup. Then the device will not work. I solved this by doing a dummy read at startup.

13. Some USB drives need to skip some frames after a cold start, otherwise they cannot be mounted. I solved this with this function:

  void MAX3421_wait_frames(uint32_t frames, uint32_t timeout)
  {
  	tuh_max3421_reg_write(0, rHIRQ, bmFRAMEIRQ, false);
  	uint32_t start = HAL_GetTick();
  	while (frames && HAL_GetTick() - start < timeout)
  	{
   		if (tuh_max3421_reg_read(0, rHIRQ, false) & bmFRAMEIRQ) {
		  tuh_max3421_reg_write(0, rHIRQ, bmFRAMEIRQ, false);
		  frames--;
   		}
  	}
  }

I use 50 frames and a 1500ms timeout. If there is no USB drive present then the timeout will run out.

Any question are always welcome.