CH32X035 port

[rhgndf]

Adds support for both CH32X035 and CH32X033.

I'm also evaluating this MCU due to it being low cost and have USB.

CH32X035 has both TX and RX CTRL bits in the same byte, so there are changes to how these registers are written in the dcd.
If the current approach isn't satisfactory, there are some alternatives:

• Make EP_TX_CTRL_WRITE a function instead of a #define
• 'Inline' the #define: EP_TX_CTRL(ep) = (EP_TX_CTRL(ep) & ~MASK) | BITS

EP4 special handling:
This is a bit confusing, and Codex/Claude has been very helpful to get that part working. In short: no DMA and no auto-toggle, so some special handling has to be built in.

EP3 no special large buffer
The code has some existing handling for large EP3 buffer, but as far as I can tell that functionality doesn't exist in ch32x035, should I #if that out for this port?

Related: adafruit/Adafruit_TinyUSB_Arduino#486

[HiFiPhile]

CH32X035 has both TX and RX CTRL bits in the same byte, so there are changes to how these registers are written in the dcd.

Seems like v103, do you have board to test with ?

[github-actions]

MemBrowse Memory Report

Top 10 targets by memory change (%) (out of 2467 targets) View Project Dashboard →

target	.text	.rodata	.data	.bss	total	% diff
ch32v103c_bluepill/dfu_runtime	8,668 → 8,796 (+128)	—	—	—	9,036 → 9,164 (+128)	+1.4%
ch32v103c_bluepill/hid_generic_inout	9,648 → 9,780 (+132)	—	—	—	10,016 → 10,148 (+132)	+1.3%
ch32v103c_bluepill/hid_multiple_interface	10,484 → 10,616 (+132)	—	—	—	10,852 → 10,984 (+132)	+1.2%
ch32v103c_bluepill/hid_boot_interface	10,504 → 10,632 (+128)	—	—	—	10,872 → 11,000 (+128)	+1.2%
ch32v103c_bluepill/hid_composite	10,732 → 10,856 (+124)	—	—	—	11,100 → 11,224 (+124)	+1.1%
ch32v103c_bluepill/midi_test	10,832 → 10,956 (+124)	—	—	—	11,200 → 11,324 (+124)	+1.1%
ch32v103c_bluepill/cdc_dual_ports	11,848 → 11,976 (+128)	—	—	—	12,216 → 12,344 (+128)	+1.0%
ch32v103c_bluepill/printer_to_cdc	12,016 → 12,144 (+128)	—	—	—	12,376 → 12,504 (+128)	+1.0%
ch32v103c_bluepill/audio_test	12,124 → 12,252 (+128)	—	—	—	12,508 → 12,636 (+128)	+1.0%
ch32v103c_bluepill/dfu	12,912 → 13,044 (+132)	—	—	—	13,376 → 13,508 (+132)	+1.0%

[rhgndf]

Seems like v103, do you have board to test with ?

I don't have the board unfortunately. I may take a look if I need a 5V capable mcu though (although py32f07x is also 5V capable but has additional DACs unlike v103)

[rhgndf]

MemBrowse Memory Report

Got claude to analyze the discrepency, here's the output verbatim:

  Why update_in got smaller

  The refactor folded the endpoint-buffer selection. Old code was a three-way branch:

  if (ep == 0)      memcpy(data.buffer[ep][TUSB_DIR_OUT], ...);  // buffer[ep][0]
  else if (ep == 3) memcpy(data.ep3_buffer.in, ...);
  else              memcpy(data.buffer[ep][TUSB_DIR_IN], ...);   // buffer[ep][1]

  New code is two-way, with the ep0 case absorbed into the inlined helper:

  if (ep == 3) memcpy(data.ep3_buffer.in, ...);
  else         memcpy(ep_buffer(ep, TUSB_DIR_IN), ...);   // buffer[ep][ep==0 ? 0 : 1]

  So the dedicated ep == 0 test-and-branch disappears; the address is now computed in a straight line as data.buffer[ep][ep==0 ? 0 : 1]. The disassembly confirms it: master has an extra li a5,3 / bne / beqz a4 cluster plus a second address computation
  that the branch version doesn't, and with RVC 2-byte instructions the savings land on exactly 8 bytes.

[hathach]

thank you, after #3515, this should be relatively easy. I have the CH32X035 board but run out of wlinke debugger (attached to hil rig). will get this mcu ported when it got on my desk

[rhgndf]

I also simplified the comments, since I found a hallucination involving X035.
Other changes:

• refactored the ep buffer code for 58x and x035
• removed ep3 in the non ep4 shared buffer case, saves 128 bytes of memory

[rhgndf]

According to the manuals, it says only EP4 needs manual toggling, maybe manual toggle should only be enabled for EP4?

[github-actions]

Hardware-in-the-loop (HIL) Test Report

hfp.json

✅ 46 passed · ❌ 10 failed · ⚪ 0 skipped · blank not run

Board	usbtest	cdc_msc_throughput	audio_test_freertos	cdc_dual_ports	cdc_msc	cdc_msc_freertos	dfu	dfu_runtime	hid_boot_interface	hid_generic_inout	midi_test	msc_dual_lun	mtp	printer_to_cdc	duration
stm32l412nucleo	✅ 30/30	✅ C 637/386k M 852/815k	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	214s
stm32f746disco	✅ 30/30	✅ C 13.6/9.7M M 15.4/30.5M	✅	❌	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅	109s
stm32f746disco-DMA	✅ 30/30	❌	✅	✅	❌	✅	✅	✅	✅	✅	❌	✅	✅	✅	162s
lpcxpresso43s67	❌ 0/30	✅ C 13.7/12.3M M 33.7/37.8M	✅	❌	✅	❌	✅	✅	✅	✅	✅	❌	✅	❌	255s

tinyusb-esp.json

✅ 12 passed · ❌ 12 failed · ⚪ 0 skipped · blank not run

Board	usbtest	msc_file_explorer_freertos	audio_test_freertos	cdc_msc_freertos	device_info	hid_composite_freertos	duration
espressif_p4_function_ev	❌ 0/1	409 KB/s	✅	✅	✅	✅	59s
espressif_p4_function_ev-DMA	❌ 0/30	409 KB/s	❌	❌	✅	✅	59s
espressif_s3_devkitm	❌ 0/1	❌	❌	❌	✅	✅	77s
espressif_s3_devkitm-DMA	❌ 0/30	❌	❌	❌	✅	✅	166s

tinyusb.json

✅ 21 passed · ❌ 326 failed · ⚪ 17 skipped · blank not run

Board	usbtest	cdc_msc_throughput	msc_file_explorer	msc_file_explorer_freertos	audio_test_freertos	cdc_dual_ports	cdc_msc	cdc_msc_freertos	cdc_msc_hid	device_info	dfu	dfu_runtime	hid_boot_interface	hid_generic_inout	host_info_to_device_cdc	midi_test	msc_dual_lun	mtp	printer_to_cdc	duration
frdm_k64f			⚪	⚪					✅	✅										9s
ek_tm4c123gxl	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	143s
metro_m4_express	❌ 0/30	❌				❌	❌	❌			❌	❌	❌	❌	❌	❌	❌	❌	❌	136s
raspberry_pi_pico_w			1106 KB/s	1016 KB/s					❌	❌										46s
feather_nrf52840_express	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	143s
raspberry_pi_pico	❌ 0/30	❌	❌	62 KB/s	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	❌	219s
raspberry_pi_pico2			1110 KB/s	1022 KB/s					✅	✅										15s
max32666fthr	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	138s
adafruit_fruit_jam	❌ 0/30	❌	62 KB/s	62 KB/s	❌	❌	❌	❌	✅	✅	❌	❌	❌	❌	❌	❌	❌	❌	❌	184s
lpcxpresso11u37	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	144s
stm32f072disco	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	141s
ra4m1_ek	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	117s
stm32f407disco	❌ 0/30	❌			❌	⚪	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	129s
stm32f723disco	❌ 0/30	❌	16384 KB/s	4096 KB/s	❌	❌	❌	❌	✅	✅	❌	❌	❌	❌		❌	❌	❌	❌	156s
stm32f723disco-DMA	❌ 0/30	❌	16912 KB/s	4096 KB/s	❌	❌	❌	❌	✅	✅	❌	❌	❌	❌		❌	❌	❌	❌	158s
stm32h743nucleo	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	134s
stm32h743nucleo-DMA	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	134s
nrf5340dk	❌ 0/30	❌				❌	❌				❌	❌	❌	❌		❌	❌	❌	❌	120s
stm32g0b1nucleo	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	124s
stm32l476disco	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	141s
stm32u083nucleo	❌ 0/30	❌			❌	❌	❌	❌			❌	❌	❌	❌		❌	❌	❌	❌	129s
nanoch32v203-fsdev	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	103s
nanoch32v203-usbfs	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	103s
ch32v103r_r1_1v0	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	140s
ch32v307v_r1_1v0-usbhs	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	126s
ch32v307v_r1_1v0-usbfs	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	125s
ch582m_evt	❌ 0/30	❌			⚪	❌	❌	⚪			❌	❌	❌	❌		❌	❌	❌	❌	130s

[HiFiPhile]

Hi, I see many comment changes, please verify are they intended.

[rhgndf]

Yes they are intended, since there was a hallucination about the x035 and I was concerned there are more, so I got my agent to shrink all of them so they can be verified easily

[HiFiPhile]

Many comments are from Ha Thach like

// CH58X EP registers split into a low block (EP0-4) and a high block (EP5-7). Walk from each
// block's first slot by the 4-byte slot stride (pointer arithmetic off slot 0, so the unused

They shoudn't be removed.

[github-actions]

Size Difference Report

Because TinyUSB code size varies by port and configuration, the metrics below represent the averaged totals across all example builds.

Note: If there is no change, only one value is shown.

Changes >1% in size

file	.text	.bss	size	% diff
dcd_ch32_usbfs.c	1659 ➙ 1688 (+29)	2444 ➙ 2316 (-128)	4103 ➙ 4004 (-99)	-2.4%
TOTAL	1659 ➙ 1688 (+29)	2444 ➙ 2316 (-128)	4103 ➙ 4004 (-99)	-2.4%

Changes <1% in size

No entries.

No changes

file	.text	.rodata	.data	.bss	size	% diff
audio_device.c	2890	0	1259	1623	4508	+0.0%
cdc_device.c	1236	16	1092	728	1963	+0.0%
cdc_host.c	6399	487	15	971	7594	+0.0%
dcd_ch32_usbhs.c	1892	0	0	481	2373	+0.0%
dcd_ci_fs.c	1924	0	0	1290	3214	+0.0%
dcd_ci_hs.c	1756	0	0	1344	2534	+0.0%
dcd_da146xx.c	3067	0	0	144	3211	+0.0%
dcd_dwc2.c	4223	19	0	265	4506	+0.0%
dcd_eptri.c	2273	0	0	259	2532	+0.0%
dcd_ft9xx.c	3284	0	0	172	3456	+0.0%
dcd_khci.c	1952	0	0	1290	3242	+0.0%
dcd_lpc17_40.c	1481	0	0	648	1805	+0.0%
dcd_lpc_ip3511.c	1463	0	0	264	1683	+0.0%
dcd_mm32f327x_otg.c	1477	0	0	1290	2767	+0.0%
dcd_msp430x5xx.c	1801	0	0	176	1977	+0.0%
dcd_musb.c	2595	0	0	179	2773	+0.0%
dcd_nrf5x.c	2939	0	0	292	3231	+0.0%
dcd_nuc120.c	1096	0	0	78	1174	+0.0%
dcd_nuc121.c	1170	0	0	101	1270	+0.0%
dcd_nuc505.c	0	0	1533	157	1690	+0.0%
dcd_rp2040.c	840	0	764	653	2257	+0.0%
dcd_rusb2.c	2918	0	0	156	3074	+0.0%
dcd_samd.c	1036	0	0	266	1302	+0.0%
dcd_samg.c	1322	0	0	72	1394	+0.0%
dcd_stm32_fsdev.c	2543	0	0	291	2834	+0.0%
dfu_device.c	776	28	712	136	912	+0.0%
dfu_rt_device.c	157	0	134	0	157	+0.0%
dwc2_common.c	603	22	0	0	615	+0.0%
ecm_rndis_device.c	1059	0	1	2759	3818	+0.0%
ehci.c	2763	0	0	6274	7783	+0.0%
fsdev_common.c	180	0	0	0	180	+0.0%
hcd_ch32_usbfs.c	2491	0	0	502	2993	+0.0%
hcd_ci_hs.c	181	0	0	0	181	+0.0%
hcd_dwc2.c	5071	25	1	545	5642	+0.0%
hcd_khci.c	2443	0	0	454	2897	+0.0%
hcd_musb.c	3071	0	0	157	3228	+0.0%
hcd_pio_usb.c	262	0	240	0	502	+0.0%
hcd_rp2040.c	1996	17	4	321	2338	+0.0%
hcd_rusb2.c	2923	0	0	245	3168	+0.0%
hcd_samd.c	2220	0	0	324	2544	+0.0%
hcd_stm32_fsdev.c	3248	0	1	420	3670	+0.0%
hid_device.c	1124	44	997	119	1242	+0.0%
hid_host.c	1246	0	0	1270	2516	+0.0%
hub.c	1384	8	8	30	1419	+0.0%
midi2_device.c	2628	52	1175	561	3211	+0.0%
midi2_host.c	1802	0	0	5921	7723	+0.0%
midi_device.c	1149	0	1007	619	1765	+0.0%
midi_host.c	1339	7	7	3538	4880	+0.0%
msc_device.c	2527	108	2293	804	3331	+0.0%
msc_host.c	1633	0	0	395	2028	+0.0%
mtp_device.c	1713	22	743	589	2309	+0.0%
ncm_device.c	1761	28	819	4393	6167	+0.0%
ohci.c	1925	0	0	2503	4428	+0.0%
printer_device.c	828	0	706	560	1387	+0.0%
rp2040_usb.c	386	35	619	11	1051	+0.0%
rusb2_common.c	160	0	16	0	176	+0.0%
tusb.c	455	0	387	3	457	+0.0%
tusb_fifo.c	855	0	486	0	850	+0.0%
typec_stm32.c	1230	8	2	19	1255	+0.0%
usbc.c	500	2	20	166	688	+0.0%
usbd.c	3530	57	90	355	3948	+0.0%
usbh.c	4967	57	82	1165	6238	+0.0%
usbtmc_device.c	2194	24	68	313	2539	+0.0%
vendor_device.c	639	0	534	559	1197	+0.0%
video_device.c	4433	5	1235	480	4905	+0.0%
TOTAL	123429	1071	17050	49700	174702	+0.0%

[HiFiPhile]

@claude review

[claude]

Claude encountered an error after 6m 4s —— View job

---

Review in progress

• Gather context (PR diff, comments, CLAUDE.md)
• Understand request (review the PR, focus on comment-shrinking concern raised by @HiFiPhile)
• Review dcd_ch32_usbfs.c changes (EP4/EP3 handling, register write approach)
• Check whether attributed comments (Ha Thach's) were inappropriately removed/shrunk
• Review BSP/board files for CH32X035
• Post final review

[Copilot]

Pull request overview

Adds a new WCH CH32X035 (and intended CH32X033) TinyUSB port by wiring the MCU into TinyUSB’s MCU selection/dependency system, introducing a new BSP family + board, and extending the shared WCH USBFS DCD to handle CH32X035’s endpoint register/buffer quirks (notably EP4 and combined TX/RX control behavior).

Changes:

• Add CH32X035 as a supported MCU option and dependency (OpenWCH SDK) and document it in README/docs.
• Extend dcd_ch32_usbfs.c + WCH register glue for CH32X035-specific register layout/buffer handling.
• Introduce a new BSP family (hw/bsp/ch32x035) with build/linker/OpenOCD support and a WeAct board definition.

Reviewed changes

Copilot reviewed 32 out of 32 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tools/get_deps.py	Adds the OpenWCH ch32x035 SDK dependency.
src/tusb_option.h	Introduces OPT_MCU_CH32X035 (MCU selection constant).
src/portable/wch/dcd_ch32_usbfs.c	Updates WCH USBFS DCD for CH32X035 register/buffer and EP0/EP4 handling.
src/portable/wch/ch32_usbfs_reg.h	Adds CH32X035 register header integration and WCH USBFS feature flags.
src/common/tusb_mcu.h	Enables WCH USBFS USBIP for CH32X035.
README.rst	Documents CH32X033/CH32X035 under supported CPUs.
hw/bsp/ch32x035/wch-riscv.cfg	Adds OpenOCD config for WCH RISC-V + WLinkE.
hw/bsp/ch32x035/system_ch32x035.h	Adds system header for CH32X035 BSP.
hw/bsp/ch32x035/system_ch32x035.c	Adds system clock implementation for CH32X035 BSP.
hw/bsp/ch32x035/linker/ch32x035.ld	Adds linker script for CH32X035 memory layout.
hw/bsp/ch32x035/family.mk	Adds Make-based family build configuration for CH32X035.
hw/bsp/ch32x035/family.cmake	Adds CMake-based family build configuration for CH32X035.
hw/bsp/ch32x035/family.c	Adds board API + interrupt handlers for CH32X035 BSP.
hw/bsp/ch32x035/ch32x035_it.h	Adds interrupt handler declarations for CH32X035 BSP.
hw/bsp/ch32x035/ch32x035_conf.h	Adds WCH peripheral library config header for CH32X035 BSP.
hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.mk	Adds board-specific Make overrides (clock, memory sizes).
hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.h	Adds WeAct board pin/LED definitions.
hw/bsp/ch32x035/boards/weact_ch32x035_core_board/board.cmake	Adds WeAct board-specific CMake definitions.
examples/device/uac2_speaker_fb/src/audio_debug.py	Updates PID used by the audio debug helper.
examples/device/uac2_speaker_fb/skip.txt	Adds CH32X035 (and other WCH MCUs) to skip list for this example.
examples/device/uac2_headset/skip.txt	Adds CH32X035 (and other WCH MCUs) to skip list for this example.
examples/device/net_lwip_webserver/skip.txt	Adds CH32X035 to skip list.
examples/device/midi_test_freertos/skip.txt	Adds CH32X035 to skip list.
examples/device/hid_composite_freertos/skip.txt	Adds CH32X035 to skip list.
examples/device/cdc_msc_freertos/skip.txt	Adds CH32X035 to skip list.
examples/device/audio_test/skip.txt	Adds CH32X035 to skip list.
examples/device/audio_test_multi_rate/skip.txt	Adds CH32X035 to skip list.
examples/device/audio_test_freertos/skip.txt	Adds CH32X035 to skip list.
examples/device/audio_4_channel_mic/skip.txt	Adds CH32X035 to skip list.
examples/device/audio_4_channel_mic_freertos/skip.txt	Adds CH32X035 to skip list.
docs/reference/dependencies.rst	Adds the hw/mcu/wch/ch32x035 dependency entry.
docs/reference/boards.rst	Adds WeAct CH32X035 board entry to the reference list.

---

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[HiFiPhile]

Thank you, please check if CH32X035 works correctly with latest changes.

[rhgndf]

I went ahead and added the change to restrict manual toggling to EP4.
The firmware works correctly on my ch32x035

[HiFiPhile]

Are you sure only EP4 needs manual toggle on CH32X035 ? From the manual there is no auto toggle bit at all.

Also ch582 needs manual toggle:

  // CH58x's hardware AUTO_TOG does not stay in sync (notably across clear-stall and multi-packet
  // bulk transfers), causing data-toggle mismatch and bus resets. Drive the toggle manually in
  // the ISR instead. CH32V103/V20x/V307 keep AUTO_TOG (this macro is undefined for them).

[rhgndf]

Yes, I'm quite sure since it is indeed in the manual under TOG_AUTO/AUTO_TOG

CH32X035

Page 223 for EP1, this exists for all EPs not 4

Page 226 for EP4

CH58x

Page 128

EP4 doesn't have auto toggle for both chips.

  // notably across clear-stall

This issue was fixed too: https://github.com/rhgndf/tinyusb/blob/e80049bfb305ce2164310a510af78814234ede1b/src/portable/wch/dcd_ch32_usbfs.c#L600
Someone with a CH58x would need to check whether that fixes it

For the multi-packet bulk transfers, it works with cdc_msc_throughput with the results:

tog	speed
manual tog	581kB/s
auto tog	631kB/s