NUCLEO-L4R5ZI - SDMMC - SDIO - no communication on CMD line

Hi,

I'm trying to get working Nuttx 10.3.0 on NUCLEO-L4R5ZI.
I'm stuck on SDIO interface. (Clock setup works, serial communication works).
I've based my work on the stm32l4r9ai-disco, as it seams for me the closest relative.

**The issue is there is no signals changing on CMD, D0-D3**
CLK is working - is about 93kHz

Here is the log:

```
ABCDF
stm32l4_rng_initialize: Initializing RNG
Mounting procfs to /proc
stm32l4_mco_initialize: STM32L4_RCC_CFGR:0x4200000F
stm32l4_mco_initialize: STM32L4_RCC_AHB2ENR:4401FF
stm32l4_sdio_initialize: Initializing SDIO slot 0
stm32l4_sdio_initialize: STM32L4_RCC_CR:0xF000563
stm32_setclkcr: CLKCR: 00000110 PWR: 00000000
stm32_reset: CLCKR: 00000110 POWER: 00000003
stm32l4_sdio_initialize: Bind SDIO to the MMC/SD driver, minor=0
stm32_registercallback: Register 0x802cf8d(0x100032d8)
stm32_callbackenable: eventset: 02
stm32_callback: Callback 0x802cf8d(0x100032d8) cbevents: 02 cdstatus: 00
stm32l4_sdio_initialize: Successfully bound SDIO to the MMC/SD driver
sdio_mediachange: cdstatus OLD: 00 NEW: 01
stm32_callback: Callback 0x802cf8d(0x100032d8) cbevents: 02 cdstatus: 01
stm32_callback: Callback to 0x802cf8d(0x100032d8)
stm32_setclkcr: CLKCR: 00000110 PWR: 00000003
stm32_sendcmd: cmd: 00000000 arg: 00000000 regval: 00000400
stm32_waitresponse: ERROR: Timeout cmd: 00000000 events: 00000080 STA: 00000000
mmcsd_sendcmdpoll: ERROR: Wait for response to cmd: 00000000 failed: -116
stm32_sendcmd: cmd: 00000208 arg: 000001aa regval: 00000448
stm32_waitresponse: ERROR: Timeout cmd: 00000208 events: 00000045 STA: 00000000
mmcsd_sendcmdpoll: ERROR: Wait for response to cmd: 00000208 failed: -116
stm32_sendcmd: cmd: 00000077 arg: 00000000 regval: 00000477

stm32_waitresponse: ERROR: Timeout cmd: 00000077 events: 00000045 STA: 00000000
mmcsd_sendcmdpoll: ERROR: Wait for response to cmd: 00000077 failed: -116
stm32_recvshortcrc: ERROR: RESCMD=00 CMD=00000077
mmcsd_cardidentify: ERROR: mmcsd_recv_r1(CMD55) failed: -22
mmcsd_cardidentify: ERROR: Failed to identify card
mmcsd_probe: ERROR: Failed to initialize card: -5
romfs_open: ERROR: Failed to find directory directory entry for 'init.d/rc.sysinit': -2
nsh: sysinit: fopen failed: 2

NuttShell (NSH) NuttX-10.3.0
nsh>
```

As I understand STM32L4R5ZI doesn't have SDMMC DMA - I've compiled without DMA.

What I've checked:
- Hardware seams to be OK - did an example with platformio and arduino framework, and SD card works properly.
- Did a setup without NCD GPIO - to simplify things.
- CPU clock seams to be OK. Checked by the MCO output.
- CLK of SDIO interface is working (about 93kHz).

Things I don't know:
- how to check if SDIO have proper clock.
- debug simple communication by SDIO.

Any constructive thoughts will be appreciated.

All the best,
Jakub