xtensa/esp32s3: cam driver fixes and GC0308 DVP enhancements

[JianyuWang0623]

Note: Please adhere to Contributing Guidelines.

Summary

Fix several bugs in the ESP32-S3 CAM driver and add features needed for 8-bit DVP camera sensors (e.g. GC0308) with LCD preview.

1. video/gc0308: report V4L2_PIX_FMT_RGB565X for 8-bit DVP output (f5145188a3b): GC0308 register 0x24 bits[3:0] = 0x06 selects RGB565 output. On an 8-bit DVP bus the high byte is clocked out first, so pixel data arrives in memory in big-endian order. Report V4L2_PIX_FMT_RGB565X so userspace can detect this and byte-swap for LE displays.

2. video/gc0308: implement V4L2 horizontal flip control (ff1bbe94508): Implement get_supported_value, get_value, set_value callbacks for IMGSENSOR_ID_HFLIP_VIDEO/STILL. Hardware mirror via register 0x14 (CISCTL_MODE1) bit[0] with zero CPU cost.

3. xtensa/esp32s3: fix esp32s3_cam uninit/stop_capture bugs (7904d712d3f):

   • stop_capture: reset DMA channel, CAM module and AFIFO under spinlock to fully quiesce hardware. Clear pending VSYNC interrupt to prevent stale ISR firing.
   • uninit: reset CAM/AFIFO before releasing DMA to prevent in-flight transfers after channel detach. Use esp_teardown_irq with correct peripheral ID (ESP32S3_PERIPH_LCD_CAM) instead of irq_detach which corrupts the shared IRQ mapping table. Mask interrupts and clear pending flags under spinlock before detaching handler. Preserve XCLK output so the sensor remains accessible via I2C.
   • set_buf/uninit: track driver-allocated vs user-provided frame buffers with fb_allocated flag to prevent double-free in USERPTR mode.

4. xtensa/esp32s3: cam driver support MMAP buffer allocation (13c7cc8a743): Implement imgdata_ops alloc/free callbacks using kmm_memalign with GDMA-derived alignment, so the V4L2 framework can use V4L2_MEMORY_MMAP. Introduce ESP32S3_CAM_EXT_MEMBLK / ESP32S3_CAM_DMA_ALIGN macros so the block size enum and byte alignment stay in sync.

5. boards/lckfb-szpi-esp32s3: camera config use landscape LCD (627e20c0377): Remove CONFIG_LCD_PORTRAIT so ST7789 defaults to landscape (320×240), matching GC0308 QVGA output and physical screen mounting.

Companion apps-side PR:

Impact

• Fixes potential crash/corruption in CAM driver uninit and stop paths (IRQ mapping table corruption, double-free, stale ISR).
• Adds MMAP support — no breaking change, USERPTR still works.
• GC0308 format change: userspace that previously assumed RGB565 must now handle the RGB565X fallback (addressed in companion apps PR).
• Board defconfig change only affects lckfb-szpi-esp32s3:camera.
• No impact on build process, documentation, or security.

Testing

Host: Ubuntu 22.04 x86_64, xtensa-esp32s3-elf-gcc

Target: ESP32-S3 (lckfb-szpi-esp32s3, ESP32-S3-WROOM-1-N16R8, PSRAM 8MB OCT) with GC0308 DVP camera and ST7789 LCD

Build and flash:

$ cd nuttx
$ make -j$(nproc) flash ESPTOOL_PORT=/dev/ttyUSB0
...
Generated: nuttx.bin
...
Hard resetting via RTS pin...

Runtime test — continuous preview:

nsh> camera 0
nximage_listener: Connected
nximage_initialize: Screen resolution (320,240)
Start video this mode is eternal. (Non stop, non save files.)

Runtime test — mirrored preview:

nsh> camera 0 -m
nximage_listener: Connected
nximage_initialize: Screen resolution (320,240)
Start video this mode is eternal. (Non stop, non save files.)

Verified:

• LCD preview displays correct colors (RGB565X byte-swap path active)
• Hardware mirror (-m) works correctly
• MMAP buffers allocated by driver with GDMA alignment (3 video buffers in RING mode)
• Repeated start/stop cycles — no crash, no resource leak
• checkpatch.sh -g apache/master..HEAD passes all checks