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

[eren-terzioglu]

Not needed for this PR but let me add it for information. After the latest Espressif's common layer update, it is possible to use Espressif common layer drivers for camera and lcd interfaces. For more information please check these files:

S3 cam_ll.h
S3 cam_hal.c
S3 lcd_ll.h