hi3516ev300 6.6 LTS: mainline drivers need vendor init for BVT-specific hardware

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Context

Porting hi3516ev300 from vendor Linux 4.9 to mainline 6.6 LTS (and now 7.0-rc6) revealed that mainline drivers for HiSilicon IP exist but miss BVT-specific hardware initialization.

Kernel branches:

• upstream-patches — 7.0-rc6 + 9 BVT patches (current, production)
• hisilicon-hi3516ev200-6.6 — 6.6.132 (archived)

Status: ALL RESOLVED ✅

All drivers ported and verified on real hi3516ev300 hardware with IMX335 sensor.

1. hisi-sfc (SPI NOR flash controller) ✅

Fix: Patched mainline driver in-place (+34 lines):

• Select SPI-NOR flash type in FMC_CFG
• Switch boot→normal mode
• Disable DTR mode in FMC_GLOBAL_CFG
• Remove quad read hwcaps (FMC doesn't set QE bit)

Upstreamable: Yes — small, clean patch to existing driver.

2. mdio-hisi-femac (MDIO bus / Ethernet PHY) ✅

Fix: Wholesale replacement with vendor driver (+345 lines) for internal FEPHY reset/trim/OTP calibration. Required for cold boot — without it, phy_id=0x00000000.

Upstreamable: Not directly. Should be a separate phy-hisi-fephy.c PHY driver for mainline. Carried as out-of-tree patch for now.

3. hisi_femac (Ethernet MAC) ✅

Fix: 1-line compatible string addition.

Upstreamable: Yes — trivial.

4. i2c-hibvt (I2C controller) ✅

Fix: New driver (1144 lines) with Kconfig/Makefile wiring. Added platform_get_irq_optional() for clean probe without IRQ errors.

Upstreamable: Yes — clean new driver, DT bindings documented.

5. Clock drivers ✅

Fix: 4 new CLK_OF_DECLARE drivers + hibvt_reset_init() in reset.c + Kconfig/Makefile wiring for ARCH_HISI_BVT.

Upstreamable: Yes — follows existing HiSilicon clock driver pattern.

6. SPI PL022 ✅

Fix: Moved DTS nodes under AMBA bus (primecell probe), changed PID to 0x00041022 (mainline driver match). Exported spi_controller_class for opensdk compat shim.

Upstreamable: DTS changes yes. spi.c export is out-of-tree only.

7. PWM ✅

Fix: Added DTS node for platform_driver probe on 5.0+.

Upstreamable: Yes — DTS only.

8. Machine descriptor ✅

Fix: 13 SoC machine descriptors with pure DT boot in arch/arm/mach-hibvt/.

Upstreamable: Yes — standard ARM platform support.

9. Boot/earlycon ✅

Fix: CONFIG_CMDLINE_EXTEND with earlycon=pl011,0x12040000 for 6.6.132+/7.0 (PL011 console registers late). DTB chosen/bootargs for U-Boot compat.

Kernel core exports (out-of-tree, NOT for mainline)

Symbol	File	Purpose
cma_get_base, cma_get_size	mm/cma.c	opensdk MMZ allocator
dma_contiguous_default_area, dma_alloc/release_from_contiguous	kernel/dma/contiguous.c	opensdk MMZ allocator
__stack_chk_guard	arch/arm/kernel/process.c	prebuilt vendor .o blobs
spi_controller_class	drivers/spi/spi.c	opensdk sensor_spi compat

Build/test status

Component	QEMU	Real HW	Kernel
SPI NOR flash	✅	✅	6.6, 7.0
Ethernet (cold+warm boot)	✅	✅	6.6, 7.0
I2C (3 buses)	✅	✅	6.6, 7.0
SPI PL022 (2 buses)	✅	✅	6.6, 7.0
PWM	✅	✅	6.6, 7.0
CMA memory allocator	✅	✅	6.6, 7.0
ISP + video pipeline	N/A	✅	6.6, 7.0
Boot (U-Boot→kernel→login)	✅	✅	6.6, 7.0
Majestic streaming	N/A	✅	6.6, 7.0

Upstreaming

Clean patch series on upstream-patches branch, ready for LKML submission:

1. DT bindings — YAML schemas for board, clock, I2C
2. Clock/reset — 4 clock drivers + hibvt_reset_init
3. I2C driver — hibvt-i2c
4. Platform + DTS — mach-hibvt, 6 SoC device trees, femac compat
5. hisi-sfc — FMC init + Kconfig fix
6. MAINTAINERS entry

All patches compile-tested on 6.6.132, 6.18.21, and 7.0-rc6.

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All drivers ported and verified on real hi3516ev300 hardware across Linux 6.6.132 and 7.0-rc6.

Clean patch series ready for LKML submission on upstream-patches branch. Upstreaming tracked separately.