[PATCH v5 0/4] Enable full UFS boot on Rockchip RK3576

[Alexey Charkov]

Rockchip RK3576 can load its bootloader from UFS among other options,
so this series adds the necessary bits and pieces to enable an end-to-end
boot from UFS (boot ROM -> SPL -> U-boot proper -> kernel).

To achieve the above, this series goes through the following:
 - Patch 1 introduces arch-independent code to enable SPL images to use
   UFS devices, including build system tweaks and a function to locate
   a U-boot image at a fixed UFS offset and LUN (SCSI device number)
 - Patch 2 adds an option to build the Rockchip reset driver for SPL
 - Patch 3 adds device-reset functionality to the Rockchip UFS glue code,
   which is required for (at least some) UFS modules to respond to
   controller commands upon initial enumeration
 - Patch 4 ties it all together for Rockchip RK3576

This has been tested on a FriendlyElec NanoPi M5 board with a Biwin
BWU3AKC46C256G UFS module. Note that booting directly from UFS masks the
issue which patch 3 aims to address, because the boot ROM initializes the
UFS module before handing over to U-boot. If, however, one boots SPL from
FSPI1 with the same driver code, the module fails to respond unless patch
3 is applied.

This depends on Jonas' recent series [3] enabling DMA writes to PMU SRAM,
without which the UFS controller will fail to load ATF and end up in an
unrecoverable error state requiring a hard reset.

Note that in my experience none of the RK3576 boards actually boot current
mainline U-boot versions without a single-word SRAM write before jumping
to DDR initialization, as done in Kwiboo's commit at [1]. Therefore, to
test this series I additionally applied commits 6b152999908b..d43031c4045e
from Kwiboo's rk3576 branch [2] (including 6b152999908b), so any testers
might want to:

git cherry-pick 6b152999908b^..d43031c4045e

from there before or after applying this series

[1] https://source.denx.de/u-boot/contributors/kwiboo/u-boot/-/commit/d43031c4045ef8aaf29c467b910207e721dabce0
[2] https://source.denx.de/u-boot/contributors/kwiboo/u-boot/-/commits/rk3576?ref_type=heads
[3] https://lore.kernel.org/all/20260108133234.4001390-1-jonas@kwiboo.se/

Signed-off-by: Alexey Charkov <alchark at gmail.com>
---
Changes in v5:
- Reverse X-mas tree in spl_ufs:spl_ufs_load_image (thanks Quentin)
- Explicit "depends on UFS" from CONFIG_SPL_UFS_SUPPORT (thanks Quentin).
  This also pulls in SCSI to avoid compilation errors.
- Split out the patch enabling the Rockchip reset driver for SPL builds
  (thanks Quentin)
- Reworded the error message when requesting the UFS reset GPIO fails
  (thanks Quentin)
- Added a note in the commit message about reset-gpios being required by
  the DT binding (thanks Quentin)
- Dropped the redundant check of GPIO validity in the reset function
  (thanks Quentin)
- Added a note about GPIO4_D0 being the only GPIO usable for UFS reset
  on RK3576 (thanks Shawn)
- Dropped "imply" symbols from the arch Kconfig, now that both GPIO
  and RESET drivers are explicitly depended on from the UFS driver
  (thanks Quentinq)
- Link to v4: https://lore.kernel.org/r/20260108-rk3576-ufs-v4-0-e8e67649f3f8@gmail.com

Changes in v4:
- Added a dependency in b4 metadata on Jonas' new series enabling DMA
  writes to PMU SRAM (thanks Jonas)
- Dropped the bounce buffer quirk altogether, as it now works as-is
- Link to v3: https://lore.kernel.org/r/20260106-rk3576-ufs-v3-0-bfe259fd6d17@gmail.com

Changes in v3:
- Added a UFSHC quirk to use the SCSI bounce buffer for addresses outside
  SDRAM, and enabled it on Rockchip (thanks Neil and Tom)
- Dropped the open-coded bounce buffer from spl_ufs.c, now unneeded
- Link to v2: https://lore.kernel.org/r/20260105-rk3576-ufs-v2-0-caba979a0d6b@gmail.com

Changes in v2:
- Rename the SPL UFS read helper function more self-descriptively (thanks Neil)
- Add an option to configure the UFS LUN used to look for the U-boot image
  in raw offset mode - or rather the SCSI device number, which most of the
  time coincides with the UFS LUN as long as the UFS device is the only
  SCSI block device the SPL sees (thanks Neil)
- Add an option to use a bounce buffer in RAM while loading U-boot from UFS,
  which helps avoid changes to common spl_fit.c code which in v1 achieved a
  similar result at a performance cost to unrelated platforms (thanks Jonas)
- Link to v1: https://lore.kernel.org/r/20251210-rk3576-ufs-v1-0-a3f9e76eb66e@gmail.com

---
Alexey Charkov (4):
      spl: Make UFS available for SPL builds
      reset: rockchip: make device resets available in SPL
      ufs: rockchip: Add device reset support
      rockchip: spl: Add support for booting from UFS

 MAINTAINERS                                  |  1 +
 arch/arm/dts/rk3576-u-boot.dtsi              | 16 ++++++++-
 arch/arm/include/asm/arch-rockchip/bootrom.h |  1 +
 arch/arm/include/asm/spl.h                   |  1 +
 arch/arm/mach-rockchip/rk3576/rk3576.c       |  1 +
 arch/arm/mach-rockchip/spl-boot-order.c      | 14 ++++++++
 common/spl/Kconfig                           | 30 +++++++++++++++++
 common/spl/Makefile                          |  1 +
 common/spl/spl_ufs.c                         | 49 ++++++++++++++++++++++++++++
 drivers/Makefile                             |  1 +
 drivers/reset/Kconfig                        |  9 +++++
 drivers/reset/Makefile                       |  2 +-
 drivers/scsi/Makefile                        |  3 ++
 drivers/ufs/Kconfig                          |  4 +++
 drivers/ufs/ufs-rockchip.c                   | 22 +++++++++++++
 drivers/ufs/ufs-rockchip.h                   |  1 +
 lib/Makefile                                 |  1 +
 17 files changed, 155 insertions(+), 2 deletions(-)
---
base-commit: 6cdd7597a2fbfc1572c1b0af23d3daf1cefa2de7
change-id: 20251210-rk3576-ufs-ac3bf4e87156
prerequisite-message-id: 20260108133234.4001390-1-jonas at kwiboo.se
prerequisite-patch-id: 3748e3880ac841dc25628911608140ebb4d4382f
prerequisite-patch-id: 671586e63ec9021b624d6cdc3b75aef53ed84972

Best regards,
-- 
Alexey Charkov <alchark at gmail.com>