[RFC 0/5] rockchip_sfc: add support for Rockchip SFC

[Chris Morgan]

From: Chris Morgan <macromorgan at hotmail.com>

Requesting comments for a proposed patchset for adding the Rockchip
serial flash controller to u-boot. The goal of these patches is to
enable it for the Odroid Go Advance so that it may eventually boot
exclusively from the SFC on mainline U-boot (I have tested this and
it works).

The specific help I need with this patch is:

1) I don't know the best way to upstream the XTX25F128B flash chip.
This chip uses a continuation code for the manufacturer ID, however I
cannot seem to find any way to actually read the continuation code.
There is a risk of this driver, used as-is, to collide with another
chip which has the same manufacturer ID with a different continuation
code.

2) The Rockchip SFC driver itself (as it is mostly as-is from the BSP
U-Boot sources) supports SPI NAND and chips of varying sizes, but my
implementation only permits me to test with a single 128Mb flash chip.
The driver itself does some checking on the bitlen in the routine
rockchip_sfc_xfer() which is what is called for the dm_spi_ops.xfer.
I'm not sure if there is a better way to do this. Additionally, I have
to bit-shift the address written to the SFC as I suspect the value is
meant to be left justified, but I never tested it further.

Additionally, it might be worth mentioning but I noticed the Rockchip
BROM will only boot the TPL/SPL off of the SFC if I write it to address
0x10000. This is not documented and different than the address looked
at for SD card booting (512 * 64 = 0x8000 for SD Card booting). Also,
like the SD card driver I can confirm that if DMA is enabled at the SPL
stage A-TF seems to fail silently, then when Linux loads it hangs.
There is an ifdef to force FIFO mode only in the SPL stage.

Tested: Read (works)
	Write (works if you write to an erased sector)
	Erase (works)
	SPL Read (works if you edit the u-boot,spl-boot-order)

Chris Morgan (5):
  spi: rockchip_sfc: add support for Rockchip SFC
  rockchip: px30: Add support for using SFC
  rockchip: px30: add the serial flash controller
  mtd: spi-nor-ids: Add XTX XT25F128B
  rockchip: px30: add support for SFC for Odroid Go Advance

 arch/arm/dts/px30.dtsi                     |  38 ++
 arch/arm/dts/rk3326-odroid-go2-u-boot.dtsi |  10 +-
 arch/arm/dts/rk3326-odroid-go2.dts         |  22 +
 arch/arm/mach-rockchip/px30/px30.c         |  64 ++
 drivers/mtd/spi/Kconfig                    |   6 +
 drivers/mtd/spi/spi-nor-ids.c              |   8 +
 drivers/spi/Kconfig                        |   8 +
 drivers/spi/Makefile                       |   1 +
 drivers/spi/rockchip_sfc.c                 | 652 +++++++++++++++++++++
 9 files changed, 926 insertions(+), 1 deletion(-)
 create mode 100644 drivers/spi/rockchip_sfc.c

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2.25.1