"program" mode on this controller can trigger up to 56 bits of data
shifting. During the operation, data in PRGDATA[0-5] will be
shifted out from MOSI, and data from MISO will be continuously filling
SHREG[0-9].
Currently this mode is used to implement transfer_one_message for 6-byte
full-duplex transfer, but it can execute a transfer for up-to 7 bytes
as long as the last byte is read only.
transfer_one_message is expected to perform full-duplex transfer,
instead of transfer with specific format. mtk_nor_spi_mem_prg is
added here to use this extra byte.
Newer version of this controller can trigger longer data shifting with
shift bytes more than PRGDATA_MAX + SHREG_MAX. This patch is implemented
with that in mind and it checks against both SHREG_MAX and PRG_CNT_MAX
for future support of new controllers.
Patch 3/3 is a fix for:
commit a59b2c7c56bf7 ("spi: spi-mtk-nor: support standard spi properties")
which breaks supports_op logic. But it can't be separated as it depends
on patch 2/3. Fortuantely the broken commit isn't in stable yet.
Chuanhong Guo (3):
spi: spi-mtk-nor: make use of full capability of prg mode
spi: spi-mtk-nor: add helper for checking prg mode ops
spi: spi-mtk-nor: fix op checks in supports_op
drivers/spi/spi-mtk-nor.c | 179 +++++++++++++++++++++++++++++++++-----
1 file changed, 158 insertions(+), 21 deletions(-)
--
2.26.2
