niansa-misc/linux
1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
Code Issues Projects Releases Packages Wiki Activity

spi: atmel-quadspi: Add support for sama7g5 QSPI

Browse source 
The sama7g5 QSPI controller uses dedicated clocks for the
QSPI Controller Interface and the QSPI Controller Core, and
requires synchronization before accessing registers or bit
fields.

QSPI_SR.SYNCBSY must be zero before accessing any of the bits:
QSPI_CR.QSPIEN, QSPI_CR.QSPIDIS, QSPI_CR.SRFRSH, QSPI_CR.SWRST,
QSPI_CR.UPDCFG, QSPI_CR.STTFR, QSPI_CR.RTOUT, QSPI_CR.LASTXFER.

Also, the QSPI controller core configuration can be updated by
writing the QSPI_CR.UPDCFG bit to ‘1’. This is needed by the
following registers: QSPI_MR, QSPI_SCR, QSPI_IAR, QSPI_WICR,
QSPI_IFR, QSPI_RICR, QSPI_SMR, QSPI_SKR,QSPI_REFRESH, QSPI_WRACNT
QSPI_PCALCFG.

The Octal SPI supports frequencies up to 200 MHZ DDR. The need
for output impedance calibration arises. To avoid the degradation
of the signal quality, a PAD calibration cell is used to adjust
the output impedance to the driven I/Os.

The transmission flow requires different sequences for setting
the configuration and for the actual transfer, than what is in
the sama5d2 and sam9x60 versions of the IP. Different interrupts
are handled. aq->ops->set_cfg() and aq->ops->transfer() are
introduced to help differentiating the flows.

Tested single and octal SPI mode with mx66lm1g45g.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211214133404.121739-1-tudor.ambarus@microchip.com
[varshini.rajendran@microchip.com: Fixed conflicts and ported to 6.1.4]
Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
[ csokas.bence: Forward-port to master and address feedback ]
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
Link: https://patch.msgid.link/20241128174316.3209354-3-csokas.bence@prolan.hu
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Tudor Ambarus 2024-11-28 18:43:15 +01:00 • committed by Mark Brown
parent c0a0203cf5
commit 5af42209a4
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 798 additions and 18 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

816
drivers/spi/atmel-quadspi.c
View file

File diff suppressed because it is too large Load diff