sama5d27_wlsom1_ek : Maximum QSPI frequency

[Fabio Estevam]

Hi Tudor,

On a sama5d27_wlsom1_ek running 6.12 or today's linux-next the QSPI
fails to probe:

 # dmesg | grep spi
 spi-nor spi0.0: unrecognized JEDEC id bytes: ff ff ff ff ff ff
 # cat /proc/mtd
 dev:    size   erasesize  name
 #

If I revert your commit 417e58ea41ab ("ARM: dts: at91-sama5d27_wlsom1:
Set sst26vf064b SPI NOR flash at its maximum frequency") then the
probe succeeds:

 # dmesg | grep spi
 6 fixed-partitions partitions found on MTD device spi0
 Creating 6 MTD partitions on "spi0":
 # cat /proc/mtd
 dev:    size   erasesize  name
 mtd0: 00040000 00001000 "at91bootstrap"
 mtd1: 000c0000 00001000 "bootloader"
 mtd2: 00040000 00001000 "bootloader env redundant"
 mtd3: 00040000 00001000 "bootloader env"
 mtd4: 00080000 00001000 "device tree"
 mtd5: 00600000 00001000 "kernel"

In U-Boot, the maximum sama5d27_wlsom1_ek SPI clock is 50MHz.

at91-sama5d2_xplained is populated with an N25Q128A QSPI that can be
clocked up to 104MHz. However, its dts limits it to 80MHz.

at91-ama5d29_curiosity is also populated with an SST26VF064B QSPI
and also restrict the maximum SPI clock to 80MHz.

Any suggestions?

Thanks,

Fabio Estevam