diff options
| author | Tudor Ambarus <tudor.ambarus@linaro.org> | 2023-03-28 10:15:17 +0000 |
|---|---|---|
| committer | Nicolas Ferre <nicolas.ferre@microchip.com> | 2023-03-30 21:20:59 +0200 |
| commit | 2c0a1faa4da5324a2ad6621b69fb7db26134b994 (patch) | |
| tree | d28b9262a0ad77caca36796d4f65e1673c1067d9 /arch/arm/boot | |
| parent | 46a8a137d8f60929923a609cdddde06e7007b0df (diff) | |
ARM: dts: at91: sam9x60ek: Set sst26vf064b SPI NOR flash at its maximum frequency
sam9x60ek populates an sst26vf064b SPI NOR flash. Its maximum operating
frequency for 2.7-3.6V is 104 MHz. As the flash is operated at 3.3V,
increase its maximum supported frequency to 104MHz. The increasing of the
spi-max-frequency value requires the setting of the
"CE# Not Active Hold Time", thus set the spi-cs-setup-ns to a value of 7.
The sst26vf064b datasheet specifies just a minimum value for the
"CE# Not Active Hold Time" and it advertises it to 5 ns. There's no
maximum time specified. I determined experimentally that 5 ns for the
spi-cs-setup-ns is not enough when the flash is operated close to its
maximum frequency and tests showed that 7 ns is just fine, so set the
spi-cs-setup-ns dt property to 7.
With the increase of frequency the reads are now faster with ~33%.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230328101517.1595738-5-tudor.ambarus@linaro.org
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Diffstat (limited to 'arch/arm/boot')
| -rw-r--r-- | arch/arm/boot/dts/at91-sam9x60ek.dts | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/boot/dts/at91-sam9x60ek.dts b/arch/arm/boot/dts/at91-sam9x60ek.dts index 180e4b1aa2f6..5cd593028aff 100644 --- a/arch/arm/boot/dts/at91-sam9x60ek.dts +++ b/arch/arm/boot/dts/at91-sam9x60ek.dts @@ -578,7 +578,8 @@ #size-cells = <1>; compatible = "jedec,spi-nor"; reg = <0>; - spi-max-frequency = <80000000>; + spi-max-frequency = <104000000>; + spi-cs-setup-ns = <7>; spi-tx-bus-width = <4>; spi-rx-bus-width = <4>; m25p,fast-read; |