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| author | Marek Vasut <marek.vasut+renesas@mailbox.org> | 2026-05-05 06:42:45 +0300 |
|---|---|---|
| committer | Geert Uytterhoeven <geert+renesas@glider.be> | 2026-05-31 11:41:55 +0300 |
| commit | ae49d5842944d4b5af80f5ec44f29c1909dac913 (patch) | |
| tree | 1eba08601cc077d2f12779a13b60ce431786ff8a | |
| parent | 67c2dd78f43f129f6c92ea4aca00035139ecea1e (diff) | |
| download | linux-ae49d5842944d4b5af80f5ec44f29c1909dac913.tar.xz | |
arm64: dts: renesas: v3msk: Specify ethernet PHY reset timings
The KSZ9031RNX reference manual [1] DS00002117K page 62 FIGURE 7-5:
POWER-UP/POWER-DOWN/RESET TIMING Note 2 states, that after the
de-assertion of reset, wait a minimum of 100 us before starting
programming on the MIIM (MDC/MDIO) interface. Set DT property
reset-deassert-us to three times that, 300 us, to provide ample
time between reset deassertion and MDIO access.
The KSZ9031RNX reference manual [1] DS00002117K page 62 TABLE 7-4:
POWER-UP/POWER-DOWN/RESET TIMING PARAMETERS row tSR Stable supply
voltages to de-assertion of reset is at minimum 10 ms. Set DT
property reset-assert-us to 10ms because the KSZ9031RNX RM does
not explicitly spell out how long the reset has to be asserted,
but this at least covers the worst case scenario.
[1] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/DataSheets/KSZ9031RNX-Data-Sheet-DS00002117.pdf
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260505034325.167797-5-marek.vasut+renesas@mailbox.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
| -rw-r--r-- | arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts b/arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts index 343f9610f892..10c9a2e9ed18 100644 --- a/arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts +++ b/arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts @@ -119,6 +119,8 @@ reg = <0>; interrupts-extended = <&gpio1 17 IRQ_TYPE_LEVEL_LOW>; reset-gpios = <&gpio1 16 GPIO_ACTIVE_LOW>; + reset-assert-us = <10000>; + reset-deassert-us = <300>; }; }; |