From mboxrd@z Thu Jan 1 00:00:00 1970 From: narmstrong@baylibre.com (Neil Armstrong) Date: Wed, 8 Feb 2017 09:45:37 +0100 Subject: [PATCH] ARM64: dts: meson-gxbb: set reset for ethernet In-Reply-To: References: <259f7102-591b-f251-5844-a864fa39e137@baylibre.com> Message-ID: <49d828c6-a3a7-4695-8aca-e9bb34a9a805@baylibre.com> To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org On 02/07/2017 09:43 PM, Heiner Kallweit wrote: > Am 06.02.2017 um 10:29 schrieb Neil Armstrong: >> On 01/29/2017 03:07 PM, Heiner Kallweit wrote: >>> Add reset control for ethernet. >>> >>> Signed-off-by: Heiner Kallweit >>> --- >>> arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi >>> index 39a774ad..753fddf6 100644 >>> --- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi >>> +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi >>> @@ -113,6 +113,8 @@ >>> <&clkc CLKID_FCLK_DIV2>, >>> <&clkc CLKID_MPLL2>; >>> clock-names = "stmmaceth", "clkin0", "clkin1"; >>> + resets = <&reset RESET_ETHERNET>; >>> + reset-names = "stmmaceth"; >>> }; >>> >>> &aobus { >>> >> >> Hi, >> >> Actually this is a no-op since the Amlogic reset controller only supports "pulse" resets and the >> STMMAC driver only supports "level" resets. If you want to use this reset, you must add the >> corresponding support code in the meson8b glue code to call device_reset(). >> > Thanks for the hint! I did some further tests to check the "nature" of the reset register bits. > Setting a reset bit and immediately reading it back always returns 0. > And the chip spec doesn't mention whether writing a reset bit triggers a reset pulse or > whether it asserts the reset line. > Therefore I'm a little clueless whether it's possible to have "level" resets. It seems that there is some "level" register in the next addresses used by the VPU reset in u-boot, but I did not get the same behaviour as the pulse reset registers. It seems the resets are not mapped the same way. Neil > >> Neil >> >