| Message ID | 20190413163423.15149-1-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Meson8b: add support for the RTC on EC-100 and Odroid-C1 | expand |
Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes: > This adds support for the RTC on the Meson8b EC-100 and Odroid-C1 > boards. Example kernel log snippet while booting my EC-100: > [ 5.713750] meson-rtc c8100740.rtc: setting system clock to 2019-04-13T16:21:48 UTC (1555172508) > > I am only 99% sure about the naming of the clock in patch 2 and 3. > The public S805 datasheet from Hardkernel shows (on page 24 for example) > that clk81 can use "XTAL/32khz" as clock input. That "XTAL/32khz" clock > is described as a mux between 24MHz (our main XTAL) and 32kHz ("that > other XTAL"). > I believe that this other 32kHz XTAL is NOT the RTC32K crystal because: > - schematics of the EC-100 and Odroid-C1 clearly show that the SoC input > for the RTC32K clock is labeled RTC32K_XI / RTC32K_XO > - GPIOAO_6 has a CLK_32KIN function (shows in EC-100 and Odroid-C1 > schematics as well as the public S805 datasheet) > - Always On domain PWR_CNTL0[11:10] (public S805 datasheet page 19) > describes it as "Alternate 32khz input clock select from GPIO pad" > > Thus I believe that the naming of the RTC32K clock is correct, but I > wanted to point out that I'm only 99% (instead of 100%) sure. > Jianxin, please let me know if you disagree with my findings. 99% confidence is higher than we normally have, so that's fine by me. :) And, we can fix if we get any updated info from Jianxin. Thanks for the detailed description. Queuing for v5.2, Kevin
This adds support for the RTC on the Meson8b EC-100 and Odroid-C1 boards. Example kernel log snippet while booting my EC-100: [ 5.713750] meson-rtc c8100740.rtc: setting system clock to 2019-04-13T16:21:48 UTC (1555172508) I am only 99% sure about the naming of the clock in patch 2 and 3. The public S805 datasheet from Hardkernel shows (on page 24 for example) that clk81 can use "XTAL/32khz" as clock input. That "XTAL/32khz" clock is described as a mux between 24MHz (our main XTAL) and 32kHz ("that other XTAL"). I believe that this other 32kHz XTAL is NOT the RTC32K crystal because: - schematics of the EC-100 and Odroid-C1 clearly show that the SoC input for the RTC32K clock is labeled RTC32K_XI / RTC32K_XO - GPIOAO_6 has a CLK_32KIN function (shows in EC-100 and Odroid-C1 schematics as well as the public S805 datasheet) - Always On domain PWR_CNTL0[11:10] (public S805 datasheet page 19) describes it as "Alternate 32khz input clock select from GPIO pad" Thus I believe that the naming of the RTC32K clock is correct, but I wanted to point out that I'm only 99% (instead of 100%) sure. Jianxin, please let me know if you disagree with my findings. Martin Blumenstingl (3): ARM: dts: meson: add support for the RTC ARM: dts: meson8b: ec100: enable the RTC ARM: dts: meson8b: odroid-c1: prepare support for the RTC arch/arm/boot/dts/meson.dtsi | 9 +++++++++ arch/arm/boot/dts/meson8.dtsi | 5 +++++ arch/arm/boot/dts/meson8b-ec100.dts | 14 ++++++++++++++ arch/arm/boot/dts/meson8b-odroidc1.dts | 14 ++++++++++++++ arch/arm/boot/dts/meson8b.dtsi | 5 +++++ 5 files changed, 47 insertions(+)