Re: [PATCH v2 2/3] rtc: sun6i: Add support for H6 RTC
From: Alexandre Belloni
Date: Thu Aug 22 2019 - 17:16:08 EST
On 20/08/2019 17:19:33+0200, megous@xxxxxxxxxx wrote:
> From: Ondrej Jirman <megous@xxxxxxxxxx>
> RTC on H6 is mostly the same as on H5 and H3. It has slight differences
> mostly in features that are not yet supported by this driver.
> Some differences are already stated in the comments in existing code.
> One other difference is that H6 has extra bit in LOSC_CTRL_REG, called
> EXT_LOSC_EN to enable/disable external low speed crystal oscillator.
> It also has bit EXT_LOSC_STA in LOSC_AUTO_SWT_STA_REG, to check whether
> external low speed oscillator is working correctly.
> This patch adds support for enabling LOSC when necessary:
> - during reparenting
> - when probing the clock
> H6 also has capacbility to automatically reparent RTC clock from
> external crystal oscillator, to internal RC oscillator, if external
> oscillator fails. This is enabled by default. Disable it during
> Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
> Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
> drivers/rtc/rtc-sun6i.c | 40 ++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 38 insertions(+), 2 deletions(-)
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering