| Message ID | 20200308135849.106333-2-jernej.skrabec@siol.net (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | ec98a87509f40324807dc179a7e3163d40709eba |
| Headers | show |
| Series | rtc: sun6i: Make external oscillator optional | expand |
On Sun, Mar 08, 2020 at 02:58:48PM +0100, Jernej Skrabec wrote: > Some boards, like OrangePi PC2 (H5), OrangePi Plus 2E (H3) and Tanix TX6 > (H6) don't have external 32kHz oscillator. Till H6, it didn't really > matter if external oscillator was enabled because HW detected error and > fall back to internal one. H6 has same functionality but it's the first > SoC which have "auto switch bypass" bit documented and always enabled in > driver. This prevents RTC to work correctly if external crystal is not > present on board. There are other side effects - all peripherals which > depends on this clock also don't work (HDMI CEC for example). > > Make clocks property optional. If it is present, select external > oscillator. If not, stay on internal. > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> Acked-by: Maxime Ripard <mripard@kernel.org> Maxime
On 08/03/2020 14:58:48+0100, Jernej Skrabec wrote: > Some boards, like OrangePi PC2 (H5), OrangePi Plus 2E (H3) and Tanix TX6 > (H6) don't have external 32kHz oscillator. Till H6, it didn't really > matter if external oscillator was enabled because HW detected error and > fall back to internal one. H6 has same functionality but it's the first > SoC which have "auto switch bypass" bit documented and always enabled in > driver. This prevents RTC to work correctly if external crystal is not > present on board. There are other side effects - all peripherals which > depends on this clock also don't work (HDMI CEC for example). > > Make clocks property optional. If it is present, select external > oscillator. If not, stay on internal. > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> > --- > drivers/rtc/rtc-sun6i.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > Applied, thanks.
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index 852f5f3b3592..415a20a936e4 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -250,19 +250,17 @@ static void __init sun6i_rtc_clk_init(struct device_node *node, writel(reg, rtc->base + SUN6I_LOSC_CTRL); } - /* Switch to the external, more precise, oscillator */ - reg |= SUN6I_LOSC_CTRL_EXT_OSC; - if (rtc->data->has_losc_en) - reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN; + /* Switch to the external, more precise, oscillator, if present */ + if (of_get_property(node, "clocks", NULL)) { + reg |= SUN6I_LOSC_CTRL_EXT_OSC; + if (rtc->data->has_losc_en) + reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN; + } writel(reg, rtc->base + SUN6I_LOSC_CTRL); /* Yes, I know, this is ugly. */ sun6i_rtc = rtc; - /* Deal with old DTs */ - if (!of_get_property(node, "clocks", NULL)) - goto err; - /* Only read IOSC name from device tree if it is exported */ if (rtc->data->export_iosc) of_property_read_string_index(node, "clock-output-names", 2, @@ -279,11 +277,13 @@ static void __init sun6i_rtc_clk_init(struct device_node *node, } parents[0] = clk_hw_get_name(rtc->int_osc); + /* If there is no external oscillator, this will be NULL and ... */ parents[1] = of_clk_get_parent_name(node, 0); rtc->hw.init = &init; init.parent_names = parents; + /* ... number of clock parents will be 1. */ init.num_parents = of_clk_get_parent_count(node) + 1; of_property_read_string_index(node, "clock-output-names", 0, &init.name);
Some boards, like OrangePi PC2 (H5), OrangePi Plus 2E (H3) and Tanix TX6 (H6) don't have external 32kHz oscillator. Till H6, it didn't really matter if external oscillator was enabled because HW detected error and fall back to internal one. H6 has same functionality but it's the first SoC which have "auto switch bypass" bit documented and always enabled in driver. This prevents RTC to work correctly if external crystal is not present on board. There are other side effects - all peripherals which depends on this clock also don't work (HDMI CEC for example). Make clocks property optional. If it is present, select external oscillator. If not, stay on internal. Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> --- drivers/rtc/rtc-sun6i.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)