diff mbox series

[v8,06/11] rtc: sun6i: Add support for RTCs without external LOSCs

Message ID 20210723153838.6785-7-andre.przywara@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: sunxi: Initial Allwinner H616 SoC support | expand

Commit Message

Andre Przywara July 23, 2021, 3:38 p.m. UTC
Some newer Allwinner RTCs (for instance the one in the H616 SoC) lack
a pin for an external 32768 Hz oscillator. As a consequence, this LOSC
can't be selected as the RTC clock source, and we must rely on the
internal RC oscillator.
To allow additions of clocks to the RTC node, add a feature bit to ignore
any provided clocks for now (the current code would think this is the
external LOSC). Later DTs and code can then for instance add the PLL
based clock input, and older kernel won't get confused.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/rtc/rtc-sun6i.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

Comments

Jernej Skrabec July 25, 2021, 6:18 a.m. UTC | #1
Hi Andre!

Dne petek, 23. julij 2021 ob 17:38:33 CEST je Andre Przywara napisal(a):
> Some newer Allwinner RTCs (for instance the one in the H616 SoC) lack
> a pin for an external 32768 Hz oscillator. As a consequence, this LOSC
> can't be selected as the RTC clock source, and we must rely on the
> internal RC oscillator.
> To allow additions of clocks to the RTC node, add a feature bit to ignore
> any provided clocks for now (the current code would think this is the
> external LOSC). Later DTs and code can then for instance add the PLL
> based clock input, and older kernel won't get confused.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  drivers/rtc/rtc-sun6i.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index f0ee20bfdccb..ef2b1027ce4c 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -134,6 +134,7 @@  struct sun6i_rtc_clk_data {
 	unsigned int export_iosc : 1;
 	unsigned int has_losc_en : 1;
 	unsigned int has_auto_swt : 1;
+	unsigned int no_ext_losc : 1;
 };
 
 #define RTC_LINEAR_DAY	BIT(0)
@@ -256,7 +257,7 @@  static void __init sun6i_rtc_clk_init(struct device_node *node,
 	}
 
 	/* Switch to the external, more precise, oscillator, if present */
-	if (of_get_property(node, "clocks", NULL)) {
+	if (!rtc->data->no_ext_losc && 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;
@@ -282,14 +283,19 @@  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);
+	if (rtc->data->no_ext_losc) {
+		parents[1] = NULL;
+		init.num_parents = 1;
+	} else {
+		/* If there is no external oscillator, this will be NULL and */
+		parents[1] = of_clk_get_parent_name(node, 0);
+		/* ... number of clock parents will be 1. */
+		init.num_parents = of_clk_get_parent_count(node) + 1;
+	}
 
 	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);