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From: Andre Przywara <andre.przywara@arm.com>
To: Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Rob Herring <robh@kernel.org>, Icenowy Zheng <icenowy@aosc.io>,
	Samuel Holland <samuel@sholland.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-sunxi@googlegroups.com, linux-sunxi@lists.linux.dev,
	linux-kernel@vger.kernel.org, Ondrej Jirman <megous@megous.com>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-rtc@vger.kernel.org
Subject: [PATCH v9 06/11] rtc: sun6i: Add support for RTCs without external LOSCs
Date: Mon,  2 Aug 2021 01:39:47 +0100	[thread overview]
Message-ID: <20210802003952.19942-7-andre.przywara@arm.com> (raw)
In-Reply-To: <20210802003952.19942-1-andre.przywara@arm.com>

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>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/rtc/rtc-sun6i.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 752bea949050..fe1bee3a4ec6 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);
 
-- 
2.17.6


  parent reply	other threads:[~2021-08-02  0:41 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-02  0:39 [PATCH v9 00/11] arm64: sunxi: Initial Allwinner H616 SoC support Andre Przywara
2021-08-02  0:39 ` [PATCH v9 01/11] dt-bindings: mfd: axp20x: Add AXP305 compatible (plus optional IRQ) Andre Przywara
2021-08-02  7:40   ` Lee Jones
2021-08-02  0:39 ` [PATCH v9 02/11] dt-bindings: rtc: sun6i: Add H616 compatible string Andre Przywara
2021-08-18  8:15   ` Maxime Ripard
2021-08-02  0:39 ` [PATCH v9 03/11] rtc: sun6i: Fix time overflow handling Andre Przywara
2021-08-02  0:39 ` [PATCH v9 04/11] rtc: sun6i: Add support for linear day storage Andre Przywara
2021-08-02  0:39 ` [PATCH v9 05/11] rtc: sun6i: Add support for broken-down alarm registers Andre Przywara
2021-08-02  0:39 ` Andre Przywara [this message]
2021-08-02  0:39 ` [PATCH v9 07/11] rtc: sun6i: Add Allwinner H616 support Andre Przywara
2021-08-02  0:39 ` [PATCH v9 08/11] arm64: dts: allwinner: Add Allwinner H616 .dtsi file Andre Przywara
2021-09-11  4:13   ` Samuel Holland
2021-08-02  0:39 ` [PATCH v9 09/11] dt-bindings: arm: sunxi: Add two H616 board compatible strings Andre Przywara
2021-08-02  0:39 ` [PATCH v9 10/11] arm64: dts: allwinner: h616: Add OrangePi Zero 2 board support Andre Przywara
2021-08-02  0:39 ` [PATCH v9 11/11] arm64: dts: allwinner: h616: Add X96 Mate TV box support Andre Przywara

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