linux-kernel - [PATCH 3/7] clk: sunxi-ng: sun6i-rtc: Add feature bit for IOSC calibration

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Message-Id: <20260121-a733-rtc-v1-3-d359437f23a7@pigmoral.tech>
Date: Wed, 21 Jan 2026 18:59:09 +0800
From: Junhui Liu <junhui.liu@...moral.tech>
To: Michael Turquette <mturquette@...libre.com>, 
 Stephen Boyd <sboyd@...nel.org>, Chen-Yu Tsai <wens@...nel.org>, 
 Jernej Skrabec <jernej.skrabec@...il.com>, 
 Samuel Holland <samuel@...lland.org>, 
 Alexandre Belloni <alexandre.belloni@...tlin.com>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Maxime Ripard <mripard@...nel.org>
Cc: linux-clk@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
 linux-sunxi@...ts.linux.dev, linux-kernel@...r.kernel.org, 
 linux-rtc@...r.kernel.org, devicetree@...r.kernel.org, 
 Junhui Liu <junhui.liu@...moral.tech>
Subject: [PATCH 3/7] clk: sunxi-ng: sun6i-rtc: Add feature bit for IOSC
 calibration

The sun6i-rtc CCU driver currently uses a global static variable to
denote whether calibration is supported, which makes IOSC operations
tightly coupled to this file.

Convert this into a feature bit to decouple the logic. This allows the
IOSC clock code to be moved into a shared module for reuse by other SoCs.

Signed-off-by: Junhui Liu <junhui.liu@...moral.tech>
---
 drivers/clk/sunxi-ng/ccu-sun6i-rtc.c | 17 +++++++++--------
 drivers/clk/sunxi-ng/ccu_common.h    |  1 +
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c
index 3088f247d927..6f888169412c 100644
--- a/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c
+++ b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c
@@ -53,8 +53,6 @@ struct sun6i_rtc_match_data {
 	u8				osc32k_fanout_nparents;
 };
 
-static bool have_iosc_calibration;
-
 static int ccu_iosc_enable(struct clk_hw *hw)
 {
 	struct ccu_common *cm = hw_to_ccu_common(hw);
@@ -81,7 +79,7 @@ static unsigned long ccu_iosc_recalc_rate(struct clk_hw *hw,
 {
 	struct ccu_common *cm = hw_to_ccu_common(hw);
 
-	if (have_iosc_calibration) {
+	if (cm->features & CCU_FEATURE_IOSC_CALIBRATION) {
 		u32 reg = readl(cm->base + IOSC_CLK_CALI_REG);
 
 		/*
@@ -120,7 +118,7 @@ static int ccu_iosc_32k_prepare(struct clk_hw *hw)
 	struct ccu_common *cm = hw_to_ccu_common(hw);
 	u32 val;
 
-	if (!have_iosc_calibration)
+	if (!(cm->features & CCU_FEATURE_IOSC_CALIBRATION))
 		return 0;
 
 	val = readl(cm->base + IOSC_CLK_CALI_REG);
@@ -135,7 +133,7 @@ static void ccu_iosc_32k_unprepare(struct clk_hw *hw)
 	struct ccu_common *cm = hw_to_ccu_common(hw);
 	u32 val;
 
-	if (!have_iosc_calibration)
+	if (!(cm->features & CCU_FEATURE_IOSC_CALIBRATION))
 		return;
 
 	val = readl(cm->base + IOSC_CLK_CALI_REG);
@@ -149,7 +147,7 @@ static unsigned long ccu_iosc_32k_recalc_rate(struct clk_hw *hw,
 	struct ccu_common *cm = hw_to_ccu_common(hw);
 	u32 val;
 
-	if (have_iosc_calibration) {
+	if (cm->features & CCU_FEATURE_IOSC_CALIBRATION) {
 		val = readl(cm->base + IOSC_CLK_CALI_REG);
 
 		/* Assume the calibrated 32k clock is accurate. */
@@ -168,7 +166,7 @@ static unsigned long ccu_iosc_32k_recalc_accuracy(struct clk_hw *hw,
 	struct ccu_common *cm = hw_to_ccu_common(hw);
 	u32 val;
 
-	if (have_iosc_calibration) {
+	if (cm->features & CCU_FEATURE_IOSC_CALIBRATION) {
 		val = readl(cm->base + IOSC_CLK_CALI_REG);
 
 		/* Assume the calibrated 32k clock is accurate. */
@@ -366,7 +364,10 @@ static int sun6i_rtc_ccu_probe(struct auxiliary_device *adev,
 		return 0;
 
 	data = match->data;
-	have_iosc_calibration = data->have_iosc_calibration;
+	if (data->have_iosc_calibration) {
+		iosc_clk.features |= CCU_FEATURE_IOSC_CALIBRATION;
+		iosc_32k_clk.features |= CCU_FEATURE_IOSC_CALIBRATION;
+	}
 
 	if (data->have_ext_osc32k) {
 		const char *fw_name;
diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h
index bbec283b9d99..d9dc24ad5503 100644
--- a/drivers/clk/sunxi-ng/ccu_common.h
+++ b/drivers/clk/sunxi-ng/ccu_common.h
@@ -21,6 +21,7 @@
 #define CCU_FEATURE_CLOSEST_RATE	BIT(9)
 #define CCU_FEATURE_DUAL_DIV		BIT(10)
 #define CCU_FEATURE_UPDATE_BIT		BIT(11)
+#define CCU_FEATURE_IOSC_CALIBRATION	BIT(12)
 
 /* MMC timing mode switch bit */
 #define CCU_MMC_NEW_TIMING_MODE		BIT(30)

-- 
2.52.0