linux-kernel - [PATCH 2/6] clk: renesas: rzv2h-cpg: Use both CLK_ON and CLK

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Message-ID: <20250328200105.176129-3-prabhakar.mahadev-lad.rj@bp.renesas.com>
Date: Fri, 28 Mar 2025 20:01:01 +0000
From: Prabhakar <prabhakar.csengg@...il.com>
To: Geert Uytterhoeven <geert+renesas@...der.be>,
	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Magnus Damm <magnus.damm@...il.com>
Cc: linux-renesas-soc@...r.kernel.org,
	linux-clk@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org,
	Prabhakar <prabhakar.csengg@...il.com>,
	Biju Das <biju.das.jz@...renesas.com>,
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: [PATCH 2/6] clk: renesas: rzv2h-cpg: Use both CLK_ON and CLK_MON bits for clock state validation

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>

Update the clock enable/disable logic to follow the latest hardware
manual's guidelines, ensuring that both CLK_ON and CLK_MON bits are used to
confirm the clock state.

According to the manual, enabling a clock requires setting the CPG_CLK_ON
bit and verifying the clock has started using the CPG_CLK_MON bit.
Similarly, disabling a clock requires clearing the CPG_CLK_ON bit and
confirming the clock has stopped via the CPG_CLK_MON bit.

Modify `rzv2h_mod_clock_is_enabled()` to check CLK_MON first and then
validate CLK_ON for a more accurate clock status evaluation.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
---
 drivers/clk/renesas/rzv2h-cpg.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/renesas/rzv2h-cpg.c b/drivers/clk/renesas/rzv2h-cpg.c
index 817a39a8b852..dec97f731e3a 100644
--- a/drivers/clk/renesas/rzv2h-cpg.c
+++ b/drivers/clk/renesas/rzv2h-cpg.c
@@ -576,11 +576,14 @@ static int rzv2h_mod_clock_is_enabled(struct clk_hw *hw)
 	if (clock->mon_index >= 0) {
 		offset = GET_CLK_MON_OFFSET(clock->mon_index);
 		bitmask = BIT(clock->mon_bit);
-	} else {
-		offset = GET_CLK_ON_OFFSET(clock->on_index);
-		bitmask = BIT(clock->on_bit);
+
+		if (!(readl(priv->base + offset) & bitmask))
+			return 0;
 	}
 
+	offset = GET_CLK_ON_OFFSET(clock->on_index);
+	bitmask = BIT(clock->on_bit);
+
 	return readl(priv->base + offset) & bitmask;
 }
 
-- 
2.49.0