From:   Alain Volmat <avolmat@me.com>
To:     Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Patrice Chotard <patrice.chotard@foss.st.com>
Cc:     Lee Jones <lee.jones@linaro.org>, linux-clk@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, Alain Volmat <avolmat@me.com>
Subject: [PATCH v2 1/2] clk: st: clkgen-fsyn: search reg within node or parent
Date:   Sat, 18 Dec 2021 22:11:56 +0100
Message-Id: <20211218211157.188214-2-avolmat@me.com>
In-Reply-To: <20211218211157.188214-1-avolmat@me.com>
References: <20211218211157.188214-1-avolmat@me.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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In order to avoid having duplicated addresses within the DT,
only have one unit-address per clockgen and each driver within
the clockgen should look at the parent node (overall clockgen)
to figure out the reg property.  Such behavior is already in
place in other STi platform clock drivers such as clk-flexgen
and clkgen-pll.  Keep backward compatibility by first looking
at reg within the node before looking into the parent node.

Signed-off-by: Alain Volmat <avolmat@me.com>
---
v2: add pr_err message when failing to get reg information

 drivers/clk/st/clkgen-fsyn.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/st/clkgen-fsyn.c b/drivers/clk/st/clkgen-fsyn.c
index 164285d6be97..582a22c04919 100644
--- a/drivers/clk/st/clkgen-fsyn.c
+++ b/drivers/clk/st/clkgen-fsyn.c
@@ -988,9 +988,18 @@ static void __init st_of_quadfs_setup(struct device_node *np,
 	void __iomem *reg;
 	spinlock_t *lock;
 
+	/*
+	 * First check for reg property within the node to keep backward
+	 * compatibility, then if reg doesn't exist look at the parent node
+	 */
 	reg = of_iomap(np, 0);
-	if (!reg)
-		return;
+	if (!reg) {
+		reg = of_iomap(of_get_parent(np), 0);
+		if (!reg) {
+			pr_err("%s: Failed to get base address\n", __func__);
+			return;
+		}
+	}
 
 	clk_parent_name = of_clk_get_parent_name(np, 0);
 	if (!clk_parent_name)
-- 
2.25.1