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From:   Krzysztof Kozlowski <krzk@kernel.org>
To:     Rob Herring <robh+dt@kernel.org>, Kukjin Kim <kgene@kernel.org>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
        "Denis GNUtoo Carikli" <GNUtoo@cyberdimension.org>,
        Simon Shields <simon@lineageos.org>
Cc:     Marek Szyprowski <m.szyprowski@samsung.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Sylwester Nawrocki <snawrocki@kernel.org>
Subject: [PATCH 06/33] ARM: dts: exynos: Correct S3C RTC bindings and enable it in Universal C210
Date:   Sun, 30 Aug 2020 15:51:33 +0200
Message-Id: <20200830135200.24304-6-krzk@kernel.org>
In-Reply-To: <20200830135200.24304-1-krzk@kernel.org>
References: <20200830135200.24304-1-krzk@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The S3C RTC requires 32768 Hz clock as input which is provided by PMIC.
However there is no clock provided for the PMIC and the driver registers
the clock as regulator.  This is an old driver which will not be updated
so add a workaround - add a fixed-clock to fill missing clock phandle
reference in S3C RTC.  The "clock" regulator in PMIC is already present
and enabled.

This allows to enable the S3C RTC and fixes dtbs_check warnings:

  arch/arm/boot/dts/exynos4210-universal_c210.dt.yaml: rtc@10070000: clocks: [[5, 346]] is too short
  arch/arm/boot/dts/exynos4210-universal_c210.dt.yaml: rtc@10070000: clock-names: ['rtc'] is too short

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 arch/arm/boot/dts/exynos4210-universal_c210.dts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm/boot/dts/exynos4210-universal_c210.dts b/arch/arm/boot/dts/exynos4210-universal_c210.dts
index 99ce53b120ac..9479e41bdc2a 100644
--- a/arch/arm/boot/dts/exynos4210-universal_c210.dts
+++ b/arch/arm/boot/dts/exynos4210-universal_c210.dts
@@ -39,6 +39,13 @@
 			compatible = "samsung,clock-xusbxti";
 			clock-frequency = <24000000>;
 		};
+
+		pmic_ap_clk: pmic-ap-clk {
+			/* Workaround for missing clock on PMIC */
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <32768>;
+		};
 	};
 
 	vemmc_reg: voltage-regulator {
@@ -537,6 +544,12 @@
 	status = "okay";
 };
 
+&rtc {
+	status = "okay";
+	clocks = <&clock CLK_RTC>, <&pmic_ap_clk>;
+	clock-names = "rtc", "rtc_src";
+};
+
 &sdhci_0 {
 	bus-width = <8>;
 	non-removable;
-- 
2.17.1