linux-kernel - [LINUX PATCH v2 1/3] clocksource: timer-cadence-ttc: Do not probe TTC device configured as PWM

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Date:   Tue, 14 Nov 2023 18:17:46 +0530
From:   Mubin Sayyed <mubin.sayyed@....com>
To:     <krzysztof.kozlowski+dt@...aro.org>,
        <u.kleine-koenig@...gutronix.de>, <thierry.reding@...il.com>,
        <robh+dt@...nel.org>, <conor+dt@...nel.org>, <tglx@...utronix.de>,
        <daniel.lezcano@...aro.org>, <michal.simek@....com>
CC:     <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-pwm@...r.kernel.org>, <git@....com>, <mubin10@...il.com>,
        Mubin Sayyed <mubin.sayyed@....com>
Subject: [LINUX PATCH v2 1/3] clocksource: timer-cadence-ttc: Do not probe TTC device configured as PWM

TTC device can act either as clocksource/clockevent or
PWM generator, it would be decided by pwm-cells property.
TTC PWM feature would be supported through separate driver
based on PWM framework.

If pwm-cells property is present in TTC node, it would be
treated as PWM device, and clocksource driver should just
skip it.

Signed-off-by: Mubin Sayyed <mubin.sayyed@....com>
---
Changes for v2:
    - Added comment regarding pwm-cells property
---
 drivers/clocksource/timer-cadence-ttc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c
index 32daaac9b132..f8fcb1a4bdd0 100644
--- a/drivers/clocksource/timer-cadence-ttc.c
+++ b/drivers/clocksource/timer-cadence-ttc.c
@@ -477,6 +477,13 @@ static int __init ttc_timer_probe(struct platform_device *pdev)
 	u32 timer_width = 16;
 	struct device_node *timer = pdev->dev.of_node;
 
+	/*
+	 * If pwm-cells property is present in TTC node,
+	 * it would be treated as PWM device.
+	 */
+	if (of_property_read_bool(timer, "#pwm-cells"))
+		return -ENODEV;
+
 	if (initialized)
 		return 0;
 
-- 
2.25.1