Re: [PATCH] pwm: tiehrpwm: fix copy-paste error in obsolete DT binding fallback

[Uwe Kleine-König]

Hello,

On Mon, Sep 28, 2026 at 11:25:09PM +0530, Manush Prajwal wrote:
> ehrpwm_pwm_probe() attempts to provide backward compatibility for older
> device trees where the functional clock "fck" was supplied by the parent
> PWMSS device rather than within the PWM child node itself.
> 
> However, when devm_clk_get() for "fck" fails, the fallback checks:
> 
> 	if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
> 		dev_warn(&pdev->dev, "Binding is obsolete.\n");
> 		clk = devm_clk_get(pdev->dev.parent, "fck");
> 	}
> 
> Because this logic was copied from pwm-tiecap.c, it mistakenly checks for
> "ti,am33xx-ecap" instead of "ti,am33xx-ehrpwm". An eHRPWM node matches
> ehrpwm_of_match ("ti,am3352-ehrpwm" or "ti,am33xx-ehrpwm") and will never
> be compatible with "ti,am33xx-ecap". Consequently, for any device tree
> using the obsolete "ti,am33xx-ehrpwm" binding, the fallback never triggers
> and probe fails with "Failed to get fck".
> 
> Fix the check to test for "ti,am33xx-ehrpwm" as intended.
> 
> Signed-off-by: Manush Prajwal <manushprajwal555@xxxxxxxxx>

Looks right, I guess it needs:
Fixes: ae5200d22716 ("pwm: pwm-ti*: Get the clock from the PWMSS parent when using old bindings")
.

I wonder: Did you find this because you still use the old bindings, or
by code inspection somehow? If the latter, maybe it's time to drop the
handling instead?

Best regards
Uwe

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