Re: [PATCH 4/8] iio: adc: axi-adc: make sure AXI clock is enabled

From: Jonathan Cameron <jic23@kernel.org>
To: Nuno Sa via B4 Relay <devnull+nuno.sa.analog.com@kernel.org>
Cc: nuno.sa@analog.com, linux-iio@vger.kernel.org,
	devicetree@vger.kernel.org,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Alexandru Ardelean <alexandru.ardelean@analog.com>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Michael Hennerich <Michael.Hennerich@analog.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Olivier Moysan <olivier.moysan@foss.st.com>
Subject: Re: [PATCH 4/8] iio: adc: axi-adc: make sure AXI clock is enabled
Date: Sat, 20 Apr 2024 16:04:42 +0100	[thread overview]
Message-ID: <20240420160442.05be6dc5@jic23-huawei> (raw)
In-Reply-To: <20240419-ad9467-new-features-v1-4-3e7628ff6d5e@analog.com>

On Fri, 19 Apr 2024 17:36:47 +0200
Nuno Sa via B4 Relay <devnull+nuno.sa.analog.com@kernel.org> wrote:

> From: Nuno Sa <nuno.sa@analog.com>
> 
> We can only access the IP core registers if the bus clock is enabled. As
> such we need to get and enable it and not rely on anyone else to do it.
> 
> Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Likewise - smells like a fix, but no fixes tag?

> ---
>  drivers/iio/adc/adi-axi-adc.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
> index a543b91124b07..e3b2158829416 100644
> --- a/drivers/iio/adc/adi-axi-adc.c
> +++ b/drivers/iio/adc/adi-axi-adc.c
> @@ -175,6 +175,7 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
>  	struct adi_axi_adc_state *st;
>  	void __iomem *base;
>  	unsigned int ver;
> +	struct clk *clk;
>  	int ret;
>  
>  	st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
> @@ -195,6 +196,10 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
>  	if (!expected_ver)
>  		return -ENODEV;
>  
> +	clk = devm_clk_get_enabled(&pdev->dev, NULL);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
>  	/*
>  	 * Force disable the core. Up to the frontend to enable us. And we can
>  	 * still read/write registers...
>