linux-kernel - Re: [PATCH v3 2/2] nvmem: imx-ocotp-ele: Support accessing controller for i.MX9

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Message-ID: <Z2RUVK/nj5Mf8hVr@lizhi-Precision-Tower-5810>
Date: Thu, 19 Dec 2024 12:13:56 -0500
From: Frank Li <Frank.li@....com>
To: "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>, devicetree@...r.kernel.org,
	imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, Peng Fan <peng.fan@....com>
Subject: Re: [PATCH v3 2/2] nvmem: imx-ocotp-ele: Support accessing
 controller for i.MX9

On Thu, Dec 19, 2024 at 10:25:18PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@....com>
>
> i.MX9 OCOTP supports a specific peripheral or function being fused
> which means disabled, so
>  - Introduce ocotp_access_gates to be container of efuse gate info
>  - Iterate each node under '/soc' to check accessing permission. If not

Nit: Iterate all nodes to ....

>    allowed to be accessed, detach the node
>
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
>  drivers/nvmem/imx-ocotp-ele.c | 183 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 182 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvmem/imx-ocotp-ele.c b/drivers/nvmem/imx-ocotp-ele.c
> index ca6dd71d8a2e29888c6e556aaea116c1a967cb5f..173863b1fd7de150576b78f03c256a151b174389 100644
> --- a/drivers/nvmem/imx-ocotp-ele.c
> +++ b/drivers/nvmem/imx-ocotp-ele.c
> @@ -5,6 +5,8 @@
>   * Copyright 2023 NXP
>   */
>
[...]
> +
> +	for_each_available_child_of_node_scoped(parent, child) {
> +		struct of_phandle_iterator it;
> +		int err;
> +		u32 id;
> +
> +		of_for_each_phandle(&it, err, child, "access-controllers",
> +				    "#access-controller-cells", 0) {
> +			struct of_phandle_args provider_args;
> +			struct device_node *provider = it.node;
> +
> +			if (err) {
> +				dev_err(dev, "Unable to get access-controllers property for node %s\n, err: %d",
> +					child->full_name, err);
> +				of_node_put(provider);
> +				return err;
> +			}
> +
> +			/* Only support one cell */
> +			if (of_phandle_iterator_args(&it, provider_args.args, 1) != 1) {
> +				dev_err(dev, "wrong args count\n");

you call of_node_put(provider) in above err branch.
why not call it here?

Frank
> +				return -EINVAL;
> +			}
> +
> +			id = provider_args.args[0];
> +
> +			dev_dbg(dev, "Checking node: %s gate: %d\n", child->full_name, id);
> +
> +			if (imx_ele_ocotp_check_access(pdev, id)) {
> +				of_detach_node(child);
> +				dev_err(dev, "%s: Not granted, device driver will not be probed\n",
> +					child->full_name);
> +			}
> +		}
> +
> +		imx_ele_ocotp_grant_access(pdev, child);
> +	}
> +
> +	return 0;
> +}
> +

[...]

>
> --
> 2.37.1
>