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Date:   Tue, 10 Oct 2023 07:20:49 +0200
From:   Marco Felsch <m.felsch@pengutronix.de>
To:     "Peng Fan (OSS)" <peng.fan@oss.nxp.com>
Cc:     shawnguo@kernel.org, s.hauer@pengutronix.de,
        Peng Fan <peng.fan@nxp.com>, linux-kernel@vger.kernel.org,
        linux-imx@nxp.com, kernel@pengutronix.de, festevam@gmail.com,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] soc: imx8mp: support 128 bits UID
Message-ID: <20231010052049.iwqn5cnk523jixq2@pengutronix.de>
References: <20231008083808.1517132-1-peng.fan@oss.nxp.com>
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In-Reply-To: <20231008083808.1517132-1-peng.fan@oss.nxp.com>
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Hi Peng,

On 23-10-08, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Current driver only supports 64bits UID for i.MX8MP, but
> i.MX8MP UID is actually 128bits, the high 64bits is at 0xE00.
> So update driver to support it.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/soc/imx/soc-imx8m.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
> index ec87d9d878f3..5dcc227d41c0 100644
> --- a/drivers/soc/imx/soc-imx8m.c
> +++ b/drivers/soc/imx/soc-imx8m.c
> @@ -24,6 +24,7 @@
>  #define OCOTP_UID_HIGH			0x420
>  
>  #define IMX8MP_OCOTP_UID_OFFSET		0x10
> +#define IMX8MP_OCOTP_UID_HIGH		0xE00
						  ^
						0xe00

>  /* Same as ANADIG_DIGPROG_IMX7D */
>  #define ANADIG_DIGPROG_IMX8MM	0x800
> @@ -34,6 +35,7 @@ struct imx8_soc_data {
>  };
>  
>  static u64 soc_uid;
> +static u64 soc_uid_h;
>  
>  #ifdef CONFIG_HAVE_ARM_SMCCC
>  static u32 imx8mq_soc_revision_from_atf(void)
> @@ -122,8 +124,15 @@ static void __init imx8mm_soc_uid(void)
>  	soc_uid <<= 32;
>  	soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW + offset);
>  
> +	if (offset) {
> +		soc_uid_h = readl_relaxed(ocotp_base + IMX8MP_OCOTP_UID_HIGH + 0x10);
> +		soc_uid_h <<= 32;
> +		soc_uid_h |= readl_relaxed(ocotp_base + IMX8MP_OCOTP_UID_HIGH);
> +	}

Since the function is very small and with this addition the shared code
is very limited. So I would rather tend to have a separate
imx8mp_soc_uid() function.

> +
>  	clk_disable_unprepare(clk);
>  	clk_put(clk);
> +
>  	iounmap(ocotp_base);
>  	of_node_put(np);
>  }
> @@ -222,7 +231,12 @@ static int __init imx8_soc_init(void)
>  		goto free_soc;
>  	}
>  
> -	soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
> +	if (soc_uid_h) {

We already do have match data can't we do something like this:

	if (id->uid_128bit)
		soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX%016llX",
							soc_uid_h, soc_uid);
	else
		soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);

Regards,
  Marco

> +		soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX%016llX",
> +							soc_uid_h, soc_uid);
> +	} else {
> +		soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
> +	}
>  	if (!soc_dev_attr->serial_number) {
>  		ret = -ENOMEM;
>  		goto free_rev;
> -- 
> 2.37.1
> 
> 
>