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References: <20190626070706.24930-1-Anson.Huang@nxp.com>
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From:   Daniel Baluta <daniel.baluta@gmail.com>
Date:   Wed, 26 Jun 2019 15:41:54 +0300
Message-ID: <CAEnQRZBsT=KY3-Gk8p1byJOqx1_y_EX-KqiBs6WnroWkT5oe_Q@mail.gmail.com>
Subject: Re: [PATCH] soc: imx-scu: Add SoC UID(unique identifier) support
To:     Anson Huang <Anson.Huang@nxp.com>
Cc:     Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        Aisheng Dong <aisheng.dong@nxp.com>,
        Abel Vesa <abel.vesa@nxp.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        dl-linux-imx <Linux-imx@nxp.com>,
        Daniel Baluta <daniel.baluta@nxp.com>
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On Wed, Jun 26, 2019 at 10:06 AM <Anson.Huang@nxp.com> wrote:
>
> From: Anson Huang <Anson.Huang@nxp.com>
>
> Add i.MX SCU SoC's UID(unique identifier) support, user
> can read it from sysfs:
>
> root@imx8qxpmek:~# cat /sys/devices/soc0/soc_uid
> 7B64280B57AC1898
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
>  drivers/soc/imx/soc-imx-scu.c | 35 +++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>
> diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
> index 676f612..8d322a1 100644
> --- a/drivers/soc/imx/soc-imx-scu.c
> +++ b/drivers/soc/imx/soc-imx-scu.c
> @@ -27,6 +27,36 @@ struct imx_sc_msg_misc_get_soc_id {
>         } data;
>  } __packed;
>
> +struct imx_sc_msg_misc_get_soc_uid {
> +       struct imx_sc_rpc_msg hdr;
> +       u32 uid_low;
> +       u32 uid_high;
> +} __packed;
> +
> +static ssize_t soc_uid_show(struct device *dev,
> +                           struct device_attribute *attr, char *buf)
> +{
> +       struct imx_sc_msg_misc_get_soc_uid msg;
> +       struct imx_sc_rpc_msg *hdr = &msg.hdr;
> +       u64 soc_uid;
> +
> +       hdr->ver = IMX_SC_RPC_VERSION;
> +       hdr->svc = IMX_SC_RPC_SVC_MISC;
> +       hdr->func = IMX_SC_MISC_FUNC_UNIQUE_ID;
> +       hdr->size = 1;
> +
> +       /* the return value of SCU FW is in correct, skip return value check */

Why do you mean by "in correct"?
> +       imx_scu_call_rpc(soc_ipc_handle, &msg, true);
> +
> +       soc_uid = msg.uid_high;
> +       soc_uid <<= 32;
> +       soc_uid |= msg.uid_low;
> +
> +       return sprintf(buf, "%016llX\n", soc_uid);

snprintf?

> +}
> +
> +static DEVICE_ATTR_RO(soc_uid);
> +
>  static int imx_scu_soc_id(void)
>  {
>         struct imx_sc_msg_misc_get_soc_id msg;
> @@ -102,6 +132,11 @@ static int imx_scu_soc_probe(struct platform_device *pdev)
>                 goto free_revision;
>         }
>
> +       ret = device_create_file(soc_device_to_device(soc_dev),
> +                                &dev_attr_soc_uid);
> +       if (ret)
> +               goto free_revision;
> +
>         return 0;
>
>  free_revision:
> --
> 2.7.4
>