Re: [PATCH V2] soc: imx-scu: Add SoC UID(unique identifier) support

From: Marco Felsch <m.felsch@pengutronix.de>
To: Anson.Huang@nxp.com
Cc: aisheng.dong@nxp.com, abel.vesa@nxp.com, shawnguo@kernel.org,
	s.hauer@pengutronix.de, linux-kernel@vger.kernel.org,
	Linux-imx@nxp.com, kernel@pengutronix.de, festevam@gmail.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH V2] soc: imx-scu: Add SoC UID(unique identifier) support
Date: Tue, 2 Jul 2019 09:35:22 +0200	[thread overview]
Message-ID: <20190702073522.blujpmxddw7brr7c@pengutronix.de> (raw)
In-Reply-To: <20190628032544.8317-1-Anson.Huang@nxp.com>

Hi Anson,

On 19-06-28 11:25, 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>
> ---
> Changes since V1:
> 	- Improve the comment of skipping SCFW API return value check for getting UID.
> ---
>  drivers/soc/imx/soc-imx-scu.c | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
> index 676f612..3eacb54 100644
> --- a/drivers/soc/imx/soc-imx-scu.c
> +++ b/drivers/soc/imx/soc-imx-scu.c
> @@ -27,6 +27,40 @@ 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;
> +
> +	/*
> +	 * SCU FW API always returns an error even the
> +	 * function is successfully executed, so skip
> +	 * returned value check.
> +	 */
> +	imx_scu_call_rpc(soc_ipc_handle, &msg, true);

Please can you add a TODO: or FIXME: tag and also provide the firmware
version containing the bug? I know that developers are very busy and
follow-up fixes never reach mainline ;)

Regards,
  Marco

> +
> +	soc_uid = msg.uid_high;
> +	soc_uid <<= 32;
> +	soc_uid |= msg.uid_low;
> +
> +	return sprintf(buf, "%016llX\n", soc_uid);
> +}
> +
> +static DEVICE_ATTR_RO(soc_uid);
> +
>  static int imx_scu_soc_id(void)
>  {
>  	struct imx_sc_msg_misc_get_soc_id msg;
> @@ -102,6 +136,11 @@ 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
> 
> 
> 

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