Re: [PATCH V3] soc: imx-scu: Add SoC UID(unique identifier) support

[Shawn Guo]

On Tue, Jul 02, 2019 at 03:45:45PM +0800, Anson.Huang@xxxxxxx wrote:
> From: Anson Huang <Anson.Huang@xxxxxxx>
> 
> 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@xxxxxxx>
> Reviewed-by: Daniel Baluta <daniel.baluta@xxxxxxx>

@Marco, are you happy with it?

Shawn

> ---
> Change since V2:
> 	- The SCU FW API for getting UID does NOT have response, so we should set
> 	  imx_scu_call_rpc()'s 3rd parameter as false and still can check the returned
> 	  value, and comment is no needed any more.
> ---
>  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..50831eb 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;
> +	int ret;
> +
> +	hdr->ver = IMX_SC_RPC_VERSION;
> +	hdr->svc = IMX_SC_RPC_SVC_MISC;
> +	hdr->func = IMX_SC_MISC_FUNC_UNIQUE_ID;
> +	hdr->size = 1;
> +
> +	ret = imx_scu_call_rpc(soc_ipc_handle, &msg, false);
> +	if (ret) {
> +		pr_err("%s: get soc uid failed, ret %d\n", __func__, ret);
> +		return ret;
> +	}
> +
> +	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
>