Messages in this thread | | | From | Daniel Baluta <> | Date | Thu, 27 Jun 2019 09:43:34 +0300 | Subject | Re: [PATCH] soc: imx-scu: Add SoC UID(unique identifier) support |
| |
On Thu, Jun 27, 2019 at 3:48 AM Anson Huang <anson.huang@nxp.com> wrote: > > Hi, Daniel > > > -----Original Message----- > > From: Daniel Baluta <daniel.baluta@gmail.com> > > Sent: Wednesday, June 26, 2019 8:42 PM > > 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> > > Subject: Re: [PATCH] soc: imx-scu: Add SoC UID(unique identifier) support > > > > 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"? > > I made a mistake, it should be "incorrect", the existing SCFW of this API returns > an error value even this API is successfully called, to make it work with current > SCFW, I have to skip the return value check for this API for now. Will send V2 patch > to fix this typo.
Thanks Anson! It makes sense now. It is a little bit sad though because we won't know when there is a "real" error :).
Lets update the comment to be more specific:
/* SCFW FW API always returns an error even the function is successfully executed, so skip returned value */
> > > + 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? > > The snprintf is to avoid buffer overflow, which in this case, I don't know the size > of "buf", and the value(u64) to be printed is with fixed length of 64, so I think > sprint is just OK.
Ok.
| |