Re: [PATCH 3/3] soc: fsl: add RCPM driver

From: Li Yang
Date: Fri Sep 07 2018 - 14:56:50 EST

On Fri, Sep 7, 2018 at 4:51 AM Ran Wang <ran.wang_1@xxxxxxx> wrote:
>
> Hi Leo,
>
> On September 05, 2018 at 11:22 Yang Li wrote:
> > -----Original Message-----
> > From: Li Yang <leoyang.li@xxxxxxx>
> > Sent: Wednesday, September 05, 2018 11:22
> > To: dongsheng.wang@xxxxxxxxxxxxxxxx
> > Cc: Ran Wang <ran.wang_1@xxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>;
> > Mark Rutland <mark.rutland@xxxxxxx>; open list:OPEN FIRMWARE AND
> > FLATTENED DEVICE TREE BINDINGS <devicetree@xxxxxxxxxxxxxxx>; linuxppc-
> > dev <linuxppc-dev@xxxxxxxxxxxxxxxx>; lkml <linux-kernel@xxxxxxxxxxxxxxx>;
> > moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE <linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx>
> > Subject: Re: [PATCH 3/3] soc: fsl: add RCPM driver
> >
> > On Tue, Sep 4, 2018 at 9:58 PM Wang, Dongsheng <dongsheng.wang@hxt-
> > semitech.com> wrote:
> > >
> > > Please change your comments style.
> >
> > Although this doesn't get into the Linux kernel coding style documentation
> > yet, Linus seems changed his mind to prefer // than /*
> > */ comment style now.
> > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml
> > .org%2Flkml%2F2017%2F11%2F25%2F133&amp;data=02%7C01%7Cran.wang_
> > 1%40nxp.com%7Cc0d88e6690384e02b95108d612dec235%7C686ea1d3bc2b4c
> > 6fa92cd99c5c301635%7C0%7C0%7C636717145285126200&amp;sdata=JIoCZp
> > WhRyW76EqgSflfTDA1f0gMQGKa%2FcbvSc5CO%2Fw%3D&amp;reserved=0
> > So the
> > // style should be acceptable for now.
> >
> > >
> > > On 2018/8/31 11:56, Ran Wang wrote:
> > > > The NXP's QorIQ Processors based on ARM Core have RCPM module (Run
> > > > Control and Power Management), which performs all device-level tasks
> > > > associated with power management such as wakeup source control.
> > > >
> > > > This driver depends on FSL platform PM driver framework which help
> > > > to isolate user and PM service provider (such as RCPM driver).
> > > >
> > > > Signed-off-by: Chenhui Zhao <chenhui.zhao@xxxxxxx>
> > > > Signed-off-by: Ying Zhang <ying.zhang22455@xxxxxxx>
> > > > Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
> > > > ---
> > > > drivers/soc/fsl/Kconfig | 6 ++
> > > > drivers/soc/fsl/Makefile | 1 +
> > > > drivers/soc/fsl/ls-rcpm.c | 153
> > > > +++++++++++++++++++++++++++++++++++++++++++++
> > > > 3 files changed, 160 insertions(+), 0 deletions(-) create mode
> > > > 100644 drivers/soc/fsl/ls-rcpm.c
> > > >
> > > > diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig index
> > > > 6517412..882330d 100644
> > > > --- a/drivers/soc/fsl/Kconfig
> > > > +++ b/drivers/soc/fsl/Kconfig
> > > > @@ -30,3 +30,9 @@ config FSL_PLAT_PM
> > > > have to know the implement details of wakeup function it require.
> > > > Besides, it is also easy for service side to upgrade its logic when
> > > > design changed and remain user side unchanged.
> > > > +
> > > > +config LS_RCPM
> > > > + bool "Freescale RCPM support"
> > > > + depends on (FSL_PLAT_PM)
> > > > + help
> > > > + This feature is to enable specified wakeup source for system sleep.
> > > > diff --git a/drivers/soc/fsl/Makefile b/drivers/soc/fsl/Makefile
> > > > index 8f9db23..43ff71a 100644
> > > > --- a/drivers/soc/fsl/Makefile
> > > > +++ b/drivers/soc/fsl/Makefile
> > > > @@ -7,3 +7,4 @@ obj-$(CONFIG_QUICC_ENGINE) += qe/
> > > > obj-$(CONFIG_CPM) += qe/
> > > > obj-$(CONFIG_FSL_GUTS) += guts.o
> > > > obj-$(CONFIG_FSL_PLAT_PM) += plat_pm.o
> > > > +obj-$(CONFIG_LS_RCPM) += ls-rcpm.o
> >
> > Probably use "_" instead of "-" for alignment.
>
> OK, will update in next version
>
> > > > diff --git a/drivers/soc/fsl/ls-rcpm.c b/drivers/soc/fsl/ls-rcpm.c
> > > > new file mode 100644 index 0000000..b0feb88
> > > > --- /dev/null
> > > > +++ b/drivers/soc/fsl/ls-rcpm.c
> > > > @@ -0,0 +1,153 @@
> > > > +// SPDX-License-Identifier: GPL-2.0 // // plat_pm.c - Freescale
> > > > +Layerscape RCPM driver
> >
> > The file name here is not the same as the real file name.
>
> Got it, will correct it.
>
> > > > +//
> > > > +// Copyright 2018 NXP
> > > > +//
> > > > +// Author: Ran Wang <ran.wang_1@xxxxxxx>,
> >
> > Where do you need the comma in the end?
>
> My bad, will remove comma in next version.
>
> > > > +
> > > > +#include <linux/init.h>
> > > > +#include <linux/module.h>
> > > > +#include <linux/platform_device.h>
> > > > +#include <linux/of_address.h>
> > > > +#include <linux/slab.h>
> > > > +#include <soc/fsl/plat_pm.h>
> > > > +
> > > > +#define MAX_COMPATIBLE_NUM 10
> > > > +
> > > > +struct rcpm_t {
> > > > + struct device *dev;
> > > > + void __iomem *ippdexpcr_addr;
> > > > + bool big_endian; /* Big/Little endian of RCPM module */
> > > > +};
> > > > +
> > > > +// rcpm_handle - Configure RCPM reg according to wake up source
> > > > +request // @user_dev: pointer to user's device struct // @flag: to
> > > > +enable(true) or disable(false) wakeup source // @handle_priv:
> > > > +pointer to struct rcpm_t instance // // Return 0 on success other
> > > > +negative errno
> >
> > Although Linus preferred this // comment style. I'm not sure if this will be
> > handled correctly by the kernel-doc compiler.
> > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww
> > w.kernel.org%2Fdoc%2Fhtml%2Fv4.18%2Fdoc-guide%2Fkernel-
> > doc.html&amp;data=02%7C01%7Cran.wang_1%40nxp.com%7Cc0d88e669038
> > 4e02b95108d612dec235%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0
> > %7C636717145285126200&amp;sdata=H7GkUNOLVG%2FCcZESzhtHBeHCbO9
> > %2FK4k9EdH30Cxq2%2BM%3D&amp;reserved=0
>
> So, do you think I need to change all comment style back to '/* ... */' ?
> Actually I feel a little bit confused here.

I think Linus's comment about // comment style applies to normal code
comment. But kernel-doc comment is a special kind of code comment
that needs to meet certain requirements. People can use the
scripts/kernel-doc tool to generate readable API documents from the
source code. It looks like you wanted to make the function
description aligned with the kernel-doc format, but kernel-doc
specifically requires to use the /* */ style(at least for now).

Regards,
Leo