Re: [PATCH] i3c: master: dw: split dw-i3c-master.c into master and bus specific parts

[vitor]

On 26/11/18 12:35, Boris Brezillon wrote:
> On Mon, 26 Nov 2018 12:06:24 +0000
> vitor <vitor.soares@xxxxxxxxxxxx> wrote:
>
> > Hi Boris,
> >
> >
> > On 23/11/18 12:50, Boris Brezillon wrote:
> > > On Fri, 23 Nov 2018 12:39:31 +0000
> > > vitor <vitor.soares@xxxxxxxxxxxx> wrote:
> > >   
> > > > Hi Boris,
> > > >
> > > >
> > > > On 22/11/18 20:02, Boris Brezillon wrote:
> > > > > On Thu, 22 Nov 2018 17:54:54 +0000
> > > > > Vitor Soares <vitor.soares@xxxxxxxxxxxx> wrote:
> > > > >      
> > > > > > From: Vitor Soares <soares@xxxxxxxxxxxx>
> > > > > >
> > > > > > This patch slipts dw-i3c-master.c into three pieces:
> > > > > > 	dw-i3c-master.c - contains the code that interacts directly with the
> > > > > > 	core in master mode.
> > > > > >
> > > > > > 	dw-i3c-platdrv.c - contains the code specific to the platform driver.
> > > > > >
> > > > > > 	dw-i3c-core.h - contains the definitions and declarations shared by
> > > > > > 	dw-i3c-master and dw-i3c-platdrv
> > > > > >
> > > > > > This patch will allow SOC integrators to add their code specific to
> > > > > > DesignWare I3C IP.
> > > > > Isn't it too early to do this change? Can't we wait until we have a SoC
> > > > > that actually embeds this IP?
> > > > I'm trying to turn it more flexible so the other can reuse the code.
> > > Looking at the separation you've done here, I don't see why you need
> > > it. All the resources you request are generic, so why not just adding a
> > > new compat in the of_match_table?
> > I understand your point.
> >
> >
> > I'm just following what it's done in others Synopsys drivers and what I
> > expect is that in the future we will have the same for the I3C.
> >
> > Some of the current generic functions might be override according with
> > SoC requirements (e.g i2c-designware, pcie-designware).
> >
> >
> > for now what do you prefer?
> I prefer that we keep the driver as is until we actually need to split
> things up.

This is already done and will benefit everyone:

ÂÂÂ - for me is better do it now than the secondary master and slave 
development.

ÂÂÂ - for the others it will easy the SoC integration avoiding 
duplicated work and doing things from scratch.


> > > >   
> > > > >      
> > > > > > Signed-off-by: Vitor Soares <soares@xxxxxxxxxxxx>
> > > > > > ---
> > > > > >     drivers/i3c/master/Kconfig          |   9 +-
> > > > > >     drivers/i3c/master/Makefile         |   5 +-
> > > > > >     drivers/i3c/master/dw-i3c-core.h    | 214 ++++++++++++++++++++++++++
> > > > > >     drivers/i3c/master/dw-i3c-master.c  | 299 ++----------------------------------
> > > > > >     drivers/i3c/master/dw-i3c-platdrv.c | 112 ++++++++++++++
> > > Just realized the driver is named dw-i3c-master, while the cadence
> > > driver is named i3c-master-cdns.c. I'll send a patch to make that
> > > consistent and follow the initial naming scheme: i3c-master-<ipname>.c.
> > As I shared with you in previous email, the structure that I have in
> > mind is this one:
> >
> > - core.h (or common.h, any though?)
> >
> > - common.c
> >
> > - master.c
> >
> > - slave.c
> >
> >
> > so for me doesn't make sense to have for instance: i3c-master-dw-slave.c
> If you have several files and they're all placed in a dw/ subdir, then
> I agree, prefixing everything with i3c-master- is useless, as you'll
> have to define a custom rule to create the i3c-master-dw.ko object.
>
> When there's a single source file, and this source file is directly
> used to create a .ko, we need this prefix, otherwise we would have
> dw.ko, and this would basically conflict with any other designware
> driver that does not have a proper prefix.
>
> > But seeing what is already in the kernel I wasn't coherent and it should
> > be named to i3c-designware-master.c
> Actually it's i3c-master-designware.c (or i3c-master-dw.c) if we follow
> what's been done for the cadence driver.

I was referring to what was made in other modules and should be applied 
here too.


> > or
> >
> >
> > follow this https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2017_7_12_430&d=DwICAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=9fGCPbkiqaG2-CJ5qrOU2Os6ZcstSNxi7UbQiF9YEBk&s=ADR3LotyBBy6e8Rv-UFW_-J8B5os_PY71QtUols3tb4&e=
> And I agree with Linus on this, except that does not apply to single
> source file drivers.
>
> > This topic rise another one related with the master folder. I understand
> > that now the subsystem doesn't have slave support but the name is
> > limited. Isn't better to have something like controller or busses? What
> > do you have in mind for the slave?
> drivers/i3c/slave/... for slave drivers and drivers/i3c/slave.c for the
> framework, just like we have drivers/i3c/master/ for master controller
> drivers and drivers/i3c/master.c.

I have to disagree here. I don't see any place on the kernel with 
.../master/ and ../slave/ folders and it is very likely that both rules 
will have some common code.

With this structure the user will have the code spread in /master and 
/slave folders...


I would like you consider to change the folder name and the names rules 
to something like in i2c.


Maybe someone else can give his opinion too.


Best regards,

Vitor Soares