RE: [PATCH v2] pwm: fix pwm-rz-mtu3.c build errors

[Biju Das]

Hi Thierry,

Thanks for the feedback.

> -----Original Message-----
> From: Thierry Reding <thierry.reding@xxxxxxxxx>
> Sent: Tuesday, July 18, 2023 12:44 PM
> To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: Randy Dunlap <rd.dunlab@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> linux-pwm@xxxxxxxxxxxxxxx; Uwe Kleine-König <u.kleine-
> koenig@xxxxxxxxxxxxxx>; Fabrizio Castro
> <fabrizio.castro.jz@xxxxxxxxxxx>; lee.jones@xxxxxxxxxx; Geert
> Uytterhoeven <geert+renesas@xxxxxxxxx>
> Subject: Re: [PATCH v2] pwm: fix pwm-rz-mtu3.c build errors
> 
> On Tue, Jul 18, 2023 at 11:26:28AM +0000, Biju Das wrote:
> > Hi Randy,
> >
> > > -----Original Message-----
> > > From: Randy Dunlap <rd.dunlab@xxxxxxxxx>
> > > Sent: Tuesday, July 18, 2023 7:41 AM
> > > To: linux-kernel@xxxxxxxxxxxxxxx; linux-pwm@xxxxxxxxxxxxxxx
> > > Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>; Thierry Reding
> > > <thierry.reding@xxxxxxxxx>; Uwe Kleine-König <u.kleine-
> > > koenig@xxxxxxxxxxxxxx>
> > > Subject: [PATCH v2] pwm: fix pwm-rz-mtu3.c build errors
> > >
> > > From: Randy Dunlap <rd.dunlab@xxxxxxxxx>
> > >
> > > When (MFD) RZ_MTU3=m and PWM_RZ_MTU3=y, there are numerous build
> errors:
> > >
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> > > drivers/pwm/pwm-rz-mtu3.c:374: undefined reference to
> `rz_mtu3_disable'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:377: undefined reference to
> > > `rz_mtu3_8bit_ch_write'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_write_tgr_registers':
> > > drivers/pwm/pwm-rz-mtu3.c:110: undefined reference to
> > > `rz_mtu3_16bit_ch_write'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> > > drivers/pwm/pwm-rz-mtu3.c:382: undefined reference to
> > > `rz_mtu3_8bit_ch_write'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_write_tgr_registers':
> > > drivers/pwm/pwm-rz-mtu3.c:110: undefined reference to
> > > `rz_mtu3_16bit_ch_write'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:111: undefined reference to
> > > `rz_mtu3_16bit_ch_write'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_config':
> > > drivers/pwm/pwm-rz-mtu3.c:397: undefined reference to
> `rz_mtu3_enable'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_disable':
> > > drivers/pwm/pwm-rz-mtu3.c:259: undefined reference to
> > > `rz_mtu3_8bit_ch_write'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:264: undefined reference to
> > > `rz_mtu3_disable'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_enable':
> > > drivers/pwm/pwm-rz-mtu3.c:230: undefined reference to
> > > `rz_mtu3_8bit_ch_write'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:234: undefined reference to
> > > `rz_mtu3_8bit_ch_write'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:238: undefined reference to
> `rz_mtu3_enable'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_is_ch_enabled':
> > > drivers/pwm/pwm-rz-mtu3.c:155: undefined reference to
> `rz_mtu3_is_enabled'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:162: undefined reference to
> > > `rz_mtu3_8bit_ch_read'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_read_tgr_registers':
> > > drivers/pwm/pwm-rz-mtu3.c:102: undefined reference to
> > > `rz_mtu3_16bit_ch_read'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:102: undefined reference to
> > > `rz_mtu3_16bit_ch_read'
> > > ld: drivers/pwm/pwm-rz-mtu3.c:103: undefined reference to
> > > `rz_mtu3_16bit_ch_read'
> > > ld: vmlinux.o: in function `rz_mtu3_pwm_get_state':
> > > drivers/pwm/pwm-rz-mtu3.c:296: undefined reference to
> > > `rz_mtu3_8bit_ch_read'
> > >
> > > Modify the dependencies of PWM_RZ_MTU3 so that COMPILE_TEST is still
> > > allowed but PWM_RZ_MTU3 depends on RZ_MTU3 if it is being built but
> > > also allow the latter not to be built.
> > >
> > > Fixes: 254d3a727421 ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
> > > Signed-off-by: Randy Dunlap <rd.dunlab@xxxxxxxxx
> > > Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> > > Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
> > > Cc: linux-pwm@xxxxxxxxxxxxxxx
> > > ---
> > > v2: fix typo in Subject;
> > >     correct my email address while infradead.org is down;
> > >
> > >  drivers/pwm/Kconfig |    3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff -- a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> > > --- a/drivers/pwm/Kconfig
> > > +++ b/drivers/pwm/Kconfig
> > > @@ -505,7 +505,8 @@ config PWM_ROCKCHIP
> > >
> > >  config PWM_RZ_MTU3
> > >  	tristate "Renesas RZ/G2L MTU3a PWM Timer support"
> > > -	depends on RZ_MTU3 || COMPILE_TEST
> > > +	depends on COMPILE_TEST
> > > +	depends on RZ_MTU3 || RZ_MTU3=n
> > >  	depends on HAS_IOMEM
> > >  	help
> > >  	  This driver exposes the MTU3a PWM Timer controller found in
> >
> >
> > The below patch also works fine,
> >
> > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index
> > 1c8dbb064ee5..56ab2f4b91fe 100644
> > --- a/drivers/pwm/Kconfig
> > +++ b/drivers/pwm/Kconfig
> > @@ -505,7 +505,7 @@ config PWM_ROCKCHIP
> >
> >  config PWM_RZ_MTU3
> >         tristate "Renesas RZ/G2L MTU3a PWM Timer support"
> > -       depends on RZ_MTU3 || COMPILE_TEST
> > +       depends on RZ_MTU3 || (COMPILE_TEST && RZ_MTU3)
> 
> That's a bit pointless, isn't it? That effectively reduces to just:
> 
> 	depends on RZ_MTU3

OK, then Uwe's solution is better.

ie, use the existing "depends on RZ_MTU3 || COMPILE_TEST"

and use

-#if IS_ENABLED(CONFIG_RZ_MTU3)

+#if IS_REACHABLE(CONFIG_RZ_MTU3) in include/linux/mfd/rz-mtu3.h

Cheers,
Biju