RE: [PATCH] mfd: rz-mtu3: link time dependencies

[Biju Das]

Hi Arnd,

Thanks for the patch. It is inline with[1]

[1] https://patchwork.ozlabs.org/project/linux-pwm/patch/ac8d6190-06ae-b538-1293-07efedbfe94e@xxxxxxxxx/#3150120

> -----Original Message-----
> From: Arnd Bergmann <arnd@xxxxxxxxxx>
> Sent: Wednesday, July 19, 2023 10:02 AM
> To: William Breathitt Gray <william.gray@xxxxxxxxxx>; Thierry Reding
> <thierry.reding@xxxxxxxxx>; Lee Jones <lee@xxxxxxxxxx>; Uwe Kleine-König
> <u.kleine-koenig@xxxxxxxxxxxxxx>; Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>; Peter Robinson
> <pbrobinson@xxxxxxxxx>; linux-iio@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-pwm@xxxxxxxxxxxxxxx
> Subject: [PATCH] mfd: rz-mtu3: link time dependencies
> 
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> The new set of drivers for RZ/G2L MTU3a tries to enable compile-testing
> the individual client drivers even when the MFD portion is disabled but
> gets it wrong, causing a link failure when the core is in a loadable
> module but the other drivers are built-in:
> 
> x86_64-linux-ld: drivers/pwm/pwm-rz-mtu3.o: in function
> `rz_mtu3_pwm_apply':
> pwm-rz-mtu3.c:(.text+0x4bf): undefined reference to
> `rz_mtu3_8bit_ch_write'
> x86_64-linux-ld: pwm-rz-mtu3.c:(.text+0x509): undefined reference to
> `rz_mtu3_disable'
> 
> arm-linux-gnueabi-ld: drivers/counter/rz-mtu3-cnt.o: in function
> `rz_mtu3_cascade_counts_enable_get':
> rz-mtu3-cnt.c:(.text+0xbec): undefined reference to
> `rz_mtu3_shared_reg_read'
> 
> It seems better not to add the extra complexity here but instead just
> use a normal hard dependency, so remove the #else portion in the header
> along with the "|| COMPILE_TEST". This could also be fixed by having
> slightly more elaborate Kconfig dependencies or using the cursed
> 'IS_REACHABLE()' helper, but in practice it's already possible to
> compile-test all these drivers by enabling the mtd portion.

Typo "mtd"->"mfd"

Otherwise looks good to me.

Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Cheers,
Biju

> 
> Fixes: 254d3a727421c ("pwm: Add Renesas RZ/G2L MTU3a PWM driver")
> Fixes: 0be8907359df4 ("counter: Add Renesas RZ/G2L MTU3a counter
> driver")
> Fixes: 654c293e1687b ("mfd: Add Renesas RZ/G2L MTU3a core driver")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/counter/Kconfig     |  2 +-
>  drivers/pwm/Kconfig         |  2 +-
>  include/linux/mfd/rz-mtu3.h | 66 -------------------------------------
>  3 files changed, 2 insertions(+), 68 deletions(-)
> 
> diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index
> 62962ae84b77d..497bc05dca4df 100644
> --- a/drivers/counter/Kconfig
> +++ b/drivers/counter/Kconfig
> @@ -92,7 +92,7 @@ config MICROCHIP_TCB_CAPTURE
> 
>  config RZ_MTU3_CNT
>  	tristate "Renesas RZ/G2L MTU3a counter driver"
> -	depends on RZ_MTU3 || COMPILE_TEST
> +	depends on RZ_MTU3
>  	help
>  	  Enable support for MTU3a counter driver found on Renesas RZ/G2L
> alike
>  	  SoCs. This IP supports both 16-bit and 32-bit phase counting
> mode diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index
> 6210babb0741a..8ebcddf91f7b7 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
>  	depends on HAS_IOMEM
>  	help
>  	  This driver exposes the MTU3a PWM Timer controller found in
> Renesas diff --git a/include/linux/mfd/rz-mtu3.h b/include/linux/mfd/rz-
> mtu3.h index c5173bc062701..8421d49500bf4 100644
> --- a/include/linux/mfd/rz-mtu3.h
> +++ b/include/linux/mfd/rz-mtu3.h
> @@ -151,7 +151,6 @@ struct rz_mtu3 {
>  	void *priv_data;
>  };
> 
> -#if IS_ENABLED(CONFIG_RZ_MTU3)
>  static inline bool rz_mtu3_request_channel(struct rz_mtu3_channel *ch)
> {
>  	mutex_lock(&ch->lock);
> @@ -188,70 +187,5 @@ void rz_mtu3_32bit_ch_write(struct rz_mtu3_channel
> *ch, u16 off, u32 val);  void rz_mtu3_shared_reg_write(struct
> rz_mtu3_channel *ch, u16 off, u16 val);  void
> rz_mtu3_shared_reg_update_bit(struct rz_mtu3_channel *ch, u16 off,
>  				   u16 pos, u8 val);
> -#else
> -static inline bool rz_mtu3_request_channel(struct rz_mtu3_channel *ch)
> -{
> -	return false;
> -}
> -
> -static inline void rz_mtu3_release_channel(struct rz_mtu3_channel *ch)
> -{ -}
> -
> -static inline bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch) -{
> -	return false;
> -}
> -
> -static inline void rz_mtu3_disable(struct rz_mtu3_channel *ch) -{ -}
> -
> -static inline int rz_mtu3_enable(struct rz_mtu3_channel *ch) -{
> -	return 0;
> -}
> -
> -static inline u8 rz_mtu3_8bit_ch_read(struct rz_mtu3_channel *ch, u16
> off) -{
> -	return 0;
> -}
> -
> -static inline u16 rz_mtu3_16bit_ch_read(struct rz_mtu3_channel *ch, u16
> off) -{
> -	return 0;
> -}
> -
> -static inline u32 rz_mtu3_32bit_ch_read(struct rz_mtu3_channel *ch, u16
> off) -{
> -	return 0;
> -}
> -
> -static inline u16 rz_mtu3_shared_reg_read(struct rz_mtu3_channel *ch,
> u16 off) -{
> -	return 0;
> -}
> -
> -static inline void rz_mtu3_8bit_ch_write(struct rz_mtu3_channel *ch,
> u16 off, u8 val) -{ -}
> -
> -static inline void rz_mtu3_16bit_ch_write(struct rz_mtu3_channel *ch,
> u16 off, u16 val) -{ -}
> -
> -static inline void rz_mtu3_32bit_ch_write(struct rz_mtu3_channel *ch,
> u16 off, u32 val) -{ -}
> -
> -static inline void rz_mtu3_shared_reg_write(struct rz_mtu3_channel *ch,
> u16 off, u16 val) -{ -}
> -
> -static inline void rz_mtu3_shared_reg_update_bit(struct rz_mtu3_channel
> *ch,
> -						 u16 off, u16 pos, u8 val)
> -{
> -}
> -#endif
> 
>  #endif /* __MFD_RZ_MTU3_H__ */
> --
> 2.39.2