The driver calls ocelot_regmap_from_resource() via <linux/mfd/ocelot.h>,
which internally uses devm_regmap_init_mmio() and requires REGMAP_MMIO.
The Kconfig entry does not select REGMAP_MMIO, causing a build failure
when no other driver in the config happens to pull in REGMAP_MMIO:

  include/linux/mfd/ocelot.h:34:24: error: implicit declaration of function 'devm_regmap_init_mmio'

Found by randconfig testing on arm64; tinyconfig reproducer below.

Fixes: 2afbbab45c26 ("pinctrl: microchip-sgpio: update to support regmap")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Boortz <bennib@mailbox.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
---
Reproducer (tinyconfig, arm64, without patch):

  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- tinyconfig
  scripts/config --enable CONFIG_PINCTRL
  scripts/config --enable CONFIG_GPIOLIB
  scripts/config --enable CONFIG_PINCTRL_MICROCHIP_SGPIO
  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
      drivers/pinctrl/pinctrl-microchip-sgpio.o
  -> CONFIG_REGMAP_MMIO absent, build fails as shown above.

 drivers/pinctrl/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index c2cdd7b2c49b..23ea76dc6261 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -426,6 +426,7 @@ config PINCTRL_MICROCHIP_SGPIO
 	select GENERIC_PINCONF
 	select GENERIC_PINCTRL_GROUPS
 	select GENERIC_PINMUX_FUNCTIONS
+	select REGMAP_MMIO
 	help
 	  Support for the serial GPIO interface used on Microsemi and
 	  Microchip SoCs. By using a serial interface, the SIO
-- 
2.55.0

On Sun, Jul 19, 2026 at 11:41:46AM +0200, Benjamin Boortz wrote:
> The driver calls ocelot_regmap_from_resource() via <linux/mfd/ocelot.h>,
> which internally uses devm_regmap_init_mmio() and requires REGMAP_MMIO.
> The Kconfig entry does not select REGMAP_MMIO, causing a build failure
> when no other driver in the config happens to pull in REGMAP_MMIO:
> 
>   include/linux/mfd/ocelot.h:34:24: error: implicit declaration of function 'devm_regmap_init_mmio'
> 
> Found by randconfig testing on arm64; tinyconfig reproducer below.
> 
> Fixes: 2afbbab45c26 ("pinctrl: microchip-sgpio: update to support regmap")
> Cc: stable@vger.kernel.org
> Signed-off-by: Benjamin Boortz <bennib@mailbox.org>
> Reviewed-by: Andy Shevchenko <andy@kernel.org>
> ---

This is v2. It misses a changelog here.

No need to resend _this_ time, just reply to this query with
what has been changed v1..v2.

-- 
With Best Regards,
Andy Shevchenko

On Sun, Jul 19, 2026 at 12:49:18PM +0300, Andy Shevchenko wrote:

>On Sun, Jul 19, 2026 at 11:41:46AM +0200, Benjamin Boortz wrote:
>> The driver calls ocelot_regmap_from_resource() via <linux/mfd/ocelot.h>,
>> which internally uses devm_regmap_init_mmio() and requires REGMAP_MMIO.
>> The Kconfig entry does not select REGMAP_MMIO, causing a build failure
>> when no other driver in the config happens to pull in REGMAP_MMIO:
>>
>>   include/linux/mfd/ocelot.h:34:24: error: implicit declaration of function 'devm_regmap_init_mmio'
>>
>> Found by randconfig testing on arm64; tinyconfig reproducer below.
>>
>> Fixes: 2afbbab45c26 ("pinctrl: microchip-sgpio: update to support regmap")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Benjamin Boortz <bennib@mailbox.org>
>> Reviewed-by: Andy Shevchenko <andy@kernel.org>
>> ---
>
>This is v2. It misses a changelog here.
>
>No need to resend _this_ time, just reply to this query with
>what has been changed v1..v2.
>
>-- 
>With Best Regards,
>Andy Shevchenko
>
>

Changes in v2:
- Reduced error block to one most significant line
- Fixed Fixes: tag to 2afbbab45c26 ("pinctrl: microchip-sgpio: update to support regmap")
- Added Reviewed-by 

BR,
Benni Boortz