drivers/tty/serial/8250/8250_aspeed_vuart.c:50:17: error: implicit declaration of function 'FIELD_PREP'

tree:   https://github.com/intel-lab-lkp/linux/commits/Gr-goire-Layet/dt-bindings-serial-8250-aspeed-add-ast2600-and-aspeed-vuart-over-pci/20260818-102914
head:   28e6fa9a9ae89ef5b7ad92e1df59fea67a5f7c0d
commit: 98949d2e1e8bfc6849ee8ee049efd883ddd970ba serial: 8250_aspeed_vuart: add VUART over PCI
date:   34 hours ago
config: powerpc-allmodconfig (https://download.01.org/0day-ci/archive/20260822/[email protected]/config)
compiler: powerpc64-linux-gcc (GCC) 16.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260822/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All errors (new ones prefixed by >>):

   drivers/tty/serial/8250/8250_aspeed_vuart.c: In function 'aspeed_ast2600_vuart_over_pci_set_enabled':
>> drivers/tty/serial/8250/8250_aspeed_vuart.c:50:17: error: implicit declaration of function 'FIELD_PREP' [-Wimplicit-function-declaration]
      50 |                 FIELD_PREP(ASPEED_SCUC24_MSI_ROUTING_MASK, 2)
         |                 ^~~~~~~~~~
   drivers/tty/serial/8250/8250_aspeed_vuart.c:480:41: note: in expansion of macro 'ASPEED_SCUC24_MSI_ROUTING_PCIE2LPC_PCIDEV1'
     480 |                                         ASPEED_SCUC24_MSI_ROUTING_PCIE2LPC_PCIDEV1);
         |                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/FIELD_PREP +50 drivers/tty/serial/8250/8250_aspeed_vuart.c

    46	
    47	#define ASPEED_SCUC24 0xC24
    48	#define  ASPEED_SCUC24_MSI_ROUTING_MASK				GENMASK(11, 10)
    49	#define  ASPEED_SCUC24_MSI_ROUTING_PCIE2LPC_PCIDEV1 \
  > 50			FIELD_PREP(ASPEED_SCUC24_MSI_ROUTING_MASK, 2)
    51	#define  ASPEED_SCUC24_RESERVED_14					BIT(14)
    52	#define  ASPEED_SCUC24_PCIDEV1_INTX_MSI_SCU560_EN	BIT(17)
    53	#define  ASPEED_SCUC24_PCIDEV1_INTX_MSI_HOST2BMC_EN	BIT(18)
    54	

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