Re: [PATCH v4 2/3] serial: 8250: Add Loongson uart driver support

[kernel test robot <lkp@intel.com>]

Hi Binbin,

kernel test robot noticed the following build warnings:

[auto build test WARNING on b601e1f41edd4667062aa7cccb4e5199814979a3]

url:    https://github.com/intel-lab-lkp/linux/commits/Binbin-Zhou/dt-bindings-serial-Add-Loongson-UART-controller/20250909-201640
base:   b601e1f41edd4667062aa7cccb4e5199814979a3
patch link:    https://lore.kernel.org/r/91ae8cd4f903ac452e337e4662bbabf8a412b061.1757318368.git.zhoubinbin%40loongson.cn
patch subject: [PATCH v4 2/3] serial: 8250: Add Loongson uart driver support
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20250910/202509102107.dmwhCV71-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250910/202509102107.dmwhCV71-lkp@intel.com/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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509102107.dmwhCV71-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/tty/serial/8250/8250_loongson.c: In function 'loongson_uart_probe':
   drivers/tty/serial/8250/8250_loongson.c:102:9: error: implicit declaration of function 'device_property_read_u32' [-Wimplicit-function-declaration]
     102 |         device_property_read_u32(dev, "clock-frequency", &uart.port.uartclk);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/tty/serial/8250/8250_loongson.c:117:28: error: implicit declaration of function 'device_get_match_data'; did you mean 'device_match_any'? [-Wimplicit-function-declaration]
     117 |         flags = (uintptr_t)device_get_match_data(dev);
         |                            ^~~~~~~~~~~~~~~~~~~~~
         |                            device_match_any
   drivers/tty/serial/8250/8250_loongson.c: At top level:
   drivers/tty/serial/8250/8250_loongson.c:179:34: error: array type has incomplete element type 'struct of_device_id'
     179 | static const struct of_device_id loongson_uart_of_ids[] = {
         |                                  ^~~~~~~~~~~~~~~~~~~~
>> drivers/tty/serial/8250/8250_loongson.c:179:34: warning: 'loongson_uart_of_ids' defined but not used [-Wunused-variable]


vim +/loongson_uart_of_ids +179 drivers/tty/serial/8250/8250_loongson.c

   175	
   176	static DEFINE_SIMPLE_DEV_PM_OPS(loongson_uart_pm_ops, loongson_uart_suspend,
   177					loongson_uart_resume);
   178	
 > 179	static const struct of_device_id loongson_uart_of_ids[] = {
   180		{ .compatible = "loongson,ls2k0500-uart", .data = (void *)LS2K0500_UART_FLAG },
   181		{ .compatible = "loongson,ls2k1500-uart", .data = (void *)LS2K1500_UART_FLAG },
   182		{ /* sentinel */ },
   183	};
   184	MODULE_DEVICE_TABLE(of, loongson_uart_of_ids);
   185	

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