[PATCH 08/10] dmaengine: Add RDA IFC driver

[kernel test robot]

Hi Dang,

kernel test robot noticed the following build errors:

[auto build test ERROR on ae2d20002576d2893ecaff25db3d7ef9190ac0b6]

url:    https://github.com/intel-lab-lkp/linux/commits/Dang-Huynh-via-B4-Relay/dt-bindings-gpio-rda-Make-interrupts-optional/20250919-025331
base:   ae2d20002576d2893ecaff25db3d7ef9190ac0b6
patch link:    https://lore.kernel.org/r/20250919-rda8810pl-mmc-v1-8-d4f08a05ba4d%40mainlining.org
patch subject: [PATCH 08/10] dmaengine: Add RDA IFC driver
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20250921/202509211252.z0s0XcXk-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/20250921/202509211252.z0s0XcXk-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 at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509211252.z0s0XcXk-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/dma/rda-ifc.c: In function 'rda_ifc_prep_slave_sg':
>> drivers/dma/rda-ifc.c:180:28: error: implicit declaration of function 'FIELD_PREP' [-Wimplicit-function-declaration]
     180 |                 control |= FIELD_PREP(IFC_CTL_SIZE, 0);
         |                            ^~~~~~~~~~


vim +/FIELD_PREP +180 drivers/dma/rda-ifc.c

   145	
   146	static struct dma_async_tx_descriptor *rda_ifc_prep_slave_sg(struct dma_chan *chan,
   147			struct scatterlist *sgl, unsigned int sg_len,
   148			enum dma_transfer_direction direction, unsigned long dma_flags,
   149			void *context)
   150	{
   151		struct rda_ifc_chan *ifc_chan = to_ifc_chan(chan);
   152		struct rda_ifc *ifc = ifc_chan->rda_ifc;
   153		struct device *dev = dmaengine_get_dma_device(chan);
   154		struct scatterlist *sg;
   155		unsigned long flags;
   156		u32 control = 0;
   157		int width;
   158		int i;
   159	
   160		if (sg_len > ifc->sg_max) {
   161			dev_err(dev, "sg_len %d overflowed (max sg %d)\n",
   162					sg_len, ifc->sg_max);
   163			return NULL;
   164		}
   165	
   166		if (direction != ifc_chan->direction) {
   167			dev_err(dev, "Inconsistent transfer direction\n");
   168			return NULL;
   169		}
   170	
   171		spin_lock_irqsave(&ifc_chan->lock, flags);
   172	
   173		if (ifc_chan->direction == DMA_DEV_TO_MEM)
   174			width = ifc_chan->sconfig.src_addr_width;
   175		else
   176			width = ifc_chan->sconfig.dst_addr_width;
   177	
   178		switch (width) {
   179		case DMA_SLAVE_BUSWIDTH_1_BYTE:
 > 180			control |= FIELD_PREP(IFC_CTL_SIZE, 0);
   181			break;
   182		case DMA_SLAVE_BUSWIDTH_2_BYTES:
   183			control |= FIELD_PREP(IFC_CTL_SIZE, 1);
   184			break;
   185		case DMA_SLAVE_BUSWIDTH_4_BYTES:
   186			control |= FIELD_PREP(IFC_CTL_SIZE, 2);
   187			break;
   188		default:
   189			return NULL;
   190		}
   191	
   192		for_each_sg(sgl, sg, sg_len, i) {
   193			if (!IS_ALIGNED(sg_dma_address(sg), width)) {
   194				dev_err(dev, "Unaligned DMA address\n");
   195				spin_unlock_irqrestore(&ifc_chan->lock, flags);
   196				return NULL;
   197			}
   198	
   199			writel(sg_dma_address(sg), ifc_chan->chan_base + IFC_REG_SG_START_ADDR + (8 * i));
   200			writel(sg_dma_len(sg), ifc_chan->chan_base + IFC_REG_SG_TC + (8 * i));
   201		}
   202	
   203		control |= FIELD_PREP(IFC_CTL_REQ_SRC, ifc_chan->request_id) |
   204			IFC_CTL_CH_RD_HW_EXCH |
   205			FIELD_PREP(IFC_CTL_SG_NUM, sg_len-1);
   206		writel(control, ifc_chan->chan_base);
   207	
   208		spin_unlock_irqrestore(&ifc_chan->lock, flags);
   209	
   210		dma_async_tx_descriptor_init(&ifc_chan->tx, chan);
   211		ifc_chan->tx.tx_submit = rda_ifc_tx_submit;
   212	
   213		return &ifc_chan->tx;
   214	}
   215	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki