Home | History | Annotate | Download | only in dev

Lines Matching refs:DMA

1 /*	$NetBSD: dma.c,v 1.29 2023/01/06 10:28:28 tsutsui Exp $	*/
29  * This file contains special code dealing with the DMA interface
32  * The DMA circuitry requires some special treatment for the peripheral
33  * devices which make use of the ST's DMA feature (the hard disk and the
35  * All devices using DMA need mutually exclusive access and can follow some
40  *	st_dmagrab:	ensure exclusive access to the DMA circuitry
41  *	st_dmafree:	free exclusive access to the DMA circuitry
42  *	st_dmawanted:	somebody is queued waiting for DMA-access
43  *	dmaint:		DMA interrupt routine, switches to the current driver
45  *	st_dmaaddr_get:	get address of last DMA-op
46  *	st_dmacomm:	program DMA, flush FIFO first
50 __KERNEL_RCSID(0, "$NetBSD: dma.c,v 1.29 2023/01/06 10:28:28 tsutsui Exp $");
60 #include <machine/dma.h>
67 	void		(*int_func)(void *);	/* Call on DMA interrupt   */
69 	int		*lock_stat;		/* status of DMA lock	   */
217 		 * Due to the logic of the ST-DMA chip, it is not possible to
229  * Setup address for DMA-transfer.
237 	DMA->dma_addr[AD_LOW ] = (ad     ) & 0xff;
238 	DMA->dma_addr[AD_MID ] = (ad >> 8) & 0xff;
239 	DMA->dma_addr[AD_HIGH] = (ad >>16) & 0xff;
243  * Get address from DMA unit.
250 	ad  = (DMA->dma_addr[AD_LOW ] & 0xff);
251 	ad |= (DMA->dma_addr[AD_MID ] & 0xff) << 8;
252 	ad |= (DMA->dma_addr[AD_HIGH] & 0xff) <<16;
257  * Program the DMA-controller to transfer 'nblk' blocks of 512 bytes.
258  * The DMA_WRBIT trick flushes the FIFO before doing DMA.
264 	DMA->dma_mode = mode;
265 	DMA->dma_mode = mode ^ DMA_WRBIT;
266 	DMA->dma_mode = mode;
267 	DMA->dma_data = nblk;
269 	DMA->dma_mode = DMA_SCREG | (mode & DMA_WRBIT);