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spivar.h revision 1.2 
      1 /* $NetBSD: spivar.h,v 1.2 2006/10/07 07:21:13 gdamore Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2006 Urbana-Champaign Independent Media Center.
      5  * Copyright (c) 2006 Garrett D'Amore.
      6  * All rights reserved.
      7  *
      8  * Portions of this code were written by Garrett D'Amore for the
      9  * Champaign-Urbana Community Wireless Network Project.
     10  *
     11  * Redistribution and use in source and binary forms, with or
     12  * without modification, are permitted provided that the following
     13  * conditions are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above
     17  *    copyright notice, this list of conditions and the following
     18  *    disclaimer in the documentation and/or other materials provided
     19  *    with the distribution.
     20  * 3. All advertising materials mentioning features or use of this
     21  *    software must display the following acknowledgements:
     22  *      This product includes software developed by the Urbana-Champaign
     23  *      Independent Media Center.
     24  *	This product includes software developed by Garrett D'Amore.
     25  * 4. Urbana-Champaign Independent Media Center's name and Garrett
     26  *    D'Amore's name may not be used to endorse or promote products
     27  *    derived from this software without specific prior written permission.
     28  *
     29  * THIS SOFTWARE IS PROVIDED BY THE URBANA-CHAMPAIGN INDEPENDENT
     30  * MEDIA CENTER AND GARRETT D'AMORE ``AS IS'' AND ANY EXPRESS OR
     31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     32  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE URBANA-CHAMPAIGN INDEPENDENT
     34  * MEDIA CENTER OR GARRETT D'AMORE BE LIABLE FOR ANY DIRECT, INDIRECT,
     35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     37  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     38  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     40  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     41  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     42  */
     43 
     44 #ifndef	_DEV_SPI_SPIVAR_H_
     45 #define	_DEV_SPI_SPIVAR_H_
     46 
     47 #include <sys/queue.h>
     48 
     49 /*
     50  * Serial Peripheral Interface bus.  This is a 4-wire bus common for
     51  * connecting flash, clocks, sensors, and various other low-speed
     52  * peripherials.
     53  */
     54 
     55 struct spi_handle;
     56 struct spi_transfer;
     57 
     58 /*
     59  * De facto standard latching modes.
     60  */
     61 #define	SPI_MODE_0	0	/* CPOL = 0, CPHA = 0 */
     62 #define	SPI_MODE_1	1	/* CPOL = 0, CPHA = 1 */
     63 #define	SPI_MODE_2	2	/* CPOL = 1, CPHA = 0 */
     64 #define	SPI_MODE_3	3	/* CPOL = 1, CPHA = 1 */
     65 /* Philips' Microwire is just Mode 0 */
     66 #define	SPI_MODE_MICROWIRE	SPI_MODE_0
     67 
     68 struct spi_controller {
     69 	void	*sct_cookie;	/* controller private data */
     70 	int	sct_nslaves;
     71 	int	(*sct_configure)(void *, int, int, int);
     72 	int	(*sct_transfer)(void *, struct spi_transfer *);
     73 };
     74 
     75 int spibus_print(void *, const char *);
     76 
     77 /* one per chip select */
     78 struct spibus_attach_args {
     79 	struct spi_controller	*sba_controller;
     80 };
     81 
     82 struct spi_attach_args {
     83 	struct spi_handle	*sa_handle;
     84 };
     85 
     86 /*
     87  * This is similar in some respects to struct buf, but we cannot use
     88  * that structure because it was not designed to support full-duplex
     89  * IO.
     90  */
     91 struct spi_chunk {
     92 	struct spi_chunk *chunk_next;
     93 	int		chunk_count;
     94 	uint8_t		*chunk_read;
     95 	const uint8_t	*chunk_write;
     96 	/* for private use by framework and bus driver */
     97 	uint8_t		*chunk_rptr;
     98 	const uint8_t	*chunk_wptr;
     99 	int		chunk_rresid;
    100 	int		chunk_wresid;
    101 };
    102 
    103 struct spi_transfer {
    104 	struct spi_chunk *st_chunks;		/* chained bufs */
    105 	SIMPLEQ_ENTRY(spi_transfer) st_chain;	/* chain of submitted jobs */
    106 	int		st_flags;
    107 	int		st_errno;
    108 	int		st_slave;
    109 	void		*st_private;
    110 	void		(*st_done)(struct spi_transfer *);
    111 	struct simplelock	st_lock;
    112 	void		*st_busprivate;
    113 };
    114 
    115 /* declare a list of transfers */
    116 SIMPLEQ_HEAD(spi_transq, spi_transfer);
    117 
    118 #define	spi_transq_init(q)	\
    119 	SIMPLEQ_INIT(q)
    120 
    121 #define	spi_transq_enqueue(q, trans)	\
    122 	SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
    123 
    124 #define	spi_transq_dequeue(q)		\
    125 	SIMPLEQ_REMOVE_HEAD(q, st_chain)
    126 
    127 #define	spi_transq_first(q)		\
    128 	SIMPLEQ_FIRST(q)
    129 
    130 #define	SPI_F_DONE		0x0001
    131 #define	SPI_F_ERROR		0x0002
    132 
    133 int spi_configure(struct spi_handle *, int mode, int speed);
    134 int spi_transfer(struct spi_handle *, struct spi_transfer *);
    135 void spi_transfer_init(struct spi_transfer *);
    136 void spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
    137 void spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
    138 void spi_wait(struct spi_transfer *);
    139 void spi_done(struct spi_transfer *, int);
    140 
    141 /* convenience wrappers */
    142 int spi_send(struct spi_handle *, int, const uint8_t *);
    143 int spi_recv(struct spi_handle *, int, uint8_t *);
    144 int spi_send_recv(struct spi_handle *, int, const uint8_t *, int, uint8_t *);
    145 
    146 #endif	/* _DEV_SPI_SPIVAR_H_ */
    147