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spivar.h revision 1.4 
      1 /* $NetBSD: spivar.h,v 1.4 2011/06/08 23:05:48 rmind 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 #include <sys/simplelock.h>
     49 
     50 /*
     51  * Serial Peripheral Interface bus.  This is a 4-wire bus common for
     52  * connecting flash, clocks, sensors, and various other low-speed
     53  * peripherials.
     54  */
     55 
     56 struct spi_handle;
     57 struct spi_transfer;
     58 
     59 /*
     60  * De facto standard latching modes.
     61  */
     62 #define	SPI_MODE_0	0	/* CPOL = 0, CPHA = 0 */
     63 #define	SPI_MODE_1	1	/* CPOL = 0, CPHA = 1 */
     64 #define	SPI_MODE_2	2	/* CPOL = 1, CPHA = 0 */
     65 #define	SPI_MODE_3	3	/* CPOL = 1, CPHA = 1 */
     66 /* Philips' Microwire is just Mode 0 */
     67 #define	SPI_MODE_MICROWIRE	SPI_MODE_0
     68 
     69 struct spi_controller {
     70 	void	*sct_cookie;	/* controller private data */
     71 	int	sct_nslaves;
     72 	int	(*sct_configure)(void *, int, int, int);
     73 	int	(*sct_transfer)(void *, struct spi_transfer *);
     74 };
     75 
     76 int spibus_print(void *, const char *);
     77 
     78 /* one per chip select */
     79 struct spibus_attach_args {
     80 	struct spi_controller	*sba_controller;
     81 };
     82 
     83 struct spi_attach_args {
     84 	struct spi_handle	*sa_handle;
     85 };
     86 
     87 /*
     88  * This is similar in some respects to struct buf, but we cannot use
     89  * that structure because it was not designed to support full-duplex
     90  * IO.
     91  */
     92 struct spi_chunk {
     93 	struct spi_chunk *chunk_next;
     94 	int		chunk_count;
     95 	uint8_t		*chunk_read;
     96 	const uint8_t	*chunk_write;
     97 	/* for private use by framework and bus driver */
     98 	uint8_t		*chunk_rptr;
     99 	const uint8_t	*chunk_wptr;
    100 	int		chunk_rresid;
    101 	int		chunk_wresid;
    102 };
    103 
    104 struct spi_transfer {
    105 	struct spi_chunk *st_chunks;		/* chained bufs */
    106 	SIMPLEQ_ENTRY(spi_transfer) st_chain;	/* chain of submitted jobs */
    107 	int		st_flags;
    108 	int		st_errno;
    109 	int		st_slave;
    110 	void		*st_private;
    111 	void		(*st_done)(struct spi_transfer *);
    112 	kmutex_t	st_lock;
    113 	kcondvar_t	st_cv;
    114 	void		*st_busprivate;
    115 };
    116 
    117 /* declare a list of transfers */
    118 SIMPLEQ_HEAD(spi_transq, spi_transfer);
    119 
    120 #define	spi_transq_init(q)	\
    121 	SIMPLEQ_INIT(q)
    122 
    123 #define	spi_transq_enqueue(q, trans)	\
    124 	SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
    125 
    126 #define	spi_transq_dequeue(q)		\
    127 	SIMPLEQ_REMOVE_HEAD(q, st_chain)
    128 
    129 #define	spi_transq_first(q)		\
    130 	SIMPLEQ_FIRST(q)
    131 
    132 #define	SPI_F_DONE		0x0001
    133 #define	SPI_F_ERROR		0x0002
    134 
    135 int spi_configure(struct spi_handle *, int mode, int speed);
    136 int spi_transfer(struct spi_handle *, struct spi_transfer *);
    137 void spi_transfer_init(struct spi_transfer *);
    138 void spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
    139 void spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
    140 void spi_wait(struct spi_transfer *);
    141 void spi_done(struct spi_transfer *, int);
    142 
    143 /* convenience wrappers */
    144 int spi_send(struct spi_handle *, int, const uint8_t *);
    145 int spi_recv(struct spi_handle *, int, uint8_t *);
    146 int spi_send_recv(struct spi_handle *, int, const uint8_t *, int, uint8_t *);
    147 
    148 #endif	/* _DEV_SPI_SPIVAR_H_ */
    149