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spivar.h revision 1.24
      1 /* $NetBSD: spivar.h,v 1.24 2025/09/14 00:28:44 thorpej 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/device.h>
     48 #include <sys/queue.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  * peripherals.
     54  */
     55 
     56 struct spi_handle;
     57 struct spi_transfer;
     58 
     59 typedef struct spi_handle *spi_handle_t;
     60 
     61 #define	SPI_MODE_CPHA	__BIT(0)
     62 #define	SPI_MODE_CPOL	__BIT(1)
     63 
     64 /*
     65  * De facto standard latching modes.
     66  */
     67 #define	SPI_MODE_0	0
     68 #define	SPI_MODE_1	SPI_MODE_CPHA
     69 #define	SPI_MODE_2	SPI_MODE_CPOL
     70 #define	SPI_MODE_3	(SPI_MODE_CPHA | SPI_MODE_CPOL)
     71 
     72 /* Philips' Microwire is just Mode 0 */
     73 #define	SPI_MODE_MICROWIRE	SPI_MODE_0
     74 
     75 /* SPI transfer speed helper macros -- converts to Hz for spi_configure(). */
     76 #define	SPI_FREQ_kHz(x)	((x) * 1000)
     77 #define	SPI_FREQ_MHz(x)	((x) * 1000000)
     78 
     79 struct spi_controller {
     80 	void	*sct_cookie;	/* controller private data */
     81 	int	sct_nslaves;
     82 	int	(*sct_configure)(void *, int, int, int);
     83 	int	(*sct_transfer)(void *, struct spi_transfer *);
     84 };
     85 
     86 int	spibus_print(void *, const char *);
     87 
     88 struct spibus_attach_args {
     89 	const struct spi_controller *sba_controller;
     90 };
     91 
     92 struct spi_attach_args {
     93 	spi_handle_t	sa_handle;
     94 
     95 	/* only set if using direct config */
     96 	const char	*sa_name;	/* name of the device */
     97 	const char	*sa_clist;	/* compatible strlist */
     98 	size_t		sa_clist_size;	/* size of compatible strlist */
     99 	devhandle_t	sa_devhandle;	/* device handle for the device */
    100 };
    101 
    102 /*
    103  * This is similar in some respects to struct buf, but we cannot use
    104  * that structure because it was not designed to support full-duplex
    105  * IO.
    106  */
    107 struct spi_chunk {
    108 	struct spi_chunk *chunk_next;
    109 	int		chunk_count;
    110 	uint8_t		*chunk_read;
    111 	const uint8_t	*chunk_write;
    112 	/* for private use by framework and bus driver */
    113 	uint8_t		*chunk_rptr;
    114 	const uint8_t	*chunk_wptr;
    115 	int		chunk_rresid;
    116 	int		chunk_wresid;
    117 };
    118 
    119 struct spi_transfer {
    120 	struct spi_chunk *st_chunks;		/* chained bufs */
    121 	SIMPLEQ_ENTRY(spi_transfer) st_chain;	/* chain of submitted jobs */
    122 	volatile int	st_flags;
    123 	int		st_errno;
    124 	int		st_slave;
    125 	void		*st_private;
    126 	void		(*st_done)(struct spi_transfer *);
    127 	kmutex_t	st_lock;
    128 	kcondvar_t	st_cv;
    129 	void		*st_busprivate;
    130 	void		*st_spiprivate;
    131 };
    132 
    133 /* declare a list of transfers */
    134 SIMPLEQ_HEAD(spi_transq, spi_transfer);
    135 
    136 #define	spi_transq_init(q)	\
    137 	SIMPLEQ_INIT(q)
    138 
    139 #define	spi_transq_enqueue(q, trans)	\
    140 	SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
    141 
    142 #define	spi_transq_dequeue(q)		\
    143 	SIMPLEQ_REMOVE_HEAD(q, st_chain)
    144 
    145 #define	spi_transq_first(q)		\
    146 	SIMPLEQ_FIRST(q)
    147 
    148 #define	SPI_F_DONE		0x0001
    149 #define	SPI_F_ERROR		0x0002
    150 
    151 static inline device_t
    152 spibus_attach(device_t dev, const struct spi_controller *sct)
    153 {
    154 	struct spibus_attach_args sba = {
    155 		.sba_controller = sct,
    156 	};
    157 	return config_found(dev, &sba, spibus_print,
    158 	    CFARGS(.iattr = "spibus",
    159 		   .devhandle = device_handle(dev)));
    160 }
    161 
    162 /*
    163  * Constants to indicate the quality of a match made by a driver's
    164  * match routine, from lowest to highest:
    165  *
    166  *	-- Default indirect match; rely on kernel config file.
    167  *
    168  *	-- Direct-config match by "compatible" string.
    169  */
    170 #define	SPI_MATCH_DEFAULT		1
    171 #define	SPI_MATCH_DIRECT_COMPATIBLE	10	/* ...and up */
    172 
    173 bool	spi_use_direct_match(const struct spi_attach_args *,
    174 	    const struct device_compatible_entry *, int *);
    175 int	spi_compatible_match(const struct spi_attach_args *,
    176 	    const struct device_compatible_entry *);
    177 const struct device_compatible_entry *
    178 	spi_compatible_lookup(const struct spi_attach_args *,
    179 	    const struct device_compatible_entry *);
    180 
    181 int	spi_configure(device_t, spi_handle_t, int, int);
    182 int	spi_transfer(spi_handle_t, struct spi_transfer *);
    183 void	spi_transfer_init(struct spi_transfer *);
    184 void	spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
    185 void	spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
    186 void	spi_wait(struct spi_transfer *);
    187 void	spi_done(struct spi_transfer *, int);
    188 
    189 /* convenience wrappers */
    190 int	spi_send(spi_handle_t, int, const uint8_t *);
    191 int	spi_recv(spi_handle_t, int, uint8_t *);
    192 int	spi_send_recv(spi_handle_t, int, const uint8_t *, int, uint8_t *);
    193 
    194 #endif	/* _DEV_SPI_SPIVAR_H_ */
    195