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spivar.h revision 1.23
      1 /* $NetBSD: spivar.h,v 1.23 2025/09/13 17:51:08 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 /* one per chip select */
     89 struct spibus_attach_args {
     90 	const struct spi_controller *sba_controller;
     91 };
     92 
     93 struct spi_attach_args {
     94 	spi_handle_t		sa_handle;
     95 
     96 	/* only set if using direct config */
     97 	int		sa_ncompat;	/* number of pointers in the
     98 					   sa_compat array */
     99 	const char **	sa_compat;	/* chip names */
    100 	devhandle_t	sa_devhandle;	/* device handle for the device */
    101 };
    102 
    103 /*
    104  * This is similar in some respects to struct buf, but we cannot use
    105  * that structure because it was not designed to support full-duplex
    106  * IO.
    107  */
    108 struct spi_chunk {
    109 	struct spi_chunk *chunk_next;
    110 	int		chunk_count;
    111 	uint8_t		*chunk_read;
    112 	const uint8_t	*chunk_write;
    113 	/* for private use by framework and bus driver */
    114 	uint8_t		*chunk_rptr;
    115 	const uint8_t	*chunk_wptr;
    116 	int		chunk_rresid;
    117 	int		chunk_wresid;
    118 };
    119 
    120 struct spi_transfer {
    121 	struct spi_chunk *st_chunks;		/* chained bufs */
    122 	SIMPLEQ_ENTRY(spi_transfer) st_chain;	/* chain of submitted jobs */
    123 	volatile int	st_flags;
    124 	int		st_errno;
    125 	int		st_slave;
    126 	void		*st_private;
    127 	void		(*st_done)(struct spi_transfer *);
    128 	kmutex_t	st_lock;
    129 	kcondvar_t	st_cv;
    130 	void		*st_busprivate;
    131 	void		*st_spiprivate;
    132 };
    133 
    134 /* declare a list of transfers */
    135 SIMPLEQ_HEAD(spi_transq, spi_transfer);
    136 
    137 #define	spi_transq_init(q)	\
    138 	SIMPLEQ_INIT(q)
    139 
    140 #define	spi_transq_enqueue(q, trans)	\
    141 	SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
    142 
    143 #define	spi_transq_dequeue(q)		\
    144 	SIMPLEQ_REMOVE_HEAD(q, st_chain)
    145 
    146 #define	spi_transq_first(q)		\
    147 	SIMPLEQ_FIRST(q)
    148 
    149 #define	SPI_F_DONE		0x0001
    150 #define	SPI_F_ERROR		0x0002
    151 
    152 static inline device_t
    153 spibus_attach(device_t dev, const struct spi_controller *sct)
    154 {
    155 	struct spibus_attach_args sba = {
    156 		.sba_controller = sct,
    157 	};
    158 	return config_found(dev, &sba, spibus_print,
    159 	    CFARGS(.iattr = "spibus",
    160 		   .devhandle = device_handle(dev)));
    161 }
    162 
    163 /*
    164  * Constants to indicate the quality of a match made by a driver's
    165  * match routine, from lowest to highest:
    166  *
    167  *	-- Default indirect match; rely on kernel config file.
    168  *
    169  *	-- Direct-config match by "compatible" string.
    170  */
    171 #define	SPI_MATCH_DEFAULT		1
    172 #define	SPI_MATCH_DIRECT_COMPATIBLE	10	/* ...and up */
    173 
    174 bool	spi_use_direct_match(const struct spi_attach_args *,
    175 	    const struct device_compatible_entry *, int *);
    176 int	spi_compatible_match(const struct spi_attach_args *, const cfdata_t,
    177 	    const struct device_compatible_entry *);
    178 const struct device_compatible_entry *
    179 	spi_compatible_lookup(const struct spi_attach_args *,
    180 	    const struct device_compatible_entry *);
    181 
    182 int	spi_configure(device_t, spi_handle_t, int, int);
    183 int	spi_transfer(spi_handle_t, struct spi_transfer *);
    184 void	spi_transfer_init(struct spi_transfer *);
    185 void	spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
    186 void	spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
    187 void	spi_wait(struct spi_transfer *);
    188 void	spi_done(struct spi_transfer *, int);
    189 
    190 /* convenience wrappers */
    191 int	spi_send(spi_handle_t, int, const uint8_t *);
    192 int	spi_recv(spi_handle_t, int, uint8_t *);
    193 int	spi_send_recv(spi_handle_t, int, const uint8_t *, int, uint8_t *);
    194 
    195 #endif	/* _DEV_SPI_SPIVAR_H_ */
    196