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      1 /* $NetBSD: spivar.h,v 1.25 2025/09/14 16:00:04 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 /* Additional transfer mode flags. */
     80 #define	SPI_F_3WIRE	__BIT(0)	/* requires 3-wire mode */
     81 #define	SPI_F_CS_HIGH	__BIT(1)	/* chip select is active-high */
     82 #define	SPI_F_LSB	__BIT(2)	/* transfer LSB first */
     83 
     84 struct spi_controller {
     85 	void	*sct_cookie;	/* controller private data */
     86 	int	sct_nslaves;
     87 	int	(*sct_configure)(void *, int, int, int);
     88 	int	(*sct_transfer)(void *, struct spi_transfer *);
     89 };
     90 
     91 int	spibus_print(void *, const char *);
     92 
     93 struct spibus_attach_args {
     94 	const struct spi_controller *sba_controller;
     95 };
     96 
     97 struct spi_attach_args {
     98 	spi_handle_t	sa_handle;
     99 
    100 	/* only set if using direct config */
    101 	const char	*sa_name;	/* name of the device */
    102 	const char	*sa_clist;	/* compatible strlist */
    103 	size_t		sa_clist_size;	/* size of compatible strlist */
    104 	devhandle_t	sa_devhandle;	/* device handle for the device */
    105 };
    106 
    107 /*
    108  * This is similar in some respects to struct buf, but we cannot use
    109  * that structure because it was not designed to support full-duplex
    110  * IO.
    111  */
    112 struct spi_chunk {
    113 	struct spi_chunk *chunk_next;
    114 	int		chunk_count;
    115 	uint8_t		*chunk_read;
    116 	const uint8_t	*chunk_write;
    117 	/* for private use by framework and bus driver */
    118 	uint8_t		*chunk_rptr;
    119 	const uint8_t	*chunk_wptr;
    120 	int		chunk_rresid;
    121 	int		chunk_wresid;
    122 };
    123 
    124 struct spi_transfer {
    125 	struct spi_chunk *st_chunks;		/* chained bufs */
    126 	SIMPLEQ_ENTRY(spi_transfer) st_chain;	/* chain of submitted jobs */
    127 	volatile int	st_flags;
    128 	int		st_errno;
    129 	int		st_slave;
    130 	void		*st_private;
    131 	void		(*st_done)(struct spi_transfer *);
    132 	kmutex_t	st_lock;
    133 	kcondvar_t	st_cv;
    134 	void		*st_busprivate;
    135 	void		*st_spiprivate;
    136 };
    137 
    138 /* declare a list of transfers */
    139 SIMPLEQ_HEAD(spi_transq, spi_transfer);
    140 
    141 #define	spi_transq_init(q)	\
    142 	SIMPLEQ_INIT(q)
    143 
    144 #define	spi_transq_enqueue(q, trans)	\
    145 	SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
    146 
    147 #define	spi_transq_dequeue(q)		\
    148 	SIMPLEQ_REMOVE_HEAD(q, st_chain)
    149 
    150 #define	spi_transq_first(q)		\
    151 	SIMPLEQ_FIRST(q)
    152 
    153 #define	SPI_F_DONE		0x0001
    154 #define	SPI_F_ERROR		0x0002
    155 
    156 static inline device_t
    157 spibus_attach(device_t dev, const struct spi_controller *sct)
    158 {
    159 	struct spibus_attach_args sba = {
    160 		.sba_controller = sct,
    161 	};
    162 	return config_found(dev, &sba, spibus_print,
    163 	    CFARGS(.iattr = "spibus",
    164 		   .devhandle = device_handle(dev)));
    165 }
    166 
    167 /*
    168  * Constants to indicate the quality of a match made by a driver's
    169  * match routine, from lowest to highest:
    170  *
    171  *	-- Default indirect match; rely on kernel config file.
    172  *
    173  *	-- Direct-config match by "compatible" string.
    174  */
    175 #define	SPI_MATCH_DEFAULT		1
    176 #define	SPI_MATCH_DIRECT_COMPATIBLE	10	/* ...and up */
    177 
    178 bool	spi_use_direct_match(const struct spi_attach_args *,
    179 	    const struct device_compatible_entry *, int *);
    180 int	spi_compatible_match(const struct spi_attach_args *,
    181 	    const struct device_compatible_entry *);
    182 const struct device_compatible_entry *
    183 	spi_compatible_lookup(const struct spi_attach_args *,
    184 	    const struct device_compatible_entry *);
    185 
    186 int	spi_configure(device_t, spi_handle_t, int, int);
    187 int	spi_transfer(spi_handle_t, struct spi_transfer *);
    188 void	spi_transfer_init(struct spi_transfer *);
    189 void	spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
    190 void	spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
    191 void	spi_wait(struct spi_transfer *);
    192 void	spi_done(struct spi_transfer *, int);
    193 
    194 /* convenience wrappers */
    195 int	spi_send(spi_handle_t, int, const uint8_t *);
    196 int	spi_recv(spi_handle_t, int, uint8_t *);
    197 int	spi_send_recv(spi_handle_t, int, const uint8_t *, int, uint8_t *);
    198 
    199 #endif	/* _DEV_SPI_SPIVAR_H_ */
    200