spivar.h revision 1.22 1 /* $NetBSD: spivar.h,v 1.22 2025/09/13 14:10:44 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/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 * peripherals.
53 */
54
55 struct spi_handle;
56 struct spi_transfer;
57
58 typedef struct spi_handle *spi_handle_t;
59
60 #define SPI_MODE_CPHA __BIT(0)
61 #define SPI_MODE_CPOL __BIT(1)
62
63 /*
64 * De facto standard latching modes.
65 */
66 #define SPI_MODE_0 0
67 #define SPI_MODE_1 SPI_MODE_CPHA
68 #define SPI_MODE_2 SPI_MODE_CPOL
69 #define SPI_MODE_3 (SPI_MODE_CPHA | SPI_MODE_CPOL)
70
71 /* Philips' Microwire is just Mode 0 */
72 #define SPI_MODE_MICROWIRE SPI_MODE_0
73
74 /* SPI transfer speed helper macros -- converts to Hz for spi_configure(). */
75 #define SPI_FREQ_kHz(x) ((x) * 1000)
76 #define SPI_FREQ_MHz(x) ((x) * 1000000)
77
78 struct spi_controller {
79 void *sct_cookie; /* controller private data */
80 int sct_nslaves;
81 int (*sct_configure)(void *, int, int, int);
82 int (*sct_transfer)(void *, struct spi_transfer *);
83 };
84
85 int spibus_print(void *, const char *);
86
87 /* one per chip select */
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 int sa_ncompat; /* number of pointers in the
97 sa_compat array */
98 const char ** sa_compat; /* chip names */
99 };
100
101 /*
102 * This is similar in some respects to struct buf, but we cannot use
103 * that structure because it was not designed to support full-duplex
104 * IO.
105 */
106 struct spi_chunk {
107 struct spi_chunk *chunk_next;
108 int chunk_count;
109 uint8_t *chunk_read;
110 const uint8_t *chunk_write;
111 /* for private use by framework and bus driver */
112 uint8_t *chunk_rptr;
113 const uint8_t *chunk_wptr;
114 int chunk_rresid;
115 int chunk_wresid;
116 };
117
118 struct spi_transfer {
119 struct spi_chunk *st_chunks; /* chained bufs */
120 SIMPLEQ_ENTRY(spi_transfer) st_chain; /* chain of submitted jobs */
121 volatile int st_flags;
122 int st_errno;
123 int st_slave;
124 void *st_private;
125 void (*st_done)(struct spi_transfer *);
126 kmutex_t st_lock;
127 kcondvar_t st_cv;
128 void *st_busprivate;
129 void *st_spiprivate;
130 };
131
132 /* declare a list of transfers */
133 SIMPLEQ_HEAD(spi_transq, spi_transfer);
134
135 #define spi_transq_init(q) \
136 SIMPLEQ_INIT(q)
137
138 #define spi_transq_enqueue(q, trans) \
139 SIMPLEQ_INSERT_TAIL(q, trans, st_chain)
140
141 #define spi_transq_dequeue(q) \
142 SIMPLEQ_REMOVE_HEAD(q, st_chain)
143
144 #define spi_transq_first(q) \
145 SIMPLEQ_FIRST(q)
146
147 #define SPI_F_DONE 0x0001
148 #define SPI_F_ERROR 0x0002
149
150 static inline device_t
151 spibus_attach(device_t dev, const struct spi_controller *sct)
152 {
153 struct spibus_attach_args sba = {
154 .sba_controller = sct,
155 };
156 return config_found(dev, &sba, spibus_print,
157 CFARGS(.iattr = "spibus",
158 .devhandle = device_handle(dev)));
159 }
160
161 /*
162 * Constants to indicate the quality of a match made by a driver's
163 * match routine, from lowest to highest:
164 *
165 * -- Default indirect match; rely on kernel config file.
166 *
167 * -- Direct-config match by "compatible" string.
168 */
169 #define SPI_MATCH_DEFAULT 1
170 #define SPI_MATCH_DIRECT_COMPATIBLE 10 /* ...and up */
171
172 bool spi_use_direct_match(const struct spi_attach_args *,
173 const struct device_compatible_entry *, int *);
174 int spi_compatible_match(const struct spi_attach_args *, const cfdata_t,
175 const struct device_compatible_entry *);
176 const struct device_compatible_entry *
177 spi_compatible_lookup(const struct spi_attach_args *,
178 const struct device_compatible_entry *);
179
180 int spi_configure(device_t, spi_handle_t, int, int);
181 int spi_transfer(spi_handle_t, struct spi_transfer *);
182 void spi_transfer_init(struct spi_transfer *);
183 void spi_chunk_init(struct spi_chunk *, int, const uint8_t *, uint8_t *);
184 void spi_transfer_add(struct spi_transfer *, struct spi_chunk *);
185 void spi_wait(struct spi_transfer *);
186 void spi_done(struct spi_transfer *, int);
187
188 /* convenience wrappers */
189 int spi_send(spi_handle_t, int, const uint8_t *);
190 int spi_recv(spi_handle_t, int, uint8_t *);
191 int spi_send_recv(spi_handle_t, int, const uint8_t *, int, uint8_t *);
192
193 #endif /* _DEV_SPI_SPIVAR_H_ */
194