1 /* $NetBSD: i2cspi.c,v 1.1 2021/12/07 17:39:55 brad Exp $ */
2
3 /*
4 * Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #ifdef __RCSID
20 __RCSID("$NetBSD: i2cspi.c,v 1.1 2021/12/07 17:39:55 brad Exp $");
21 #endif
22
23 /* Functions that know how to talk to scmd(4) */
24
25 #include <inttypes.h>
26 #include <stdbool.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <unistd.h>
30 #include <err.h>
31 #include <fcntl.h>
32 #include <string.h>
33 #include <limits.h>
34 #include <errno.h>
35
36 #include <dev/ic/scmdreg.h>
37
38 #include "scmdctl.h"
39 #include "responses.h"
40
41 #define EXTERN
42 #include "i2cspi.h"
43
44 int i2cspi_clear(int, bool);
45 int i2cspi_read_register(int, bool, int, uint8_t, uint8_t, uint8_t *);
46 int i2cspi_write_register(int, bool, int, uint8_t, uint8_t);
47
48
49 /* The scmd(4) presents the register space as a linear chunk that can
50 * be seek to read and written to without any real messing around
51 */
52 static int
i2cspi_phy_read_register(int fd,bool debug,uint8_t reg,int rlen,uint8_t * buf)53 i2cspi_phy_read_register(int fd, bool debug, uint8_t reg, int rlen, uint8_t *buf)
54 {
55 int err;
56
57 if (rlen <= 0)
58 return EINVAL;
59
60 err = lseek(fd, reg, SEEK_SET);
61 if (err != -1) {
62 err = read(fd, buf, rlen);
63 if (err == -1)
64 err = errno;
65 else
66 err = 0;
67 } else {
68 err = errno;
69 }
70
71 if (debug)
72 fprintf(stderr,"i2cspi_phy_read_register: reg: 0x%02X: rlen: %d: return err: %d\n",reg, rlen, err);
73
74 return err;
75 }
76
77 static int
i2cspi_phy_write_register(int fd,bool debug,uint8_t reg,uint8_t buf)78 i2cspi_phy_write_register(int fd, bool debug, uint8_t reg, uint8_t buf)
79 {
80 int err;
81
82 err = lseek(fd, reg, SEEK_SET);
83 if (err != -1) {
84 err = write(fd, &buf, 1);
85 if (err == -1)
86 err = errno;
87 else
88 err = 0;
89 } else {
90 err = errno;
91 }
92
93 if (debug)
94 fprintf(stderr,"i2cspi_phy_write_register: reg: 0x%02X: return err: %d\n",reg, err);
95
96 return err;
97 }
98
99 int
i2cspi_clear(int fd,bool debug)100 i2cspi_clear(int fd, bool debug)
101 {
102 return 0;
103 }
104
105 int
i2cspi_read_register(int fd,bool debug,int a_module,uint8_t reg,uint8_t reg_end,uint8_t * r)106 i2cspi_read_register(int fd, bool debug, int a_module, uint8_t reg, uint8_t reg_end, uint8_t *r)
107 {
108 if (reg > SCMD_LAST_REG ||
109 reg_end > SCMD_LAST_REG)
110 return EINVAL;
111
112 if (reg_end < reg)
113 return EINVAL;
114
115 if (debug)
116 fprintf(stderr,"i2cspi_read_register: reg: %d ; reg_rend: %d ; rlen: %d\n",reg, reg_end, reg_end - reg + 1);
117
118 return i2cspi_phy_read_register(fd, debug, reg + (SCMD_REG_SIZE * a_module), reg_end - reg + 1, r);
119 }
120
121 int
i2cspi_write_register(int fd,bool debug,int a_module,uint8_t reg,uint8_t reg_v)122 i2cspi_write_register(int fd, bool debug, int a_module, uint8_t reg, uint8_t reg_v)
123 {
124 int err;
125
126 if (reg > SCMD_LAST_REG)
127 return EINVAL;
128
129 err = i2cspi_phy_write_register(fd, debug, reg + (SCMD_REG_SIZE * a_module), reg_v);
130
131 return err;
132 }
133