1 /* $NetBSD: tsciic.c,v 1.4 2021/08/07 16:18:41 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Julian Coleman.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33
34 __KERNEL_RCSID(0, "$NetBSD: tsciic.c,v 1.4 2021/08/07 16:18:41 thorpej Exp $");
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/device.h>
39
40 #include <alpha/pci/tsreg.h>
41 #include <alpha/pci/tsvar.h>
42
43 #include <dev/i2c/i2cvar.h>
44 #include <dev/i2c/i2c_bitbang.h>
45 #include <dev/i2c/ddcvar.h>
46
47 /* I2C glue */
48 static int tsciic_send_start(void *, int);
49 static int tsciic_send_stop(void *, int);
50 static int tsciic_initiate_xfer(void *, i2c_addr_t, int);
51 static int tsciic_read_byte(void *, uint8_t *, int);
52 static int tsciic_write_byte(void *, uint8_t, int);
53
54 /* I2C bitbang glue */
55 static void tsciicbb_set_bits(void *, uint32_t);
56 static void tsciicbb_set_dir(void *, uint32_t);
57 static uint32_t tsciicbb_read(void *);
58
59 #define MPD_BIT_SDA 0x01
60 #define MPD_BIT_SCL 0x02
61 static const struct i2c_bitbang_ops tsciicbb_ops = {
62 tsciicbb_set_bits,
63 tsciicbb_set_dir,
64 tsciicbb_read,
65 {
66 MPD_BIT_SDA,
67 MPD_BIT_SCL,
68 0,
69 0
70 }
71 };
72
73 void
tsciic_init(device_t self)74 tsciic_init(device_t self)
75 {
76 struct tsciic_softc *sc = device_private(self);
77 struct i2cbus_attach_args iba;
78
79 iic_tag_init(&sc->sc_i2c);
80 sc->sc_i2c.ic_cookie = sc;
81 sc->sc_i2c.ic_send_start = tsciic_send_start;
82 sc->sc_i2c.ic_send_stop = tsciic_send_stop;
83 sc->sc_i2c.ic_initiate_xfer = tsciic_initiate_xfer;
84 sc->sc_i2c.ic_read_byte = tsciic_read_byte;
85 sc->sc_i2c.ic_write_byte = tsciic_write_byte;
86
87 memset(&iba, 0, sizeof(iba));
88 iba.iba_tag = &sc->sc_i2c;
89
90 config_found(self, &iba, iicbus_print, CFARGS_NONE);
91 }
92
93 /* I2C bitbanging */
94 static void
tsciicbb_set_bits(void * cookie,uint32_t bits)95 tsciicbb_set_bits(void *cookie, uint32_t bits)
96 {
97 uint64_t val;
98
99 val = (bits & MPD_BIT_SDA ? MPD_DS : 0) |
100 (bits & MPD_BIT_SCL ? MPD_CKS : 0);
101 alpha_mb();
102 STQP(TS_C_MPD) = val;
103 alpha_mb();
104 }
105
106 static void
tsciicbb_set_dir(void * cookie,uint32_t dir)107 tsciicbb_set_dir(void *cookie, uint32_t dir)
108 {
109 /* Nothing to do */
110 }
111
112 static uint32_t
tsciicbb_read(void * cookie)113 tsciicbb_read(void *cookie)
114 {
115 uint64_t val;
116 uint32_t bits;
117
118 val = LDQP(TS_C_MPD);
119 bits = (val & MPD_DR ? MPD_BIT_SDA : 0) |
120 (val & MPD_CKR ? MPD_BIT_SCL : 0);
121 return bits;
122 }
123
124 /* higher level I2C stuff */
125 static int
tsciic_send_start(void * cookie,int flags)126 tsciic_send_start(void *cookie, int flags)
127 {
128 return (i2c_bitbang_send_start(cookie, flags, &tsciicbb_ops));
129 }
130
131 static int
tsciic_send_stop(void * cookie,int flags)132 tsciic_send_stop(void *cookie, int flags)
133 {
134 return (i2c_bitbang_send_stop(cookie, flags, &tsciicbb_ops));
135 }
136
137 static int
tsciic_initiate_xfer(void * cookie,i2c_addr_t addr,int flags)138 tsciic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
139 {
140 return (i2c_bitbang_initiate_xfer(cookie, addr, flags,
141 &tsciicbb_ops));
142 }
143
144 static int
tsciic_read_byte(void * cookie,uint8_t * valp,int flags)145 tsciic_read_byte(void *cookie, uint8_t *valp, int flags)
146 {
147 return (i2c_bitbang_read_byte(cookie, valp, flags, &tsciicbb_ops));
148 }
149
150 static int
tsciic_write_byte(void * cookie,uint8_t val,int flags)151 tsciic_write_byte(void *cookie, uint8_t val, int flags)
152 {
153 return (i2c_bitbang_write_byte(cookie, val, flags, &tsciicbb_ops));
154 }
155