1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 #include "opt_platform.h"
30
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/systm.h>
36
37 #include <dev/iicbus/iicbus.h>
38 #include <dev/iicbus/iiconf.h>
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 #include <dev/ofw/openfirm.h>
42
43 #include "iicbus_if.h"
44 #include "iicmux_if.h"
45
46
47 static struct ofw_compat_data compat_data[] = {
48 {"nxp,pca9547", 1},
49 {NULL, 0}
50 };
51 IICBUS_FDT_PNP_INFO(compat_data);
52
53 #include <dev/iicbus/mux/iicmux.h>
54
55 struct pca9547_softc {
56 struct iicmux_softc mux;
57 device_t dev;
58 bool idle_disconnect;
59 };
60
61 static int
pca9547_bus_select(device_t dev,int busidx,struct iic_reqbus_data * rd)62 pca9547_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd)
63 {
64 struct pca9547_softc *sc = device_get_softc(dev);
65 uint8_t busbits;
66
67 /*
68 * The iicmux caller ensures busidx is between 0 and the number of buses
69 * we passed to iicmux_init_softc(), no need for validation here. If
70 * the fdt data has the idle_disconnect property we idle the bus by
71 * selecting no downstream buses, otherwise we just leave the current
72 * bus active. The upper bits of control register 3 activate the
73 * downstream buses; bit 7 is the first bus, bit 6 the second, etc.
74 */
75 if (busidx == IICMUX_SELECT_IDLE) {
76 if (sc->idle_disconnect)
77 busbits = 0;
78 else
79 return (0);
80 } else {
81 busbits = 0x8 | (busidx & 0x7);
82 }
83
84 /*
85 * We have to add the IIC_RECURSIVE flag because the iicmux core has
86 * already reserved the bus for us, and iicdev_writeto() is going to try
87 * to reserve it again, which is allowed with the recursive flag.
88 */
89
90 return (iicdev_writeto(dev, busbits, NULL, 0,
91 rd->flags | IIC_RECURSIVE));
92 }
93
94 static int
pca9547_probe(device_t dev)95 pca9547_probe(device_t dev)
96 {
97 if (!ofw_bus_status_okay(dev))
98 return (ENXIO);
99
100 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
101 return (ENXIO);
102
103 device_set_desc(dev, "PCA9547 IIC bus multiplexor");
104 return (BUS_PROBE_DEFAULT);
105 }
106
107 static int
pca9547_attach(device_t dev)108 pca9547_attach(device_t dev)
109 {
110 struct pca9547_softc *sc;
111 phandle_t node;
112 int rv;
113
114 sc = device_get_softc(dev);
115 sc ->dev = dev;
116
117 node = ofw_bus_get_node(dev);
118 sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect");
119
120 rv = iicmux_attach(sc->dev, device_get_parent(dev), 8);
121 if (rv != 0)
122 return (rv);
123 rv = bus_generic_attach(dev);
124
125 return (rv);
126 }
127
128 static int
pca9547_detach(device_t dev)129 pca9547_detach(device_t dev)
130 {
131 int rv;
132
133 rv = iicmux_detach(dev);
134 if (rv != 0)
135 return (rv);
136
137 return (0);
138 }
139
140 static device_method_t pca9547_methods[] = {
141 /* device methods */
142 DEVMETHOD(device_probe, pca9547_probe),
143 DEVMETHOD(device_attach, pca9547_attach),
144 DEVMETHOD(device_detach, pca9547_detach),
145
146 /* iicmux methods */
147 DEVMETHOD(iicmux_bus_select, pca9547_bus_select),
148
149 DEVMETHOD_END
150 };
151
152 DEFINE_CLASS_1(iicmux, pca9547_driver, pca9547_methods,
153 sizeof(struct pca9547_softc), iicmux_driver);
154 DRIVER_MODULE(pca_iicmux, iicbus, pca9547_driver, 0, 0);
155 DRIVER_MODULE(iicbus, iicmux, iicbus_driver, 0, 0);
156 DRIVER_MODULE(ofw_iicbus, iicmux, ofw_iicbus_driver, 0, 0);
157 MODULE_DEPEND(pca9547, iicmux, 1, 1, 1);
158 MODULE_DEPEND(pca9547, iicbus, 1, 1, 1);
159