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__FBSDID("$FreeBSD$");
30
31#include "opt_platform.h"
32
33#include <sys/param.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#include <sys/systm.h>
38
39#include <dev/iicbus/iicbus.h>
40#include <dev/iicbus/iiconf.h>
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/ofw_bus_subr.h>
43#include <dev/ofw/openfirm.h>
44
45#include "iicbus_if.h"
46#include "iicmux_if.h"
47
48
49static struct ofw_compat_data compat_data[] = {
50	{"nxp,pca9547",		1},
51	{NULL,			0}
52};
53IICBUS_FDT_PNP_INFO(compat_data);
54
55#include <dev/iicbus/mux/iicmux.h>
56
57struct pca9547_softc {
58	struct iicmux_softc mux;
59	device_t	dev;
60	bool idle_disconnect;
61};
62
63static int
64pca9547_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd)
65{
66	struct pca9547_softc *sc = device_get_softc(dev);
67	uint8_t busbits;
68
69	/*
70	 * The iicmux caller ensures busidx is between 0 and the number of buses
71	 * we passed to iicmux_init_softc(), no need for validation here.  If
72	 * the fdt data has the idle_disconnect property we idle the bus by
73	 * selecting no downstream buses, otherwise we just leave the current
74	 * bus active.  The upper bits of control register 3 activate the
75	 * downstream buses; bit 7 is the first bus, bit 6 the second, etc.
76	 */
77	if (busidx == IICMUX_SELECT_IDLE) {
78		if (sc->idle_disconnect)
79			busbits = 0;
80		else
81			return (0);
82	} else {
83		busbits = 0x8 | (busidx & 0x7);
84	}
85
86	/*
87	 * We have to add the IIC_RECURSIVE flag because the iicmux core has
88	 * already reserved the bus for us, and iicdev_writeto() is going to try
89	 * to reserve it again, which is allowed with the recursive flag.
90	 */
91
92	return (iicdev_writeto(dev, busbits, NULL, 0,
93	    rd->flags | IIC_RECURSIVE));
94}
95
96static int
97pca9547_probe(device_t dev)
98{
99	if (!ofw_bus_status_okay(dev))
100		return (ENXIO);
101
102	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
103		return (ENXIO);
104
105	device_set_desc(dev, "PCA9547 IIC bus multiplexor");
106	return (BUS_PROBE_DEFAULT);
107}
108
109static int
110pca9547_attach(device_t dev)
111{
112	struct pca9547_softc *sc;
113	phandle_t node;
114	int rv;
115
116	sc = device_get_softc(dev);
117	sc ->dev = dev;
118
119	node = ofw_bus_get_node(dev);
120	sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect");
121
122	rv = iicmux_attach(sc->dev, device_get_parent(dev), 8);
123	if (rv != 0)
124		return (rv);
125	rv = bus_generic_attach(dev);
126
127	return (rv);
128}
129
130static int
131pca9547_detach(device_t dev)
132{
133	int rv;
134
135	rv = iicmux_detach(dev);
136	if (rv != 0)
137		return (rv);
138
139	return (0);
140}
141
142static device_method_t pca9547_methods[] = {
143	/* device methods */
144	DEVMETHOD(device_probe,			pca9547_probe),
145	DEVMETHOD(device_attach,		pca9547_attach),
146	DEVMETHOD(device_detach,		pca9547_detach),
147
148	/* iicmux methods */
149	DEVMETHOD(iicmux_bus_select,		pca9547_bus_select),
150
151	DEVMETHOD_END
152};
153
154static devclass_t pca9547_devclass;
155DEFINE_CLASS_1(iicmux, pca9547_driver, pca9547_methods,
156    sizeof(struct pca9547_softc), iicmux_driver);
157DRIVER_MODULE(pca_iicmux, iicbus, pca9547_driver, pca9547_devclass, 0, 0);
158DRIVER_MODULE(iicbus, iicmux, iicbus_driver, iicbus_devclass, 0, 0);
159DRIVER_MODULE(ofw_iicbus, iicmux, ofw_iicbus_driver, ofw_iicbus_devclass,
160    0, 0);
161MODULE_DEPEND(pca9547, iicmux, 1, 1, 1);
162MODULE_DEPEND(pca9547, iicbus, 1, 1, 1);
163