1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 <sys/param.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/libkern.h>
35#include <sys/lock.h>
36#include <sys/module.h>
37
38#include <dev/fdt/fdt_common.h>
39#include <dev/ofw/ofw_bus.h>
40#include <dev/ofw/ofw_bus_subr.h>
41#include <dev/ofw/openfirm.h>
42#include <dev/pwm/pwmbus.h>
43
44#include "pwmbus_if.h"
45
46struct ofw_pwmbus_ivars {
47	struct pwmbus_ivars	base;
48	struct ofw_bus_devinfo	devinfo;
49};
50
51struct ofw_pwmbus_softc {
52	struct pwmbus_softc	base;
53};
54
55/*
56 * bus_if methods...
57 */
58
59static device_t
60ofw_pwmbus_add_child(device_t dev, u_int order, const char *name, int unit)
61{
62	device_t child;
63	struct ofw_pwmbus_ivars *ivars;
64
65	if ((ivars = malloc(sizeof(struct ofw_pwmbus_ivars), M_DEVBUF,
66	    M_NOWAIT | M_ZERO)) == NULL) {
67		return (NULL);
68	}
69
70	if ((child = device_add_child_ordered(dev, order, name, unit)) == NULL) {
71		free(ivars, M_DEVBUF);
72		return (NULL);
73	}
74
75	ivars->devinfo.obd_node = -1;
76	device_set_ivars(child, ivars);
77
78	return (child);
79}
80
81static void
82ofw_pwmbus_child_deleted(device_t dev, device_t child)
83{
84	struct ofw_pwmbus_ivars *ivars;
85
86	ivars = device_get_ivars(child);
87	if (ivars != NULL) {
88		ofw_bus_gen_destroy_devinfo(&ivars->devinfo);
89		free(ivars, M_DEVBUF);
90	}
91}
92
93static const struct ofw_bus_devinfo *
94ofw_pwmbus_get_devinfo(device_t bus, device_t dev)
95{
96	struct ofw_pwmbus_ivars *ivars;
97
98	ivars = device_get_ivars(dev);
99	return (&ivars->devinfo);
100}
101
102/*
103 * device_if methods...
104 */
105
106static int
107ofw_pwmbus_probe(device_t dev)
108{
109
110	if (ofw_bus_get_node(dev) == -1) {
111		return (ENXIO);
112	}
113	device_set_desc(dev, "OFW PWM bus");
114
115	return (BUS_PROBE_DEFAULT);
116}
117
118static int
119ofw_pwmbus_attach(device_t dev)
120{
121	struct ofw_pwmbus_softc *sc;
122	struct ofw_pwmbus_ivars *ivars;
123	phandle_t node;
124	device_t child, parent;
125	pcell_t  chan;
126	bool any_children;
127
128	sc = device_get_softc(dev);
129	sc->base.dev = dev;
130	parent = device_get_parent(dev);
131
132	if (PWMBUS_CHANNEL_COUNT(parent, &sc->base.nchannels) != 0 ||
133	    sc->base.nchannels == 0) {
134		device_printf(dev, "No channels on parent %s\n",
135		    device_get_nameunit(parent));
136		return (ENXIO);
137	}
138
139	/*
140	 * Attach the children found in the fdt node of the hardware controller.
141	 * Hardware controllers must implement the ofw_bus_get_node method so
142	 * that our call to ofw_bus_get_node() gets back the controller's node.
143	 */
144	any_children = false;
145	node = ofw_bus_get_node(dev);
146	for (node = OF_child(node); node != 0; node = OF_peer(node)) {
147		/*
148		 * The child has to have a reg property; its value is the
149		 * channel number so range-check it.
150		 */
151		if (OF_getencprop(node, "reg", &chan, sizeof(chan)) == -1)
152			continue;
153		if (chan >= sc->base.nchannels)
154			continue;
155
156		if ((child = ofw_pwmbus_add_child(dev, 0, NULL, -1)) == NULL)
157			continue;
158
159		ivars = device_get_ivars(child);
160		ivars->base.pi_channel = chan;
161
162		/* Set up the standard ofw devinfo. */
163		if (ofw_bus_gen_setup_devinfo(&ivars->devinfo, node) != 0) {
164			device_delete_child(dev, child);
165			continue;
166		}
167		any_children = true;
168	}
169
170	/*
171	 * If we didn't find any children in the fdt data, add a pwmc(4) child
172	 * for each channel, like the base pwmbus does.  The idea is that if
173	 * there is any fdt data, then we do exactly what it says and nothing
174	 * more, otherwise we just provide generic userland access to all the
175	 * pwm channels that exist like the base pwmbus's attach code does.
176	 */
177	if (!any_children) {
178		for (chan = 0; chan < sc->base.nchannels; ++chan) {
179			child = ofw_pwmbus_add_child(dev, 0, "pwmc", -1);
180			if (child == NULL) {
181				device_printf(dev, "failed to add pwmc child "
182				    " device for channel %u\n", chan);
183				continue;
184			}
185			ivars = device_get_ivars(child);
186			ivars->base.pi_channel = chan;
187		}
188	}
189	bus_enumerate_hinted_children(dev);
190	bus_generic_probe(dev);
191
192	return (bus_generic_attach(dev));
193}
194
195static device_method_t ofw_pwmbus_methods[] = {
196	/* Device interface */
197	DEVMETHOD(device_probe,           ofw_pwmbus_probe),
198	DEVMETHOD(device_attach,          ofw_pwmbus_attach),
199
200	/* Bus interface */
201	DEVMETHOD(bus_child_pnpinfo_str,  ofw_bus_gen_child_pnpinfo_str),
202	DEVMETHOD(bus_add_child,          ofw_pwmbus_add_child),
203	DEVMETHOD(bus_child_deleted,      ofw_pwmbus_child_deleted),
204
205	/* ofw_bus interface */
206	DEVMETHOD(ofw_bus_get_devinfo,    ofw_pwmbus_get_devinfo),
207	DEVMETHOD(ofw_bus_get_compat,     ofw_bus_gen_get_compat),
208	DEVMETHOD(ofw_bus_get_model,      ofw_bus_gen_get_model),
209	DEVMETHOD(ofw_bus_get_name,       ofw_bus_gen_get_name),
210	DEVMETHOD(ofw_bus_get_node,       ofw_bus_gen_get_node),
211	DEVMETHOD(ofw_bus_get_type,       ofw_bus_gen_get_type),
212
213	DEVMETHOD_END
214};
215
216devclass_t ofw_pwmbus_devclass;
217
218DEFINE_CLASS_1(pwmbus, ofw_pwmbus_driver, ofw_pwmbus_methods,
219    sizeof(struct pwmbus_softc), pwmbus_driver);
220EARLY_DRIVER_MODULE(ofw_pwmbus, pwm, ofw_pwmbus_driver, ofw_pwmbus_devclass,
221    0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
222MODULE_VERSION(ofw_pwmbus, 1);
223MODULE_DEPEND(ofw_pwmbus, pwmbus, 1, 1, 1);
224