xref: /freebsd/sys/dev/pwm/pwmbus.c (revision d6eb98610fa65663bf0df4574b7cb2c5c4ffda71)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_platform.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/endian.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 
43 #include <dev/pwm/pwmbus.h>
44 
45 #include "pwmbus_if.h"
46 
47 /*
48  * bus_if methods...
49  */
50 
51 static device_t
52 pwmbus_add_child(device_t dev, u_int order, const char *name, int unit)
53 {
54 	device_t child;
55 	struct pwmbus_ivars *ivars;
56 
57 	child = device_add_child_ordered(dev, order, name, unit);
58 	if (child == NULL)
59 		return (child);
60 
61 	ivars = malloc(sizeof(struct pwmbus_ivars), M_DEVBUF, M_NOWAIT | M_ZERO);
62 	if (ivars == NULL) {
63 		device_delete_child(dev, child);
64 		return (NULL);
65 	}
66 	device_set_ivars(child, ivars);
67 
68 	return (child);
69 }
70 
71 static int
72 pwmbus_child_location_str(device_t dev, device_t child, char *buf, size_t blen)
73 {
74 	struct pwmbus_ivars *ivars;
75 
76 	ivars = device_get_ivars(child);
77 	snprintf(buf, blen, "hwdev=%s channel=%u",
78 	    device_get_nameunit(device_get_parent(dev)), ivars->pi_channel);
79 
80 	return (0);
81 }
82 
83 static int
84 pwmbus_child_pnpinfo_str(device_t dev, device_t child, char *buf,
85     size_t buflen)
86 {
87 	*buf = '\0';
88 	return (0);
89 }
90 
91 static void
92 pwmbus_hinted_child(device_t dev, const char *dname, int dunit)
93 {
94 	struct pwmbus_ivars *ivars;
95 	device_t child;
96 
97 	child = pwmbus_add_child(dev, 0, dname, dunit);
98 
99 	/*
100 	 * If there is a channel hint, use it.  Otherwise pi_channel was
101 	 * initialized to zero, so that's the channel we'll use.
102 	 */
103 	ivars = device_get_ivars(child);
104 	resource_int_value(dname, dunit, "channel", &ivars->pi_channel);
105 }
106 
107 static int
108 pwmbus_print_child(device_t dev, device_t child)
109 {
110 	struct pwmbus_ivars *ivars;
111 	int rv;
112 
113 	ivars = device_get_ivars(child);
114 
115 	rv  = bus_print_child_header(dev, child);
116 	rv += printf(" channel %u", ivars->pi_channel);
117 	rv += bus_print_child_footer(dev, child);
118 
119 	return (rv);
120 }
121 
122 static void
123 pwmbus_probe_nomatch(device_t dev, device_t child)
124 {
125 	struct pwmbus_ivars *ivars;
126 
127 	ivars = device_get_ivars(child);
128 	if (ivars != NULL)
129 		device_printf(dev, "<unknown> on channel %u\n",
130 		    ivars->pi_channel);
131 
132 	return;
133 }
134 
135 static int
136 pwmbus_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
137 {
138 	struct pwmbus_ivars *ivars;
139 
140 	ivars = device_get_ivars(child);
141 
142 	switch (which) {
143 	case PWMBUS_IVAR_CHANNEL:
144 		*(u_int *)result = ivars->pi_channel;
145 		break;
146 	default:
147 		return (EINVAL);
148 	}
149 
150 	return (0);
151 }
152 
153 /*
154  * device_if methods...
155  */
156 
157 static int
158 pwmbus_probe(device_t dev)
159 {
160 	device_set_desc(dev, "PWM bus");
161 	return (BUS_PROBE_GENERIC);
162 }
163 
164 static int
165 pwmbus_attach(device_t dev)
166 {
167 	struct pwmbus_softc *sc;
168 	struct pwmbus_ivars *ivars;
169 	device_t child, parent;
170 	u_int chan;
171 
172 	sc = device_get_softc(dev);
173 	sc->dev = dev;
174 	parent = device_get_parent(dev);
175 
176 	if (PWMBUS_CHANNEL_COUNT(parent, &sc->nchannels) != 0 ||
177 	    sc->nchannels == 0) {
178 		device_printf(sc->dev, "No channels on parent %s\n",
179 		    device_get_nameunit(parent));
180 		return (ENXIO);
181 	}
182 
183 	/* Add a pwmc(4) child for each channel. */
184 	for (chan = 0; chan < sc->nchannels; ++chan) {
185 		if ((child = pwmbus_add_child(sc->dev, 0, "pwmc", -1)) == NULL) {
186 			device_printf(dev, "failed to add pwmc child device "
187 			    "for channel %u\n", chan);
188 			continue;
189 		}
190 		ivars = device_get_ivars(child);
191 		ivars->pi_channel = chan;
192 	}
193 
194 	bus_enumerate_hinted_children(dev);
195 	bus_generic_probe(dev);
196 
197 	return (bus_generic_attach(dev));
198 }
199 
200 static int
201 pwmbus_detach(device_t dev)
202 {
203 	int rv;
204 
205 	if ((rv = bus_generic_detach(dev)) == 0)
206 		rv = device_delete_children(dev);
207 
208 	return (rv);
209 }
210 
211 /*
212  * pwmbus_if methods...
213  */
214 
215 static int
216 pwmbus_channel_config(device_t dev, u_int chan, u_int period, u_int duty)
217 {
218 	return (PWMBUS_CHANNEL_CONFIG(device_get_parent(dev), chan, period, duty));
219 }
220 
221 static int
222 pwmbus_channel_get_config(device_t dev, u_int chan, u_int *period, u_int *duty)
223 {
224 	return (PWMBUS_CHANNEL_GET_CONFIG(device_get_parent(dev), chan, period, duty));
225 }
226 
227 static int
228 pwmbus_channel_get_flags(device_t dev, u_int chan, uint32_t *flags)
229 {
230 	return (PWMBUS_CHANNEL_GET_FLAGS(device_get_parent(dev), chan, flags));
231 }
232 
233 static int
234 pwmbus_channel_enable(device_t dev, u_int chan, bool enable)
235 {
236 	return (PWMBUS_CHANNEL_ENABLE(device_get_parent(dev), chan, enable));
237 }
238 
239 static int
240 pwmbus_channel_set_flags(device_t dev, u_int chan, uint32_t flags)
241 {
242 	return (PWMBUS_CHANNEL_SET_FLAGS(device_get_parent(dev), chan, flags));
243 }
244 
245 static int
246 pwmbus_channel_is_enabled(device_t dev, u_int chan, bool *enable)
247 {
248 	return (PWMBUS_CHANNEL_IS_ENABLED(device_get_parent(dev), chan, enable));
249 }
250 
251 static int
252 pwmbus_channel_count(device_t dev, u_int *nchannel)
253 {
254 	return (PWMBUS_CHANNEL_COUNT(device_get_parent(dev), nchannel));
255 }
256 
257 static device_method_t pwmbus_methods[] = {
258 	/* device_if */
259 	DEVMETHOD(device_probe,  pwmbus_probe),
260 	DEVMETHOD(device_attach, pwmbus_attach),
261 	DEVMETHOD(device_detach, pwmbus_detach),
262 
263         /* bus_if */
264 	DEVMETHOD(bus_add_child,		pwmbus_add_child),
265 	DEVMETHOD(bus_child_location_str,	pwmbus_child_location_str),
266 	DEVMETHOD(bus_child_pnpinfo_str,	pwmbus_child_pnpinfo_str),
267 	DEVMETHOD(bus_hinted_child,		pwmbus_hinted_child),
268 	DEVMETHOD(bus_print_child,		pwmbus_print_child),
269 	DEVMETHOD(bus_probe_nomatch,		pwmbus_probe_nomatch),
270 	DEVMETHOD(bus_read_ivar,		pwmbus_read_ivar),
271 
272         /* pwmbus_if  */
273 	DEVMETHOD(pwmbus_channel_count,		pwmbus_channel_count),
274 	DEVMETHOD(pwmbus_channel_config,	pwmbus_channel_config),
275 	DEVMETHOD(pwmbus_channel_get_config,	pwmbus_channel_get_config),
276 	DEVMETHOD(pwmbus_channel_set_flags,	pwmbus_channel_set_flags),
277 	DEVMETHOD(pwmbus_channel_get_flags,	pwmbus_channel_get_flags),
278 	DEVMETHOD(pwmbus_channel_enable,	pwmbus_channel_enable),
279 	DEVMETHOD(pwmbus_channel_is_enabled,	pwmbus_channel_is_enabled),
280 
281 	DEVMETHOD_END
282 };
283 
284 driver_t pwmbus_driver = {
285 	"pwmbus",
286 	pwmbus_methods,
287 	sizeof(struct pwmbus_softc),
288 };
289 devclass_t pwmbus_devclass;
290 
291 EARLY_DRIVER_MODULE(pwmbus, pwm, pwmbus_driver, pwmbus_devclass, 0, 0,
292   BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
293 MODULE_VERSION(pwmbus, 1);
294