1/*-
2 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/module.h>
37#include <sys/mutex.h>
38#include <sys/resource.h>
39#include <sys/rman.h>
40#include <sys/sysctl.h>
41
42#include <machine/bus.h>
43
44#include <dev/fdt/fdt_common.h>
45#include <dev/ofw/openfirm.h>
46#include <dev/ofw/ofw_bus.h>
47#include <dev/ofw/ofw_bus_subr.h>
48
49#include "am335x_pwm.h"
50
51#define	ECAP_TSCTR		0x00
52#define	ECAP_CAP1		0x08
53#define	ECAP_CAP2		0x0C
54#define	ECAP_CAP3		0x10
55#define	ECAP_CAP4		0x14
56#define	ECAP_ECCTL2		0x2A
57#define		ECCTL2_MODE_APWM		(1 << 9)
58#define		ECCTL2_SYNCO_SEL		(3 << 6)
59#define		ECCTL2_TSCTRSTOP_FREERUN	(1 << 4)
60
61#define	ECAP_READ2(_sc, reg)	bus_read_2((_sc)->sc_mem_res, reg);
62#define	ECAP_WRITE2(_sc, reg, value)	\
63    bus_write_2((_sc)->sc_mem_res, reg, value);
64#define	ECAP_READ4(_sc, reg)	bus_read_4((_sc)->sc_mem_res, reg);
65#define	ECAP_WRITE4(_sc, reg, value)	\
66    bus_write_4((_sc)->sc_mem_res, reg, value);
67
68#define	PWM_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
69#define	PWM_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
70#define	PWM_LOCK_INIT(_sc)	mtx_init(&(_sc)->sc_mtx, \
71    device_get_nameunit(_sc->sc_dev), "am335x_ecap softc", MTX_DEF)
72#define	PWM_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
73
74static device_probe_t am335x_ecap_probe;
75static device_attach_t am335x_ecap_attach;
76static device_detach_t am335x_ecap_detach;
77
78struct am335x_ecap_softc {
79	device_t		sc_dev;
80	struct mtx		sc_mtx;
81	struct resource		*sc_mem_res;
82	int			sc_mem_rid;
83};
84
85static device_method_t am335x_ecap_methods[] = {
86	DEVMETHOD(device_probe,		am335x_ecap_probe),
87	DEVMETHOD(device_attach,	am335x_ecap_attach),
88	DEVMETHOD(device_detach,	am335x_ecap_detach),
89
90	DEVMETHOD_END
91};
92
93static driver_t am335x_ecap_driver = {
94	"am335x_ecap",
95	am335x_ecap_methods,
96	sizeof(struct am335x_ecap_softc),
97};
98
99static devclass_t am335x_ecap_devclass;
100
101/*
102 * API function to set period/duty cycles for ECAPx
103 */
104int
105am335x_pwm_config_ecap(int unit, int period, int duty)
106{
107	device_t dev;
108	struct am335x_ecap_softc *sc;
109	uint16_t reg;
110
111	dev = devclass_get_device(am335x_ecap_devclass, unit);
112	if (dev == NULL)
113		return (ENXIO);
114
115	if (duty > period)
116		return (EINVAL);
117
118	if (period == 0)
119		return (EINVAL);
120
121	sc = device_get_softc(dev);
122	PWM_LOCK(sc);
123
124	reg = ECAP_READ2(sc, ECAP_ECCTL2);
125	reg |= ECCTL2_MODE_APWM | ECCTL2_TSCTRSTOP_FREERUN | ECCTL2_SYNCO_SEL;
126	ECAP_WRITE2(sc, ECAP_ECCTL2, reg);
127
128	/* CAP3 in APWM mode is APRD shadow register */
129	ECAP_WRITE4(sc, ECAP_CAP3, period - 1);
130
131	/* CAP4 in APWM mode is ACMP shadow register */
132	ECAP_WRITE4(sc, ECAP_CAP4, duty);
133	/* Restart counter */
134	ECAP_WRITE4(sc, ECAP_TSCTR, 0);
135
136	PWM_UNLOCK(sc);
137
138	return (0);
139}
140
141static int
142am335x_ecap_probe(device_t dev)
143{
144
145	if (!ofw_bus_status_okay(dev))
146		return (ENXIO);
147
148	if (!ofw_bus_is_compatible(dev, "ti,am33xx-ecap"))
149		return (ENXIO);
150
151	device_set_desc(dev, "AM335x eCAP");
152
153	return (BUS_PROBE_DEFAULT);
154}
155
156static int
157am335x_ecap_attach(device_t dev)
158{
159	struct am335x_ecap_softc *sc;
160
161	sc = device_get_softc(dev);
162	sc->sc_dev = dev;
163
164	PWM_LOCK_INIT(sc);
165
166	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
167	    &sc->sc_mem_rid, RF_ACTIVE);
168	if (sc->sc_mem_res == NULL) {
169		device_printf(dev, "cannot allocate memory resources\n");
170		goto fail;
171	}
172
173	return (0);
174
175fail:
176	PWM_LOCK_DESTROY(sc);
177	return (ENXIO);
178}
179
180static int
181am335x_ecap_detach(device_t dev)
182{
183	struct am335x_ecap_softc *sc;
184
185	sc = device_get_softc(dev);
186
187	PWM_LOCK(sc);
188	if (sc->sc_mem_res)
189		bus_release_resource(dev, SYS_RES_MEMORY,
190		    sc->sc_mem_rid, sc->sc_mem_res);
191	PWM_UNLOCK(sc);
192
193	PWM_LOCK_DESTROY(sc);
194
195
196	return (0);
197}
198
199DRIVER_MODULE(am335x_ecap, am335x_pwmss, am335x_ecap_driver, am335x_ecap_devclass, 0, 0);
200MODULE_VERSION(am335x_ecap, 1);
201MODULE_DEPEND(am335x_ecap, am335x_pwmss, 1, 1, 1);
202