xref: /freebsd/sys/arm/ti/am335x/am335x_ecap.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 #include <sys/kernel.h>
32 #include <sys/limits.h>
33 #include <sys/lock.h>
34 #include <sys/module.h>
35 #include <sys/mutex.h>
36 #include <sys/resource.h>
37 #include <sys/rman.h>
38 #include <sys/sysctl.h>
39 
40 #include <machine/bus.h>
41 
42 #include <dev/ofw/openfirm.h>
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include "am335x_pwm.h"
47 
48 #define	ECAP_TSCTR		0x00
49 #define	ECAP_CAP1		0x08
50 #define	ECAP_CAP2		0x0C
51 #define	ECAP_CAP3		0x10
52 #define	ECAP_CAP4		0x14
53 #define	ECAP_ECCTL2		0x2A
54 #define		ECCTL2_MODE_APWM		(1 << 9)
55 #define		ECCTL2_SYNCO_SEL		(3 << 6)
56 #define		ECCTL2_TSCTRSTOP_FREERUN	(1 << 4)
57 
58 #define	ECAP_READ2(_sc, reg)	bus_read_2((_sc)->sc_mem_res, reg);
59 #define	ECAP_WRITE2(_sc, reg, value)	\
60     bus_write_2((_sc)->sc_mem_res, reg, value);
61 #define	ECAP_READ4(_sc, reg)	bus_read_4((_sc)->sc_mem_res, reg);
62 #define	ECAP_WRITE4(_sc, reg, value)	\
63     bus_write_4((_sc)->sc_mem_res, reg, value);
64 
65 #define	PWM_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
66 #define	PWM_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
67 #define	PWM_LOCK_INIT(_sc)	mtx_init(&(_sc)->sc_mtx, \
68     device_get_nameunit(_sc->sc_dev), "am335x_ecap softc", MTX_DEF)
69 #define	PWM_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
70 
71 static device_probe_t am335x_ecap_probe;
72 static device_attach_t am335x_ecap_attach;
73 static device_detach_t am335x_ecap_detach;
74 
75 struct am335x_ecap_softc {
76 	device_t		sc_dev;
77 	struct mtx		sc_mtx;
78 	struct resource		*sc_mem_res;
79 	int			sc_mem_rid;
80 };
81 
82 static struct ofw_compat_data compat_data[] = {
83 	{"ti,am3352-ecap",	true},
84 	{"ti,am33xx-ecap",	true},
85 	{NULL,			false},
86 };
87 SIMPLEBUS_PNP_INFO(compat_data);
88 
89 static device_method_t am335x_ecap_methods[] = {
90 	DEVMETHOD(device_probe,		am335x_ecap_probe),
91 	DEVMETHOD(device_attach,	am335x_ecap_attach),
92 	DEVMETHOD(device_detach,	am335x_ecap_detach),
93 
94 	DEVMETHOD_END
95 };
96 
97 static driver_t am335x_ecap_driver = {
98 	"am335x_ecap",
99 	am335x_ecap_methods,
100 	sizeof(struct am335x_ecap_softc),
101 };
102 
103 /*
104  * API function to set period/duty cycles for ECAPx
105  */
106 int
107 am335x_pwm_config_ecap(int unit, int period, int duty)
108 {
109 	device_t dev;
110 	struct am335x_ecap_softc *sc;
111 	uint16_t reg;
112 
113 	dev = devclass_get_device(devclass_find(am335x_ecap_driver.name), unit);
114 	if (dev == NULL)
115 		return (ENXIO);
116 
117 	if (duty > period)
118 		return (EINVAL);
119 
120 	if (period == 0)
121 		return (EINVAL);
122 
123 	sc = device_get_softc(dev);
124 	PWM_LOCK(sc);
125 
126 	reg = ECAP_READ2(sc, ECAP_ECCTL2);
127 	reg |= ECCTL2_MODE_APWM | ECCTL2_TSCTRSTOP_FREERUN | ECCTL2_SYNCO_SEL;
128 	ECAP_WRITE2(sc, ECAP_ECCTL2, reg);
129 
130 	/* CAP3 in APWM mode is APRD shadow register */
131 	ECAP_WRITE4(sc, ECAP_CAP3, period - 1);
132 
133 	/* CAP4 in APWM mode is ACMP shadow register */
134 	ECAP_WRITE4(sc, ECAP_CAP4, duty);
135 	/* Restart counter */
136 	ECAP_WRITE4(sc, ECAP_TSCTR, 0);
137 
138 	PWM_UNLOCK(sc);
139 
140 	return (0);
141 }
142 
143 static int
144 am335x_ecap_probe(device_t dev)
145 {
146 
147 	if (!ofw_bus_status_okay(dev))
148 		return (ENXIO);
149 
150 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
151 		return (ENXIO);
152 
153 	device_set_desc(dev, "AM335x eCAP");
154 
155 	return (BUS_PROBE_DEFAULT);
156 }
157 
158 static int
159 am335x_ecap_attach(device_t dev)
160 {
161 	struct am335x_ecap_softc *sc;
162 
163 	sc = device_get_softc(dev);
164 	sc->sc_dev = dev;
165 
166 	PWM_LOCK_INIT(sc);
167 
168 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
169 	    &sc->sc_mem_rid, RF_ACTIVE);
170 	if (sc->sc_mem_res == NULL) {
171 		device_printf(dev, "cannot allocate memory resources\n");
172 		goto fail;
173 	}
174 
175 	return (0);
176 
177 fail:
178 	PWM_LOCK_DESTROY(sc);
179 	return (ENXIO);
180 }
181 
182 static int
183 am335x_ecap_detach(device_t dev)
184 {
185 	struct am335x_ecap_softc *sc;
186 
187 	sc = device_get_softc(dev);
188 
189 	PWM_LOCK(sc);
190 	if (sc->sc_mem_res)
191 		bus_release_resource(dev, SYS_RES_MEMORY,
192 		    sc->sc_mem_rid, sc->sc_mem_res);
193 	PWM_UNLOCK(sc);
194 
195 	PWM_LOCK_DESTROY(sc);
196 
197 	return (0);
198 }
199 
200 DRIVER_MODULE(am335x_ecap, am335x_pwmss, am335x_ecap_driver, 0, 0);
201 MODULE_VERSION(am335x_ecap, 1);
202 MODULE_DEPEND(am335x_ecap, am335x_pwmss, 1, 1, 1);
203