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 device_method_t am335x_ecap_methods[] = {
83 DEVMETHOD(device_probe, am335x_ecap_probe),
84 DEVMETHOD(device_attach, am335x_ecap_attach),
85 DEVMETHOD(device_detach, am335x_ecap_detach),
86
87 DEVMETHOD_END
88 };
89
90 static driver_t am335x_ecap_driver = {
91 "am335x_ecap",
92 am335x_ecap_methods,
93 sizeof(struct am335x_ecap_softc),
94 };
95
96 static devclass_t am335x_ecap_devclass;
97
98 /*
99 * API function to set period/duty cycles for ECAPx
100 */
101 int
am335x_pwm_config_ecap(int unit,int period,int duty)102 am335x_pwm_config_ecap(int unit, int period, int duty)
103 {
104 device_t dev;
105 struct am335x_ecap_softc *sc;
106 uint16_t reg;
107
108 dev = devclass_get_device(am335x_ecap_devclass, unit);
109 if (dev == NULL)
110 return (ENXIO);
111
112 if (duty > period)
113 return (EINVAL);
114
115 if (period == 0)
116 return (EINVAL);
117
118 sc = device_get_softc(dev);
119 PWM_LOCK(sc);
120
121 reg = ECAP_READ2(sc, ECAP_ECCTL2);
122 reg |= ECCTL2_MODE_APWM | ECCTL2_TSCTRSTOP_FREERUN | ECCTL2_SYNCO_SEL;
123 ECAP_WRITE2(sc, ECAP_ECCTL2, reg);
124
125 /* CAP3 in APWM mode is APRD shadow register */
126 ECAP_WRITE4(sc, ECAP_CAP3, period - 1);
127
128 /* CAP4 in APWM mode is ACMP shadow register */
129 ECAP_WRITE4(sc, ECAP_CAP4, duty);
130 /* Restart counter */
131 ECAP_WRITE4(sc, ECAP_TSCTR, 0);
132
133 PWM_UNLOCK(sc);
134
135 return (0);
136 }
137
138 static int
am335x_ecap_probe(device_t dev)139 am335x_ecap_probe(device_t dev)
140 {
141
142 if (!ofw_bus_status_okay(dev))
143 return (ENXIO);
144
145 if (!ofw_bus_is_compatible(dev, "ti,am33xx-ecap"))
146 return (ENXIO);
147
148 device_set_desc(dev, "AM335x eCAP");
149
150 return (BUS_PROBE_DEFAULT);
151 }
152
153 static int
am335x_ecap_attach(device_t dev)154 am335x_ecap_attach(device_t dev)
155 {
156 struct am335x_ecap_softc *sc;
157
158 sc = device_get_softc(dev);
159 sc->sc_dev = dev;
160
161 PWM_LOCK_INIT(sc);
162
163 sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
164 &sc->sc_mem_rid, RF_ACTIVE);
165 if (sc->sc_mem_res == NULL) {
166 device_printf(dev, "cannot allocate memory resources\n");
167 goto fail;
168 }
169
170 return (0);
171
172 fail:
173 PWM_LOCK_DESTROY(sc);
174 return (ENXIO);
175 }
176
177 static int
am335x_ecap_detach(device_t dev)178 am335x_ecap_detach(device_t dev)
179 {
180 struct am335x_ecap_softc *sc;
181
182 sc = device_get_softc(dev);
183
184 PWM_LOCK(sc);
185 if (sc->sc_mem_res)
186 bus_release_resource(dev, SYS_RES_MEMORY,
187 sc->sc_mem_rid, sc->sc_mem_res);
188 PWM_UNLOCK(sc);
189
190 PWM_LOCK_DESTROY(sc);
191
192 return (0);
193 }
194
195 DRIVER_MODULE(am335x_ecap, am335x_pwmss, am335x_ecap_driver, am335x_ecap_devclass, 0, 0);
196 MODULE_VERSION(am335x_ecap, 1);
197 MODULE_DEPEND(am335x_ecap, am335x_pwmss, 1, 1, 1);
198