1 /* $NetBSD: gpiopwm.c,v 1.7 2017/10/28 04:53:56 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2011 Marc Balmer <marc@msys.ch>
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 ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 /*
29 * Driver for pulsing GPIO pins in software
30 */
31
32 #include <sys/param.h>
33 #include <sys/device.h>
34 #include <sys/gpio.h>
35 #include <sys/sysctl.h>
36
37 #include <dev/gpio/gpiovar.h>
38
39 #include "ioconf.h"
40
41 #define GPIOPWM_NPINS 1
42
43 struct gpiopwm_softc {
44 device_t sc_dev;
45 void *sc_gpio;
46 struct gpio_pinmap sc_map;
47 int _map[GPIOPWM_NPINS];
48
49 callout_t sc_pulse;
50 int sc_ticks_on;
51 int sc_ticks_off;
52
53 struct sysctllog *sc_log;
54 int sc_dying;
55 };
56
57 int gpiopwm_match(device_t, cfdata_t, void *);
58 void gpiopwm_attach(device_t, device_t, void *);
59 int gpiopwm_detach(device_t, int);
60 int gpiopwm_activate(device_t, enum devact);
61 static int gpiopwm_set_on(SYSCTLFN_ARGS);
62 static int gpiopwm_set_off(SYSCTLFN_ARGS);
63 static void gpiopwm_pulse(void *);
64
65 CFATTACH_DECL_NEW(gpiopwm, sizeof(struct gpiopwm_softc),
66 gpiopwm_match, gpiopwm_attach, gpiopwm_detach, gpiopwm_activate);
67
68 int
gpiopwm_match(device_t parent,cfdata_t cf,void * aux)69 gpiopwm_match(device_t parent, cfdata_t cf,
70 void *aux)
71 {
72 struct gpio_attach_args *ga = aux;
73
74 if (strcmp(ga->ga_dvname, cf->cf_name))
75 return 0;
76
77 if (ga->ga_offset == -1)
78 return 0;
79
80 /* Check number of pins, must be 1 */
81 if (gpio_npins(ga->ga_mask) != GPIOPWM_NPINS) {
82 aprint_debug("%s: invalid pin mask 0x%02x\n", cf->cf_name,
83 ga->ga_mask);
84 return 0;
85 }
86 return 1;
87 }
88
89 void
gpiopwm_attach(device_t parent,device_t self,void * aux)90 gpiopwm_attach(device_t parent, device_t self, void *aux)
91 {
92 struct gpiopwm_softc *sc = device_private(self);
93 struct gpio_attach_args *ga = aux;
94 const struct sysctlnode *node;
95
96 sc->sc_dev = self;
97
98 /* Map pin */
99 sc->sc_gpio = ga->ga_gpio;
100 sc->sc_map.pm_map = sc->_map;
101 if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
102 &sc->sc_map)) {
103 aprint_error(": can't map pin\n");
104 return;
105 }
106 aprint_normal(" [%d]", sc->sc_map.pm_map[0]);
107 if (!pmf_device_register(self, NULL, NULL))
108 aprint_error_dev(self, "couldn't establish power handler\n");
109
110 callout_init(&sc->sc_pulse, CALLOUT_MPSAFE);
111 callout_setfunc(&sc->sc_pulse, gpiopwm_pulse, sc);
112
113 sysctl_createv(&sc->sc_log, 0, NULL, &node,
114 0,
115 CTLTYPE_NODE, device_xname(sc->sc_dev),
116 SYSCTL_DESCR("GPIO software PWM"),
117 NULL, 0, NULL, 0,
118 CTL_HW, CTL_CREATE, CTL_EOL);
119
120 if (node == NULL) {
121 aprint_error(": can't create sysctl node\n");
122 return;
123 }
124
125 sysctl_createv(&sc->sc_log, 0, &node, NULL,
126 CTLFLAG_READWRITE,
127 CTLTYPE_INT, "on",
128 SYSCTL_DESCR("PWM 'on' period in ticks"),
129 gpiopwm_set_on, 0, (void *)sc, 0,
130 CTL_CREATE, CTL_EOL);
131 sysctl_createv(&sc->sc_log, 0, &node, NULL,
132 CTLFLAG_READWRITE,
133 CTLTYPE_INT, "off",
134 SYSCTL_DESCR("PWM 'off' period in ticks"),
135 gpiopwm_set_off, 0, (void *)sc, 0,
136 CTL_CREATE, CTL_EOL);
137
138 aprint_normal("\n");
139 return;
140 }
141
142 int
gpiopwm_detach(device_t self,int flags)143 gpiopwm_detach(device_t self, int flags)
144 {
145 struct gpiopwm_softc *sc = device_private(self);
146
147 callout_halt(&sc->sc_pulse, NULL);
148 callout_destroy(&sc->sc_pulse);
149 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
150
151 pmf_device_deregister(self);
152 gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
153
154 if (sc->sc_log != NULL) {
155 sysctl_teardown(&sc->sc_log);
156 sc->sc_log = NULL;
157 }
158 return 0;
159 }
160
161 static int
gpiopwm_set_on(SYSCTLFN_ARGS)162 gpiopwm_set_on(SYSCTLFN_ARGS)
163 {
164 struct sysctlnode node;
165 struct gpiopwm_softc *sc;
166 int val, error;
167
168 node = *rnode;
169 sc = node.sysctl_data;
170
171 callout_halt(&sc->sc_pulse, NULL);
172 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
173 node.sysctl_data = &val;
174
175 val = sc->sc_ticks_on;
176 error = sysctl_lookup(SYSCTLFN_CALL(&node));
177 if (error || newp == NULL)
178 return error;
179
180 sc->sc_ticks_on = val;
181 if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) {
182 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
183 callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
184 }
185 return 0;
186 }
187
188 static int
gpiopwm_set_off(SYSCTLFN_ARGS)189 gpiopwm_set_off(SYSCTLFN_ARGS)
190 {
191 struct sysctlnode node;
192 struct gpiopwm_softc *sc;
193 int val, error;
194
195 node = *rnode;
196 sc = node.sysctl_data;
197
198 callout_halt(&sc->sc_pulse, NULL);
199 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
200 node.sysctl_data = &val;
201
202 val = sc->sc_ticks_off;
203 error = sysctl_lookup(SYSCTLFN_CALL(&node));
204 if (error || newp == NULL)
205 return error;
206
207 sc->sc_ticks_off = val;
208 if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) {
209 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
210 callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
211 }
212 return 0;
213 }
214
215 static void
gpiopwm_pulse(void * arg)216 gpiopwm_pulse(void *arg)
217 {
218 struct gpiopwm_softc *sc;
219
220 sc = arg;
221 if (gpio_pin_read(sc->sc_gpio, &sc->sc_map, 0) == GPIO_PIN_HIGH) {
222 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW);
223 callout_schedule(&sc->sc_pulse, sc->sc_ticks_off);
224 } else {
225 gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH);
226 callout_schedule(&sc->sc_pulse, sc->sc_ticks_on);
227 }
228 }
229
230 int
gpiopwm_activate(device_t self,enum devact act)231 gpiopwm_activate(device_t self, enum devact act)
232 {
233 struct gpiopwm_softc *sc = device_private(self);
234
235 switch (act) {
236 case DVACT_DEACTIVATE:
237 sc->sc_dying = 1;
238 return 0;
239 default:
240 return EOPNOTSUPP;
241 }
242 }
243