xref: /freebsd/sys/dev/gpio/gpioregulator.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
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 ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22  * 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  * $FreeBSD$
27  */
28 
29 /*
30  * GPIO controlled regulators
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/rman.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/gpio.h>
43 
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 
47 #include <dev/gpio/gpiobusvar.h>
48 
49 #include <dev/extres/regulator/regulator.h>
50 
51 #include "regdev_if.h"
52 
53 struct gpioregulator_state {
54 	int			val;
55 	uint32_t		mask;
56 };
57 
58 struct gpioregulator_init_def {
59 	struct regnode_init_def		reg_init_def;
60 	struct gpiobus_pin		*enable_pin;
61 	int				enable_pin_valid;
62 	int				startup_delay_us;
63 	int				nstates;
64 	struct gpioregulator_state	*states;
65 	int				npins;
66 	struct gpiobus_pin		**pins;
67 };
68 
69 struct gpioregulator_reg_sc {
70 	struct regnode			*regnode;
71 	device_t			base_dev;
72 	struct regnode_std_param	*param;
73 	struct gpioregulator_init_def	*def;
74 };
75 
76 struct gpioregulator_softc {
77 	device_t			dev;
78 	struct gpioregulator_reg_sc	*reg_sc;
79 	struct gpioregulator_init_def	init_def;
80 };
81 
82 static int
83 gpioregulator_regnode_init(struct regnode *regnode)
84 {
85 	struct gpioregulator_reg_sc *sc;
86 	int error, n;
87 
88 	sc = regnode_get_softc(regnode);
89 
90 	if (sc->def->enable_pin_valid == 1) {
91 		error = gpio_pin_setflags(sc->def->enable_pin, GPIO_PIN_OUTPUT);
92 		if (error != 0)
93 			return (error);
94 	}
95 
96 	for (n = 0; n < sc->def->npins; n++) {
97 		error = gpio_pin_setflags(sc->def->pins[n], GPIO_PIN_OUTPUT);
98 		if (error != 0)
99 			return (error);
100 	}
101 
102 	return (0);
103 }
104 
105 static int
106 gpioregulator_regnode_enable(struct regnode *regnode, bool enable, int *udelay)
107 {
108 	struct gpioregulator_reg_sc *sc;
109 	bool active;
110 	int error;
111 
112 	sc = regnode_get_softc(regnode);
113 
114 	if (sc->def->enable_pin_valid == 1) {
115 		active = enable;
116 		if (!sc->param->enable_active_high)
117 			active = !active;
118 		error = gpio_pin_set_active(sc->def->enable_pin, active);
119 		if (error != 0)
120 			return (error);
121 	}
122 
123 	*udelay = sc->def->startup_delay_us;
124 
125 	return (0);
126 }
127 
128 static int
129 gpioregulator_regnode_set_voltage(struct regnode *regnode, int min_uvolt,
130     int max_uvolt, int *udelay)
131 {
132 	struct gpioregulator_reg_sc *sc;
133 	const struct gpioregulator_state *state;
134 	int error, n;
135 
136 	sc = regnode_get_softc(regnode);
137 	state = NULL;
138 
139 	for (n = 0; n < sc->def->nstates; n++) {
140 		if (sc->def->states[n].val >= min_uvolt &&
141 		    sc->def->states[n].val <= max_uvolt) {
142 			state = &sc->def->states[n];
143 			break;
144 		}
145 	}
146 	if (state == NULL)
147 		return (EINVAL);
148 
149 	for (n = 0; n < sc->def->npins; n++) {
150 		error = gpio_pin_set_active(sc->def->pins[n],
151 		    (state->mask >> n) & 1);
152 		if (error != 0)
153 			return (error);
154 	}
155 
156 	*udelay = sc->def->startup_delay_us;
157 
158 	return (0);
159 }
160 
161 static int
162 gpioregulator_regnode_get_voltage(struct regnode *regnode, int *uvolt)
163 {
164 	struct gpioregulator_reg_sc *sc;
165 	uint32_t mask;
166 	int error, n;
167 	bool active;
168 
169 	sc = regnode_get_softc(regnode);
170 	mask = 0;
171 
172 	for (n = 0; n < sc->def->npins; n++) {
173 		error = gpio_pin_is_active(sc->def->pins[n], &active);
174 		if (error != 0)
175 			return (error);
176 		mask |= (active << n);
177 	}
178 
179 	for (n = 0; n < sc->def->nstates; n++) {
180 		if (sc->def->states[n].mask == mask) {
181 			*uvolt = sc->def->states[n].val;
182 			return (0);
183 		}
184 	}
185 
186 	return (EIO);
187 }
188 
189 static regnode_method_t gpioregulator_regnode_methods[] = {
190 	/* Regulator interface */
191 	REGNODEMETHOD(regnode_init,	gpioregulator_regnode_init),
192 	REGNODEMETHOD(regnode_enable,	gpioregulator_regnode_enable),
193 	REGNODEMETHOD(regnode_set_voltage, gpioregulator_regnode_set_voltage),
194 	REGNODEMETHOD(regnode_get_voltage, gpioregulator_regnode_get_voltage),
195 	REGNODEMETHOD_END
196 };
197 DEFINE_CLASS_1(gpioregulator_regnode, gpioregulator_regnode_class,
198     gpioregulator_regnode_methods, sizeof(struct gpioregulator_reg_sc),
199     regnode_class);
200 
201 static int
202 gpioregulator_parse_fdt(struct gpioregulator_softc *sc)
203 {
204 	uint32_t *pstates, mask;
205 	phandle_t node;
206 	ssize_t len;
207 	int error, n;
208 
209 	node = ofw_bus_get_node(sc->dev);
210 	pstates = NULL;
211 	mask = 0;
212 
213 	error = regulator_parse_ofw_stdparam(sc->dev, node,
214 	    &sc->init_def.reg_init_def);
215 	if (error != 0)
216 		return (error);
217 
218 	/* "states" property (required) */
219 	len = OF_getencprop_alloc(node, "states", sizeof(*pstates),
220 	    (void **)&pstates);
221 	if (len < 2) {
222 		device_printf(sc->dev, "invalid 'states' property\n");
223 		error = EINVAL;
224 		goto done;
225 	}
226 	sc->init_def.nstates = len / 2;
227 	sc->init_def.states = malloc(sc->init_def.nstates *
228 	    sizeof(*sc->init_def.states), M_DEVBUF, M_WAITOK);
229 	for (n = 0; n < sc->init_def.nstates; n++) {
230 		sc->init_def.states[n].val = pstates[n * 2 + 0];
231 		sc->init_def.states[n].mask = pstates[n * 2 + 1];
232 		mask |= sc->init_def.states[n].mask;
233 	}
234 
235 	/* "startup-delay-us" property (optional) */
236 	len = OF_getencprop(node, "startup-delay-us",
237 	    &sc->init_def.startup_delay_us,
238 	    sizeof(sc->init_def.startup_delay_us));
239 	if (len <= 0)
240 		sc->init_def.startup_delay_us = 0;
241 
242 	/* "enable-gpio" property (optional) */
243 	error = gpio_pin_get_by_ofw_property(sc->dev, node, "enable-gpio",
244 	    &sc->init_def.enable_pin);
245 	if (error == 0)
246 		sc->init_def.enable_pin_valid = 1;
247 
248 	/* "gpios" property */
249 	sc->init_def.npins = 32 - __builtin_clz(mask);
250 	sc->init_def.pins = malloc(sc->init_def.npins *
251 	    sizeof(sc->init_def.pins), M_DEVBUF, M_WAITOK);
252 	for (n = 0; n < sc->init_def.npins; n++) {
253 		error = gpio_pin_get_by_ofw_idx(sc->dev, node, n,
254 		    &sc->init_def.pins[n]);
255 		if (error != 0) {
256 			device_printf(sc->dev, "cannot get pin %d\n", n);
257 			goto done;
258 		}
259 	}
260 
261 done:
262 	if (error != 0) {
263 		for (n = 0; n < sc->init_def.npins; n++) {
264 			if (sc->init_def.pins[n] != NULL)
265 				gpio_pin_release(sc->init_def.pins[n]);
266 		}
267 
268 		free(sc->init_def.states, M_DEVBUF);
269 		free(sc->init_def.pins, M_DEVBUF);
270 
271 	}
272 	OF_prop_free(pstates);
273 
274 	return (error);
275 }
276 
277 static int
278 gpioregulator_probe(device_t dev)
279 {
280 
281 	if (!ofw_bus_is_compatible(dev, "regulator-gpio"))
282 		return (ENXIO);
283 
284 	device_set_desc(dev, "GPIO controlled regulator");
285 	return (BUS_PROBE_GENERIC);
286 }
287 
288 static int
289 gpioregulator_attach(device_t dev)
290 {
291 	struct gpioregulator_softc *sc;
292 	struct regnode *regnode;
293 	phandle_t node;
294 	int error;
295 
296 	sc = device_get_softc(dev);
297 	sc->dev = dev;
298 	node = ofw_bus_get_node(dev);
299 
300 	error = gpioregulator_parse_fdt(sc);
301 	if (error != 0) {
302 		device_printf(dev, "cannot parse parameters\n");
303 		return (ENXIO);
304 	}
305 	sc->init_def.reg_init_def.id = 1;
306 	sc->init_def.reg_init_def.ofw_node = node;
307 
308 	regnode = regnode_create(dev, &gpioregulator_regnode_class,
309 	    &sc->init_def.reg_init_def);
310 	if (regnode == NULL) {
311 		device_printf(dev, "cannot create regulator\n");
312 		return (ENXIO);
313 	}
314 
315 	sc->reg_sc = regnode_get_softc(regnode);
316 	sc->reg_sc->regnode = regnode;
317 	sc->reg_sc->base_dev = dev;
318 	sc->reg_sc->param = regnode_get_stdparam(regnode);
319 	sc->reg_sc->def = &sc->init_def;
320 
321 	regnode_register(regnode);
322 
323 	return (0);
324 }
325 
326 
327 static device_method_t gpioregulator_methods[] = {
328 	/* Device interface */
329 	DEVMETHOD(device_probe,		gpioregulator_probe),
330 	DEVMETHOD(device_attach,	gpioregulator_attach),
331 
332 	/* Regdev interface */
333 	DEVMETHOD(regdev_map,		regdev_default_ofw_map),
334 
335 	DEVMETHOD_END
336 };
337 
338 static driver_t gpioregulator_driver = {
339 	"gpioregulator",
340 	gpioregulator_methods,
341 	sizeof(struct gpioregulator_softc),
342 };
343 
344 static devclass_t gpioregulator_devclass;
345 
346 EARLY_DRIVER_MODULE(gpioregulator, simplebus, gpioregulator_driver,
347     gpioregulator_devclass, 0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LAST);
348 MODULE_VERSION(gpioregulator, 1);
349