xref: /freebsd/sys/dev/gpio/gpiomdio.c (revision adf376485712c8fffbf3be330d505a969647f479)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019 Rubicon Communications, LLC (Netgate)
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_platform.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/gpio.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/socket.h>
40 
41 #include <net/if.h>
42 #include <net/if_media.h>
43 #include <net/if_types.h>
44 
45 #include <dev/fdt/fdt_common.h>
46 #include <dev/gpio/gpiobusvar.h>
47 #include <dev/mii/mii_bitbang.h>
48 #include <dev/mii/miivar.h>
49 #include <dev/ofw/ofw_bus.h>
50 
51 #include "gpiobus_if.h"
52 #include "miibus_if.h"
53 
54 #define	GPIOMDIO_MDC_DFLT	0
55 #define	GPIOMDIO_MDIO_DFLT	1
56 #define	GPIOMDIO_MIN_PINS	2
57 
58 #define	MDO_BIT			0x01
59 #define	MDI_BIT			0x02
60 #define	MDC_BIT			0x04
61 #define	MDIRPHY_BIT		0x08
62 #define	MDIRHOST_BIT		0x10
63 #define	MDO			sc->miibb_ops.mbo_bits[MII_BIT_MDO]
64 #define	MDI			sc->miibb_ops.mbo_bits[MII_BIT_MDI]
65 #define	MDC			sc->miibb_ops.mbo_bits[MII_BIT_MDC]
66 #define	MDIRPHY			sc->miibb_ops.mbo_bits[MII_BIT_DIR_HOST_PHY]
67 #define	MDIRHOST		sc->miibb_ops.mbo_bits[MII_BIT_DIR_PHY_HOST]
68 
69 static uint32_t gpiomdio_bb_read(device_t);
70 static void gpiomdio_bb_write(device_t, uint32_t);
71 
72 struct gpiomdio_softc
73 {
74 	device_t		sc_dev;
75 	device_t		sc_busdev;
76 	int			mdc_pin;
77 	int			mdio_pin;
78 	struct mii_bitbang_ops	miibb_ops;
79 };
80 
81 
82 static int
83 gpiomdio_probe(device_t dev)
84 {
85 	struct gpiobus_ivar *devi;
86 
87 	if (!ofw_bus_status_okay(dev))
88 		return (ENXIO);
89 	if (!ofw_bus_is_compatible(dev, "freebsd,gpiomdio"))
90 		return (ENXIO);
91 	devi = GPIOBUS_IVAR(dev);
92 	if (devi->npins < GPIOMDIO_MIN_PINS) {
93 		device_printf(dev,
94 		    "gpiomdio needs at least %d GPIO pins (only %d given).\n",
95 		    GPIOMDIO_MIN_PINS, devi->npins);
96 		return (ENXIO);
97 	}
98 	device_set_desc(dev, "GPIO MDIO bit-banging Bus driver");
99 
100 	return (BUS_PROBE_DEFAULT);
101 }
102 
103 static int
104 gpiomdio_attach(device_t dev)
105 {
106 	phandle_t		node;
107 	pcell_t			pin;
108 	struct gpiobus_ivar	*devi;
109 	struct gpiomdio_softc	*sc;
110 
111 	sc = device_get_softc(dev);
112 	sc->sc_dev = dev;
113 	sc->sc_busdev = device_get_parent(dev);
114 
115 	if ((node = ofw_bus_get_node(dev)) == -1)
116 		return (ENXIO);
117 	if (OF_getencprop(node, "mdc", &pin, sizeof(pin)) > 0)
118 		sc->mdc_pin = (int)pin;
119 	if (OF_getencprop(node, "mdio", &pin, sizeof(pin)) > 0)
120 		sc->mdio_pin = (int)pin;
121 
122 	if (sc->mdc_pin < 0 || sc->mdc_pin > 1)
123 		sc->mdc_pin = GPIOMDIO_MDC_DFLT;
124 	if (sc->mdio_pin < 0 || sc->mdio_pin > 1)
125 		sc->mdio_pin = GPIOMDIO_MDIO_DFLT;
126 
127 	devi = GPIOBUS_IVAR(dev);
128 	device_printf(dev, "MDC pin: %d, MDIO pin: %d\n",
129 	    devi->pins[sc->mdc_pin], devi->pins[sc->mdio_pin]);
130 
131 	/* Initialize mii_bitbang_ops. */
132 	MDO = MDO_BIT;
133 	MDI = MDI_BIT;
134 	MDC = MDC_BIT;
135 	MDIRPHY = MDIRPHY_BIT;
136 	MDIRHOST = MDIRHOST_BIT;
137 	sc->miibb_ops.mbo_read = gpiomdio_bb_read;
138 	sc->miibb_ops.mbo_write = gpiomdio_bb_write;
139 
140 	/* Register our MDIO Bus device. */
141 	OF_device_register_xref(OF_xref_from_node(node), dev);
142 
143 	return (0);
144 }
145 
146 static uint32_t
147 gpiomdio_bb_read(device_t dev)
148 {
149 	struct gpiomdio_softc *sc;
150 	unsigned int val;
151 
152 	sc = device_get_softc(dev);
153 	GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, &val);
154 
155 	return (val != 0 ? MDI_BIT : 0);
156 }
157 
158 static void
159 gpiomdio_bb_write(device_t dev, uint32_t val)
160 {
161 	struct gpiomdio_softc *sc;
162 
163 	sc = device_get_softc(dev);
164 
165 	/* Set the data pin state. */
166 	if ((val & (MDIRPHY_BIT | MDO_BIT)) == (MDIRPHY_BIT | MDO_BIT))
167 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, 1);
168 	else if ((val & (MDIRPHY_BIT | MDO_BIT)) == MDIRPHY_BIT)
169 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, 0);
170 	if (val & MDIRPHY_BIT)
171 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdio_pin,
172 		    GPIO_PIN_OUTPUT);
173 	else if (val & MDIRHOST_BIT)
174 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdio_pin,
175 		    GPIO_PIN_INPUT);
176 
177 	/* And now the clock state. */
178 	if (val & MDC_BIT)
179 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdc_pin, 1);
180 	else
181 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdc_pin, 0);
182 	GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdc_pin,
183 	    GPIO_PIN_OUTPUT);
184 }
185 
186 static int
187 gpiomdio_readreg(device_t dev, int phy, int reg)
188 {
189 	struct gpiomdio_softc	*sc;
190 
191 	sc = device_get_softc(dev);
192 
193 	return (mii_bitbang_readreg(dev, &sc->miibb_ops, phy, reg));
194 }
195 
196 static int
197 gpiomdio_writereg(device_t dev, int phy, int reg, int val)
198 {
199 	struct gpiomdio_softc	*sc;
200 
201 	sc = device_get_softc(dev);
202 	mii_bitbang_writereg(dev, &sc->miibb_ops, phy, reg, val);
203 
204 	return (0);
205 }
206 
207 static phandle_t
208 gpiomdio_get_node(device_t bus, device_t dev)
209 {
210 
211 	return (ofw_bus_get_node(bus));
212 }
213 
214 static device_method_t gpiomdio_methods[] = {
215 	/* Device interface */
216 	DEVMETHOD(device_probe,		gpiomdio_probe),
217 	DEVMETHOD(device_attach,	gpiomdio_attach),
218 	DEVMETHOD(device_detach,	bus_generic_detach),
219 
220 	/* MDIO interface */
221 	DEVMETHOD(miibus_readreg,	gpiomdio_readreg),
222 	DEVMETHOD(miibus_writereg,	gpiomdio_writereg),
223 
224 	/* OFW bus interface */
225 	DEVMETHOD(ofw_bus_get_node,	gpiomdio_get_node),
226 
227 	DEVMETHOD_END
228 };
229 
230 static driver_t gpiomdio_driver = {
231 	"gpiomdio",
232 	gpiomdio_methods,
233 	sizeof(struct gpiomdio_softc),
234 };
235 
236 EARLY_DRIVER_MODULE(gpiomdio, gpiobus, gpiomdio_driver, 0, 0,
237     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
238 DRIVER_MODULE(miibus, gpiomdio, miibus_driver, 0, 0);
239 MODULE_DEPEND(gpiomdio, gpiobus, 1, 1, 1);
240 MODULE_DEPEND(gpiomdio, miibus, 1, 1, 1);
241 MODULE_DEPEND(gpiomdio, mii_bitbang, 1, 1, 1);
242