xref: /freebsd/sys/dev/iicbus/ofw_iicbus.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@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 unmodified, this list of conditions, and the following
10  *    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 ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/libkern.h>
34 #include <sys/lock.h>
35 #include <sys/module.h>
36 #include <sys/mutex.h>
37 
38 #include <dev/iicbus/iicbus.h>
39 #include <dev/iicbus/iiconf.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 #include <dev/ofw/openfirm.h>
43 
44 #include "iicbus_if.h"
45 
46 /* Methods */
47 static device_probe_t ofw_iicbus_probe;
48 static device_attach_t ofw_iicbus_attach;
49 static device_t ofw_iicbus_add_child(device_t dev, u_int order,
50     const char *name, int unit);
51 static const struct ofw_bus_devinfo *ofw_iicbus_get_devinfo(device_t bus,
52     device_t dev);
53 
54 static device_method_t ofw_iicbus_methods[] = {
55 	/* Device interface */
56 	DEVMETHOD(device_probe,		ofw_iicbus_probe),
57 	DEVMETHOD(device_attach,	ofw_iicbus_attach),
58 
59 	/* Bus interface */
60 	DEVMETHOD(bus_child_pnpinfo_str, ofw_bus_gen_child_pnpinfo_str),
61 	DEVMETHOD(bus_add_child,	ofw_iicbus_add_child),
62 
63 	/* ofw_bus interface */
64 	DEVMETHOD(ofw_bus_get_devinfo,	ofw_iicbus_get_devinfo),
65 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
66 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
67 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
68 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
69 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
70 
71 	DEVMETHOD_END
72 };
73 
74 struct ofw_iicbus_devinfo {
75 	struct iicbus_ivar	opd_dinfo;	/* Must be the first. */
76 	struct ofw_bus_devinfo	opd_obdinfo;
77 };
78 
79 devclass_t ofw_iicbus_devclass;
80 
81 DEFINE_CLASS_1(iicbus, ofw_iicbus_driver, ofw_iicbus_methods,
82     sizeof(struct iicbus_softc), iicbus_driver);
83 EARLY_DRIVER_MODULE(ofw_iicbus, iicbb, ofw_iicbus_driver, ofw_iicbus_devclass,
84     0, 0, BUS_PASS_BUS);
85 EARLY_DRIVER_MODULE(ofw_iicbus, iichb, ofw_iicbus_driver, ofw_iicbus_devclass,
86     0, 0, BUS_PASS_BUS);
87 EARLY_DRIVER_MODULE(ofw_iicbus, twsi, ofw_iicbus_driver, ofw_iicbus_devclass,
88     0, 0, BUS_PASS_BUS);
89 MODULE_VERSION(ofw_iicbus, 1);
90 MODULE_DEPEND(ofw_iicbus, iicbus, 1, 1, 1);
91 
92 static int
93 ofw_iicbus_probe(device_t dev)
94 {
95 
96 	if (ofw_bus_get_node(dev) == -1)
97 		return (ENXIO);
98 	device_set_desc(dev, "OFW I2C bus");
99 
100 	return (0);
101 }
102 
103 static int
104 ofw_iicbus_attach(device_t dev)
105 {
106 	struct iicbus_softc *sc = IICBUS_SOFTC(dev);
107 	struct ofw_iicbus_devinfo *dinfo;
108 	phandle_t child, node, root;
109 	pcell_t freq, paddr;
110 	device_t childdev;
111 	ssize_t compatlen;
112 	char compat[255];
113 	char *curstr;
114 	u_int iic_addr_8bit = 0;
115 
116 	sc->dev = dev;
117 	mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF);
118 
119 	/*
120 	 * If there is a clock-frequency property for the device node, use it as
121 	 * the starting value for the bus frequency.  Then call the common
122 	 * routine that handles the tunable/sysctl which allows the FDT value to
123 	 * be overridden by the user.
124 	 */
125 	node = ofw_bus_get_node(dev);
126 	freq = 0;
127 	OF_getencprop(node, "clock-frequency", &freq, sizeof(freq));
128 	iicbus_init_frequency(dev, freq);
129 
130 	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
131 
132 	bus_generic_probe(dev);
133 	bus_enumerate_hinted_children(dev);
134 
135 	/*
136 	 * Check if we're running on a PowerMac, needed for the I2C
137 	 * address below.
138 	 */
139 	root = OF_peer(0);
140 	compatlen = OF_getprop(root, "compatible", compat,
141 				sizeof(compat));
142 	if (compatlen != -1) {
143 	    for (curstr = compat; curstr < compat + compatlen;
144 		curstr += strlen(curstr) + 1) {
145 		if (strncmp(curstr, "MacRISC", 7) == 0)
146 		    iic_addr_8bit = 1;
147 	    }
148 	}
149 
150 	/*
151 	 * Attach those children represented in the device tree.
152 	 */
153 	for (child = OF_child(node); child != 0; child = OF_peer(child)) {
154 		/*
155 		 * Try to get the I2C address first from the i2c-address
156 		 * property, then try the reg property.  It moves around
157 		 * on different systems.
158 		 */
159 		if (OF_getencprop(child, "i2c-address", &paddr,
160 		    sizeof(paddr)) == -1)
161 			if (OF_getencprop(child, "reg", &paddr,
162 			    sizeof(paddr)) == -1)
163 				continue;
164 
165 		/*
166 		 * Now set up the I2C and OFW bus layer devinfo and add it
167 		 * to the bus.
168 		 */
169 		dinfo = malloc(sizeof(struct ofw_iicbus_devinfo), M_DEVBUF,
170 		    M_NOWAIT | M_ZERO);
171 		if (dinfo == NULL)
172 			continue;
173 		/*
174 		 * FreeBSD drivers expect I2C addresses to be expressed as
175 		 * 8-bit values.  Apple OFW data contains 8-bit values, but
176 		 * Linux FDT data contains 7-bit values, so shift them up to
177 		 * 8-bit format.
178 		 */
179 		if (iic_addr_8bit)
180 		    dinfo->opd_dinfo.addr = paddr;
181 		else
182 		    dinfo->opd_dinfo.addr = paddr << 1;
183 
184 		if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, child) !=
185 		    0) {
186 			free(dinfo, M_DEVBUF);
187 			continue;
188 		}
189 
190 		childdev = device_add_child(dev, NULL, -1);
191 		resource_list_init(&dinfo->opd_dinfo.rl);
192 		ofw_bus_intr_to_rl(childdev, child,
193 					&dinfo->opd_dinfo.rl, NULL);
194 		device_set_ivars(childdev, dinfo);
195 	}
196 
197 	/* Register bus */
198 	OF_device_register_xref(OF_xref_from_node(node), dev);
199 	return (bus_generic_attach(dev));
200 }
201 
202 static device_t
203 ofw_iicbus_add_child(device_t dev, u_int order, const char *name, int unit)
204 {
205 	device_t child;
206 	struct ofw_iicbus_devinfo *devi;
207 
208 	child = device_add_child_ordered(dev, order, name, unit);
209 	if (child == NULL)
210 		return (child);
211 	devi = malloc(sizeof(struct ofw_iicbus_devinfo), M_DEVBUF,
212 	    M_NOWAIT | M_ZERO);
213 	if (devi == NULL) {
214 		device_delete_child(dev, child);
215 		return (0);
216 	}
217 
218 	/*
219 	 * NULL all the OFW-related parts of the ivars for non-OFW
220 	 * children.
221 	 */
222 	devi->opd_obdinfo.obd_node = -1;
223 	devi->opd_obdinfo.obd_name = NULL;
224 	devi->opd_obdinfo.obd_compat = NULL;
225 	devi->opd_obdinfo.obd_type = NULL;
226 	devi->opd_obdinfo.obd_model = NULL;
227 
228 	device_set_ivars(child, devi);
229 
230 	return (child);
231 }
232 
233 static const struct ofw_bus_devinfo *
234 ofw_iicbus_get_devinfo(device_t bus, device_t dev)
235 {
236 	struct ofw_iicbus_devinfo *dinfo;
237 
238 	dinfo = device_get_ivars(dev);
239 	return (&dinfo->opd_obdinfo);
240 }
241