2 * Copyright (c) 1998, 2001 Nicolas Souchu
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 * Autoconfiguration and support routines for the Philips serial I2C bus
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
42 #include <sys/sysctl.h>
45 #include <dev/iicbus/iiconf.h>
46 #include <dev/iicbus/iicbus.h>
48 #include "iicbus_if.h"
50 /* See comments below for why auto-scanning is a bad idea. */
54 iicbus_probe(device_t dev)
57 device_set_desc(dev, "Philips I2C bus");
59 /* Allow other subclasses to override this driver. */
60 return (BUS_PROBE_GENERIC);
65 iic_probe_device(device_t dev, u_char addr)
70 if ((addr & 1) == 0) {
71 /* is device writable? */
72 if (!iicbus_start(dev, (u_char)addr, 0)) {
77 /* is device readable? */
78 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
87 * We add all the devices which we know about.
88 * The generic attach routine will attach them if they are alive.
91 iicbus_attach(device_t dev)
96 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
100 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF);
101 iicbus_init_frequency(dev, 0);
102 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
103 if (resource_int_value(device_get_name(dev),
104 device_get_unit(dev), "strict", &strict) == 0)
109 /* device probing is meaningless since the bus is supposed to be
110 * hot-plug. Moreover, some I2C chips do not appreciate random
111 * accesses like stop after start to fast, reads for less than
115 printf("Probing for devices on iicbus%d:", device_get_unit(dev));
117 /* probe any devices */
118 for (addr = 16; addr < 240; addr++) {
119 if (iic_probe_device(dev, (u_char)addr)) {
120 printf(" <%x>", addr);
125 bus_generic_probe(dev);
126 bus_enumerate_hinted_children(dev);
127 bus_generic_attach(dev);
132 iicbus_detach(device_t dev)
134 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
136 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
137 bus_generic_detach(dev);
138 device_delete_children(dev);
139 mtx_destroy(&sc->lock);
144 iicbus_print_child(device_t dev, device_t child)
146 struct iicbus_ivar *devi = IICBUS_IVAR(child);
149 retval += bus_print_child_header(dev, child);
151 retval += printf(" at addr %#x", devi->addr);
152 resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld");
153 retval += bus_print_child_footer(dev, child);
159 iicbus_probe_nomatch(device_t bus, device_t child)
161 struct iicbus_ivar *devi = IICBUS_IVAR(child);
163 device_printf(bus, "<unknown card> at addr %#x\n", devi->addr);
167 iicbus_child_location_str(device_t bus, device_t child, char *buf,
170 struct iicbus_ivar *devi = IICBUS_IVAR(child);
172 snprintf(buf, buflen, "addr=%#x", devi->addr);
177 iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
185 iicbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
187 struct iicbus_ivar *devi = IICBUS_IVAR(child);
192 case IICBUS_IVAR_ADDR:
193 *result = devi->addr;
200 iicbus_add_child(device_t dev, u_int order, const char *name, int unit)
203 struct iicbus_ivar *devi;
205 child = device_add_child_ordered(dev, order, name, unit);
208 devi = malloc(sizeof(struct iicbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
210 device_delete_child(dev, child);
213 resource_list_init(&devi->rl);
214 device_set_ivars(child, devi);
219 iicbus_hinted_child(device_t bus, const char *dname, int dunit)
223 struct iicbus_ivar *devi;
225 child = BUS_ADD_CHILD(bus, 0, dname, dunit);
226 devi = IICBUS_IVAR(child);
227 resource_int_value(dname, dunit, "addr", &devi->addr);
228 if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
229 if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
231 "warning: bus_set_resource() failed\n");
235 static struct resource_list *
236 iicbus_get_resource_list(device_t bus __unused, device_t child)
238 struct iicbus_ivar *devi;
240 devi = IICBUS_IVAR(child);
245 iicbus_generic_intr(device_t dev, int event, char *buf)
252 iicbus_null_callback(device_t dev, int index, caddr_t data)
259 iicbus_null_repeated_start(device_t dev, u_char addr)
262 return (IIC_ENOTSUPP);
266 iicbus_init_frequency(device_t dev, u_int bus_freq)
268 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
271 * If a bus frequency value was passed in, use it. Otherwise initialize
272 * it first to the standard i2c 100KHz frequency, then override that
273 * from a hint if one exists.
276 sc->bus_freq = bus_freq;
278 sc->bus_freq = 100000;
279 resource_int_value(device_get_name(dev), device_get_unit(dev),
280 "frequency", (int *)&sc->bus_freq);
283 * Set up the sysctl that allows the bus frequency to be changed.
284 * It is flagged as a tunable so that the user can set the value in
285 * loader(8), and that will override any other setting from any source.
286 * The sysctl tunable/value is the one most directly controlled by the
287 * user and thus the one that always takes precedence.
289 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
290 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
291 OID_AUTO, "frequency", CTLFLAG_RW | CTLFLAG_TUN, &sc->bus_freq,
292 sc->bus_freq, "Bus frequency in Hz");
296 iicbus_get_frequency(device_t dev, u_char speed)
298 struct iicbus_softc *sc = IICBUS_SOFTC(dev);
301 * If the frequency has not been configured for the bus, or the request
302 * is specifically for SLOW speed, use the standard 100KHz rate, else
303 * use the configured bus speed.
305 if (sc->bus_freq == 0 || speed == IIC_SLOW)
307 return (sc->bus_freq);
310 static device_method_t iicbus_methods[] = {
311 /* device interface */
312 DEVMETHOD(device_probe, iicbus_probe),
313 DEVMETHOD(device_attach, iicbus_attach),
314 DEVMETHOD(device_detach, iicbus_detach),
317 DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
318 DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
319 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
320 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
321 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource),
322 DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
323 DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource),
324 DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
325 DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource),
326 DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list),
327 DEVMETHOD(bus_add_child, iicbus_add_child),
328 DEVMETHOD(bus_print_child, iicbus_print_child),
329 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch),
330 DEVMETHOD(bus_read_ivar, iicbus_read_ivar),
331 DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str),
332 DEVMETHOD(bus_child_location_str, iicbus_child_location_str),
333 DEVMETHOD(bus_hinted_child, iicbus_hinted_child),
335 /* iicbus interface */
336 DEVMETHOD(iicbus_transfer, iicbus_transfer),
337 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency),
342 driver_t iicbus_driver = {
345 sizeof(struct iicbus_softc),
348 devclass_t iicbus_devclass;
350 MODULE_VERSION(iicbus, IICBUS_MODVER);
351 DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0);