2 * Copyright (c) 2006 Warner Losh. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
28 * Generic IIC eeprom support, modeled after the AT24C family of products.
30 #include <sys/param.h>
31 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/resource.h>
39 #include <machine/bus.h>
40 #include <dev/iicbus/iiconf.h>
41 #include <dev/iicbus/iicbus.h>
43 #include "iicbus_if.h"
45 #define IIC_M_WR 0 /* write operation */
46 #define MAX_RD_SZ 256 /* Largest read size we support */
47 #define MAX_WR_SZ 256 /* Largest write size we support */
50 device_t sc_dev; /* Myself */
51 struct sx sc_lock; /* basically a perimeter lock */
52 struct cdev *cdev; /* user interface */
54 int size; /* How big am I? */
55 int type; /* What type 8 or 16 bit? */
56 int rd_sz; /* What's the read page size */
57 int wr_sz; /* What's the write page size */
60 #define ICEE_LOCK(_sc) sx_xlock(&(_sc)->sc_lock)
61 #define ICEE_UNLOCK(_sc) sx_xunlock(&(_sc)->sc_lock)
62 #define ICEE_LOCK_INIT(_sc) sx_init(&_sc->sc_lock, "icee")
63 #define ICEE_LOCK_DESTROY(_sc) sx_destroy(&_sc->sc_lock);
64 #define ICEE_ASSERT_LOCKED(_sc) sx_assert(&_sc->sc_lock, SA_XLOCKED);
65 #define ICEE_ASSERT_UNLOCKED(_sc) sx_assert(&_sc->sc_lock, SA_UNLOCKED);
66 #define CDEV2SOFTC(dev) ((dev)->si_drv1)
69 static d_open_t icee_open;
70 static d_close_t icee_close;
71 static d_read_t icee_read;
72 static d_write_t icee_write;
74 static struct cdevsw icee_cdevsw =
76 .d_version = D_VERSION,
77 .d_flags = D_TRACKCLOSE,
79 .d_close = icee_close,
85 icee_probe(device_t dev)
87 /* XXX really probe? -- not until we know the size... */
88 device_set_desc(dev, "I2C EEPROM");
89 return (BUS_PROBE_NOWILDCARD);
93 icee_attach(device_t dev)
95 struct icee_softc *sc = device_get_softc(dev);
100 sc->addr = iicbus_get_addr(dev);
102 dname = device_get_name(dev);
103 dunit = device_get_unit(dev);
104 resource_int_value(dname, dunit, "size", &sc->size);
105 resource_int_value(dname, dunit, "type", &sc->type);
106 resource_int_value(dname, dunit, "rd_sz", &sc->rd_sz);
107 if (sc->rd_sz > MAX_RD_SZ)
108 sc->rd_sz = MAX_RD_SZ;
109 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
111 device_printf(dev, "size: %d bytes bus_width: %d-bits\n",
113 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
114 GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
115 if (sc->cdev == NULL) {
119 sc->cdev->si_drv1 = sc;
126 icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
133 icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
140 icee_read(struct cdev *dev, struct uio *uio, int ioflag)
142 struct icee_softc *sc;
144 uint8_t data[MAX_RD_SZ];
145 int error, i, len, slave;
146 struct iic_msg msgs[2] = {
147 { 0, IIC_M_WR, 1, addr },
148 { 0, IIC_M_RD, 0, data },
151 sc = CDEV2SOFTC(dev);
152 if (uio->uio_offset == sc->size)
154 if (uio->uio_offset > sc->size)
156 if (sc->type != 8 && sc->type != 16)
160 while (uio->uio_resid > 0) {
161 if (uio->uio_offset >= sc->size)
163 len = MIN(sc->rd_sz - (uio->uio_offset & (sc->rd_sz - 1)),
167 slave = (uio->uio_offset >> 7) | sc->addr;
170 addr[0] = uio->uio_offset & 0xff;
173 slave = sc->addr | (uio->uio_offset >> 15);
176 addr[0] = (uio->uio_offset >> 8) & 0xff;
177 addr[1] = uio->uio_offset & 0xff;
180 for (i = 0; i < 2; i++)
181 msgs[i].slave = slave;
182 error = iicbus_transfer(sc->sc_dev, msgs, 2);
185 error = uiomove(data, len, uio);
194 * Write to the part. We use three transfers here since we're actually
195 * doing a write followed by a read to make sure that the write finished.
196 * It is easier to encode the dummy read here than to break things up
197 * into smaller chunks...
200 icee_write(struct cdev *dev, struct uio *uio, int ioflag)
202 struct icee_softc *sc;
203 int error, len, slave, waitlimit;
204 uint8_t data[MAX_WR_SZ + 2];
205 struct iic_msg wr[1] = {
206 { 0, IIC_M_WR, 0, data },
208 struct iic_msg rd[1] = {
209 { 0, IIC_M_RD, 1, data },
212 sc = CDEV2SOFTC(dev);
213 if (uio->uio_offset >= sc->size)
215 if (sc->type != 8 && sc->type != 16)
219 while (uio->uio_resid > 0) {
220 if (uio->uio_offset >= sc->size)
222 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
226 slave = (uio->uio_offset >> 7) | sc->addr;
228 data[0] = uio->uio_offset & 0xff;
231 slave = sc->addr | (uio->uio_offset >> 15);
233 data[0] = (uio->uio_offset >> 8) & 0xff;
234 data[1] = uio->uio_offset & 0xff;
238 error = uiomove(data + sc->type / 8, len, uio);
241 error = iicbus_transfer(sc->sc_dev, wr, 1);
244 // Now wait for the write to be done by trying to read
250 error = iicbus_transfer(sc->sc_dev, rd, 1);
251 } while (waitlimit-- > 0 && error != 0);
253 printf("waiting for write failed %d\n", error);
261 static device_method_t icee_methods[] = {
262 DEVMETHOD(device_probe, icee_probe),
263 DEVMETHOD(device_attach, icee_attach),
268 static driver_t icee_driver = {
271 sizeof(struct icee_softc),
273 static devclass_t icee_devclass;
275 DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
276 MODULE_VERSION(icee, 1);
277 MODULE_DEPEND(icee, iicbus, 1, 1, 1);