2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2006 Warner Losh. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 * Generic IIC eeprom support, modeled after the AT24C family of products.
33 #include "opt_platform.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/resource.h>
44 #include <machine/bus.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
51 #include <dev/iicbus/iiconf.h>
52 #include <dev/iicbus/iicbus.h>
54 #include "iicbus_if.h"
57 * AT24 parts have a "write page size" that differs per-device, and a "read page
58 * size" that is always equal to the full device size. We define maximum values
59 * here to limit how long we occupy the bus with a single transfer, and because
60 * there are temporary buffers of these sizes allocated on the stack.
62 #define MAX_RD_SZ 256 /* Largest read size we support */
63 #define MAX_WR_SZ 256 /* Largest write size we support */
66 device_t dev; /* Myself */
67 struct cdev *cdev; /* user interface */
68 int addr; /* Slave address on the bus */
69 int size; /* How big am I? */
70 int type; /* What address type 8 or 16 bit? */
71 int wr_sz; /* What's the write page size */
82 static struct eeprom_desc type_desc[] = {
83 { 8, 128, 8, "AT24C01"},
84 { 8, 256, 8, "AT24C02"},
85 { 8, 512, 16, "AT24C04"},
86 { 8, 1024, 16, "AT24C08"},
87 { 8, 2 * 1024, 16, "AT24C16"},
88 {16, 4 * 1024, 32, "AT24C32"},
89 {16, 8 * 1024, 32, "AT24C64"},
90 {16, 16 * 1024, 64, "AT24C128"},
91 {16, 32 * 1024, 64, "AT24C256"},
92 {16, 64 * 1024, 128, "AT24C512"},
93 {16, 128 * 1024, 256, "AT24CM01"},
96 static struct ofw_compat_data compat_data[] = {
97 {"atmel,24c01", (uintptr_t)(&type_desc[0])},
98 {"atmel,24c02", (uintptr_t)(&type_desc[1])},
99 {"atmel,24c04", (uintptr_t)(&type_desc[2])},
100 {"atmel,24c08", (uintptr_t)(&type_desc[3])},
101 {"atmel,24c16", (uintptr_t)(&type_desc[4])},
102 {"atmel,24c32", (uintptr_t)(&type_desc[5])},
103 {"atmel,24c64", (uintptr_t)(&type_desc[6])},
104 {"atmel,24c128", (uintptr_t)(&type_desc[7])},
105 {"atmel,24c256", (uintptr_t)(&type_desc[8])},
106 {"atmel,24c512", (uintptr_t)(&type_desc[9])},
107 {"atmel,24c1024", (uintptr_t)(&type_desc[10])},
108 {NULL, (uintptr_t)NULL},
112 #define CDEV2SOFTC(dev) ((dev)->si_drv1)
115 static d_open_t icee_open;
116 static d_close_t icee_close;
117 static d_read_t icee_read;
118 static d_write_t icee_write;
120 static struct cdevsw icee_cdevsw =
122 .d_version = D_VERSION,
123 .d_flags = D_TRACKCLOSE,
125 .d_close = icee_close,
127 .d_write = icee_write
132 icee_probe(device_t dev)
134 struct eeprom_desc *d;
136 if (!ofw_bus_status_okay(dev))
139 d = (struct eeprom_desc *)
140 ofw_bus_search_compatible(dev, compat_data)->ocd_data;
144 device_set_desc(dev, d->name);
145 return (BUS_PROBE_DEFAULT);
149 icee_init(struct icee_softc *sc)
151 struct eeprom_desc *d;
153 d = (struct eeprom_desc *)
154 ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data;
156 return; /* attach will see sc->size == 0 and return error */
160 sc->wr_sz = d->wr_sz;
164 icee_probe(device_t dev)
167 device_set_desc(dev, "I2C EEPROM");
168 return (BUS_PROBE_NOWILDCARD);
172 icee_init(struct icee_softc *sc)
177 dname = device_get_name(sc->dev);
178 dunit = device_get_unit(sc->dev);
179 resource_int_value(dname, dunit, "size", &sc->size);
180 resource_int_value(dname, dunit, "type", &sc->type);
181 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
186 icee_attach(device_t dev)
188 struct icee_softc *sc = device_get_softc(dev);
191 sc->addr = iicbus_get_addr(dev);
193 if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) {
194 device_printf(sc->dev, "Missing config data, "
195 "these cannot be zero: size %d type %d wr_sz %d\n",
196 sc->size, sc->type, sc->wr_sz);
200 device_printf(dev, "size: %d bytes, addressing: %d-bits\n",
202 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
203 GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
204 if (sc->cdev == NULL) {
207 sc->cdev->si_drv1 = sc;
212 icee_detach(device_t dev)
214 struct icee_softc *sc = device_get_softc(dev);
216 destroy_dev(sc->cdev);
221 icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
223 struct icee_softc *sc;
225 sc = CDEV2SOFTC(dev);
226 if (device_get_state(sc->dev) < DS_BUSY)
227 device_busy(sc->dev);
233 icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
235 struct icee_softc *sc;
237 sc = CDEV2SOFTC(dev);
238 device_unbusy(sc->dev);
243 icee_read(struct cdev *dev, struct uio *uio, int ioflag)
245 struct icee_softc *sc;
247 uint8_t data[MAX_RD_SZ];
248 int error, i, len, slave;
249 struct iic_msg msgs[2] = {
250 { 0, IIC_M_WR, 1, addr },
251 { 0, IIC_M_RD, 0, data },
254 sc = CDEV2SOFTC(dev);
255 if (uio->uio_offset == sc->size)
257 if (uio->uio_offset > sc->size)
259 if (sc->type != 8 && sc->type != 16)
262 while (uio->uio_resid > 0) {
263 if (uio->uio_offset >= sc->size)
265 len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
269 slave = (uio->uio_offset >> 7) | sc->addr;
272 addr[0] = uio->uio_offset & 0xff;
275 slave = sc->addr | (uio->uio_offset >> 15);
278 addr[0] = (uio->uio_offset >> 8) & 0xff;
279 addr[1] = uio->uio_offset & 0xff;
282 for (i = 0; i < 2; i++)
283 msgs[i].slave = slave;
284 error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
286 error = iic2errno(error);
289 error = uiomove(data, len, uio);
297 * Write to the part. We use three transfers here since we're actually
298 * doing a write followed by a read to make sure that the write finished.
299 * It is easier to encode the dummy read here than to break things up
300 * into smaller chunks...
303 icee_write(struct cdev *dev, struct uio *uio, int ioflag)
305 struct icee_softc *sc;
306 int error, len, slave, waitlimit;
307 uint8_t data[MAX_WR_SZ + 2];
308 struct iic_msg wr[1] = {
309 { 0, IIC_M_WR, 0, data },
311 struct iic_msg rd[1] = {
312 { 0, IIC_M_RD, 1, data },
315 sc = CDEV2SOFTC(dev);
316 if (uio->uio_offset >= sc->size)
318 if (sc->type != 8 && sc->type != 16)
322 while (uio->uio_resid > 0) {
323 if (uio->uio_offset >= sc->size)
325 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
329 slave = (uio->uio_offset >> 7) | sc->addr;
331 data[0] = uio->uio_offset & 0xff;
334 slave = sc->addr | (uio->uio_offset >> 15);
336 data[0] = (uio->uio_offset >> 8) & 0xff;
337 data[1] = uio->uio_offset & 0xff;
341 error = uiomove(data + sc->type / 8, len, uio);
344 error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
346 error = iic2errno(error);
349 /* Read after write to wait for write-done. */
353 error = iicbus_transfer_excl(sc->dev, rd, 1,
355 } while (waitlimit-- > 0 && error != 0);
357 error = iic2errno(error);
364 static device_method_t icee_methods[] = {
365 DEVMETHOD(device_probe, icee_probe),
366 DEVMETHOD(device_attach, icee_attach),
367 DEVMETHOD(device_detach, icee_detach),
372 static driver_t icee_driver = {
375 sizeof(struct icee_softc),
377 static devclass_t icee_devclass;
379 DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
380 MODULE_VERSION(icee, 1);
381 MODULE_DEPEND(icee, iicbus, 1, 1, 1);