2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
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>
43 #include <sys/sysctl.h>
45 #include <machine/bus.h>
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
52 #include <dev/iicbus/iiconf.h>
53 #include <dev/iicbus/iicbus.h>
55 #include "iicbus_if.h"
58 * AT24 parts have a "write page size" that differs per-device, and a "read page
59 * size" that is always equal to the full device size. We define maximum values
60 * here to limit how long we occupy the bus with a single transfer, and because
61 * there are temporary buffers of these sizes allocated on the stack.
63 #define MAX_RD_SZ 256 /* Largest read size we support */
64 #define MAX_WR_SZ 256 /* Largest write size we support */
67 device_t dev; /* Myself */
68 struct cdev *cdev; /* user interface */
69 int addr; /* Slave address on the bus */
70 int size; /* How big am I? */
71 int type; /* What address type 8 or 16 bit? */
72 int wr_sz; /* What's the write page size */
83 static struct eeprom_desc type_desc[] = {
84 { 8, 128, 8, "AT24C01"},
85 { 8, 256, 8, "AT24C02"},
86 { 8, 512, 16, "AT24C04"},
87 { 8, 1024, 16, "AT24C08"},
88 { 8, 2 * 1024, 16, "AT24C16"},
89 {16, 4 * 1024, 32, "AT24C32"},
90 {16, 8 * 1024, 32, "AT24C64"},
91 {16, 16 * 1024, 64, "AT24C128"},
92 {16, 32 * 1024, 64, "AT24C256"},
93 {16, 64 * 1024, 128, "AT24C512"},
94 {16, 128 * 1024, 256, "AT24CM01"},
97 static struct ofw_compat_data compat_data[] = {
98 {"atmel,24c01", (uintptr_t)(&type_desc[0])},
99 {"atmel,24c02", (uintptr_t)(&type_desc[1])},
100 {"atmel,24c04", (uintptr_t)(&type_desc[2])},
101 {"atmel,24c08", (uintptr_t)(&type_desc[3])},
102 {"atmel,24c16", (uintptr_t)(&type_desc[4])},
103 {"atmel,24c32", (uintptr_t)(&type_desc[5])},
104 {"atmel,24c64", (uintptr_t)(&type_desc[6])},
105 {"atmel,24c128", (uintptr_t)(&type_desc[7])},
106 {"atmel,24c256", (uintptr_t)(&type_desc[8])},
107 {"atmel,24c512", (uintptr_t)(&type_desc[9])},
108 {"atmel,24c1024", (uintptr_t)(&type_desc[10])},
109 {NULL, (uintptr_t)NULL},
113 #define CDEV2SOFTC(dev) ((dev)->si_drv1)
116 static d_read_t icee_read;
117 static d_write_t icee_write;
119 static struct cdevsw icee_cdevsw =
121 .d_version = D_VERSION,
123 .d_write = icee_write
128 icee_probe(device_t dev)
130 struct eeprom_desc *d;
132 if (!ofw_bus_status_okay(dev))
135 d = (struct eeprom_desc *)
136 ofw_bus_search_compatible(dev, compat_data)->ocd_data;
140 device_set_desc(dev, d->name);
141 return (BUS_PROBE_DEFAULT);
145 icee_init(struct icee_softc *sc)
147 struct eeprom_desc *d;
149 d = (struct eeprom_desc *)
150 ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data;
152 return; /* attach will see sc->size == 0 and return error */
156 sc->wr_sz = d->wr_sz;
160 icee_probe(device_t dev)
163 device_set_desc(dev, "I2C EEPROM");
164 return (BUS_PROBE_NOWILDCARD);
168 icee_init(struct icee_softc *sc)
173 dname = device_get_name(sc->dev);
174 dunit = device_get_unit(sc->dev);
175 resource_int_value(dname, dunit, "size", &sc->size);
176 resource_int_value(dname, dunit, "type", &sc->type);
177 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
182 icee_attach(device_t dev)
184 struct icee_softc *sc = device_get_softc(dev);
185 struct sysctl_ctx_list *ctx;
186 struct sysctl_oid_list *tree;
189 sc->addr = iicbus_get_addr(dev);
191 if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) {
192 device_printf(sc->dev, "Missing config data, "
193 "these cannot be zero: size %d type %d wr_sz %d\n",
194 sc->size, sc->type, sc->wr_sz);
198 device_printf(dev, "size: %d bytes, addressing: %d-bits\n",
200 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
201 GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
202 if (sc->cdev == NULL) {
205 sc->cdev->si_drv1 = sc;
207 ctx = device_get_sysctl_ctx(dev);
208 tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
209 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "address_size", CTLFLAG_RD,
210 &sc->type, 0, "Memory array address size in bits");
211 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "device_size", CTLFLAG_RD,
212 &sc->size, 0, "Memory array capacity in bytes");
213 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "write_size", CTLFLAG_RD,
214 &sc->wr_sz, 0, "Memory array page write size in bytes");
220 icee_detach(device_t dev)
222 struct icee_softc *sc = device_get_softc(dev);
224 destroy_dev(sc->cdev);
229 icee_read(struct cdev *dev, struct uio *uio, int ioflag)
231 struct icee_softc *sc;
233 uint8_t data[MAX_RD_SZ];
234 int error, i, len, slave;
235 struct iic_msg msgs[2] = {
236 { 0, IIC_M_WR, 1, addr },
237 { 0, IIC_M_RD, 0, data },
240 sc = CDEV2SOFTC(dev);
241 if (uio->uio_offset == sc->size)
243 if (uio->uio_offset > sc->size)
245 if (sc->type != 8 && sc->type != 16)
248 while (uio->uio_resid > 0) {
249 if (uio->uio_offset >= sc->size)
251 len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
255 slave = (uio->uio_offset >> 7) | sc->addr;
258 addr[0] = uio->uio_offset & 0xff;
261 slave = sc->addr | (uio->uio_offset >> 15);
264 addr[0] = (uio->uio_offset >> 8) & 0xff;
265 addr[1] = uio->uio_offset & 0xff;
268 for (i = 0; i < 2; i++)
269 msgs[i].slave = slave;
270 error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
272 error = iic2errno(error);
275 error = uiomove(data, len, uio);
283 * Write to the part. We use three transfers here since we're actually
284 * doing a write followed by a read to make sure that the write finished.
285 * It is easier to encode the dummy read here than to break things up
286 * into smaller chunks...
289 icee_write(struct cdev *dev, struct uio *uio, int ioflag)
291 struct icee_softc *sc;
292 int error, len, slave, waitlimit;
293 uint8_t data[MAX_WR_SZ + 2];
294 struct iic_msg wr[1] = {
295 { 0, IIC_M_WR, 0, data },
297 struct iic_msg rd[1] = {
298 { 0, IIC_M_RD, 1, data },
301 sc = CDEV2SOFTC(dev);
302 if (uio->uio_offset >= sc->size)
304 if (sc->type != 8 && sc->type != 16)
308 while (uio->uio_resid > 0) {
309 if (uio->uio_offset >= sc->size)
311 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
315 slave = (uio->uio_offset >> 7) | sc->addr;
317 data[0] = uio->uio_offset & 0xff;
320 slave = sc->addr | (uio->uio_offset >> 15);
322 data[0] = (uio->uio_offset >> 8) & 0xff;
323 data[1] = uio->uio_offset & 0xff;
327 error = uiomove(data + sc->type / 8, len, uio);
330 error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
332 error = iic2errno(error);
335 /* Read after write to wait for write-done. */
339 error = iicbus_transfer_excl(sc->dev, rd, 1,
341 } while (waitlimit-- > 0 && error != 0);
343 error = iic2errno(error);
350 static device_method_t icee_methods[] = {
351 DEVMETHOD(device_probe, icee_probe),
352 DEVMETHOD(device_attach, icee_attach),
353 DEVMETHOD(device_detach, icee_detach),
358 static driver_t icee_driver = {
361 sizeof(struct icee_softc),
363 static devclass_t icee_devclass;
365 DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
366 MODULE_VERSION(icee, 1);
367 MODULE_DEPEND(icee, iicbus, 1, 1, 1);
368 IICBUS_FDT_PNP_INFO(compat_data);