FreeBSD/Linux Kernel Cross Reference
sys/dev/iicbus/icee.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
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.
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 * Generic IIC eeprom support, modeled after the AT24C family of products.
31 */
32
33 #include "opt_platform.h"
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/resource.h>
42 #include <sys/sx.h>
43 #include <sys/sysctl.h>
44 #include <sys/uio.h>
45 #include <machine/bus.h>
46
47 #ifdef FDT
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50 #endif
51
52 #include <dev/iicbus/iiconf.h>
53 #include <dev/iicbus/iicbus.h>
54
55 #include "iicbus_if.h"
56
57 /*
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.
62 */
63 #define MAX_RD_SZ 256 /* Largest read size we support */
64 #define MAX_WR_SZ 256 /* Largest write size we support */
65
66 struct icee_softc {
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 */
73 };
74
75 #ifdef FDT
76 struct eeprom_desc {
77 int type;
78 int size;
79 int wr_sz;
80 const char *name;
81 };
82
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"},
95 };
96
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},
110 };
111 #endif
112
113 #define CDEV2SOFTC(dev) ((dev)->si_drv1)
114
115 /* cdev routines */
116 static d_read_t icee_read;
117 static d_write_t icee_write;
118
119 static struct cdevsw icee_cdevsw =
120 {
121 .d_version = D_VERSION,
122 .d_read = icee_read,
123 .d_write = icee_write
124 };
125
126 static int
127 icee_probe(device_t dev)
128 {
129 #ifdef FDT
130 struct eeprom_desc *d;
131
132 if (!ofw_bus_status_okay(dev))
133 return (ENXIO);
134
135 d = (struct eeprom_desc *)
136 ofw_bus_search_compatible(dev, compat_data)->ocd_data;
137 if (d != NULL) {
138 device_set_desc(dev, d->name);
139 return (BUS_PROBE_DEFAULT);
140 }
141 #endif
142 device_set_desc(dev, "I2C EEPROM");
143 return (BUS_PROBE_NOWILDCARD);
144 }
145
146 static int
147 icee_init(struct icee_softc *sc)
148 {
149 const char *dname;
150 int dunit;
151 #ifdef FDT
152 struct eeprom_desc *d;
153
154 d = (struct eeprom_desc *)
155 ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data;
156 if (d != NULL) {
157 sc->size = d->size;
158 sc->type = d->type;
159 sc->wr_sz = d->wr_sz;
160 return (0);
161 }
162 #endif
163 dname = device_get_name(sc->dev);
164 dunit = device_get_unit(sc->dev);
165 if (resource_int_value(dname, dunit, "type", &sc->type) != 0)
166 return (ENOENT);
167 if (resource_int_value(dname, dunit, "size", &sc->size) != 0)
168 return (ENOENT);
169 if (resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz) != 0)
170 return (ENOENT);
171 return (0);
172 }
173
174 static int
175 icee_attach(device_t dev)
176 {
177 struct icee_softc *sc = device_get_softc(dev);
178 struct sysctl_ctx_list *ctx;
179 struct sysctl_oid_list *tree;
180
181 sc->dev = dev;
182 sc->addr = iicbus_get_addr(dev);
183 if (icee_init(sc) != 0)
184 return (EINVAL);
185 if (bootverbose)
186 device_printf(dev, "size: %d bytes, addressing: %d-bits\n",
187 sc->size, sc->type);
188 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
189 GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
190 if (sc->cdev == NULL) {
191 return (ENOMEM);
192 }
193 sc->cdev->si_drv1 = sc;
194
195 ctx = device_get_sysctl_ctx(dev);
196 tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
197 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "address_size", CTLFLAG_RD,
198 &sc->type, 0, "Memory array address size in bits");
199 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "device_size", CTLFLAG_RD,
200 &sc->size, 0, "Memory array capacity in bytes");
201 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "write_size", CTLFLAG_RD,
202 &sc->wr_sz, 0, "Memory array page write size in bytes");
203
204 return (0);
205 }
206
207 static int
208 icee_detach(device_t dev)
209 {
210 struct icee_softc *sc = device_get_softc(dev);
211
212 destroy_dev(sc->cdev);
213 return (0);
214 }
215
216 static int
217 icee_read(struct cdev *dev, struct uio *uio, int ioflag)
218 {
219 struct icee_softc *sc;
220 uint8_t addr[2];
221 uint8_t data[MAX_RD_SZ];
222 int error, i, len, slave;
223 struct iic_msg msgs[2] = {
224 { 0, IIC_M_WR, 1, addr },
225 { 0, IIC_M_RD, 0, data },
226 };
227
228 sc = CDEV2SOFTC(dev);
229 if (uio->uio_offset == sc->size)
230 return (0);
231 if (uio->uio_offset > sc->size)
232 return (EIO);
233 if (sc->type != 8 && sc->type != 16)
234 return (EINVAL);
235 slave = error = 0;
236 while (uio->uio_resid > 0) {
237 if (uio->uio_offset >= sc->size)
238 break;
239 len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
240 uio->uio_resid);
241 switch (sc->type) {
242 case 8:
243 slave = (uio->uio_offset >> 7) | sc->addr;
244 msgs[0].len = 1;
245 msgs[1].len = len;
246 addr[0] = uio->uio_offset & 0xff;
247 break;
248 case 16:
249 slave = sc->addr | (uio->uio_offset >> 15);
250 msgs[0].len = 2;
251 msgs[1].len = len;
252 addr[0] = (uio->uio_offset >> 8) & 0xff;
253 addr[1] = uio->uio_offset & 0xff;
254 break;
255 }
256 for (i = 0; i < 2; i++)
257 msgs[i].slave = slave;
258 error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
259 if (error) {
260 error = iic2errno(error);
261 break;
262 }
263 error = uiomove(data, len, uio);
264 if (error)
265 break;
266 }
267 return (error);
268 }
269
270 /*
271 * Write to the part. We use three transfers here since we're actually
272 * doing a write followed by a read to make sure that the write finished.
273 * It is easier to encode the dummy read here than to break things up
274 * into smaller chunks...
275 */
276 static int
277 icee_write(struct cdev *dev, struct uio *uio, int ioflag)
278 {
279 struct icee_softc *sc;
280 int error, len, slave, waitlimit;
281 uint8_t data[MAX_WR_SZ + 2];
282 struct iic_msg wr[1] = {
283 { 0, IIC_M_WR, 0, data },
284 };
285 struct iic_msg rd[1] = {
286 { 0, IIC_M_RD, 1, data },
287 };
288
289 sc = CDEV2SOFTC(dev);
290 if (uio->uio_offset >= sc->size)
291 return (EIO);
292 if (sc->type != 8 && sc->type != 16)
293 return (EINVAL);
294
295 slave = error = 0;
296 while (uio->uio_resid > 0) {
297 if (uio->uio_offset >= sc->size)
298 break;
299 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
300 uio->uio_resid);
301 switch (sc->type) {
302 case 8:
303 slave = (uio->uio_offset >> 7) | sc->addr;
304 wr[0].len = 1 + len;
305 data[0] = uio->uio_offset & 0xff;
306 break;
307 case 16:
308 slave = sc->addr | (uio->uio_offset >> 15);
309 wr[0].len = 2 + len;
310 data[0] = (uio->uio_offset >> 8) & 0xff;
311 data[1] = uio->uio_offset & 0xff;
312 break;
313 }
314 wr[0].slave = slave;
315 error = uiomove(data + sc->type / 8, len, uio);
316 if (error)
317 break;
318 error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
319 if (error) {
320 error = iic2errno(error);
321 break;
322 }
323 /* Read after write to wait for write-done. */
324 waitlimit = 10000;
325 rd[0].slave = slave;
326 do {
327 error = iicbus_transfer_excl(sc->dev, rd, 1,
328 IIC_INTRWAIT);
329 } while (waitlimit-- > 0 && error != 0);
330 if (error) {
331 error = iic2errno(error);
332 break;
333 }
334 }
335 return error;
336 }
337
338 static device_method_t icee_methods[] = {
339 DEVMETHOD(device_probe, icee_probe),
340 DEVMETHOD(device_attach, icee_attach),
341 DEVMETHOD(device_detach, icee_detach),
342
343 DEVMETHOD_END
344 };
345
346 static driver_t icee_driver = {
347 "icee",
348 icee_methods,
349 sizeof(struct icee_softc),
350 };
351
352 DRIVER_MODULE(icee, iicbus, icee_driver, 0, 0);
353 MODULE_VERSION(icee, 1);
354 MODULE_DEPEND(icee, iicbus, 1, 1, 1);
355 IICBUS_FDT_PNP_INFO(compat_data);
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