2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1998 Nicolas Souchu
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
40 #include <dev/iicbus/iiconf.h>
41 #include <dev/iicbus/iicbus.h>
42 #include "iicbus_if.h"
45 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values.
48 iic2errno(int iic_status)
51 case IIC_NOERR: return (0);
52 case IIC_EBUSERR: return (EALREADY);
53 case IIC_ENOACK: return (EIO);
54 case IIC_ETIMEOUT: return (ETIMEDOUT);
55 case IIC_EBUSBSY: return (EWOULDBLOCK);
56 case IIC_ESTATUS: return (EPROTO);
57 case IIC_EUNDERFLOW: return (EIO);
58 case IIC_EOVERFLOW: return (EOVERFLOW);
59 case IIC_ENOTSUPP: return (EOPNOTSUPP);
60 case IIC_ENOADDR: return (EADDRNOTAVAIL);
61 case IIC_ERESOURCE: return (ENOMEM);
62 default: return (EIO);
70 iicbus_intr(device_t bus, int event, char *buf)
72 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
74 /* call owner's intr routine */
76 IICBUS_INTR(sc->owner, event, buf);
82 iicbus_poll(struct iicbus_softc *sc, int how)
86 IICBUS_ASSERT_LOCKED(sc);
88 case IIC_WAIT | IIC_INTR:
89 error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0);
92 case IIC_WAIT | IIC_NOINTR:
93 error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0);
104 * iicbus_request_bus()
106 * Allocate the device to perform transfers.
108 * how : IIC_WAIT or IIC_DONTWAIT
111 iicbus_request_bus(device_t bus, device_t dev, int how)
113 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
118 while (error == 0 && sc->owner != NULL && sc->owner != dev)
119 error = iicbus_poll(sc, how);
123 if (sc->owner == NULL) {
126 * Drop the lock around the call to the bus driver, it
127 * should be allowed to sleep in the IIC_WAIT case.
128 * Drivers might also need to grab locks that would
129 * cause a LOR if our lock is held.
132 /* Ask the underlying layers if the request is ok */
133 error = IICBUS_CALLBACK(device_get_parent(bus),
134 IIC_REQUEST_BUS, (caddr_t)&how);
151 * iicbus_release_bus()
153 * Release the device allocated with iicbus_request_dev()
156 iicbus_release_bus(device_t bus, device_t dev)
158 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
162 if (sc->owner != dev) {
164 return (IIC_EBUSBSY);
167 if (--sc->owncount == 0) {
168 /* Drop the lock while informing the low-level driver. */
170 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
182 * Test if the iicbus is started by the controller
185 iicbus_started(device_t bus)
187 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
189 return (sc->started);
195 * Send start condition to the slave addressed by 'slave'
198 iicbus_start(device_t bus, u_char slave, int timeout)
200 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
204 return (IIC_ESTATUS); /* protocol error, bus already started */
206 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
215 * iicbus_repeated_start()
217 * Send start condition to the slave addressed by 'slave'
220 iicbus_repeated_start(device_t bus, u_char slave, int timeout)
222 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
226 return (IIC_ESTATUS); /* protocol error, bus not started */
228 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
239 * Send stop condition to the bus
242 iicbus_stop(device_t bus)
244 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
248 return (IIC_ESTATUS); /* protocol error, bus not started */
250 error = IICBUS_STOP(device_get_parent(bus));
252 /* refuse any further access */
261 * Write a block of data to the slave previously started by
262 * iicbus_start() call
265 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
267 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
269 /* a slave must have been started for writing */
270 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
271 return (IIC_ESTATUS);
273 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
279 * Read a block of data from the slave previously started by
283 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
285 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
287 /* a slave must have been started for reading */
288 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
289 return (IIC_ESTATUS);
291 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
295 * iicbus_write_byte()
297 * Write a byte to the slave previously started by iicbus_start() call
300 iicbus_write_byte(device_t bus, char byte, int timeout)
302 struct iicbus_softc *sc = device_get_softc(bus);
306 /* a slave must have been started for writing */
307 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
308 return (IIC_ESTATUS);
310 return (iicbus_write(bus, &data, 1, &sent, timeout));
316 * Read a byte from the slave previously started by iicbus_start() call
319 iicbus_read_byte(device_t bus, char *byte, int timeout)
321 struct iicbus_softc *sc = device_get_softc(bus);
324 /* a slave must have been started for reading */
325 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
326 return (IIC_ESTATUS);
328 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
332 * iicbus_block_write()
334 * Write a block of data to slave ; start/stop protocol managed
337 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
339 u_char addr = slave & ~LSB;
342 if ((error = iicbus_start(bus, addr, 0)))
345 error = iicbus_write(bus, buf, len, sent, 0);
353 * iicbus_block_read()
355 * Read a block of data from slave ; start/stop protocol managed
358 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
360 u_char addr = slave | LSB;
363 if ((error = iicbus_start(bus, addr, 0)))
366 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
376 * Do an aribtrary number of transfers on the iicbus. We pass these
377 * raw requests to the bridge driver. If the bridge driver supports
378 * them directly, then it manages all the details. If not, it can use
379 * the helper function iicbus_transfer_gen() which will do the
380 * transfers at a low level.
382 * Pointers passed in as part of iic_msg must be kernel pointers.
383 * Callers that have user addresses to manage must do so on their own.
386 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
389 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
393 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
399 bus = device_get_parent(dev);
400 error = iicbus_request_bus(bus, dev, how);
402 error = IICBUS_TRANSFER(bus, msgs, nmsgs);
403 iicbus_release_bus(bus, dev);
408 * Generic version of iicbus_transfer that calls the appropriate
409 * routines to accomplish this. See note above about acceptable
413 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
415 int i, error, lenread, lenwrote, nkid, rpstart, addr;
416 device_t *children, bus;
417 bool nostop, started;
419 if ((error = device_get_children(dev, &children, &nkid)) != 0)
420 return (IIC_ERESOURCE);
422 free(children, M_TEMP);
423 return (IIC_ENOTSUPP);
427 free(children, M_TEMP);
428 nostop = iicbus_get_nostop(dev);
430 for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
431 addr = msgs[i].slave;
432 if (msgs[i].flags & IIC_M_RD)
437 if (!(msgs[i].flags & IIC_M_NOSTART)) {
439 error = iicbus_repeated_start(bus, addr, 0);
441 error = iicbus_start(bus, addr, 0);
447 if (msgs[i].flags & IIC_M_RD)
448 error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
449 &lenread, IIC_LAST_READ, 0);
451 error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
456 if ((msgs[i].flags & IIC_M_NOSTOP) != 0 ||
457 (nostop && i + 1 < nmsgs)) {
458 rpstart = 1; /* Next message gets repeated start */
464 if (error != 0 && started)
470 iicdev_readfrom(device_t slavedev, uint8_t regaddr, void *buffer,
471 uint16_t buflen, int waithow)
473 struct iic_msg msgs[2];
477 * Two transfers back to back with a repeat-start between them; first we
478 * write the address-within-device, then we read from the device.
480 slaveaddr = iicbus_get_addr(slavedev);
482 msgs[0].slave = slaveaddr;
483 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
485 msgs[0].buf = ®addr;
487 msgs[1].slave = slaveaddr;
488 msgs[1].flags = IIC_M_RD;
489 msgs[1].len = buflen;
490 msgs[1].buf = buffer;
492 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));
495 int iicdev_writeto(device_t slavedev, uint8_t regaddr, void *buffer,
496 uint16_t buflen, int waithow)
498 struct iic_msg msgs[2];
502 * Two transfers back to back with no stop or start between them; first
503 * we write the address then we write the data to that address, all in a
504 * single transfer from two scattered buffers.
506 slaveaddr = iicbus_get_addr(slavedev);
508 msgs[0].slave = slaveaddr;
509 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
511 msgs[0].buf = ®addr;
513 msgs[1].slave = slaveaddr;
514 msgs[1].flags = IIC_M_WR | IIC_M_NOSTART;
515 msgs[1].len = buflen;
516 msgs[1].buf = buffer;
518 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));