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);
87 switch (how & IIC_INTRWAIT) {
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);
119 if (sc->owner == NULL)
121 if ((how & IIC_RECURSIVE) && sc->owner == dev)
123 if ((error = iicbus_poll(sc, how)) != 0)
129 if (sc->owner == NULL) {
132 * Mark the device busy while it owns the bus, to
133 * prevent detaching the device, bus, or hardware
134 * controller, until ownership is relinquished. If the
135 * device is doing IO from its probe method before
136 * attaching, it cannot be busied; mark the bus busy.
138 if (device_get_state(dev) < DS_ATTACHING)
142 device_busy(sc->busydev);
144 * Drop the lock around the call to the bus driver, it
145 * should be allowed to sleep in the IIC_WAIT case.
146 * Drivers might also need to grab locks that would
147 * cause a LOR if our lock is held.
150 /* Ask the underlying layers if the request is ok */
151 error = IICBUS_CALLBACK(device_get_parent(bus),
152 IIC_REQUEST_BUS, (caddr_t)&how);
159 device_unbusy(sc->busydev);
170 * iicbus_release_bus()
172 * Release the device allocated with iicbus_request_dev()
175 iicbus_release_bus(device_t bus, device_t dev)
177 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
181 if (sc->owner != dev) {
183 return (IIC_EBUSBSY);
186 if (--sc->owncount == 0) {
187 /* Drop the lock while informing the low-level driver. */
189 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
193 device_unbusy(sc->busydev);
202 * Test if the iicbus is started by the controller
205 iicbus_started(device_t bus)
207 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
209 return (sc->started);
215 * Send start condition to the slave addressed by 'slave'
218 iicbus_start(device_t bus, u_char slave, int timeout)
220 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
224 return (IIC_ESTATUS); /* protocol error, bus already started */
226 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
235 * iicbus_repeated_start()
237 * Send start condition to the slave addressed by 'slave'
240 iicbus_repeated_start(device_t bus, u_char slave, int timeout)
242 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
246 return (IIC_ESTATUS); /* protocol error, bus not started */
248 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
259 * Send stop condition to the bus
262 iicbus_stop(device_t bus)
264 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
268 return (IIC_ESTATUS); /* protocol error, bus not started */
270 error = IICBUS_STOP(device_get_parent(bus));
272 /* refuse any further access */
281 * Write a block of data to the slave previously started by
282 * iicbus_start() call
285 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
287 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
289 /* a slave must have been started for writing */
290 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
291 return (IIC_ESTATUS);
293 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
299 * Read a block of data from the slave previously started by
303 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
305 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
307 /* a slave must have been started for reading */
308 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
309 return (IIC_ESTATUS);
311 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
315 * iicbus_write_byte()
317 * Write a byte to the slave previously started by iicbus_start() call
320 iicbus_write_byte(device_t bus, char byte, int timeout)
322 struct iicbus_softc *sc = device_get_softc(bus);
326 /* a slave must have been started for writing */
327 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
328 return (IIC_ESTATUS);
330 return (iicbus_write(bus, &data, 1, &sent, timeout));
336 * Read a byte from the slave previously started by iicbus_start() call
339 iicbus_read_byte(device_t bus, char *byte, int timeout)
341 struct iicbus_softc *sc = device_get_softc(bus);
344 /* a slave must have been started for reading */
345 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
346 return (IIC_ESTATUS);
348 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
352 * iicbus_block_write()
354 * Write a block of data to slave ; start/stop protocol managed
357 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
359 u_char addr = slave & ~LSB;
362 if ((error = iicbus_start(bus, addr, 0)))
365 error = iicbus_write(bus, buf, len, sent, 0);
373 * iicbus_block_read()
375 * Read a block of data from slave ; start/stop protocol managed
378 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
380 u_char addr = slave | LSB;
383 if ((error = iicbus_start(bus, addr, 0)))
386 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
396 * Do an aribtrary number of transfers on the iicbus. We pass these
397 * raw requests to the bridge driver. If the bridge driver supports
398 * them directly, then it manages all the details. If not, it can use
399 * the helper function iicbus_transfer_gen() which will do the
400 * transfers at a low level.
402 * Pointers passed in as part of iic_msg must be kernel pointers.
403 * Callers that have user addresses to manage must do so on their own.
406 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
409 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
413 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
419 bus = device_get_parent(dev);
420 error = iicbus_request_bus(bus, dev, how);
422 error = IICBUS_TRANSFER(bus, msgs, nmsgs);
423 iicbus_release_bus(bus, dev);
428 * Generic version of iicbus_transfer that calls the appropriate
429 * routines to accomplish this. See note above about acceptable
433 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
435 int i, error, lenread, lenwrote, nkid, rpstart, addr;
436 device_t *children, bus;
439 if ((error = device_get_children(dev, &children, &nkid)) != 0)
440 return (IIC_ERESOURCE);
442 free(children, M_TEMP);
443 return (IIC_ENOTSUPP);
447 free(children, M_TEMP);
449 for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
450 addr = msgs[i].slave;
451 if (msgs[i].flags & IIC_M_RD)
456 if (!(msgs[i].flags & IIC_M_NOSTART)) {
458 error = iicbus_repeated_start(bus, addr, 0);
460 error = iicbus_start(bus, addr, 0);
466 if (msgs[i].flags & IIC_M_RD)
467 error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
468 &lenread, IIC_LAST_READ, 0);
470 error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
475 if (!(msgs[i].flags & IIC_M_NOSTOP)) {
479 rpstart = 1; /* Next message gets repeated start */
482 if (error != 0 && started)
488 iicdev_readfrom(device_t slavedev, uint8_t regaddr, void *buffer,
489 uint16_t buflen, int waithow)
491 struct iic_msg msgs[2];
495 * Two transfers back to back with a repeat-start between them; first we
496 * write the address-within-device, then we read from the device.
498 slaveaddr = iicbus_get_addr(slavedev);
500 msgs[0].slave = slaveaddr;
501 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
503 msgs[0].buf = ®addr;
505 msgs[1].slave = slaveaddr;
506 msgs[1].flags = IIC_M_RD;
507 msgs[1].len = buflen;
508 msgs[1].buf = buffer;
510 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));
513 int iicdev_writeto(device_t slavedev, uint8_t regaddr, void *buffer,
514 uint16_t buflen, int waithow)
516 struct iic_msg msgs[2];
520 * Two transfers back to back with no stop or start between them; first
521 * we write the address then we write the data to that address, all in a
522 * single transfer from two scattered buffers.
524 slaveaddr = iicbus_get_addr(slavedev);
526 msgs[0].slave = slaveaddr;
527 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
529 msgs[0].buf = ®addr;
531 msgs[1].slave = slaveaddr;
532 msgs[1].flags = IIC_M_WR | IIC_M_NOSTART;
533 msgs[1].len = buflen;
534 msgs[1].buf = buffer;
536 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));