/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998 Nicolas Souchu
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/bus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbus_if.h"
/*
* Encode a system errno value into the IIC_Exxxxx space by setting the
* IIC_ERRNO marker bit, so that iic2errno() can turn it back into a plain
* system errno value later. This lets controller- and bus-layer code get
* important system errno values (such as EINTR/ERESTART) back to the caller.
*/
int
errno2iic(int errno)
{
return ((errno == 0) ? 0 : errno | IIC_ERRNO);
}
/*
* Translate IIC_Exxxxx status values to vaguely-equivelent errno values.
*/
int
iic2errno(int iic_status)
{
switch (iic_status) {
case IIC_NOERR: return (0);
case IIC_EBUSERR: return (EALREADY);
case IIC_ENOACK: return (EIO);
case IIC_ETIMEOUT: return (ETIMEDOUT);
case IIC_EBUSBSY: return (EWOULDBLOCK);
case IIC_ESTATUS: return (EPROTO);
case IIC_EUNDERFLOW: return (EIO);
case IIC_EOVERFLOW: return (EOVERFLOW);
case IIC_ENOTSUPP: return (EOPNOTSUPP);
case IIC_ENOADDR: return (EADDRNOTAVAIL);
case IIC_ERESOURCE: return (ENOMEM);
default:
/*
* If the high bit is set, that means it's a system errno value
* that was encoded into the IIC_Exxxxxx space by setting the
* IIC_ERRNO marker bit. If lots of high-order bits are set,
* then it's one of the negative pseudo-errors such as ERESTART
* and we return it as-is. Otherwise it's a plain "small
* positive integer" errno, so just remove the IIC_ERRNO marker
* bit. If it's some unknown number without the high bit set,
* there isn't much we can do except call it an I/O error.
*/
if ((iic_status & IIC_ERRNO) == 0)
return (EIO);
if ((iic_status & 0xFFFF0000) != 0)
return (iic_status);
return (iic_status & ~IIC_ERRNO);
}
}
/*
* iicbus_intr()
*/
void
iicbus_intr(device_t bus, int event, char *buf)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
/* call owner's intr routine */
if (sc->owner)
IICBUS_INTR(sc->owner, event, buf);
return;
}
static int
iicbus_poll(struct iicbus_softc *sc, int how)
{
int error;
IICBUS_ASSERT_LOCKED(sc);
switch (how & IIC_INTRWAIT) {
case IIC_WAIT | IIC_INTR:
error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0);
break;
case IIC_WAIT | IIC_NOINTR:
error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0);
break;
default:
return (IIC_EBUSBSY);
}
return (errno2iic(error));
}
/*
* iicbus_request_bus()
*
* Allocate the device to perform transfers.
*
* how : IIC_WAIT or IIC_DONTWAIT
*/
int
iicbus_request_bus(device_t bus, device_t dev, int how)
{
struct iic_reqbus_data reqdata;
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
int error = 0;
IICBUS_LOCK(sc);
for (;;) {
if (sc->owner == NULL)
break;
if ((how & IIC_RECURSIVE) && sc->owner == dev)
break;
if ((error = iicbus_poll(sc, how)) != 0)
break;
}
if (error == 0) {
++sc->owncount;
if (sc->owner == NULL) {
sc->owner = dev;
/*
* Mark the device busy while it owns the bus, to
* prevent detaching the device, bus, or hardware
* controller, until ownership is relinquished. If the
* device is doing IO from its probe method before
* attaching, it cannot be busied; mark the bus busy.
*/
if (device_get_state(dev) < DS_ATTACHING)
sc->busydev = bus;
else
sc->busydev = dev;
device_busy(sc->busydev);
/*
* Drop the lock around the call to the bus driver, it
* should be allowed to sleep in the IIC_WAIT case.
* Drivers might also need to grab locks that would
* cause a LOR if our lock is held.
*/
IICBUS_UNLOCK(sc);
/* Ask the underlying layers if the request is ok */
reqdata.dev = dev;
reqdata.bus = bus;
reqdata.flags = how | IIC_REQBUS_DEV;
error = IICBUS_CALLBACK(device_get_parent(bus),
IIC_REQUEST_BUS, (caddr_t)&reqdata);
IICBUS_LOCK(sc);
if (error != 0) {
sc->owner = NULL;
sc->owncount = 0;
wakeup_one(sc);
device_unbusy(sc->busydev);
}
}
}
IICBUS_UNLOCK(sc);
return (error);
}
/*
* iicbus_release_bus()
*
* Release the device allocated with iicbus_request_dev()
*/
int
iicbus_release_bus(device_t bus, device_t dev)
{
struct iic_reqbus_data reqdata;
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
IICBUS_LOCK(sc);
if (sc->owner != dev) {
IICBUS_UNLOCK(sc);
return (IIC_EBUSBSY);
}
if (--sc->owncount == 0) {
/* Drop the lock while informing the low-level driver. */
IICBUS_UNLOCK(sc);
reqdata.dev = dev;
reqdata.bus = bus;
reqdata.flags = IIC_REQBUS_DEV;
IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
(caddr_t)&reqdata);
IICBUS_LOCK(sc);
sc->owner = NULL;
wakeup_one(sc);
device_unbusy(sc->busydev);
}
IICBUS_UNLOCK(sc);
return (0);
}
/*
* iicbus_started()
*
* Test if the iicbus is started by the controller
*/
int
iicbus_started(device_t bus)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
return (sc->started);
}
/*
* iicbus_start()
*
* Send start condition to the slave addressed by 'slave'
*/
int
iicbus_start(device_t bus, u_char slave, int timeout)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
int error = 0;
if (sc->started)
return (IIC_ESTATUS); /* protocol error, bus already started */
if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
sc->started = slave;
else
sc->started = 0;
return (error);
}
/*
* iicbus_repeated_start()
*
* Send start condition to the slave addressed by 'slave'
*/
int
iicbus_repeated_start(device_t bus, u_char slave, int timeout)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
int error = 0;
if (!sc->started)
return (IIC_ESTATUS); /* protocol error, bus not started */
if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
sc->started = slave;
else
sc->started = 0;
return (error);
}
/*
* iicbus_stop()
*
* Send stop condition to the bus
*/
int
iicbus_stop(device_t bus)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
int error = 0;
if (!sc->started)
return (IIC_ESTATUS); /* protocol error, bus not started */
error = IICBUS_STOP(device_get_parent(bus));
/* refuse any further access */
sc->started = 0;
return (error);
}
/*
* iicbus_write()
*
* Write a block of data to the slave previously started by
* iicbus_start() call
*/
int
iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
/* a slave must have been started for writing */
if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
return (IIC_ESTATUS);
return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
}
/*
* iicbus_read()
*
* Read a block of data from the slave previously started by
* iicbus_read() call
*/
int
iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
{
struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
/* a slave must have been started for reading */
if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
return (IIC_ESTATUS);
return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
}
/*
* iicbus_write_byte()
*
* Write a byte to the slave previously started by iicbus_start() call
*/
int
iicbus_write_byte(device_t bus, char byte, int timeout)
{
struct iicbus_softc *sc = device_get_softc(bus);
char data = byte;
int sent;
/* a slave must have been started for writing */
if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
return (IIC_ESTATUS);
return (iicbus_write(bus, &data, 1, &sent, timeout));
}
/*
* iicbus_read_byte()
*
* Read a byte from the slave previously started by iicbus_start() call
*/
int
iicbus_read_byte(device_t bus, char *byte, int timeout)
{
struct iicbus_softc *sc = device_get_softc(bus);
int read;
/* a slave must have been started for reading */
if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
return (IIC_ESTATUS);
return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
}
/*
* iicbus_block_write()
*
* Write a block of data to slave ; start/stop protocol managed
*/
int
iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
{
u_char addr = slave & ~LSB;
int error;
if ((error = iicbus_start(bus, addr, 0)))
return (error);
error = iicbus_write(bus, buf, len, sent, 0);
iicbus_stop(bus);
return (error);
}
/*
* iicbus_block_read()
*
* Read a block of data from slave ; start/stop protocol managed
*/
int
iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
{
u_char addr = slave | LSB;
int error;
if ((error = iicbus_start(bus, addr, 0)))
return (error);
error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
iicbus_stop(bus);
return (error);
}
/*
* iicbus_transfer()
*
* Do an aribtrary number of transfers on the iicbus. We pass these
* raw requests to the bridge driver. If the bridge driver supports
* them directly, then it manages all the details. If not, it can use
* the helper function iicbus_transfer_gen() which will do the
* transfers at a low level.
*
* Pointers passed in as part of iic_msg must be kernel pointers.
* Callers that have user addresses to manage must do so on their own.
*/
int
iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
{
return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
}
int
iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
int how)
{
device_t bus;
int error;
bus = device_get_parent(dev);
error = iicbus_request_bus(bus, dev, how);
if (error == 0)
error = IICBUS_TRANSFER(bus, msgs, nmsgs);
iicbus_release_bus(bus, dev);
return (error);
}
/*
* Generic version of iicbus_transfer that calls the appropriate
* routines to accomplish this. See note above about acceptable
* buffer addresses.
*/
int
iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
int i, error, lenread, lenwrote, nkid, rpstart, addr;
device_t *children, bus;
bool started;
if ((error = device_get_children(dev, &children, &nkid)) != 0)
return (IIC_ERESOURCE);
if (nkid != 1) {
free(children, M_TEMP);
return (IIC_ENOTSUPP);
}
bus = children[0];
rpstart = 0;
free(children, M_TEMP);
started = false;
for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
addr = msgs[i].slave;
if (msgs[i].flags & IIC_M_RD)
addr |= LSB;
else
addr &= ~LSB;
if (!(msgs[i].flags & IIC_M_NOSTART)) {
if (rpstart)
error = iicbus_repeated_start(bus, addr, 0);
else
error = iicbus_start(bus, addr, 0);
if (error != 0)
break;
started = true;
}
if (msgs[i].flags & IIC_M_RD)
error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
&lenread, IIC_LAST_READ, 0);
else
error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
&lenwrote, 0);
if (error != 0)
break;
if (!(msgs[i].flags & IIC_M_NOSTOP)) {
rpstart = 0;
iicbus_stop(bus);
} else {
rpstart = 1; /* Next message gets repeated start */
}
}
if (error != 0 && started)
iicbus_stop(bus);
return (error);
}
int
iicdev_readfrom(device_t slavedev, uint8_t regaddr, void *buffer,
uint16_t buflen, int waithow)
{
struct iic_msg msgs[2];
uint8_t slaveaddr;
/*
* Two transfers back to back with a repeat-start between them; first we
* write the address-within-device, then we read from the device.
*/
slaveaddr = iicbus_get_addr(slavedev);
msgs[0].slave = slaveaddr;
msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
msgs[0].len = 1;
msgs[0].buf = ®addr;
msgs[1].slave = slaveaddr;
msgs[1].flags = IIC_M_RD;
msgs[1].len = buflen;
msgs[1].buf = buffer;
return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));
}
int iicdev_writeto(device_t slavedev, uint8_t regaddr, void *buffer,
uint16_t buflen, int waithow)
{
struct iic_msg msg;
uint8_t local_buffer[32];
uint8_t *bufptr;
size_t bufsize;
int error;
/*
* Ideally, we would do two transfers back to back with no stop or start
* between them using an array of 2 iic_msgs; first we'd write the
* address byte using the IIC_M_NOSTOP flag, then we write the data
* using IIC_M_NOSTART, all in a single transfer. Unfortunately,
* several i2c hardware drivers don't support that (perhaps because the
* hardware itself can't support it). So instead we gather the
* scattered bytes into a single buffer here before writing them using a
* single iic_msg. This function is typically used to write a few bytes
* at a time, so we try to use a small local buffer on the stack, but
* fall back to allocating a temporary buffer when necessary.
*/
bufsize = buflen + 1;
if (bufsize <= sizeof(local_buffer)) {
bufptr = local_buffer;
} else {
bufptr = malloc(bufsize, M_DEVBUF,
(waithow & IIC_WAIT) ? M_WAITOK : M_NOWAIT);
if (bufptr == NULL)
return (errno2iic(ENOMEM));
}
bufptr[0] = regaddr;
memcpy(&bufptr[1], buffer, buflen);
msg.slave = iicbus_get_addr(slavedev);
msg.flags = IIC_M_WR;
msg.len = bufsize;
msg.buf = bufptr;
error = iicbus_transfer_excl(slavedev, &msg, 1, waithow);
if (bufptr != local_buffer)
free(bufptr, M_DEVBUF);
return (error);
}
