freebsd-nq/sys/dev/isl/isl.c
Andriy Gapon 448897d366 add iic interface to ig4 driver, move isl and cyapa to iicbus
Summary:
The hardware does not expose a classic SMBus interface.
Instead it has a lower level interface that can express a far richer
I2C protocol than what smbus offers.  However, the interface does not
provide a way to explicitly generate the I2C stop and start conditions.
It's only possible to request that the stop condition is generated
after transferring the next byte in either direction.  So, at least
one data byte must always be transferred.
Thus, some I2C sequences are impossible to generate, e.g., an equivalent
of smbus quick command (<start>-<slave addr>-<r/w bit>-<stop>).

At the same time isl(4) and cyapa(4) are moved to iicbus and now they use
iicbus_transfer for communication.  Previously they used smbus_trans()
interface that is not defined by the SMBus protocol and was implemented
only by ig4(4).  In fact, that interface was impossible to implement
for the typical SMBus controllers like intpm(4) or ichsmb(4) where
a type of the SMBus command must be programmed.

The plan is to remove smbus_trans() and all its uses.
As an aside, the smbus_trans() method deviates from the standard,
but perhaps backwards, FreeBSD convention of using 8-bit slave
addresses (shifted by 1 bit to the left).  The method expects
7-bit addresses.

There is a user facing consequence of this change.
A user must now provide device hints for isl and cyapa that specify an iicbus to use
and a slave address on it.
On Chromebook hardware where isl and cyapa devices are commonly found
it is also possible to use a new chromebook_platform(4) driver that
automatically configures isl and cyapa devices.  There is no need to
provide the device hints in that case,

Right now smbus(4) driver tries to discover all slaves on the bus.
That is very dangerous.  Fortunately, the probing code uses smbus_trans()
to do its job, so it is really enabled for ig4 only.
The plan is to remove that auto-probing code and smbus_trans().

Tested by:	grembo, Matthias Apitz <guru@unixarea.de> (w/o
		chromebook_platform)
Discussed with:	grembo, imp
Reviewed by:	wblock (docs)
MFC after:	1 month
Relnotes:	yes
Differential Revision: https://reviews.freebsd.org/D8172
2016-10-30 12:15:33 +00:00

345 lines
8.3 KiB
C

/*-
* Copyright (c) 2015 Michael Gmelin <freebsd@grem.de>
* 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("$FreeBSD$");
/*
* Driver for intersil I2C ISL29018 Digital Ambient Light Sensor and Proximity
* Sensor with Interrupt Function, only tested connected over SMBus (ig4iic).
*
* Datasheet:
* http://www.intersil.com/en/products/optoelectronics/ambient-light-and-proximity-sensors/light-to-digital-sensors/ISL29018.html
* http://www.intersil.com/content/dam/Intersil/documents/isl2/isl29018.pdf
*/
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/lockmgr.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/poll.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/systm.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/isl/isl.h>
#include "iicbus_if.h"
#include "bus_if.h"
#include "device_if.h"
#define ISL_METHOD_ALS 0x10
#define ISL_METHOD_IR 0x11
#define ISL_METHOD_PROX 0x12
#define ISL_METHOD_RESOLUTION 0x13
#define ISL_METHOD_RANGE 0x14
struct isl_softc {
device_t dev;
struct sx isl_sx;
};
/* Returns < 0 on problem. */
static int isl_read_sensor(device_t dev, uint8_t cmd_mask);
static int
isl_read_byte(device_t dev, uint8_t reg, uint8_t *val)
{
uint16_t addr = iicbus_get_addr(dev);
struct iic_msg msgs[] = {
{ addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
{ addr, IIC_M_RD, 1, val },
};
return (iicbus_transfer(dev, msgs, nitems(msgs)));
}
static int
isl_write_byte(device_t dev, uint8_t reg, uint8_t val)
{
uint16_t addr = iicbus_get_addr(dev);
uint8_t bytes[] = { reg, val };
struct iic_msg msgs[] = {
{ addr, IIC_M_WR, nitems(bytes), bytes },
};
return (iicbus_transfer(dev, msgs, nitems(msgs)));
}
/*
* Initialize the device
*/
static int
init_device(device_t dev, int probe)
{
int error;
/*
* init procedure: send 0x00 to test ref and cmd reg 1
*/
error = isl_write_byte(dev, REG_TEST, 0);
if (error)
goto done;
error = isl_write_byte(dev, REG_CMD1, 0);
if (error)
goto done;
pause("islinit", hz/100);
done:
if (error && !probe)
device_printf(dev, "Unable to initialize\n");
return (error);
}
static int isl_probe(device_t);
static int isl_attach(device_t);
static int isl_detach(device_t);
static int isl_sysctl(SYSCTL_HANDLER_ARGS);
static devclass_t isl_devclass;
static device_method_t isl_methods[] = {
/* device interface */
DEVMETHOD(device_probe, isl_probe),
DEVMETHOD(device_attach, isl_attach),
DEVMETHOD(device_detach, isl_detach),
DEVMETHOD_END
};
static driver_t isl_driver = {
"isl",
isl_methods,
sizeof(struct isl_softc),
};
#if 0
static void
isl_identify(driver_t *driver, device_t parent)
{
if (device_find_child(parent, "asl", -1)) {
if (bootverbose)
printf("asl: device(s) already created\n");
return;
}
/* Check if we can communicate to our slave. */
if (init_device(dev, 0x88, 1) == 0)
BUS_ADD_CHILD(parent, ISA_ORDER_SPECULATIVE, "isl", -1);
}
#endif
static int
isl_probe(device_t dev)
{
uint32_t addr = iicbus_get_addr(dev);
if (addr != 0x88)
return (ENXIO);
if (init_device(dev, 1) != 0)
return (ENXIO);
device_set_desc(dev, "ISL Digital Ambient Light Sensor");
return (BUS_PROBE_VENDOR);
}
static int
isl_attach(device_t dev)
{
struct isl_softc *sc;
struct sysctl_ctx_list *sysctl_ctx;
struct sysctl_oid *sysctl_tree;
int use_als;
int use_ir;
int use_prox;
sc = device_get_softc(dev);
sc->dev = dev;
if (init_device(dev, 0) != 0)
return (ENXIO);
sx_init(&sc->isl_sx, "ISL read lock");
sysctl_ctx = device_get_sysctl_ctx(dev);
sysctl_tree = device_get_sysctl_tree(dev);
use_als = isl_read_sensor(dev, CMD1_MASK_ALS_ONCE) >= 0;
use_ir = isl_read_sensor(dev, CMD1_MASK_IR_ONCE) >= 0;
use_prox = isl_read_sensor(dev, CMD1_MASK_PROX_ONCE) >= 0;
if (use_als) {
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
"als", CTLTYPE_INT | CTLFLAG_RD,
sc, ISL_METHOD_ALS, isl_sysctl, "I",
"Current ALS sensor read-out");
}
if (use_ir) {
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
"ir", CTLTYPE_INT | CTLFLAG_RD,
sc, ISL_METHOD_IR, isl_sysctl, "I",
"Current IR sensor read-out");
}
if (use_prox) {
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
"prox", CTLTYPE_INT | CTLFLAG_RD,
sc, ISL_METHOD_PROX, isl_sysctl, "I",
"Current proximity sensor read-out");
}
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
"resolution", CTLTYPE_INT | CTLFLAG_RD,
sc, ISL_METHOD_RESOLUTION, isl_sysctl, "I",
"Current proximity sensor resolution");
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree), OID_AUTO,
"range", CTLTYPE_INT | CTLFLAG_RD,
sc, ISL_METHOD_RANGE, isl_sysctl, "I",
"Current proximity sensor range");
return (0);
}
static int
isl_detach(device_t dev)
{
struct isl_softc *sc;
sc = device_get_softc(dev);
sx_destroy(&sc->isl_sx);
return (0);
}
static int
isl_sysctl(SYSCTL_HANDLER_ARGS)
{
static int resolutions[] = { 16, 12, 8, 4};
static int ranges[] = { 1000, 4000, 16000, 64000};
struct isl_softc *sc;
uint8_t rbyte;
int arg;
int resolution;
int range;
sc = (struct isl_softc *)oidp->oid_arg1;
arg = -1;
sx_xlock(&sc->isl_sx);
if (isl_read_byte(sc->dev, REG_CMD2, &rbyte) != 0) {
sx_xunlock(&sc->isl_sx);
return (-1);
}
resolution = resolutions[(rbyte & CMD2_MASK_RESOLUTION)
>> CMD2_SHIFT_RESOLUTION];
range = ranges[(rbyte & CMD2_MASK_RANGE) >> CMD2_SHIFT_RANGE];
switch (oidp->oid_arg2) {
case ISL_METHOD_ALS:
arg = (isl_read_sensor(sc->dev,
CMD1_MASK_ALS_ONCE) * range) >> resolution;
break;
case ISL_METHOD_IR:
arg = isl_read_sensor(sc->dev, CMD1_MASK_IR_ONCE);
break;
case ISL_METHOD_PROX:
arg = isl_read_sensor(sc->dev, CMD1_MASK_PROX_ONCE);
break;
case ISL_METHOD_RESOLUTION:
arg = (1 << resolution);
break;
case ISL_METHOD_RANGE:
arg = range;
break;
}
sx_xunlock(&sc->isl_sx);
SYSCTL_OUT(req, &arg, sizeof(arg));
return (0);
}
static int
isl_read_sensor(device_t dev, uint8_t cmd_mask)
{
uint8_t rbyte;
uint8_t cmd;
int ret;
if (isl_read_byte(dev, REG_CMD1, &rbyte) != 0) {
device_printf(dev,
"Couldn't read first byte before issuing command %d\n",
cmd_mask);
return (-1);
}
cmd = (rbyte & 0x1f) | cmd_mask;
if (isl_write_byte(dev, REG_CMD1, cmd) != 0) {
device_printf(dev, "Couldn't write command %d\n", cmd_mask);
return (-1);
}
pause("islconv", hz/10);
if (isl_read_byte(dev, REG_DATA1, &rbyte) != 0) {
device_printf(dev,
"Couldn't read first byte after command %d\n", cmd_mask);
return (-1);
}
ret = rbyte;
if (isl_read_byte(dev, REG_DATA2, &rbyte) != 0) {
device_printf(dev, "Couldn't read second byte after command %d\n", cmd_mask);
return (-1);
}
ret += rbyte << 8;
return (ret);
}
DRIVER_MODULE(isl, iicbus, isl_driver, isl_devclass, NULL, NULL);
MODULE_DEPEND(isl, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(isl, 1);