freebsd-dev/sys/dev/iicbus/max6690.c
Andreas Tobler 1b49664037 - Improve error handling.
- Add a retry loop for the i2c sensor reading.
- Check on busy status of the chip and on invalid values.
- Fix a typo in a comment.
- Replace the constant 2732 with the ZERO_C_TO_K macro.

Approved by:	nwhitehorn (mentor)
2011-06-04 09:23:54 +00:00

378 lines
9.6 KiB
C

/*-
* Copyright (c) 2010 Andreas Tobler
* 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 ``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 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/bus.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/callout.h>
#include <sys/conf.h>
#include <sys/cpu.h>
#include <sys/ctype.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/limits.h>
#include <machine/bus.h>
#include <machine/md_var.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <powerpc/powermac/powermac_thermal.h>
/* Inlet, Backside, U3 Heatsink sensor: MAX6690. */
#define MAX6690_INT_TEMP 0x0
#define MAX6690_EXT_TEMP 0x1
#define MAX6690_RSL_STATUS 0x2
#define MAX6690_EEXT_TEMP 0x10
#define MAX6690_IEXT_TEMP 0x11
#define MAX6690_TEMP_MASK 0xe0
struct max6690_sensor {
struct pmac_therm therm;
device_t dev;
int id;
};
/* Regular bus attachment functions */
static int max6690_probe(device_t);
static int max6690_attach(device_t);
/* Utility functions */
static int max6690_sensor_read(struct max6690_sensor *sens);
static int max6690_sensor_sysctl(SYSCTL_HANDLER_ARGS);
static void max6690_start(void *xdev);
static int max6690_read(device_t dev, uint32_t addr, uint8_t reg,
uint8_t *data);
struct max6690_softc {
device_t sc_dev;
struct intr_config_hook enum_hook;
uint32_t sc_addr;
struct max6690_sensor *sc_sensors;
int sc_nsensors;
};
static device_method_t max6690_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, max6690_probe),
DEVMETHOD(device_attach, max6690_attach),
{ 0, 0 },
};
static driver_t max6690_driver = {
"max6690",
max6690_methods,
sizeof(struct max6690_softc)
};
static devclass_t max6690_devclass;
DRIVER_MODULE(max6690, iicbus, max6690_driver, max6690_devclass, 0, 0);
MALLOC_DEFINE(M_MAX6690, "max6690", "Temp-Monitor MAX6690");
static int
max6690_read(device_t dev, uint32_t addr, uint8_t reg, uint8_t *data)
{
uint8_t buf[4];
uint8_t busy[1], rsl;
int err, try = 0;
/* Busy register RSL. */
rsl = MAX6690_RSL_STATUS;
/* first read the status register, 0x2. If busy, retry. */
struct iic_msg msg[4] = {
{ addr, IIC_M_WR | IIC_M_NOSTOP, 1, &rsl },
{ addr, IIC_M_RD, 1, busy },
{ addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
{ addr, IIC_M_RD, 1, buf },
};
for (;;)
{
err = iicbus_transfer(dev, msg, 4);
if (err != 0)
goto retry;
if (busy[0] & 0x80)
goto retry;
/* Check for invalid value and retry. */
if (buf[0] == 0xff)
goto retry;
*data = *((uint8_t*)buf);
return (0);
retry:
if (++try > 5) {
device_printf(dev, "iicbus read failed\n");
return (-1);
}
pause("max6690_read", hz);
}
}
static int
max6690_probe(device_t dev)
{
const char *name, *compatible;
struct max6690_softc *sc;
name = ofw_bus_get_name(dev);
compatible = ofw_bus_get_compat(dev);
if (!name)
return (ENXIO);
if (strcmp(name, "temp-monitor") != 0 ||
strcmp(compatible, "max6690") != 0)
return (ENXIO);
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_addr = iicbus_get_addr(dev);
device_set_desc(dev, "Temp-Monitor MAX6690");
return (0);
}
/*
* This function returns the number of sensors. If we call it the second time
* and we have allocated memory for sc->sc_sensors, we fill in the properties.
*/
static int
max6690_fill_sensor_prop(device_t dev)
{
phandle_t child;
struct max6690_softc *sc;
u_int id[8];
char location[96];
int i = 0, j, len = 0, prop_len, prev_len = 0;
sc = device_get_softc(dev);
child = ofw_bus_get_node(dev);
/* Fill the sensor location property. */
prop_len = OF_getprop(child, "hwsensor-location", location,
sizeof(location));
while (len < prop_len) {
if (sc->sc_sensors != NULL)
strcpy(sc->sc_sensors[i].therm.name, location + len);
prev_len = strlen(location + len) + 1;
len += prev_len;
i++;
}
if (sc->sc_sensors == NULL)
return (i);
/* Fill the sensor id property. */
prop_len = OF_getprop(child, "hwsensor-id", id, sizeof(id));
for (j = 0; j < i; j++)
sc->sc_sensors[j].id = (id[j] & 0xf);
/* Fill the sensor zone property. */
prop_len = OF_getprop(child, "hwsensor-zone", id, sizeof(id));
for (j = 0; j < i; j++)
sc->sc_sensors[j].therm.zone = id[j];
/* Set up remaining sensor properties */
for (j = 0; j < i; j++) {
sc->sc_sensors[j].dev = dev;
sc->sc_sensors[j].therm.target_temp = 400 + ZERO_C_TO_K;
sc->sc_sensors[j].therm.max_temp = 800 + ZERO_C_TO_K;
sc->sc_sensors[j].therm.read =
(int (*)(struct pmac_therm *))(max6690_sensor_read);
}
return (i);
}
static int
max6690_attach(device_t dev)
{
struct max6690_softc *sc;
sc = device_get_softc(dev);
sc->enum_hook.ich_func = max6690_start;
sc->enum_hook.ich_arg = dev;
/* We have to wait until interrupts are enabled. I2C read and write
* only works if the interrupts are available.
* The unin/i2c is controlled by the htpic on unin. But this is not
* the master. The openpic on mac-io is controlling the htpic.
* This one gets attached after the mac-io probing and then the
* interrupts will be available.
*/
if (config_intrhook_establish(&sc->enum_hook) != 0)
return (ENOMEM);
return (0);
}
static void
max6690_start(void *xdev)
{
struct max6690_softc *sc;
struct sysctl_oid *oid, *sensroot_oid;
struct sysctl_ctx_list *ctx;
char sysctl_name[32];
int i, j;
device_t dev = (device_t)xdev;
sc = device_get_softc(dev);
sc->sc_nsensors = 0;
/* Count the actual number of sensors. */
sc->sc_nsensors = max6690_fill_sensor_prop(dev);
device_printf(dev, "%d sensors detected.\n", sc->sc_nsensors);
if (sc->sc_nsensors == 0)
device_printf(dev, "WARNING: No MAX6690 sensors detected!\n");
sc->sc_sensors = malloc (sc->sc_nsensors * sizeof(struct max6690_sensor),
M_MAX6690, M_WAITOK | M_ZERO);
ctx = device_get_sysctl_ctx(dev);
sensroot_oid = SYSCTL_ADD_NODE(ctx,
SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "sensor",
CTLFLAG_RD, 0, "MAX6690 Sensor Information");
/* Now we can fill the properties into the allocated struct. */
sc->sc_nsensors = max6690_fill_sensor_prop(dev);
/* Register with powermac_thermal */
for (i = 0; i < sc->sc_nsensors; i++)
pmac_thermal_sensor_register(&sc->sc_sensors[i].therm);
/* Add sysctls for the sensors. */
for (i = 0; i < sc->sc_nsensors; i++) {
for (j = 0; j < strlen(sc->sc_sensors[i].therm.name); j++) {
sysctl_name[j] =
tolower(sc->sc_sensors[i].therm.name[j]);
if (isspace(sysctl_name[j]))
sysctl_name[j] = '_';
}
sysctl_name[j] = 0;
oid = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(sensroot_oid),
OID_AUTO,
sysctl_name, CTLFLAG_RD, 0,
"Sensor Information");
/* I use i to pass the sensor id. */
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "temp",
CTLTYPE_INT | CTLFLAG_RD, dev, i % 2,
max6690_sensor_sysctl, "IK",
"Sensor Temp in °C");
}
/* Dump sensor location & ID. */
if (bootverbose) {
device_printf(dev, "Sensors\n");
for (i = 0; i < sc->sc_nsensors; i++) {
device_printf(dev, "Location : %s ID: %d\n",
sc->sc_sensors[i].therm.name,
sc->sc_sensors[i].id);
}
}
config_intrhook_disestablish(&sc->enum_hook);
}
static int
max6690_sensor_read(struct max6690_sensor *sens)
{
uint8_t reg_int = 0, reg_ext = 0;
uint8_t integer = 0;
uint8_t fraction = 0;
int err, temp;
struct max6690_softc *sc;
sc = device_get_softc(sens->dev);
/* The internal sensor id's are even, the external are odd. */
if ((sens->id % 2) == 0) {
reg_int = MAX6690_INT_TEMP;
reg_ext = MAX6690_IEXT_TEMP;
} else {
reg_int = MAX6690_EXT_TEMP;
reg_ext = MAX6690_EEXT_TEMP;
}
err = max6690_read(sc->sc_dev, sc->sc_addr, reg_int, &integer);
err = max6690_read(sc->sc_dev, sc->sc_addr, reg_ext, &fraction);
if (err < 0)
return (-1);
fraction &= MAX6690_TEMP_MASK;
/* The temperature is in tenth kelvin, the fractional part resolution
is 0.125.
*/
temp = (integer * 10) + (fraction >> 5) * 10 / 8;
return (temp + ZERO_C_TO_K);
}
static int
max6690_sensor_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
struct max6690_softc *sc;
struct max6690_sensor *sens;
int error;
unsigned int temp;
dev = arg1;
sc = device_get_softc(dev);
sens = &sc->sc_sensors[arg2];
temp = max6690_sensor_read(sens);
if (temp < 0)
return (EIO);
error = sysctl_handle_int(oidp, &temp, 0, req);
return (error);
}