qemu/hw/misc/tmp105.c
Corey Minyard 2ac4c5f4d2 i2c: have I2C receive operation return uint8_t
It is never supposed to fail and cannot return an error, so just
have it return the proper type.  Have it return 0xff on nothing
available, since that's what would happen on a real bus.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-02-27 21:06:08 -06:00

275 lines
6.9 KiB
C

/*
* Texas Instruments TMP105 temperature sensor.
*
* Copyright (C) 2008 Nokia Corporation
* Written by Andrzej Zaborowski <andrew@openedhand.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 or
* (at your option) version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/i2c/i2c.h"
#include "tmp105.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
static void tmp105_interrupt_update(TMP105State *s)
{
qemu_set_irq(s->pin, s->alarm ^ ((~s->config >> 2) & 1)); /* POL */
}
static void tmp105_alarm_update(TMP105State *s)
{
if ((s->config >> 0) & 1) { /* SD */
if ((s->config >> 7) & 1) /* OS */
s->config &= ~(1 << 7); /* OS */
else
return;
}
if ((s->config >> 1) & 1) { /* TM */
if (s->temperature >= s->limit[1])
s->alarm = 1;
else if (s->temperature < s->limit[0])
s->alarm = 1;
} else {
if (s->temperature >= s->limit[1])
s->alarm = 1;
else if (s->temperature < s->limit[0])
s->alarm = 0;
}
tmp105_interrupt_update(s);
}
static void tmp105_get_temperature(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
TMP105State *s = TMP105(obj);
int64_t value = s->temperature * 1000 / 256;
visit_type_int(v, name, &value, errp);
}
/* Units are 0.001 centigrades relative to 0 C. s->temperature is 8.8
* fixed point, so units are 1/256 centigrades. A simple ratio will do.
*/
static void tmp105_set_temperature(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
TMP105State *s = TMP105(obj);
Error *local_err = NULL;
int64_t temp;
visit_type_int(v, name, &temp, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (temp >= 128000 || temp < -128000) {
error_setg(errp, "value %" PRId64 ".%03" PRIu64 " C is out of range",
temp / 1000, temp % 1000);
return;
}
s->temperature = (int16_t) (temp * 256 / 1000);
tmp105_alarm_update(s);
}
static const int tmp105_faultq[4] = { 1, 2, 4, 6 };
static void tmp105_read(TMP105State *s)
{
s->len = 0;
if ((s->config >> 1) & 1) { /* TM */
s->alarm = 0;
tmp105_interrupt_update(s);
}
switch (s->pointer & 3) {
case TMP105_REG_TEMPERATURE:
s->buf[s->len ++] = (((uint16_t) s->temperature) >> 8);
s->buf[s->len ++] = (((uint16_t) s->temperature) >> 0) &
(0xf0 << ((~s->config >> 5) & 3)); /* R */
break;
case TMP105_REG_CONFIG:
s->buf[s->len ++] = s->config;
break;
case TMP105_REG_T_LOW:
s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 8;
s->buf[s->len ++] = ((uint16_t) s->limit[0]) >> 0;
break;
case TMP105_REG_T_HIGH:
s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 8;
s->buf[s->len ++] = ((uint16_t) s->limit[1]) >> 0;
break;
}
}
static void tmp105_write(TMP105State *s)
{
switch (s->pointer & 3) {
case TMP105_REG_TEMPERATURE:
break;
case TMP105_REG_CONFIG:
if (s->buf[0] & ~s->config & (1 << 0)) /* SD */
printf("%s: TMP105 shutdown\n", __func__);
s->config = s->buf[0];
s->faults = tmp105_faultq[(s->config >> 3) & 3]; /* F */
tmp105_alarm_update(s);
break;
case TMP105_REG_T_LOW:
case TMP105_REG_T_HIGH:
if (s->len >= 3)
s->limit[s->pointer & 1] = (int16_t)
((((uint16_t) s->buf[0]) << 8) | s->buf[1]);
tmp105_alarm_update(s);
break;
}
}
static uint8_t tmp105_rx(I2CSlave *i2c)
{
TMP105State *s = TMP105(i2c);
if (s->len < 2) {
return s->buf[s->len ++];
} else {
return 0xff;
}
}
static int tmp105_tx(I2CSlave *i2c, uint8_t data)
{
TMP105State *s = TMP105(i2c);
if (s->len == 0) {
s->pointer = data;
s->len++;
} else {
if (s->len <= 2) {
s->buf[s->len - 1] = data;
}
s->len++;
tmp105_write(s);
}
return 0;
}
static int tmp105_event(I2CSlave *i2c, enum i2c_event event)
{
TMP105State *s = TMP105(i2c);
if (event == I2C_START_RECV) {
tmp105_read(s);
}
s->len = 0;
return 0;
}
static int tmp105_post_load(void *opaque, int version_id)
{
TMP105State *s = opaque;
s->faults = tmp105_faultq[(s->config >> 3) & 3]; /* F */
tmp105_interrupt_update(s);
return 0;
}
static const VMStateDescription vmstate_tmp105 = {
.name = "TMP105",
.version_id = 0,
.minimum_version_id = 0,
.post_load = tmp105_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT8(len, TMP105State),
VMSTATE_UINT8_ARRAY(buf, TMP105State, 2),
VMSTATE_UINT8(pointer, TMP105State),
VMSTATE_UINT8(config, TMP105State),
VMSTATE_INT16(temperature, TMP105State),
VMSTATE_INT16_ARRAY(limit, TMP105State, 2),
VMSTATE_UINT8(alarm, TMP105State),
VMSTATE_I2C_SLAVE(i2c, TMP105State),
VMSTATE_END_OF_LIST()
}
};
static void tmp105_reset(I2CSlave *i2c)
{
TMP105State *s = TMP105(i2c);
s->temperature = 0;
s->pointer = 0;
s->config = 0;
s->faults = tmp105_faultq[(s->config >> 3) & 3];
s->alarm = 0;
tmp105_interrupt_update(s);
}
static void tmp105_realize(DeviceState *dev, Error **errp)
{
I2CSlave *i2c = I2C_SLAVE(dev);
TMP105State *s = TMP105(i2c);
qdev_init_gpio_out(&i2c->qdev, &s->pin, 1);
tmp105_reset(&s->i2c);
}
static void tmp105_initfn(Object *obj)
{
object_property_add(obj, "temperature", "int",
tmp105_get_temperature,
tmp105_set_temperature, NULL, NULL, NULL);
}
static void tmp105_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
dc->realize = tmp105_realize;
k->event = tmp105_event;
k->recv = tmp105_rx;
k->send = tmp105_tx;
dc->vmsd = &vmstate_tmp105;
}
static const TypeInfo tmp105_info = {
.name = TYPE_TMP105,
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(TMP105State),
.instance_init = tmp105_initfn,
.class_init = tmp105_class_init,
};
static void tmp105_register_types(void)
{
type_register_static(&tmp105_info);
}
type_init(tmp105_register_types)