diff mbox series

[v4,1/2] hw/misc: add an EMC141{3,4} device model

Message ID 20201122105134.671-1-wangzhiqiang.bj@bytedance.com
State New
Headers show
Series [v4,1/2] hw/misc: add an EMC141{3,4} device model | expand

Commit Message

John Wang Nov. 22, 2020, 10:51 a.m. UTC
Largely inspired by the TMP421 temperature sensor, here is a model for
the EMC1413/EMC1414 temperature sensors.

Specs can be found here :
  http://ww1.microchip.com/downloads/en/DeviceDoc/20005274A.pdf

Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
---
v4:
  -Fix QOM style name
  -Add unittest
v3:
  - update the link to the spec
  - Rename emc1413.c to emc141x.c
  - Add sensors_count in EMC141XClass
  - Make emc1413_read/write easier to review :)
v2:
  - Remove DeviceInfo
  - commit message: TMP423 -> TMP421
---
 hw/arm/Kconfig                 |   1 +
 hw/misc/Kconfig                |   4 +
 hw/misc/emc141x.c              | 326 +++++++++++++++++++++++++++++++++
 hw/misc/meson.build            |   1 +
 include/hw/misc/emc141x_regs.h |  37 ++++
 tests/qtest/emc141x-test.c     |  81 ++++++++
 tests/qtest/meson.build        |   1 +
 7 files changed, 451 insertions(+)
 create mode 100644 hw/misc/emc141x.c
 create mode 100644 include/hw/misc/emc141x_regs.h
 create mode 100644 tests/qtest/emc141x-test.c

Comments

Cédric Le Goater Nov. 23, 2020, 12:21 p.m. UTC | #1
On 11/22/20 11:51 AM, John Wang wrote:
> Largely inspired by the TMP421 temperature sensor, here is a model for
> the EMC1413/EMC1414 temperature sensors.
> 
> Specs can be found here :
>   http://ww1.microchip.com/downloads/en/DeviceDoc/20005274A.pdf
> 
> Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.

> ---
> v4:
>   -Fix QOM style name
>   -Add unittest
> v3:
>   - update the link to the spec
>   - Rename emc1413.c to emc141x.c
>   - Add sensors_count in EMC141XClass
>   - Make emc1413_read/write easier to review :)
> v2:
>   - Remove DeviceInfo
>   - commit message: TMP423 -> TMP421
> ---
>  hw/arm/Kconfig                 |   1 +
>  hw/misc/Kconfig                |   4 +
>  hw/misc/emc141x.c              | 326 +++++++++++++++++++++++++++++++++
>  hw/misc/meson.build            |   1 +
>  include/hw/misc/emc141x_regs.h |  37 ++++
>  tests/qtest/emc141x-test.c     |  81 ++++++++
>  tests/qtest/meson.build        |   1 +
>  7 files changed, 451 insertions(+)
>  create mode 100644 hw/misc/emc141x.c
>  create mode 100644 include/hw/misc/emc141x_regs.h
>  create mode 100644 tests/qtest/emc141x-test.c
> 
> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index e69a9009cf..eb8a8844cf 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -407,6 +407,7 @@ config ASPEED_SOC
>      select SSI_M25P80
>      select TMP105
>      select TMP421
> +    select EMC141X
>      select UNIMP
>      select LED
>  
> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index dc44dc14f6..cf18ac08e6 100644
> --- a/hw/misc/Kconfig
> +++ b/hw/misc/Kconfig
> @@ -13,6 +13,10 @@ config TMP421
>      bool
>      depends on I2C
>  
> +config EMC141X
> +    bool
> +    depends on I2C
> +
>  config ISA_DEBUG
>      bool
>      depends on ISA_BUS
> diff --git a/hw/misc/emc141x.c b/hw/misc/emc141x.c
> new file mode 100644
> index 0000000000..f7c53d48a4
> --- /dev/null
> +++ b/hw/misc/emc141x.c
> @@ -0,0 +1,326 @@
> +/*
> + * SMSC EMC141X temperature sensor.
> + *
> + * Copyright (c) 2020 Bytedance Corporation
> + * Written by John Wang <wangzhiqiang.bj@bytedance.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/i2c/i2c.h"
> +#include "migration/vmstate.h"
> +#include "qapi/error.h"
> +#include "qapi/visitor.h"
> +#include "qemu/module.h"
> +#include "qom/object.h"
> +#include "hw/misc/emc141x_regs.h"
> +
> +#define SENSORS_COUNT_MAX    4
> +
> +struct EMC141XState {
> +    I2CSlave parent_obj;
> +    struct {
> +        uint8_t raw_temp_min;
> +        uint8_t raw_temp_current;
> +        uint8_t raw_temp_max;
> +    } sensor[SENSORS_COUNT_MAX];
> +    uint8_t len;
> +    uint8_t data;
> +    uint8_t pointer;
> +};
> +
> +struct EMC141XClass {
> +    I2CSlaveClass parent_class;
> +    uint8_t model;
> +    unsigned sensors_count;
> +};
> +
> +#define TYPE_EMC141X "emc141x"
> +OBJECT_DECLARE_TYPE(EMC141XState, EMC141XClass, EMC141X)
> +
> +static void emc141x_get_temperature(Object *obj, Visitor *v, const char *name,
> +                                    void *opaque, Error **errp)
> +{
> +    EMC141XState *s = EMC141X(obj);
> +    EMC141XClass *sc = EMC141X_GET_CLASS(s);
> +    int64_t value;
> +    unsigned tempid;
> +
> +    if (sscanf(name, "temperature%u", &tempid) != 1) {
> +        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
> +        return;
> +    }
> +
> +    if (tempid >= sc->sensors_count) {
> +        error_setg(errp, "error reading %s", name);
> +        return;
> +    }
> +
> +    value = s->sensor[tempid].raw_temp_current * 1000;
> +
> +    visit_type_int(v, name, &value, errp);
> +}
> +
> +static void emc141x_set_temperature(Object *obj, Visitor *v, const char *name,
> +                                    void *opaque, Error **errp)
> +{
> +    EMC141XState *s = EMC141X(obj);
> +    EMC141XClass *sc = EMC141X_GET_CLASS(s);
> +    int64_t temp;
> +    unsigned tempid;
> +
> +    if (!visit_type_int(v, name, &temp, errp)) {
> +        return;
> +    }
> +
> +    if (sscanf(name, "temperature%u", &tempid) != 1) {
> +        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
> +        return;
> +    }
> +
> +    if (tempid >= sc->sensors_count) {
> +        error_setg(errp, "error reading %s", name);
> +        return;
> +    }
> +
> +    s->sensor[tempid].raw_temp_current = temp / 1000;
> +}
> +
> +static void emc141x_read(EMC141XState *s)
> +{
> +    EMC141XClass *sc = EMC141X_GET_CLASS(s);
> +    switch (s->pointer) {
> +    case EMC141X_DEVICE_ID:
> +        s->data = sc->model;
> +        break;
> +    case EMC141X_MANUFACTURER_ID:
> +        s->data = MANUFACTURER_ID;
> +        break;
> +    case EMC141X_REVISION:
> +        s->data = REVISION;
> +        break;
> +    case EMC141X_TEMP_HIGH0:
> +        s->data = s->sensor[0].raw_temp_current;
> +        break;
> +    case EMC141X_TEMP_HIGH1:
> +        s->data = s->sensor[1].raw_temp_current;
> +        break;
> +    case EMC141X_TEMP_HIGH2:
> +        s->data = s->sensor[2].raw_temp_current;
> +        break;
> +    case EMC141X_TEMP_HIGH3:
> +        s->data = s->sensor[3].raw_temp_current;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH0:
> +        s->data = s->sensor[0].raw_temp_max;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH1:
> +        s->data = s->sensor[1].raw_temp_max;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH2:
> +        s->data = s->sensor[2].raw_temp_max;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH3:
> +        s->data = s->sensor[3].raw_temp_max;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH0:
> +        s->data = s->sensor[0].raw_temp_min;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH1:
> +        s->data = s->sensor[1].raw_temp_min;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH2:
> +        s->data = s->sensor[2].raw_temp_min;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH3:
> +        s->data = s->sensor[3].raw_temp_min;
> +        break;
> +    default:
> +        s->data = 0;
> +    }
> +}
> +
> +static void emc141x_write(EMC141XState *s)
> +{
> +    switch (s->pointer) {
> +    case EMC141X_TEMP_MAX_HIGH0:
> +        s->sensor[0].raw_temp_max = s->data;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH1:
> +        s->sensor[1].raw_temp_max = s->data;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH2:
> +        s->sensor[2].raw_temp_max = s->data;
> +        break;
> +    case EMC141X_TEMP_MAX_HIGH3:
> +        s->sensor[3].raw_temp_max = s->data;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH0:
> +        s->sensor[0].raw_temp_min = s->data;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH1:
> +        s->sensor[1].raw_temp_min = s->data;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH2:
> +        s->sensor[2].raw_temp_min = s->data;
> +        break;
> +    case EMC141X_TEMP_MIN_HIGH3:
> +        s->sensor[3].raw_temp_min = s->data;
> +        break;
> +    default:
> +        s->data = 0;
> +    }
> +}
> +
> +static uint8_t emc141x_rx(I2CSlave *i2c)
> +{
> +    EMC141XState *s = EMC141X(i2c);
> +
> +    if (s->len == 0) {
> +        s->len++;
> +        return s->data;
> +    } else {
> +        return 0xff;
> +    }
> +}
> +
> +static int emc141x_tx(I2CSlave *i2c, uint8_t data)
> +{
> +    EMC141XState *s = EMC141X(i2c);
> +
> +    if (s->len == 0) {
> +        /* first byte is the reg pointer */
> +        s->pointer = data;
> +        s->len++;
> +    } else if (s->len == 1) {
> +        s->data = data;
> +        emc141x_write(s);
> +    }
> +
> +    return 0;
> +}
> +
> +static int emc141x_event(I2CSlave *i2c, enum i2c_event event)
> +{
> +    EMC141XState *s = EMC141X(i2c);
> +
> +    if (event == I2C_START_RECV) {
> +        emc141x_read(s);
> +    }
> +
> +    s->len = 0;
> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_emc141x = {
> +    .name = "EMC141X",
> +    .version_id = 0,
> +    .minimum_version_id = 0,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT8(len, EMC141XState),
> +        VMSTATE_UINT8(data, EMC141XState),
> +        VMSTATE_UINT8(pointer, EMC141XState),
> +        VMSTATE_I2C_SLAVE(parent_obj, EMC141XState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static void emc141x_reset(DeviceState *dev)
> +{
> +    EMC141XState *s = EMC141X(dev);
> +    int i;
> +
> +    for (i = 0; i < SENSORS_COUNT_MAX; i++) {
> +        s->sensor[i].raw_temp_max = 0x55;
> +    }
> +    s->pointer = 0;
> +    s->len = 0;
> +}
> +
> +static void emc141x_initfn(Object *obj)
> +{
> +    object_property_add(obj, "temperature0", "int",
> +                        emc141x_get_temperature,
> +                        emc141x_set_temperature, NULL, NULL);
> +    object_property_add(obj, "temperature1", "int",
> +                        emc141x_get_temperature,
> +                        emc141x_set_temperature, NULL, NULL);
> +    object_property_add(obj, "temperature2", "int",
> +                        emc141x_get_temperature,
> +                        emc141x_set_temperature, NULL, NULL);
> +    object_property_add(obj, "temperature3", "int",
> +                        emc141x_get_temperature,
> +                        emc141x_set_temperature, NULL, NULL);
> +}
> +
> +static void emc141x_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
> +
> +    dc->reset = emc141x_reset;
> +    k->event = emc141x_event;
> +    k->recv = emc141x_rx;
> +    k->send = emc141x_tx;
> +    dc->vmsd = &vmstate_emc141x;
> +}
> +
> +static void emc1413_class_init(ObjectClass *klass, void *data)
> +{
> +    EMC141XClass *ec = EMC141X_CLASS(klass);
> +
> +    emc141x_class_init(klass, data);
> +    ec->model = EMC1413_DEVICE_ID;
> +    ec->sensors_count = 3;
> +}
> +
> +static void emc1414_class_init(ObjectClass *klass, void *data)
> +{
> +    EMC141XClass *ec = EMC141X_CLASS(klass);
> +
> +    emc141x_class_init(klass, data);
> +    ec->model = EMC1414_DEVICE_ID;
> +    ec->sensors_count = 4;
> +}
> +
> +static const TypeInfo emc141x_info = {
> +    .name          = TYPE_EMC141X,
> +    .parent        = TYPE_I2C_SLAVE,
> +    .instance_size = sizeof(EMC141XState),
> +    .class_size    = sizeof(EMC141XClass),
> +    .instance_init = emc141x_initfn,
> +    .abstract      = true,
> +};
> +
> +static const TypeInfo emc1413_info = {
> +    .name          = "emc1413",
> +    .parent        = TYPE_EMC141X,
> +    .class_init    = emc1413_class_init,
> +};
> +
> +static const TypeInfo emc1414_info = {
> +    .name          = "emc1414",
> +    .parent        = TYPE_EMC141X,
> +    .class_init    = emc1414_class_init,
> +};
> +
> +static void emc141x_register_types(void)
> +{
> +    type_register_static(&emc141x_info);
> +    type_register_static(&emc1413_info);
> +    type_register_static(&emc1414_info);
> +}
> +
> +type_init(emc141x_register_types)
> diff --git a/hw/misc/meson.build b/hw/misc/meson.build
> index 1cd48e8a0f..ce15ffceb9 100644
> --- a/hw/misc/meson.build
> +++ b/hw/misc/meson.build
> @@ -9,6 +9,7 @@ softmmu_ss.add(when: 'CONFIG_PCI_TESTDEV', if_true: files('pci-testdev.c'))
>  softmmu_ss.add(when: 'CONFIG_SGA', if_true: files('sga.c'))
>  softmmu_ss.add(when: 'CONFIG_TMP105', if_true: files('tmp105.c'))
>  softmmu_ss.add(when: 'CONFIG_TMP421', if_true: files('tmp421.c'))
> +softmmu_ss.add(when: 'CONFIG_EMC141X', if_true: files('emc141x.c'))
>  softmmu_ss.add(when: 'CONFIG_UNIMP', if_true: files('unimp.c'))
>  softmmu_ss.add(when: 'CONFIG_EMPTY_SLOT', if_true: files('empty_slot.c'))
>  softmmu_ss.add(when: 'CONFIG_LED', if_true: files('led.c'))
> diff --git a/include/hw/misc/emc141x_regs.h b/include/hw/misc/emc141x_regs.h
> new file mode 100644
> index 0000000000..0560fb7c5c
> --- /dev/null
> +++ b/include/hw/misc/emc141x_regs.h
> @@ -0,0 +1,37 @@
> +/*
> + * SMSC EMC141X temperature sensor.
> + *
> + * Browse the data sheet:
> + *
> + *    http://ww1.microchip.com/downloads/en/DeviceDoc/20005274A.pdf
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * later. See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef TMP105_REGS_H
> +#define TMP105_REGS_H
> +
> +#define EMC1413_DEVICE_ID                0x21
> +#define EMC1414_DEVICE_ID                0x25
> +#define MANUFACTURER_ID                  0x5d
> +#define REVISION                         0x04
> +
> +/* the EMC141X registers */
> +#define EMC141X_TEMP_HIGH0               0x00
> +#define EMC141X_TEMP_HIGH1               0x01
> +#define EMC141X_TEMP_HIGH2               0x23
> +#define EMC141X_TEMP_HIGH3               0x2a
> +#define EMC141X_TEMP_MAX_HIGH0           0x05
> +#define EMC141X_TEMP_MIN_HIGH0           0x06
> +#define EMC141X_TEMP_MAX_HIGH1           0x07
> +#define EMC141X_TEMP_MIN_HIGH1           0x08
> +#define EMC141X_TEMP_MAX_HIGH2           0x15
> +#define EMC141X_TEMP_MIN_HIGH2           0x16
> +#define EMC141X_TEMP_MAX_HIGH3           0x2c
> +#define EMC141X_TEMP_MIN_HIGH3           0x2d
> +#define EMC141X_DEVICE_ID                0xfd
> +#define EMC141X_MANUFACTURER_ID          0xfe
> +#define EMC141X_REVISION                 0xff
> +
> +#endif
> diff --git a/tests/qtest/emc141x-test.c b/tests/qtest/emc141x-test.c
> new file mode 100644
> index 0000000000..714058806a
> --- /dev/null
> +++ b/tests/qtest/emc141x-test.c
> @@ -0,0 +1,81 @@
> +/*
> + * QTest testcase for the EMC141X temperature sensor
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +
> +#include "libqtest-single.h"
> +#include "libqos/qgraph.h"
> +#include "libqos/i2c.h"
> +#include "qapi/qmp/qdict.h"
> +#include "hw/misc/emc141x_regs.h"
> +
> +#define EMC1414_TEST_ID   "emc1414-test"
> +
> +static int qmp_emc1414_get_temperature(const char *id)
> +{
> +    QDict *response;
> +    int ret;
> +
> +    response = qmp("{ 'execute': 'qom-get', 'arguments': { 'path': %s, "
> +                   "'property': 'temperature0' } }", id);
> +    g_assert(qdict_haskey(response, "return"));
> +    ret = qdict_get_int(response, "return");
> +    qobject_unref(response);
> +    return ret;
> +}
> +
> +static void qmp_emc1414_set_temperature(const char *id, int value)
> +{
> +    QDict *response;
> +
> +    response = qmp("{ 'execute': 'qom-set', 'arguments': { 'path': %s, "
> +                   "'property': 'temperature0', 'value': %d } }", id, value);
> +    g_assert(qdict_haskey(response, "return"));
> +    qobject_unref(response);
> +}
> +
> +static void send_and_receive(void *obj, void *data, QGuestAllocator *alloc)
> +{
> +    uint16_t value;
> +    QI2CDevice *i2cdev = (QI2CDevice *)obj;
> +
> +    value = qmp_emc1414_get_temperature(EMC1414_TEST_ID);
> +    g_assert_cmpuint(value, ==, 0);
> +
> +    value = i2c_get8(i2cdev, EMC141X_TEMP_HIGH0);
> +    g_assert_cmphex(value, ==, 0);
> +
> +    /* The default max value is 85C, 0x55=85 */
> +    value = i2c_get8(i2cdev, EMC141X_TEMP_MAX_HIGH0);
> +    g_assert_cmphex(value, ==, 0x55);
> +
> +    value = i2c_get8(i2cdev, EMC141X_TEMP_MIN_HIGH0);
> +    g_assert_cmphex(value, ==, 0);
> +
> +    /* 3000mc = 30C */
> +    qmp_emc1414_set_temperature(EMC1414_TEST_ID, 30000);
> +    value = qmp_emc1414_get_temperature(EMC1414_TEST_ID);
> +    g_assert_cmpuint(value, ==, 30000);
> +
> +    value = i2c_get8(i2cdev, EMC141X_TEMP_HIGH0);
> +    g_assert_cmphex(value, ==, 30);
> +
> +}
> +
> +static void emc1414_register_nodes(void)
> +{
> +    QOSGraphEdgeOptions opts = {
> +        .extra_device_opts = "id=" EMC1414_TEST_ID ",address=0x70"
> +    };
> +    add_qi2c_address(&opts, &(QI2CAddress) { 0x70 });
> +
> +    qos_node_create_driver("emc1414", i2c_device_create);
> +    qos_node_consumes("emc1414", "i2c-bus", &opts);
> +
> +    qos_add_test("tx-rx", "emc1414", send_and_receive, NULL);
> +}
> +libqos_init(emc1414_register_nodes);
> diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
> index c19f1c8503..d776befd6e 100644
> --- a/tests/qtest/meson.build
> +++ b/tests/qtest/meson.build
> @@ -188,6 +188,7 @@ qos_test_ss.add(
>    'sdhci-test.c',
>    'spapr-phb-test.c',
>    'tmp105-test.c',
> +  'emc141x-test.c',
>    'usb-hcd-ohci-test.c',
>    'virtio-test.c',
>    'virtio-blk-test.c',
>
diff mbox series

Patch

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index e69a9009cf..eb8a8844cf 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -407,6 +407,7 @@  config ASPEED_SOC
     select SSI_M25P80
     select TMP105
     select TMP421
+    select EMC141X
     select UNIMP
     select LED
 
diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
index dc44dc14f6..cf18ac08e6 100644
--- a/hw/misc/Kconfig
+++ b/hw/misc/Kconfig
@@ -13,6 +13,10 @@  config TMP421
     bool
     depends on I2C
 
+config EMC141X
+    bool
+    depends on I2C
+
 config ISA_DEBUG
     bool
     depends on ISA_BUS
diff --git a/hw/misc/emc141x.c b/hw/misc/emc141x.c
new file mode 100644
index 0000000000..f7c53d48a4
--- /dev/null
+++ b/hw/misc/emc141x.c
@@ -0,0 +1,326 @@ 
+/*
+ * SMSC EMC141X temperature sensor.
+ *
+ * Copyright (c) 2020 Bytedance Corporation
+ * Written by John Wang <wangzhiqiang.bj@bytedance.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/i2c/i2c.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "qemu/module.h"
+#include "qom/object.h"
+#include "hw/misc/emc141x_regs.h"
+
+#define SENSORS_COUNT_MAX    4
+
+struct EMC141XState {
+    I2CSlave parent_obj;
+    struct {
+        uint8_t raw_temp_min;
+        uint8_t raw_temp_current;
+        uint8_t raw_temp_max;
+    } sensor[SENSORS_COUNT_MAX];
+    uint8_t len;
+    uint8_t data;
+    uint8_t pointer;
+};
+
+struct EMC141XClass {
+    I2CSlaveClass parent_class;
+    uint8_t model;
+    unsigned sensors_count;
+};
+
+#define TYPE_EMC141X "emc141x"
+OBJECT_DECLARE_TYPE(EMC141XState, EMC141XClass, EMC141X)
+
+static void emc141x_get_temperature(Object *obj, Visitor *v, const char *name,
+                                    void *opaque, Error **errp)
+{
+    EMC141XState *s = EMC141X(obj);
+    EMC141XClass *sc = EMC141X_GET_CLASS(s);
+    int64_t value;
+    unsigned tempid;
+
+    if (sscanf(name, "temperature%u", &tempid) != 1) {
+        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
+        return;
+    }
+
+    if (tempid >= sc->sensors_count) {
+        error_setg(errp, "error reading %s", name);
+        return;
+    }
+
+    value = s->sensor[tempid].raw_temp_current * 1000;
+
+    visit_type_int(v, name, &value, errp);
+}
+
+static void emc141x_set_temperature(Object *obj, Visitor *v, const char *name,
+                                    void *opaque, Error **errp)
+{
+    EMC141XState *s = EMC141X(obj);
+    EMC141XClass *sc = EMC141X_GET_CLASS(s);
+    int64_t temp;
+    unsigned tempid;
+
+    if (!visit_type_int(v, name, &temp, errp)) {
+        return;
+    }
+
+    if (sscanf(name, "temperature%u", &tempid) != 1) {
+        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
+        return;
+    }
+
+    if (tempid >= sc->sensors_count) {
+        error_setg(errp, "error reading %s", name);
+        return;
+    }
+
+    s->sensor[tempid].raw_temp_current = temp / 1000;
+}
+
+static void emc141x_read(EMC141XState *s)
+{
+    EMC141XClass *sc = EMC141X_GET_CLASS(s);
+    switch (s->pointer) {
+    case EMC141X_DEVICE_ID:
+        s->data = sc->model;
+        break;
+    case EMC141X_MANUFACTURER_ID:
+        s->data = MANUFACTURER_ID;
+        break;
+    case EMC141X_REVISION:
+        s->data = REVISION;
+        break;
+    case EMC141X_TEMP_HIGH0:
+        s->data = s->sensor[0].raw_temp_current;
+        break;
+    case EMC141X_TEMP_HIGH1:
+        s->data = s->sensor[1].raw_temp_current;
+        break;
+    case EMC141X_TEMP_HIGH2:
+        s->data = s->sensor[2].raw_temp_current;
+        break;
+    case EMC141X_TEMP_HIGH3:
+        s->data = s->sensor[3].raw_temp_current;
+        break;
+    case EMC141X_TEMP_MAX_HIGH0:
+        s->data = s->sensor[0].raw_temp_max;
+        break;
+    case EMC141X_TEMP_MAX_HIGH1:
+        s->data = s->sensor[1].raw_temp_max;
+        break;
+    case EMC141X_TEMP_MAX_HIGH2:
+        s->data = s->sensor[2].raw_temp_max;
+        break;
+    case EMC141X_TEMP_MAX_HIGH3:
+        s->data = s->sensor[3].raw_temp_max;
+        break;
+    case EMC141X_TEMP_MIN_HIGH0:
+        s->data = s->sensor[0].raw_temp_min;
+        break;
+    case EMC141X_TEMP_MIN_HIGH1:
+        s->data = s->sensor[1].raw_temp_min;
+        break;
+    case EMC141X_TEMP_MIN_HIGH2:
+        s->data = s->sensor[2].raw_temp_min;
+        break;
+    case EMC141X_TEMP_MIN_HIGH3:
+        s->data = s->sensor[3].raw_temp_min;
+        break;
+    default:
+        s->data = 0;
+    }
+}
+
+static void emc141x_write(EMC141XState *s)
+{
+    switch (s->pointer) {
+    case EMC141X_TEMP_MAX_HIGH0:
+        s->sensor[0].raw_temp_max = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH1:
+        s->sensor[1].raw_temp_max = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH2:
+        s->sensor[2].raw_temp_max = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH3:
+        s->sensor[3].raw_temp_max = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH0:
+        s->sensor[0].raw_temp_min = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH1:
+        s->sensor[1].raw_temp_min = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH2:
+        s->sensor[2].raw_temp_min = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH3:
+        s->sensor[3].raw_temp_min = s->data;
+        break;
+    default:
+        s->data = 0;
+    }
+}
+
+static uint8_t emc141x_rx(I2CSlave *i2c)
+{
+    EMC141XState *s = EMC141X(i2c);
+
+    if (s->len == 0) {
+        s->len++;
+        return s->data;
+    } else {
+        return 0xff;
+    }
+}
+
+static int emc141x_tx(I2CSlave *i2c, uint8_t data)
+{
+    EMC141XState *s = EMC141X(i2c);
+
+    if (s->len == 0) {
+        /* first byte is the reg pointer */
+        s->pointer = data;
+        s->len++;
+    } else if (s->len == 1) {
+        s->data = data;
+        emc141x_write(s);
+    }
+
+    return 0;
+}
+
+static int emc141x_event(I2CSlave *i2c, enum i2c_event event)
+{
+    EMC141XState *s = EMC141X(i2c);
+
+    if (event == I2C_START_RECV) {
+        emc141x_read(s);
+    }
+
+    s->len = 0;
+    return 0;
+}
+
+static const VMStateDescription vmstate_emc141x = {
+    .name = "EMC141X",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(len, EMC141XState),
+        VMSTATE_UINT8(data, EMC141XState),
+        VMSTATE_UINT8(pointer, EMC141XState),
+        VMSTATE_I2C_SLAVE(parent_obj, EMC141XState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void emc141x_reset(DeviceState *dev)
+{
+    EMC141XState *s = EMC141X(dev);
+    int i;
+
+    for (i = 0; i < SENSORS_COUNT_MAX; i++) {
+        s->sensor[i].raw_temp_max = 0x55;
+    }
+    s->pointer = 0;
+    s->len = 0;
+}
+
+static void emc141x_initfn(Object *obj)
+{
+    object_property_add(obj, "temperature0", "int",
+                        emc141x_get_temperature,
+                        emc141x_set_temperature, NULL, NULL);
+    object_property_add(obj, "temperature1", "int",
+                        emc141x_get_temperature,
+                        emc141x_set_temperature, NULL, NULL);
+    object_property_add(obj, "temperature2", "int",
+                        emc141x_get_temperature,
+                        emc141x_set_temperature, NULL, NULL);
+    object_property_add(obj, "temperature3", "int",
+                        emc141x_get_temperature,
+                        emc141x_set_temperature, NULL, NULL);
+}
+
+static void emc141x_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
+
+    dc->reset = emc141x_reset;
+    k->event = emc141x_event;
+    k->recv = emc141x_rx;
+    k->send = emc141x_tx;
+    dc->vmsd = &vmstate_emc141x;
+}
+
+static void emc1413_class_init(ObjectClass *klass, void *data)
+{
+    EMC141XClass *ec = EMC141X_CLASS(klass);
+
+    emc141x_class_init(klass, data);
+    ec->model = EMC1413_DEVICE_ID;
+    ec->sensors_count = 3;
+}
+
+static void emc1414_class_init(ObjectClass *klass, void *data)
+{
+    EMC141XClass *ec = EMC141X_CLASS(klass);
+
+    emc141x_class_init(klass, data);
+    ec->model = EMC1414_DEVICE_ID;
+    ec->sensors_count = 4;
+}
+
+static const TypeInfo emc141x_info = {
+    .name          = TYPE_EMC141X,
+    .parent        = TYPE_I2C_SLAVE,
+    .instance_size = sizeof(EMC141XState),
+    .class_size    = sizeof(EMC141XClass),
+    .instance_init = emc141x_initfn,
+    .abstract      = true,
+};
+
+static const TypeInfo emc1413_info = {
+    .name          = "emc1413",
+    .parent        = TYPE_EMC141X,
+    .class_init    = emc1413_class_init,
+};
+
+static const TypeInfo emc1414_info = {
+    .name          = "emc1414",
+    .parent        = TYPE_EMC141X,
+    .class_init    = emc1414_class_init,
+};
+
+static void emc141x_register_types(void)
+{
+    type_register_static(&emc141x_info);
+    type_register_static(&emc1413_info);
+    type_register_static(&emc1414_info);
+}
+
+type_init(emc141x_register_types)
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index 1cd48e8a0f..ce15ffceb9 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -9,6 +9,7 @@  softmmu_ss.add(when: 'CONFIG_PCI_TESTDEV', if_true: files('pci-testdev.c'))
 softmmu_ss.add(when: 'CONFIG_SGA', if_true: files('sga.c'))
 softmmu_ss.add(when: 'CONFIG_TMP105', if_true: files('tmp105.c'))
 softmmu_ss.add(when: 'CONFIG_TMP421', if_true: files('tmp421.c'))
+softmmu_ss.add(when: 'CONFIG_EMC141X', if_true: files('emc141x.c'))
 softmmu_ss.add(when: 'CONFIG_UNIMP', if_true: files('unimp.c'))
 softmmu_ss.add(when: 'CONFIG_EMPTY_SLOT', if_true: files('empty_slot.c'))
 softmmu_ss.add(when: 'CONFIG_LED', if_true: files('led.c'))
diff --git a/include/hw/misc/emc141x_regs.h b/include/hw/misc/emc141x_regs.h
new file mode 100644
index 0000000000..0560fb7c5c
--- /dev/null
+++ b/include/hw/misc/emc141x_regs.h
@@ -0,0 +1,37 @@ 
+/*
+ * SMSC EMC141X temperature sensor.
+ *
+ * Browse the data sheet:
+ *
+ *    http://ww1.microchip.com/downloads/en/DeviceDoc/20005274A.pdf
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later. See the COPYING file in the top-level directory.
+ */
+
+#ifndef TMP105_REGS_H
+#define TMP105_REGS_H
+
+#define EMC1413_DEVICE_ID                0x21
+#define EMC1414_DEVICE_ID                0x25
+#define MANUFACTURER_ID                  0x5d
+#define REVISION                         0x04
+
+/* the EMC141X registers */
+#define EMC141X_TEMP_HIGH0               0x00
+#define EMC141X_TEMP_HIGH1               0x01
+#define EMC141X_TEMP_HIGH2               0x23
+#define EMC141X_TEMP_HIGH3               0x2a
+#define EMC141X_TEMP_MAX_HIGH0           0x05
+#define EMC141X_TEMP_MIN_HIGH0           0x06
+#define EMC141X_TEMP_MAX_HIGH1           0x07
+#define EMC141X_TEMP_MIN_HIGH1           0x08
+#define EMC141X_TEMP_MAX_HIGH2           0x15
+#define EMC141X_TEMP_MIN_HIGH2           0x16
+#define EMC141X_TEMP_MAX_HIGH3           0x2c
+#define EMC141X_TEMP_MIN_HIGH3           0x2d
+#define EMC141X_DEVICE_ID                0xfd
+#define EMC141X_MANUFACTURER_ID          0xfe
+#define EMC141X_REVISION                 0xff
+
+#endif
diff --git a/tests/qtest/emc141x-test.c b/tests/qtest/emc141x-test.c
new file mode 100644
index 0000000000..714058806a
--- /dev/null
+++ b/tests/qtest/emc141x-test.c
@@ -0,0 +1,81 @@ 
+/*
+ * QTest testcase for the EMC141X temperature sensor
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "libqtest-single.h"
+#include "libqos/qgraph.h"
+#include "libqos/i2c.h"
+#include "qapi/qmp/qdict.h"
+#include "hw/misc/emc141x_regs.h"
+
+#define EMC1414_TEST_ID   "emc1414-test"
+
+static int qmp_emc1414_get_temperature(const char *id)
+{
+    QDict *response;
+    int ret;
+
+    response = qmp("{ 'execute': 'qom-get', 'arguments': { 'path': %s, "
+                   "'property': 'temperature0' } }", id);
+    g_assert(qdict_haskey(response, "return"));
+    ret = qdict_get_int(response, "return");
+    qobject_unref(response);
+    return ret;
+}
+
+static void qmp_emc1414_set_temperature(const char *id, int value)
+{
+    QDict *response;
+
+    response = qmp("{ 'execute': 'qom-set', 'arguments': { 'path': %s, "
+                   "'property': 'temperature0', 'value': %d } }", id, value);
+    g_assert(qdict_haskey(response, "return"));
+    qobject_unref(response);
+}
+
+static void send_and_receive(void *obj, void *data, QGuestAllocator *alloc)
+{
+    uint16_t value;
+    QI2CDevice *i2cdev = (QI2CDevice *)obj;
+
+    value = qmp_emc1414_get_temperature(EMC1414_TEST_ID);
+    g_assert_cmpuint(value, ==, 0);
+
+    value = i2c_get8(i2cdev, EMC141X_TEMP_HIGH0);
+    g_assert_cmphex(value, ==, 0);
+
+    /* The default max value is 85C, 0x55=85 */
+    value = i2c_get8(i2cdev, EMC141X_TEMP_MAX_HIGH0);
+    g_assert_cmphex(value, ==, 0x55);
+
+    value = i2c_get8(i2cdev, EMC141X_TEMP_MIN_HIGH0);
+    g_assert_cmphex(value, ==, 0);
+
+    /* 3000mc = 30C */
+    qmp_emc1414_set_temperature(EMC1414_TEST_ID, 30000);
+    value = qmp_emc1414_get_temperature(EMC1414_TEST_ID);
+    g_assert_cmpuint(value, ==, 30000);
+
+    value = i2c_get8(i2cdev, EMC141X_TEMP_HIGH0);
+    g_assert_cmphex(value, ==, 30);
+
+}
+
+static void emc1414_register_nodes(void)
+{
+    QOSGraphEdgeOptions opts = {
+        .extra_device_opts = "id=" EMC1414_TEST_ID ",address=0x70"
+    };
+    add_qi2c_address(&opts, &(QI2CAddress) { 0x70 });
+
+    qos_node_create_driver("emc1414", i2c_device_create);
+    qos_node_consumes("emc1414", "i2c-bus", &opts);
+
+    qos_add_test("tx-rx", "emc1414", send_and_receive, NULL);
+}
+libqos_init(emc1414_register_nodes);
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index c19f1c8503..d776befd6e 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -188,6 +188,7 @@  qos_test_ss.add(
   'sdhci-test.c',
   'spapr-phb-test.c',
   'tmp105-test.c',
+  'emc141x-test.c',
   'usb-hcd-ohci-test.c',
   'virtio-test.c',
   'virtio-blk-test.c',