Re: [PATCH v2 1/2] hw/misc: add an EMC141{3,4} device model

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Hi John,

On 10/8/20 11:02 AM, John Wang wrote:
> Largely inspired by the TMP421 temperature sensor, here is a model for
> the EMC1413 temperature sensors.

"EMC1413/EMC1414" as you aim to model both.

> 
> Specs can be found here :
>    https://pdf1.alldatasheet.com/datasheet-pdf/view/533713/SMSC/EMC1413.html

Please update to:

Datasheet "Microchip EMC1413/EMC1414 DS20005274A" available here:
http://ww1.microchip.com/downloads/en/DeviceDoc/20005274A.pdf

> 
> Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
> ---
> v2:
>    - Remove DeviceInfo
>    - commit message: TMP423 -> TMP421
> ---
>   hw/arm/Kconfig      |   1 +
>   hw/misc/Kconfig     |   4 +
>   hw/misc/emc1413.c   | 305 ++++++++++++++++++++++++++++++++++++++++++++
>   hw/misc/meson.build |   1 +
>   4 files changed, 311 insertions(+)
>   create mode 100644 hw/misc/emc1413.c
> 
> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index f303c6bead..8801ada145 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -402,6 +402,7 @@ config ASPEED_SOC
>       select SSI_M25P80
>       select TMP105
>       select TMP421
> +    select EMC1413
>       select UNIMP
>   
>   config MPS2
> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index 3185456110..91badf2d4d 100644
> --- a/hw/misc/Kconfig
> +++ b/hw/misc/Kconfig
> @@ -13,6 +13,10 @@ config TMP421
>       bool
>       depends on I2C
>   
> +config EMC1413
> +    bool
> +    depends on I2C
> +
>   config ISA_DEBUG
>       bool
>       depends on ISA_BUS
> diff --git a/hw/misc/emc1413.c b/hw/misc/emc1413.c

Can you rename it emc141x.c please?

> new file mode 100644
> index 0000000000..160a59495a
> --- /dev/null
> +++ b/hw/misc/emc1413.c
> @@ -0,0 +1,305 @@
> +/*
> + * 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"
> +
> +#define DEVICE_ID_REG                    0xfd
> +#define MANUFACTURER_ID_REG              0xfe
> +#define REVISION_REG                     0xff

> +#define EMC1413_DEVICE_ID                0x21
> +#define EMC1414_DEVICE_ID                0x25
> +

Please add ...:

#define SENSORS_COUNT_MAX 4

> +struct EMC141XState {
> +    I2CSlave i2c;
> +    uint8_t temperature[4];
> +    uint8_t min[4];
> +    uint8_t max[4];

... and use it here (alternatively you can use the .heap).

> +    uint8_t len;
> +    uint8_t data;
> +    uint8_t pointer;
> +};
> +
> +struct EMC141XClass {
> +    I2CSlaveClass parent_class;
> +    uint8_t model;

Please add here ...:

        unsigned sensors_count;

... which is 1+2 for the EMC1413 and 1+3 for the EMC1414.

> +};
> +
> +#define TYPE_EMC141X "emc141x"
> +OBJECT_DECLARE_TYPE(EMC141XState, EMC141XClass, EMC141X)
> +
> +
> +/* 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
> +
> +static void emc141x_get_temperature(Object *obj, Visitor *v, const char *name,
> +                                   void *opaque, Error **errp)
> +{
> +    EMC141XState *s = EMC141X(obj);

        EMC141XClass *sc = ...

> +    int64_t value;
> +    int tempid;
> +
> +    if (sscanf(name, "temperature%d", &tempid) != 1) {
> +        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
> +        return;
> +    }
> +
> +    if (tempid >= 4 || tempid < 0) {

You have to check sc->sensors_count.

> +        error_setg(errp, "error reading %s", name);
> +        return;
> +    }
> +
> +    value = s->temperature[tempid] * 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);
> +    int64_t temp;
> +    int tempid;
> +
> +    if (!visit_type_int(v, name, &temp, errp)) {
> +        return;
> +    }
> +
> +    if (sscanf(name, "temperature%d", &tempid) != 1) {
> +        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
> +        return;
> +    }
> +
> +    if (tempid >= 4 || tempid < 0) {
> +        error_setg(errp, "error reading %s", name);
> +        return;
> +    }
> +
> +    s->temperature[tempid] = temp / 1000;
> +}
> +
> +struct emc141x_reg {
> +    uint8_t addr;
> +    uint8_t *data;
> +};
> +
> +static void emc141x_read(EMC141XState *s)
> +{
> +    EMC141XClass *sc = EMC141X_GET_CLASS(s);
> +    uint8_t smsc_manufacturer_id = 0x5d;
> +    uint8_t revision = 0x04;
> +    struct emc141x_reg emc141x_regs[] = {
> +        {DEVICE_ID_REG, &sc->model},
> +        {MANUFACTURER_ID_REG, &smsc_manufacturer_id},
> +        {REVISION_REG, &revision},
> +        {EMC141X_TEMP_HIGH0, &s->temperature[0]},
> +        {EMC141X_TEMP_HIGH1, &s->temperature[1]},
> +        {EMC141X_TEMP_HIGH2, &s->temperature[2]},
> +        {EMC141X_TEMP_HIGH3, &s->temperature[3]},
> +        {EMC141X_TEMP_MAX_HIGH0, &s->max[0]},
> +        {EMC141X_TEMP_MAX_HIGH1, &s->max[1]},
> +        {EMC141X_TEMP_MAX_HIGH2, &s->max[2]},
> +        {EMC141X_TEMP_MAX_HIGH3, &s->max[3]},
> +        {EMC141X_TEMP_MIN_HIGH0, &s->min[0]},
> +        {EMC141X_TEMP_MIN_HIGH1, &s->min[1]},
> +        {EMC141X_TEMP_MIN_HIGH2, &s->min[2]},
> +        {EMC141X_TEMP_MIN_HIGH3, &s->min[3]},
> +    };
> +    size_t i;
> +    for (i = 0; i < ARRAY_SIZE(emc141x_regs); i++) {
> +        if (emc141x_regs[i].addr == s->pointer) {
> +            s->data = *(emc141x_regs[i].data);

This function seems over complex... So bug prone.

tmp421_read() is easier to review.

> +            return;
> +        }
> +    }
> +}
> +
> +static void emc141x_write(EMC141XState *s)
> +{
> +    struct emc141x_reg emc141x_regs[] = {
> +        {EMC141X_TEMP_MAX_HIGH0, &s->max[0]},
> +        {EMC141X_TEMP_MAX_HIGH1, &s->max[1]},
> +        {EMC141X_TEMP_MAX_HIGH2, &s->max[2]},
> +        {EMC141X_TEMP_MAX_HIGH3, &s->max[3]},
> +        {EMC141X_TEMP_MIN_HIGH0, &s->min[0]},
> +        {EMC141X_TEMP_MIN_HIGH1, &s->min[1]},
> +        {EMC141X_TEMP_MIN_HIGH2, &s->min[2]},
> +        {EMC141X_TEMP_MIN_HIGH3, &s->min[3]},
> +    };
> +    size_t i;
> +    for (i = 0; i < ARRAY_SIZE(emc141x_regs); i++) {
> +        if (emc141x_regs[i].addr == s->pointer) {
> +            *(emc141x_regs[i].data) = s->data;

Ditto.

> +            return;
> +        }
> +    }
> +}
> +
> +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_UINT8_ARRAY(temperature, EMC141XState, 4),
> +        VMSTATE_UINT8_ARRAY(min, EMC141XState, 4),
> +        VMSTATE_UINT8_ARRAY(max, EMC141XState, 4),
> +        VMSTATE_I2C_SLAVE(i2c, EMC141XState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static void emc141x_reset(I2CSlave *i2c)
> +{
> +    EMC141XState *s = EMC141X(i2c);
> +
> +    memset(s->temperature, 0, sizeof(s->temperature));
> +    memset(s->min, 0, sizeof(s->min));
> +    memset(s->max, 0x55, sizeof(s->max));
> +    s->pointer = 0;
> +    s->len = 0;
> +}
> +
> +static void emc141x_realize(DeviceState *dev, Error **errp)
> +{
> +    EMC141XState *s = EMC141X(dev);
> +
> +    emc141x_reset(&s->i2c);
> +}
> +
> +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);
> +    EMC141XClass *sc = EMC141X_CLASS(klass);
> +
> +    dc->realize = emc141x_realize;

This handler does not realize anything, so please change
to dc->reset instead.

> +    k->event = emc141x_event;
> +    k->recv = emc141x_rx;
> +    k->send = emc141x_tx;
> +    dc->vmsd = &vmstate_emc141x;
> +    sc->model = (uintptr_t)data;
> +}
> +
> +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    = emc141x_class_init,

Please add emc1413_class_init() with

  ec->model = EMC1413_DEVICE_ID;
  ec->sensors_count = 3;


> +    .class_data    = (void *)EMC1413_DEVICE_ID,
> +};
> +
> +static const TypeInfo emc1414_info = {
> +    .name          = "emc1414",
> +    .parent        = TYPE_EMC141X,
> +    .class_init    = emc141x_class_init,

Please add emc1414_class_init():

  ec->model = EMC1414_DEVICE_ID;
  ec->sensors_count = 4;

> +    .class_data    = (void *)EMC1414_DEVICE_ID,
> +};
> +
> +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 793d45b1dc..08821c72ba 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_EMC1413', if_true: files('emc1413.c'))

I'd use CONFIG_EMC141X.

>   softmmu_ss.add(when: 'CONFIG_UNIMP', if_true: files('unimp.c'))
>   softmmu_ss.add(when: 'CONFIG_EMPTY_SLOT', if_true: files('empty_slot.c'))
>   
>