[PATCH v3 1/2] hw/misc: add an EMC141{3,4} device model

[John Wang]

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>
---
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   | 347 ++++++++++++++++++++++++++++++++++++++++++++
 hw/misc/meson.build |   1 +
 4 files changed, 353 insertions(+)
 create mode 100644 hw/misc/emc141x.c

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 7d040827af..3dd651a236 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -403,6 +403,7 @@ config ASPEED_SOC
     select SSI_M25P80
     select TMP105
     select TMP421
+    select EMC141X
     select UNIMP
 
 config MPS2
diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
index 3185456110..169d087d3d 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..a2bce74719
--- /dev/null
+++ b/hw/misc/emc141x.c
@@ -0,0 +1,347 @@
+/*
+ * 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 EMC1413_DEVICE_ID                0x21
+#define EMC1414_DEVICE_ID                0x25
+#define MANUFACTURER_ID                  0x5d
+#define REVISION                         0x04
+
+#define SENSORS_COUNT_MAX    4
+
+struct EMC141XState {
+    I2CSlave i2c;
+    uint8_t temperature[SENSORS_COUNT_MAX];
+    uint8_t min[SENSORS_COUNT_MAX];
+    uint8_t max[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)
+
+
+/* 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
+
+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;
+    int tempid;
+
+    if (sscanf(name, "temperature%d", &tempid) != 1) {
+        error_setg(errp, "error reading %s: %s", name, g_strerror(errno));
+        return;
+    }
+
+    if (tempid >= sc->sensors_count || tempid < 0) {
+        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);
+    EMC141XClass *sc = EMC141X_GET_CLASS(s);
+    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 >= sc->sensors_count || tempid < 0) {
+        error_setg(errp, "error reading %s", name);
+        return;
+    }
+
+    s->temperature[tempid] = 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->temperature[0];
+        break;
+    case EMC141X_TEMP_HIGH1:
+        s->data = s->temperature[1];
+        break;
+    case EMC141X_TEMP_HIGH2:
+        s->data = s->temperature[2];
+        break;
+    case EMC141X_TEMP_HIGH3:
+        s->data = s->temperature[3];
+        break;
+    case EMC141X_TEMP_MAX_HIGH0:
+        s->data = s->max[0];
+        break;
+    case EMC141X_TEMP_MAX_HIGH1:
+        s->data = s->max[1];
+        break;
+    case EMC141X_TEMP_MAX_HIGH2:
+        s->data = s->max[2];
+        break;
+    case EMC141X_TEMP_MAX_HIGH3:
+        s->data = s->max[3];
+        break;
+    case EMC141X_TEMP_MIN_HIGH0:
+        s->data = s->min[0];
+        break;
+    case EMC141X_TEMP_MIN_HIGH1:
+        s->data = s->min[1];
+        break;
+    case EMC141X_TEMP_MIN_HIGH2:
+        s->data = s->min[2];
+        break;
+    case EMC141X_TEMP_MIN_HIGH3:
+        s->data = s->min[3];
+        break;
+    default:
+        s->data = 0;
+    }
+}
+
+static void emc141x_write(EMC141XState *s)
+{
+    switch (s->pointer) {
+    case EMC141X_TEMP_MAX_HIGH0:
+        s->max[0] = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH1:
+        s->max[1] = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH2:
+        s->max[2] = s->data;
+        break;
+    case EMC141X_TEMP_MAX_HIGH3:
+        s->max[3] = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH0:
+        s->min[0] = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH1:
+        s->min[1] = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH2:
+        s->min[2] = s->data;
+        break;
+    case EMC141X_TEMP_MIN_HIGH3:
+        s->min[3] = 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_UINT8_ARRAY(temperature, EMC141XState, SENSORS_COUNT_MAX),
+        VMSTATE_UINT8_ARRAY(min, EMC141XState, SENSORS_COUNT_MAX),
+        VMSTATE_UINT8_ARRAY(max, EMC141XState, SENSORS_COUNT_MAX),
+        VMSTATE_I2C_SLAVE(i2c, EMC141XState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void emc141x_reset(DeviceState *dev)
+{
+    EMC141XState *s = EMC141X(dev);
+
+    memset(s->min, 0, sizeof(s->min));
+    memset(s->max, 0x55, sizeof(s->max));
+    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 793d45b1dc..b18693c9af 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'))
 
-- 
2.17.1