This commit adds emulation of the magnetometer on the LSM303DLHC.
It allows the magnetometer's X, Y and Z outputs to be set via the
mag_x, mag_y and mag_z properties, as well as the 12-bit
temperature output via the temperature property.
Signed-off-by: Kevin Townsend <kevin.towns...@linaro.org>
---
hw/sensor/Kconfig | 4 +
hw/sensor/lsm303dlhc_mag.c | 502 +++++++++++++++++++++++++++++++++++++
hw/sensor/meson.build | 1 +
3 files changed, 507 insertions(+)
create mode 100644 hw/sensor/lsm303dlhc_mag.c
diff --git a/hw/sensor/Kconfig b/hw/sensor/Kconfig
index a2b55a4fdb..f9d0177433 100644
--- a/hw/sensor/Kconfig
+++ b/hw/sensor/Kconfig
@@ -17,3 +17,7 @@ config ADM1272
config MAX34451
bool
depends on I2C
+
+config LSM303DLHC_MAG
+ bool
+ depends on I2C
\ No newline at end of file
diff --git a/hw/sensor/lsm303dlhc_mag.c b/hw/sensor/lsm303dlhc_mag.c
new file mode 100644
index 0000000000..009b6dae6b
--- /dev/null
+++ b/hw/sensor/lsm303dlhc_mag.c
@@ -0,0 +1,502 @@
+/*
+ * LSM303DLHC I2C magnetometer.
+ *
+ * Copyright (C) 2021 Linaro Ltd.
+ * Written by Kevin Townsend <kevin.towns...@linaro.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/*
+ * The I2C address associated with this device is set on the command-line when
+ * initialising the machine, but the following address is standard: 0x1E.
+ */
+
+#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 "qemu/log.h"
+#include "qemu/bswap.h"
+
+/* Property Names */
+#define LSM303DLHC_MSG_PROP_MAGX ("mag_x")
+#define LSM303DLHC_MSG_PROP_MAGY ("mag_y")
+#define LSM303DLHC_MSG_PROP_MAGZ ("mag_z")
+#define LSM303DLHC_MSG_PROP_TEMP ("temperature")
+
+enum LSM303DLHC_Mag_Reg {
+ LSM303DLHC_MAG_REG_CRA = 0x00,
+ LSM303DLHC_MAG_REG_CRB = 0x01,
+ LSM303DLHC_MAG_REG_MR = 0x02,
+ LSM303DLHC_MAG_REG_OUT_X_H = 0x03,
+ LSM303DLHC_MAG_REG_OUT_X_L = 0x04,
+ LSM303DLHC_MAG_REG_OUT_Z_H = 0x05,
+ LSM303DLHC_MAG_REG_OUT_Z_L = 0x06,
+ LSM303DLHC_MAG_REG_OUT_Y_H = 0x07,
+ LSM303DLHC_MAG_REG_OUT_Y_L = 0x08,
+ LSM303DLHC_MAG_REG_SR = 0x09,
+ LSM303DLHC_MAG_REG_IRA = 0x0A,
+ LSM303DLHC_MAG_REG_IRB = 0x0B,
+ LSM303DLHC_MAG_REG_IRC = 0x0C,
+ LSM303DLHC_MAG_REG_TEMP_OUT_H = 0x31,
+ LSM303DLHC_MAG_REG_TEMP_OUT_L = 0x32
+};
+
+typedef struct LSM303DLHC_Mag_State {
+ I2CSlave parent_obj;
+
+ uint8_t cra;
+ uint8_t crb;
+ uint8_t mr;
+
+ /**
+ * @brief X-axis register value in LSB. Exact relationship to gauss
+ * varies depending on the current gain settings.
+ */
+ int16_t x;
+
+ /**
+ * @brief Z-axis register value in LSB. Exact relationship to gauss
+ * varies depending on the current gain settings.
+ */
+ int16_t z;
+
+ /**
+ * @brief Y-axis register value in LSB. Exact relationship to gauss
+ * varies depending on the current gain settings.
+ */
+ int16_t y;
+
+ uint8_t sr;
+ uint8_t ira;
+ uint8_t irb;
+ uint8_t irc;
+
+ /**
+ * @brief Temperature in LSB where 1 degree C = 8 lsb.
+ */
+ int16_t temperature;
+
+ uint8_t len;
+ uint8_t buf[6];
+ uint8_t pointer;
+} LSM303DLHC_Mag_State;
+
+#define TYPE_LSM303DLHC_MAG "lsm303dlhc_mag"
+OBJECT_DECLARE_SIMPLE_TYPE(LSM303DLHC_Mag_State, LSM303DLHC_MAG)
+
+/**
+ * @brief Get handler for the mag_* property. This will be called
+ * whenever the public 'mag_*' property is read, such as via
+ * qom-get in the QEMU monitor.
+ */
+static void lsm303dlhc_mag_get_xyz(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(obj);
+ int64_t value;
+
+ if (strcmp(name, LSM303DLHC_MSG_PROP_MAGX) == 0) {
+ value = s->x;
+ } else if (strcmp(name, LSM303DLHC_MSG_PROP_MAGY) == 0) {
+ value = s->y;
+ } else if (strcmp(name, LSM303DLHC_MSG_PROP_MAGZ) == 0) {
+ value = s->z;
+ } else {
+ error_setg(errp, "unknown property: %s", name);
+ return;
+ }
+
+ visit_type_int(v, name, &value, errp);
+}
+
+/**
+ * @brief Set handler for the mag_* property. This will be called
+ * whenever the public 'mag_*' property is set, such as via
+ * qom-set in the QEMU monitor.
+ */
+static void lsm303dlhc_mag_set_xyz(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(obj);
+ int64_t value;
+
+ if (!visit_type_int(v, name, &value, errp)) {
+ return;
+ }
+
+ if (value > 2047 || value < -2048) {
+ error_setg(errp, "value %d lsb is out of range", value);
+ return;
+ }
+
+ if (strcmp(name, LSM303DLHC_MSG_PROP_MAGX) == 0) {
+ s->x = (int16_t)value;
+ } else if (strcmp(name, LSM303DLHC_MSG_PROP_MAGY) == 0) {
+ s->y = (int16_t)value;
+ } else if (strcmp(name, LSM303DLHC_MSG_PROP_MAGZ) == 0) {
+ s->z = (int16_t)value;
+ } else {
+ error_setg(errp, "unknown property: %s", name);
+ return;
+ }
+}
+
+/**
+ * @brief Get handler for the temperature property. This will be called
+ * whenever the public 'temperature' property is read, such as via
+ * qom-get in the QEMU monitor.
+ */
+static void lsm303dlhc_mag_get_temperature(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(obj);
+ int64_t value;
+
+ value = s->temperature;
+
+ visit_type_int(v, name, &value, errp);
+}
+
+/**
+ * @brief Set handler for the temperature property. This will be called
+ * whenever the public 'temperature' property is set, such as via
+ * qom-set in the QEMU monitor.
+ */
+static void lsm303dlhc_mag_set_temperature(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(obj);
+ int64_t value;
+
+ if (!visit_type_int(v, name, &value, errp)) {
+ return;
+ }
+
+ if (value > 2047 || value < -2048) {
+ error_setg(errp, "value %d lsb is out of range", value);
+ return;
+ }
+
+ s->temperature = (int16_t)value;
+}
+
+/**
+ * @brief Callback handler whenever a 'I2C_START_RECV' (read) event is
received.
+ */
+static void lsm303dlhc_mag_read(LSM303DLHC_Mag_State *s)
+{
+ s->len = 0;
+
+ /*
+ * The address pointer on the LSM303DLHC auto-increments whenever a byte
+ * is read, without the master device having to request the next address.
+ *
+ * The auto-increment process has the following logic:
+ *
+ * - if (s->pointer == 8) then s->pointer = 3
+ * - else: if (s->pointer >= 12) then s->pointer = 0
+ * - else: s->pointer += 1
+ *
+ * Reading an invalid address return 0.
+ *
+ * The auto-increment logic is only taken into account in this driver
+ * for the LSM303DLHC_MAG_REG_OUT_X_H and LSM303DLHC_MAG_REG_TEMP_OUT_H
+ * registers, which are the two common uses cases for it. Accessing either
+ * of these registers will also populate the rest of the related dataset.
+ */
+
+ switch (s->pointer) {
+ case LSM303DLHC_MAG_REG_CRA:
+ s->buf[s->len++] = s->cra;
+ break;
+ case LSM303DLHC_MAG_REG_CRB:
+ s->buf[s->len++] = s->crb;
+ break;
+ case LSM303DLHC_MAG_REG_MR:
+ s->buf[s->len++] = s->mr;
+ break;
+ case LSM303DLHC_MAG_REG_OUT_X_H:
+ stw_be_p(s->buf, s->x);
+ s->len += sizeof(s->x);
+ stw_be_p(s->buf + 2, s->z);
+ s->len += sizeof(s->z);
+ stw_be_p(s->buf + 4, s->y);
+ s->len += sizeof(s->y);
+ break;
+ case LSM303DLHC_MAG_REG_OUT_X_L:
+ s->buf[s->len++] = (uint8_t)(s->x);
+ break;
+ case LSM303DLHC_MAG_REG_OUT_Z_H:
+ s->buf[s->len++] = (uint8_t)(s->z >> 8);
+ break;
+ case LSM303DLHC_MAG_REG_OUT_Z_L:
+ s->buf[s->len++] = (uint8_t)(s->z);
+ break;
+ case LSM303DLHC_MAG_REG_OUT_Y_H:
+ s->buf[s->len++] = (uint8_t)(s->y >> 8);
+ break;
+ case LSM303DLHC_MAG_REG_OUT_Y_L:
+ s->buf[s->len++] = (uint8_t)(s->y);
+ break;
+ case LSM303DLHC_MAG_REG_SR:
+ s->buf[s->len++] = s->sr;
+ break;
+ case LSM303DLHC_MAG_REG_IRA:
+ s->buf[s->len++] = s->ira;
+ break;
+ case LSM303DLHC_MAG_REG_IRB:
+ s->buf[s->len++] = s->irb;
+ break;
+ case LSM303DLHC_MAG_REG_IRC:
+ s->buf[s->len++] = s->irc;
+ break;
+ case LSM303DLHC_MAG_REG_TEMP_OUT_H:
+ /* Check if the temperature sensor is enabled of not (CRA & 0x80). */
+ if (s->cra & 0x80) {
+ s->buf[s->len++] = (uint8_t)(s->temperature >> 8);
+ s->buf[s->len++] = (uint8_t)(s->temperature & 0xf0);
+ } else {
+ s->buf[s->len++] = 0;
+ s->buf[s->len++] = 0;
+ }
+ break;
+ case LSM303DLHC_MAG_REG_TEMP_OUT_L:
+ if (s->cra & 0x80) {
+ s->buf[s->len++] = (uint8_t)(s->temperature & 0xf0);
+ } else {
+ s->buf[s->len++] = 0;
+ }
+ break;
+ default:
+ s->buf[s->len++] = 0;
+ break;
+ }
+}
+
+/**
+ * @brief Callback handler when a device attempts to write to a register.
+ */
+static void lsm303dlhc_mag_write(LSM303DLHC_Mag_State *s)
+{
+ switch (s->pointer) {
+ case LSM303DLHC_MAG_REG_CRA:
+ s->cra = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_CRB:
+ s->crb = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_MR:
+ s->mr = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_SR:
+ s->sr = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_IRA:
+ s->ira = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_IRB:
+ s->irb = s->buf[0];
+ break;
+ case LSM303DLHC_MAG_REG_IRC:
+ s->irc = s->buf[0];
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "reg is read-only: 0x%02X", s->buf[0]);
+ break;
+ }
+}
+
+/**
+ * @brief Low-level slave-to-master transaction handler.
+ */
+static uint8_t lsm303dlhc_mag_recv(I2CSlave *i2c)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(i2c);
+
+ if (s->len < 6) {
+ return s->buf[s->len++];
+ } else {
+ return 0xff;
+ }
+}
+
+/**
+ * @brief Low-level master-to-slave transaction handler.
+ */
+static int lsm303dlhc_mag_send(I2CSlave *i2c, uint8_t data)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(i2c);
+
+ if (s->len == 0) {
+ /* First byte is the reg pointer */
+ s->pointer = data;
+ s->len++;
+ } else if (s->len == 1) {
+ /* Second byte is the new register value. */
+ s->buf[0] = data;
+ lsm303dlhc_mag_write(s);
+ } else {
+ g_assert_not_reached();
+ }
+
+ return 0;
+}
+
+/**
+ * @brief Bus state change handler.
+ */
+static int lsm303dlhc_mag_event(I2CSlave *i2c, enum i2c_event event)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(i2c);
+
+ switch (event) {
+ case I2C_START_SEND:
+ break;
+ case I2C_START_RECV:
+ lsm303dlhc_mag_read(s);
+ break;
+ case I2C_FINISH:
+ break;
+ case I2C_NACK:
+ break;
+ }
+
+ s->len = 0;
+ return 0;
+}
+
+/**
+ * @brief Device data description using VMSTATE macros.
+ */
+static const VMStateDescription vmstate_lsm303dlhc_mag = {
+ .name = "LSM303DLHC_MAG",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+
+ VMSTATE_I2C_SLAVE(parent_obj, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(len, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8_ARRAY(buf, LSM303DLHC_Mag_State, 6),
+ VMSTATE_UINT8(pointer, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(cra, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(crb, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(mr, LSM303DLHC_Mag_State),
+ VMSTATE_INT16(x, LSM303DLHC_Mag_State),
+ VMSTATE_INT16(z, LSM303DLHC_Mag_State),
+ VMSTATE_INT16(y, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(sr, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(ira, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(irb, LSM303DLHC_Mag_State),
+ VMSTATE_UINT8(irc, LSM303DLHC_Mag_State),
+ VMSTATE_INT16(temperature, LSM303DLHC_Mag_State),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+/**
+ * @brief Put the device into post-reset default state.
+ */
+static void lsm303dlhc_mag_default_cfg(I2CSlave *i2c)
+{
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(i2c);
+
+ /* Set the device into is default reset state. */
+ s->len = 0;
+ s->pointer = 0; /* Current register. */
+ memset(s->buf, 0, sizeof(s->buf));
+ s->cra = 0x08; /* Temp Enabled = 0, Data Rate = 3.0 Hz. */
+ s->crb = 0x20; /* Gain = +/- 1.3 Guas. */
+ s->mr = 0x1; /* Operating Mode = Single conversion. */
+ s->x = 0;
+ s->z = 0;
+ s->y = 0;
+ s->sr = 0x1; /* DRDY = 1. */
+ s->ira = 0x48;
+ s->irb = 0x34;
+ s->irc = 0x33;
+ s->temperature = 0; /* Default to 0 degrees C (0/8 lsb = 0 C). */
+}
+
+/**
+ * @brief Callback handler when DeviceState 'reset' is set to true.
+ */
+static void lsm303dlhc_mag_reset(DeviceState *dev)
+{
+ I2CSlave *i2c = I2C_SLAVE(dev);
+ LSM303DLHC_Mag_State *s = LSM303DLHC_MAG(i2c);
+
+ /* Set the device into is default reset state. */
+ lsm303dlhc_mag_default_cfg(&s->parent_obj);
+}
+
+/**
+ * @brief Initialisation of any public properties.
+ *
+ * @note Properties are an object's external interface, and are set before the
+ * object is started. The 'temperature' property here enables the
+ * temperature registers to be set by the host OS, for example, or via
+ * the QEMU monitor interface using commands like 'qom-set' and
'qom-get'.
+ */
+static void lsm303dlhc_mag_initfn(Object *obj)
+{
+ object_property_add(obj, LSM303DLHC_MSG_PROP_MAGX, "int",
+ lsm303dlhc_mag_get_xyz,
+ lsm303dlhc_mag_set_xyz, NULL, NULL);
+
+ object_property_add(obj, LSM303DLHC_MSG_PROP_MAGY, "int",
+ lsm303dlhc_mag_get_xyz,
+ lsm303dlhc_mag_set_xyz, NULL, NULL);
+
+ object_property_add(obj, LSM303DLHC_MSG_PROP_MAGZ, "int",
+ lsm303dlhc_mag_get_xyz,
+ lsm303dlhc_mag_set_xyz, NULL, NULL);
+
+ object_property_add(obj, LSM303DLHC_MSG_PROP_TEMP, "int",
+ lsm303dlhc_mag_get_temperature,
+ lsm303dlhc_mag_set_temperature, NULL, NULL);
+}
+
+/**
+ * @brief Set the virtual method pointers (bus state change, tx/rx, etc.).
+ */
+static void lsm303dlhc_mag_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
+
+ /* DeviceState 'reset' handler. */
+ dc->reset = lsm303dlhc_mag_reset;
+
+ /* VM State description (device data). */
+ dc->vmsd = &vmstate_lsm303dlhc_mag;
+
+ /* Bus state change handler. */
+ k->event = lsm303dlhc_mag_event;
+
+ /* Slave to master handler. */
+ k->recv = lsm303dlhc_mag_recv;
+
+ /* Master to slave handler. */
+ k->send = lsm303dlhc_mag_send;
+}
+
+static const TypeInfo lsm303dlhc_mag_info = {
+ .name = TYPE_LSM303DLHC_MAG,
+ .parent = TYPE_I2C_SLAVE,
+ .instance_size = sizeof(LSM303DLHC_Mag_State),
+ .instance_init = lsm303dlhc_mag_initfn,
+ .class_init = lsm303dlhc_mag_class_init,
+};
+
+static void lsm303dlhc_mag_register_types(void)
+{
+ type_register_static(&lsm303dlhc_mag_info);
+}
+
+type_init(lsm303dlhc_mag_register_types)
diff --git a/hw/sensor/meson.build b/hw/sensor/meson.build
index 034e3e0207..95406abd24 100644
--- a/hw/sensor/meson.build
+++ b/hw/sensor/meson.build
@@ -3,3 +3,4 @@ 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_ADM1272', if_true: files('adm1272.c'))
softmmu_ss.add(when: 'CONFIG_MAX34451', if_true: files('max34451.c'))
+softmmu_ss.add(when: 'CONFIG_LSM303DLHC_MAG', if_true:
files('lsm303dlhc_mag.c'))
--
2.30.1 (Apple Git-130)
