OpenE2K
/
qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity
qemu-e2k/hw/sensor/lsm303dlhc_mag.c

557 lines
15 KiB
C
Raw Normal View History

hw/sensor: Add lsm303dlhc magnetometer device 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. Sensor can be enabled with 'CONFIG_LSM303DLHC_MAG=y'. Signed-off-by: Kevin Townsend <kevin.townsend@linaro.org> Message-id: 20220130095032.35392-1-kevin.townsend@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-01-30 10:50:32 +01:00
/*
* LSM303DLHC I2C magnetometer.
*
* Copyright (C) 2021 Linaro Ltd.
* Written by Kevin Townsend <kevin.townsend@linaro.org>
*
* Based on: https://www.st.com/resource/en/datasheet/lsm303dlhc.pdf
*
* 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.
*
* Get and set functions for 'mag-x', 'mag-y' and 'mag-z' assume that
* 1 = 0.001 uT. (NOTE the 1 gauss = 100 uT, so setting a value of 100,000
* would be equal to 1 gauss or 100 uT.)
*
* Get and set functions for 'temperature' assume that 1 = 0.001 C, so 23.6 C
* would be equal to 23600.
*/
#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"
enum LSM303DLHCMagReg {
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 LSM303DLHCMagState {
I2CSlave parent_obj;
uint8_t cra;
uint8_t crb;
uint8_t mr;
int16_t x;
int16_t z;
int16_t y;
int16_t x_lock;
int16_t z_lock;
int16_t y_lock;
uint8_t sr;
uint8_t ira;
uint8_t irb;
uint8_t irc;
int16_t temperature;
int16_t temperature_lock;
uint8_t len;
uint8_t buf;
uint8_t pointer;
} LSM303DLHCMagState;
#define TYPE_LSM303DLHC_MAG "lsm303dlhc_mag"
OBJECT_DECLARE_SIMPLE_TYPE(LSM303DLHCMagState, LSM303DLHC_MAG)
/*
* Conversion factor from Gauss to sensor values for each GN gain setting,
* in units "lsb per Gauss" (see data sheet table 3). There is no documented
* behaviour if the GN setting in CRB is incorrectly set to 0b000;
* we arbitrarily make it the same as 0b001.
*/
uint32_t xy_gain[] = { 1100, 1100, 855, 670, 450, 400, 330, 230 };
uint32_t z_gain[] = { 980, 980, 760, 600, 400, 355, 295, 205 };
static void lsm303dlhc_mag_get_x(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int gm = extract32(s->crb, 5, 3);
/* Convert to uT where 1000 = 1 uT. Conversion factor depends on gain. */
int64_t value = muldiv64(s->x, 100000, xy_gain[gm]);
visit_type_int(v, name, &value, errp);
}
static void lsm303dlhc_mag_get_y(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int gm = extract32(s->crb, 5, 3);
/* Convert to uT where 1000 = 1 uT. Conversion factor depends on gain. */
int64_t value = muldiv64(s->y, 100000, xy_gain[gm]);
visit_type_int(v, name, &value, errp);
}
static void lsm303dlhc_mag_get_z(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int gm = extract32(s->crb, 5, 3);
/* Convert to uT where 1000 = 1 uT. Conversion factor depends on gain. */
int64_t value = muldiv64(s->z, 100000, z_gain[gm]);
visit_type_int(v, name, &value, errp);
}
static void lsm303dlhc_mag_set_x(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int64_t value;
int64_t reg;
int gm = extract32(s->crb, 5, 3);
if (!visit_type_int(v, name, &value, errp)) {
return;
}
reg = muldiv64(value, xy_gain[gm], 100000);
/* Make sure we are within a 12-bit limit. */
if (reg > 2047 || reg < -2048) {
error_setg(errp, "value %" PRId64 " out of register's range", value);
return;
}
s->x = (int16_t)reg;
}
static void lsm303dlhc_mag_set_y(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int64_t value;
int64_t reg;
int gm = extract32(s->crb, 5, 3);
if (!visit_type_int(v, name, &value, errp)) {
return;
}
reg = muldiv64(value, xy_gain[gm], 100000);
/* Make sure we are within a 12-bit limit. */
if (reg > 2047 || reg < -2048) {
error_setg(errp, "value %" PRId64 " out of register's range", value);
return;
}
s->y = (int16_t)reg;
}
static void lsm303dlhc_mag_set_z(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int64_t value;
int64_t reg;
int gm = extract32(s->crb, 5, 3);
if (!visit_type_int(v, name, &value, errp)) {
return;
}
reg = muldiv64(value, z_gain[gm], 100000);
/* Make sure we are within a 12-bit limit. */
if (reg > 2047 || reg < -2048) {
error_setg(errp, "value %" PRId64 " out of register's range", value);
return;
}
s->z = (int16_t)reg;
}
/*
* Get handler for the temperature property.
*/
static void lsm303dlhc_mag_get_temperature(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int64_t value;
/* Convert to 1 lsb = 0.125 C to 1 = 0.001 C for 'temperature' property. */
value = s->temperature * 125;
visit_type_int(v, name, &value, errp);
}
/*
* Set handler for the temperature property.
*/
static void lsm303dlhc_mag_set_temperature(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(obj);
int64_t value;
if (!visit_type_int(v, name, &value, errp)) {
return;
}
/* Input temperature is in 0.001 C units. Convert to 1 lsb = 0.125 C. */
value /= 125;
if (value > 2047 || value < -2048) {
error_setg(errp, "value %" PRId64 " lsb is out of range", value);
return;
}
s->temperature = (int16_t)value;
}
/*
* Callback handler whenever a 'I2C_START_RECV' (read) event is received.
*/
static void lsm303dlhc_mag_read(LSM303DLHCMagState *s)
{
/*
* Set the LOCK bit whenever a new read attempt is made. This will be
* cleared in I2C_FINISH. Note that DRDY is always set to 1 in this driver.
*/
s->sr = 0x3;
/*
* Copy the current X/Y/Z and temp. values into the locked registers so
* that 'mag-x', 'mag-y', 'mag-z' and 'temperature' can continue to be
* updated via QOM, etc., without corrupting the current read event.
*/
s->x_lock = s->x;
s->z_lock = s->z;
s->y_lock = s->y;
s->temperature_lock = s->temperature;
}
/*
* Callback handler whenever a 'I2C_FINISH' event is received.
*/
static void lsm303dlhc_mag_finish(LSM303DLHCMagState *s)
{
/*
* Clear the LOCK bit when the read attempt terminates.
* This bit is initially set in the I2C_START_RECV handler.
*/
s->sr = 0x1;
}
/*
* Callback handler when a device attempts to write to a register.
*/
static void lsm303dlhc_mag_write(LSM303DLHCMagState *s)
{
switch (s->pointer) {
case LSM303DLHC_MAG_REG_CRA:
s->cra = s->buf;
break;
case LSM303DLHC_MAG_REG_CRB:
/* Make sure gain is at least 1, falling back to 1 on an error. */
if (s->buf >> 5 == 0) {
s->buf = 1 << 5;
}
s->crb = s->buf;
break;
case LSM303DLHC_MAG_REG_MR:
s->mr = s->buf;
break;
case LSM303DLHC_MAG_REG_SR:
s->sr = s->buf;
break;
case LSM303DLHC_MAG_REG_IRA:
s->ira = s->buf;
break;
case LSM303DLHC_MAG_REG_IRB:
s->irb = s->buf;
break;
case LSM303DLHC_MAG_REG_IRC:
s->irc = s->buf;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "reg is read-only: 0x%02X", s->buf);
break;
}
}
/*
* Low-level master-to-slave transaction handler.
*/
static int lsm303dlhc_mag_send(I2CSlave *i2c, uint8_t data)
{
LSM303DLHCMagState *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 = data;
lsm303dlhc_mag_write(s);
} else {
g_assert_not_reached();
}
return 0;
}
/*
* Low-level slave-to-master transaction handler (read attempts).
*/
static uint8_t lsm303dlhc_mag_recv(I2CSlave *i2c)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(i2c);
uint8_t resp;
switch (s->pointer) {
case LSM303DLHC_MAG_REG_CRA:
resp = s->cra;
break;
case LSM303DLHC_MAG_REG_CRB:
resp = s->crb;
break;
case LSM303DLHC_MAG_REG_MR:
resp = s->mr;
break;
case LSM303DLHC_MAG_REG_OUT_X_H:
resp = (uint8_t)(s->x_lock >> 8);
break;
case LSM303DLHC_MAG_REG_OUT_X_L:
resp = (uint8_t)(s->x_lock);
break;
case LSM303DLHC_MAG_REG_OUT_Z_H:
resp = (uint8_t)(s->z_lock >> 8);
break;
case LSM303DLHC_MAG_REG_OUT_Z_L:
resp = (uint8_t)(s->z_lock);
break;
case LSM303DLHC_MAG_REG_OUT_Y_H:
resp = (uint8_t)(s->y_lock >> 8);
break;
case LSM303DLHC_MAG_REG_OUT_Y_L:
resp = (uint8_t)(s->y_lock);
break;
case LSM303DLHC_MAG_REG_SR:
resp = s->sr;
break;
case LSM303DLHC_MAG_REG_IRA:
resp = s->ira;
break;
case LSM303DLHC_MAG_REG_IRB:
resp = s->irb;
break;
case LSM303DLHC_MAG_REG_IRC:
resp = s->irc;
break;
case LSM303DLHC_MAG_REG_TEMP_OUT_H:
/* Check if the temperature sensor is enabled or not (CRA & 0x80). */
if (s->cra & 0x80) {
resp = (uint8_t)(s->temperature_lock >> 8);
} else {
resp = 0;
}
break;
case LSM303DLHC_MAG_REG_TEMP_OUT_L:
if (s->cra & 0x80) {
resp = (uint8_t)(s->temperature_lock & 0xff);
} else {
resp = 0;
}
break;
default:
resp = 0;
break;
}
/*
* 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.
*/
if (s->pointer == LSM303DLHC_MAG_REG_OUT_Y_L) {
s->pointer = LSM303DLHC_MAG_REG_OUT_X_H;
} else if (s->pointer == LSM303DLHC_MAG_REG_IRC) {
s->pointer = LSM303DLHC_MAG_REG_CRA;
} else {
s->pointer++;
}
return resp;
}
/*
* Bus state change handler.
*/
static int lsm303dlhc_mag_event(I2CSlave *i2c, enum i2c_event event)
{
LSM303DLHCMagState *s = LSM303DLHC_MAG(i2c);
switch (event) {
case I2C_START_SEND:
break;
case I2C_START_RECV:
lsm303dlhc_mag_read(s);
break;
case I2C_FINISH:
lsm303dlhc_mag_finish(s);
break;
case I2C_NACK:
break;
}
s->len = 0;
return 0;
}
/*
* 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, LSM303DLHCMagState),
VMSTATE_UINT8(len, LSM303DLHCMagState),
VMSTATE_UINT8(buf, LSM303DLHCMagState),
VMSTATE_UINT8(pointer, LSM303DLHCMagState),
VMSTATE_UINT8(cra, LSM303DLHCMagState),
VMSTATE_UINT8(crb, LSM303DLHCMagState),
VMSTATE_UINT8(mr, LSM303DLHCMagState),
VMSTATE_INT16(x, LSM303DLHCMagState),
VMSTATE_INT16(z, LSM303DLHCMagState),
VMSTATE_INT16(y, LSM303DLHCMagState),
VMSTATE_INT16(x_lock, LSM303DLHCMagState),
VMSTATE_INT16(z_lock, LSM303DLHCMagState),
VMSTATE_INT16(y_lock, LSM303DLHCMagState),
VMSTATE_UINT8(sr, LSM303DLHCMagState),
VMSTATE_UINT8(ira, LSM303DLHCMagState),
VMSTATE_UINT8(irb, LSM303DLHCMagState),
VMSTATE_UINT8(irc, LSM303DLHCMagState),
VMSTATE_INT16(temperature, LSM303DLHCMagState),
VMSTATE_INT16(temperature_lock, LSM303DLHCMagState),
VMSTATE_END_OF_LIST()
}
};
/*
* Put the device into post-reset default state.
*/
static void lsm303dlhc_mag_default_cfg(LSM303DLHCMagState *s)
{
/* Set the device into is default reset state. */
s->len = 0;
s->pointer = 0; /* Current register. */
s->buf = 0; /* Shared buffer. */
s->cra = 0x10; /* Temp Enabled = 0, Data Rate = 15.0 Hz. */
s->crb = 0x20; /* Gain = +/- 1.3 Gauss. */
s->mr = 0x3; /* Operating Mode = Sleep. */
s->x = 0;
s->z = 0;
s->y = 0;
s->x_lock = 0;
s->z_lock = 0;
s->y_lock = 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). */
s->temperature_lock = 0;
}
/*
* Callback handler when DeviceState 'reset' is set to true.
*/
static void lsm303dlhc_mag_reset(DeviceState *dev)
{
I2CSlave *i2c = I2C_SLAVE(dev);
LSM303DLHCMagState *s = LSM303DLHC_MAG(i2c);
/* Set the device into its default reset state. */
lsm303dlhc_mag_default_cfg(s);
}
/*
* Initialisation of any public properties.
*/
static void lsm303dlhc_mag_initfn(Object *obj)
{
object_property_add(obj, "mag-x", "int",
lsm303dlhc_mag_get_x,
lsm303dlhc_mag_set_x, NULL, NULL);
object_property_add(obj, "mag-y", "int",
lsm303dlhc_mag_get_y,
lsm303dlhc_mag_set_y, NULL, NULL);
object_property_add(obj, "mag-z", "int",
lsm303dlhc_mag_get_z,
lsm303dlhc_mag_set_z, NULL, NULL);
object_property_add(obj, "temperature", "int",
lsm303dlhc_mag_get_temperature,
lsm303dlhc_mag_set_temperature, NULL, NULL);
}
/*
* 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);
dc->reset = lsm303dlhc_mag_reset;
dc->vmsd = &vmstate_lsm303dlhc_mag;
k->event = lsm303dlhc_mag_event;
k->recv = lsm303dlhc_mag_recv;
k->send = lsm303dlhc_mag_send;
}
static const TypeInfo lsm303dlhc_mag_info = {
.name = TYPE_LSM303DLHC_MAG,
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(LSM303DLHCMagState),
.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)