diff options
author | Kevin Townsend <kevin.townsend@linaro.org> | 2022-01-30 10:50:32 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2022-02-08 10:56:29 +0000 |
commit | 4fd1ebb10593087d45d2f56f7f3d13447d24802c (patch) | |
tree | 596bff2b0a8588e6ac02004e0f067a1f9b5dc2b5 /hw | |
parent | d7d359c4ac1cafd1051c5f6f7ff8349aba579718 (diff) | |
download | qemu-4fd1ebb10593087d45d2f56f7f3d13447d24802c.zip qemu-4fd1ebb10593087d45d2f56f7f3d13447d24802c.tar.gz qemu-4fd1ebb10593087d45d2f56f7f3d13447d24802c.tar.bz2 |
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>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/sensor/Kconfig | 4 | ||||
-rw-r--r-- | hw/sensor/lsm303dlhc_mag.c | 556 | ||||
-rw-r--r-- | hw/sensor/meson.build | 1 |
3 files changed, 561 insertions, 0 deletions
diff --git a/hw/sensor/Kconfig b/hw/sensor/Kconfig index 9c8a049..b317f91 100644 --- a/hw/sensor/Kconfig +++ b/hw/sensor/Kconfig @@ -21,3 +21,7 @@ config ADM1272 config MAX34451 bool depends on I2C + +config LSM303DLHC_MAG + bool + depends on I2C diff --git a/hw/sensor/lsm303dlhc_mag.c b/hw/sensor/lsm303dlhc_mag.c new file mode 100644 index 0000000..4c98ddb --- /dev/null +++ b/hw/sensor/lsm303dlhc_mag.c @@ -0,0 +1,556 @@ +/* + * 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) diff --git a/hw/sensor/meson.build b/hw/sensor/meson.build index 059c4ca..d1bba29 100644 --- a/hw/sensor/meson.build +++ b/hw/sensor/meson.build @@ -4,3 +4,4 @@ softmmu_ss.add(when: 'CONFIG_DPS310', if_true: files('dps310.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')) |