diff options
Diffstat (limited to 'driver/mag_bmm150.c')
-rw-r--r-- | driver/mag_bmm150.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/driver/mag_bmm150.c b/driver/mag_bmm150.c new file mode 100644 index 0000000000..54a4598e77 --- /dev/null +++ b/driver/mag_bmm150.c @@ -0,0 +1,214 @@ +/* Copyright 2015 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/** + * BMM150 compass behing a BMI160 + */ + +#include "accelgyro.h" +#include "common.h" +#include "console.h" +#include "driver/accelgyro_bmi160.h" +#include "driver/mag_bmm150.h" +#include "hooks.h" +#include "i2c.h" +#include "task.h" +#include "timer.h" +#include "util.h" + +#define CPUTS(outstr) cputs(CC_ACCEL, outstr) +#define CPRINTF(format, args...) cprintf(CC_ACCEL, format, ## args) +#define CPRINTS(format, args...) cprints(CC_ACCEL, format, ## args) + + +/**************************************************************************** +* Copyright (C) 2011 - 2014 Bosch Sensortec GmbH +* +****************************************************************************/ +/*************************************************************************** +* License: +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions are met: +* +* Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* +* Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in the +* documentation and/or other materials provided with the distribution. +* +* Neither the name of the copyright holder nor the names of the +* contributors may be used to endorse or promote products derived from +* this software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +* DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR +* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE +* +* The information provided is believed to be accurate and reliable. +* The copyright holder assumes no responsibility for the consequences of use +* of such information nor for any infringement of patents or +* other rights of third parties which may result from its use. +* No license is granted by implication or otherwise under any patent or +* patent rights of the copyright holder. +*/ + +#include "mag_bmm150.h" + +#define BMI150_READ_16BIT_COM_REG(store_, addr_) do { \ + int val; \ + raw_mag_read8(s->i2c_addr, (addr_), &val); \ + store_ = val; \ + raw_mag_read8(s->i2c_addr, (addr_) + 1, &val); \ + store_ |= (val << 8); \ +} while (0) + + +int bmm150_init(const struct motion_sensor_t *s) +{ + int ret; + int val; + struct bmm150_comp_registers *regs = BMM150_COMP_REG(s); + + /* Set the compass from Suspend to Sleep */ + ret = raw_mag_write8(s->i2c_addr, BMM150_PWR_CTRL, BMM150_PWR_ON); + /* Now we can read the device id */ + ret = raw_mag_read8(s->i2c_addr, BMM150_CHIP_ID, &val); + if (ret) + return EC_ERROR_UNKNOWN; + + if (val != BMM150_CHIP_ID_MAJOR) + return EC_ERROR_ACCESS_DENIED; + + /* Read the private registers for compensation */ + ret = raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_X1, &val); + if (ret) + return EC_ERROR_UNKNOWN; + regs->dig1[X] = val; + raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_Y1, &val); + regs->dig1[Y] = val; + raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_X2, &val); + regs->dig2[X] = val; + raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_Y2, &val); + regs->dig2[Y] = val; + + raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_XY1, &val); + regs->dig_xy1 = val; + + raw_mag_read8(s->i2c_addr, BMM150_REGA_DIG_XY2, &val); + regs->dig_xy2 = val; + + BMI150_READ_16BIT_COM_REG(regs->dig_z1, BMM150_REGA_DIG_Z1_LSB); + BMI150_READ_16BIT_COM_REG(regs->dig_z2, BMM150_REGA_DIG_Z2_LSB); + BMI150_READ_16BIT_COM_REG(regs->dig_z3, BMM150_REGA_DIG_Z3_LSB); + BMI150_READ_16BIT_COM_REG(regs->dig_z4, BMM150_REGA_DIG_Z4_LSB); + BMI150_READ_16BIT_COM_REG(regs->dig_xyz1, BMM150_REGA_DIG_XYZ1_LSB); + + /* + * Set the compass forced mode, to sleep after each measure. + */ + ret = raw_mag_write8(s->i2c_addr, BMM150_OP_CTRL, + BMM150_OP_MODE_FORCED << BMM150_OP_MODE_OFFSET); + + return ret; +} + +void bmm150_temp_compensate_xy(const struct motion_sensor_t *s, + vector_3_t raw, + vector_3_t comp, + int r) +{ + int inter, axis; + struct bmm150_comp_registers *regs = BMM150_COMP_REG(s); + if (r == 0) + inter = 0; + else + inter = ((int)regs->dig_xyz1 << 14) / r - (1 << 14); + + for (axis = X; axis <= Y; axis++) { + if (raw[axis] == BMM150_FLIP_OVERFLOW_ADCVAL) { + comp[axis] = BMM150_OVERFLOW_OUTPUT; + continue; + } + /* + * The formula is, using 4 LSB for precision: + * (mdata_x * ((((dig_xy2 * i^2 / 268435456) + + * i * dig_xy1) / 16384) + 256) * + * (dig2 + 160)) / 8192 + dig1 * 8.0f + * To prevent precision loss, we calculate at << 12: + * 1 / 268435456 = 1 >> 28 = 1 >> (7 + 9 + 12) + * 1 / 16384 = 1 >> (-7 + 9 + 12) + * 256 = 1 << (20 - 12) + */ + comp[axis] = (int)regs->dig_xy2 * ((inter * inter) >> 7); + comp[axis] += inter * ((int)regs->dig_xy1 << 7); + comp[axis] >>= 9; + comp[axis] += 1 << (8 + 12); + comp[axis] *= (int)regs->dig2[axis] + 160; + comp[axis] >>= 12; + comp[axis] *= raw[axis]; + comp[axis] >>= 13; + comp[axis] += (int)regs->dig1[axis] << 3; + } +} + +void bmm150_temp_compensate_z(const struct motion_sensor_t *s, + vector_3_t raw, + vector_3_t comp, + int r) +{ + int dividend, divisor; + struct bmm150_comp_registers *regs = BMM150_COMP_REG(s); + + if (raw[Z] == BMM150_HALL_OVERFLOW_ADCVAL) { + comp[Z] = BMM150_OVERFLOW_OUTPUT; + return; + } + /* + * The formula is + * ((z - dig_z4) * 131072 - dig_z3 * (r - dig_xyz1)) / + * ((dig_z2 + dig_z1 * r / 32768) * 4); + * + * We spread 4 so we multiply by 131072 / 4 == (1<<15) only. + */ + dividend = (raw[Z] - (int)regs->dig_z4) << 15; + dividend -= (regs->dig_z3 * (r - (int)regs->dig_xyz1)) >> 2; + /* add 1 << 15 to round to next integer. */ + divisor = (int)regs->dig_z1 * (r << 1) + (1 << 15); + divisor >>= 16; + divisor += (int)regs->dig_z2; + comp[Z] = dividend / divisor; + if (comp[Z] > (1 << 15) || comp[Z] < -(1 << 15)) + comp[Z] = BMM150_OVERFLOW_OUTPUT; +} + +void bmm150_normalize(const struct motion_sensor_t *s, + vector_3_t v, + uint8_t *data) +{ + uint16_t r; + vector_3_t raw; + + /* X and Y are two's complement 13 bits vectors */ + raw[X] = ((int16_t)(data[0] | (data[1] << 8))) >> 3; + raw[Y] = ((int16_t)(data[2] | (data[3] << 8))) >> 3; + /* X and Y are two's complement 15 bits vectors */ + raw[Z] = ((int16_t)(data[4] | (data[5] << 8))) >> 1; + + /* RHALL value to compensate with - unsigned 14 bits */ + r = (data[6] | (data[7] << 8)) >> 2; + + bmm150_temp_compensate_xy(s, raw, v, r); + bmm150_temp_compensate_z(s, raw, v, r); +} + |