/* * Copyright (C) 2012 Lorenz Meier. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. Neither the name of the author or the names of 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 THE * COPYRIGHT OWNER 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. */ /* * Driver for the Measurement Specialties MS5611 barometric pressure sensor */ #include #include #include #include #include #include #include #include #include #include #include #include "chip.h" #include "px4fmu-internal.h" #include #include /* internal conversion time: 9.17 ms, so should not be read at rates higher than 100 Hz */ #define MS5611_MIN_INTER_MEASUREMENT_INTERVAL 9200 #define MS5611_ADDRESS_1 0x76 /* address select pins pulled high (PX4FMU series v1.6+) */ #define MS5611_ADDRESS_2 0x77 /* address select pins pulled low (PX4FMU prototypes) */ #define ADDR_RESET_CMD 0x1E /* read from this address to reset chip (0b0011110 on bus) */ #define ADDR_CMD_CONVERT_D1 0x48 /* 4096 samples to this address to start conversion (0b01001000 on bus) */ #define ADDR_CMD_CONVERT_D2 0x58 /* 4096 samples */ #define ADDR_DATA 0x00 /* address of 3 bytes / 32bit pressure data */ #define ADDR_PROM_SETUP 0xA0 /* address of 8x 2 bytes factory and calibration data */ #define ADDR_PROM_C1 0xA2 /* address of 6x 2 bytes calibration data */ static FAR struct ms5611_dev_s ms5611_dev; static ssize_t ms5611_read(struct file *filp, FAR char *buffer, size_t buflen); static int ms5611_ioctl(struct file *filp, int cmd, unsigned long arg); static const struct file_operations ms5611_fops = { .read = ms5611_read, .ioctl = ms5611_ioctl, }; struct ms5611_prom_s { uint16_t factory_setup; uint16_t c1_pressure_sens; uint16_t c2_pressure_offset; uint16_t c3_temp_coeff_pres_sens; uint16_t c4_temp_coeff_pres_offset; uint16_t c5_reference_temp; uint16_t c6_temp_coeff_temp; uint16_t serial_and_crc; } __attribute__((packed)); union ms5611_prom_u { uint16_t c[8]; struct ms5611_prom_s s; } __attribute__((packed)); struct ms5611_dev_s { union ms5611_prom_u prom; struct i2c_dev_s *i2c; struct ms5611_buffer *buffer; } __attribute__((packed)); static FAR uint8_t MS5611_ADDRESS; static FAR struct { /* status register and data as read back from the device */ float pressure; float altitude; float temperature; uint32_t d1_raw; uint32_t d2_raw; uint32_t measurements_count; uint8_t last_state; uint64_t last_read; } ms5611_report = { .pressure = 0.0f, .altitude = 0.0f, .temperature = 0.0f, .last_state = 0, /* make sure the first readout can be performed */ .last_read = 0, }; static int ms5611_read_prom(void); int ms5611_reset() { int ret; printf("[ms5611 drv] Resettet I2C2 BUS\n"); up_i2cuninitialize(ms5611_dev.i2c); ms5611_dev.i2c = up_i2cinitialize(2); I2C_SETFREQUENCY(ms5611_dev.i2c, 400000); return ret; } static bool read_values(float *data) { int ret; uint8_t cmd_data[3]; /* check validity of pointer */ if (data == NULL) { *get_errno_ptr() = EINVAL; return -EINVAL; } /* only start reading when data is available */ if (ms5611_report.measurements_count > 0) { /* do not read more often than at minimum 9.17 ms intervals */ if ((hrt_absolute_time() - ms5611_report.last_read) < MS5611_MIN_INTER_MEASUREMENT_INTERVAL) { /* set errno to 'come back later' */ ret = -EAGAIN; goto handle_return; } else { /* set new value */ ms5611_report.last_read = hrt_absolute_time(); } /* Read out last measurement */ cmd_data[0] = 0x00; struct i2c_msg_s msgv[2] = { { .addr = MS5611_ADDRESS, .flags = 0, .buffer = cmd_data, .length = 1 }, { .addr = MS5611_ADDRESS, .flags = I2C_M_READ, .buffer = cmd_data, .length = 3 } }; ret = I2C_TRANSFER(ms5611_dev.i2c, msgv, 2); if (ret != OK) goto handle_return; /* at value 1 the last reading was temperature */ if (ms5611_report.last_state == 1) { /* put temperature into the raw set */ ms5611_report.d2_raw = (((uint32_t)cmd_data[0]) << 16) | (((uint32_t)cmd_data[1]) << 8) | ((uint32_t)cmd_data[2]); } else { /* put altitude into the raw set */ ms5611_report.d1_raw = (((uint32_t)cmd_data[0]) << 16) | (((uint32_t)cmd_data[1]) << 8) | ((uint32_t)cmd_data[2]); } } ms5611_report.measurements_count++; /* * this block reads four pressure values and one temp value, * resulting in 80 Hz pressure update and 20 Hz temperature updates * at 100 Hz continuous operation. */ if (ms5611_report.last_state == 0) { /* request first a temperature reading */ cmd_data[0] = ADDR_CMD_CONVERT_D2; } else { /* request pressure reading */ cmd_data[0] = ADDR_CMD_CONVERT_D1; } if (ms5611_report.last_state == 3) { ms5611_report.last_state = 0; } else { ms5611_report.last_state++; } /* write measurement command */ struct i2c_msg_s conv_cmd[1] = { { .addr = MS5611_ADDRESS, .flags = 0, .buffer = cmd_data, .length = 1 }, }; ret = I2C_TRANSFER(ms5611_dev.i2c, conv_cmd, 1); if (ret != OK) goto handle_return; /* only write back values after first complete set */ if (ms5611_report.measurements_count > 2) { /* Calculate results */ /* temperature calculation */ int32_t dT = ms5611_report.d2_raw - (((int32_t)ms5611_dev.prom.s.c5_reference_temp)*256); int64_t temp_int64 = 2000 + (((int64_t)dT)*ms5611_dev.prom.s.c6_temp_coeff_temp)/8388608; /* pressure calculation */ int64_t offset = (int64_t)ms5611_dev.prom.s.c2_pressure_offset * 65536 + ((int64_t)dT*ms5611_dev.prom.s.c4_temp_coeff_pres_offset)/128; int64_t sens = (int64_t)ms5611_dev.prom.s.c1_pressure_sens * 32768 + ((int64_t)dT*ms5611_dev.prom.s.c3_temp_coeff_pres_sens)/256; /* it's pretty cold, second order temperature compensation needed */ if (temp_int64 < 2000) { /* second order temperature compensation */ int64_t temp2 = (((int64_t)dT)*dT) >> 31; int64_t tmp_64 = (temp_int64-2000)*(temp_int64-2000); int64_t offset2 = (5*tmp_64)>>1; int64_t sens2 = (5*tmp_64)>>2; temp_int64 = temp_int64 - temp2; offset = offset - offset2; sens = sens - sens2; } int64_t press_int64 = (((ms5611_report.d1_raw*sens)/2097152-offset)/32768); ms5611_report.temperature = temp_int64 / 100.0f; ms5611_report.pressure = press_int64 / 100.0f; /* convert as double for max. precision, store as float (more than enough precision) */ ms5611_report.altitude = (44330.0 * (1.0 - pow((press_int64 / 101325.0), 0.190295))); /* Write back float values */ data[0] = ms5611_report.pressure; data[1] = ms5611_report.altitude; data[2] = ms5611_report.temperature; } else { /* not ready, try again */ ret = -EINPROGRESS; } /* return 1 if new data is available, 0 else */ handle_return: if (ret == OK) { return (sizeof(ms5611_report.d1_raw) + sizeof(ms5611_report.altitude) + sizeof(ms5611_report.d2_raw)); } else { errno = -ret; if (errno == ETIMEDOUT || ret == ETIMEDOUT) ms5611_reset(); return ret; } } static ssize_t ms5611_read(struct file *filp, char *buffer, size_t buflen) { /* if the buffer is large enough, and data are available, return success */ if (buflen >= 12) { return read_values((float *)buffer); } /* buffer too small */ errno = ENOSPC; return -ENOSPC; } static int ms5611_ioctl(struct file *filp, int cmd, unsigned long arg) { return -ENOSYS; // switch (cmd) { // case MS5611_SETRATE: // if ((arg & REG1_RATE_LP_MASK) == arg) { // set_rate(arg); // result = 0; // dev.rate = arg; // } // break; // // case MS5611_SETBUFFER: // dev.buffer = (struct ms5611_buffer *)arg; // result = 0; // break; // } // // if (result) // errno = EINVAL; // return result; } int ms5611_crc4(uint16_t n_prom[]) { /* routine ported from MS5611 application note */ int16_t cnt; uint16_t n_rem; uint16_t crc_read; uint8_t n_bit; n_rem = 0x00; /* save the read crc */ crc_read = n_prom[7]; /* remove CRC byte */ n_prom[7] = (0xFF00 & (n_prom[7])); for (cnt = 0; cnt < 16; cnt++) { /* uneven bytes */ if (cnt & 1) { n_rem ^= (uint8_t) ((n_prom[cnt>>1]) & 0x00FF); } else { n_rem ^= (uint8_t) (n_prom[cnt>>1] >> 8); } for (n_bit = 8; n_bit > 0; n_bit--) { if (n_rem & 0x8000) { n_rem = (n_rem << 1) ^ 0x3000; } else { n_rem = (n_rem << 1); } } } /* final 4 bit remainder is CRC value */ n_rem = (0x000F & (n_rem >> 12)); n_prom[7] = crc_read; /* return 0 == OK if CRCs match, 1 else */ return !((0x000F & crc_read) == (n_rem ^ 0x00)); } int ms5611_read_prom() { /* read PROM data */ uint8_t prom_buf[2] = {255,255}; int retval = 0; for (int i = 0; i < 8; i++) { uint8_t cmd = {ADDR_PROM_SETUP + (i*2)}; I2C_SETADDRESS(ms5611_dev.i2c, MS5611_ADDRESS, 7); retval = I2C_WRITEREAD(ms5611_dev.i2c, &cmd, 1, prom_buf, 2); /* assemble 16 bit value and convert from big endian (sensor) to little endian (MCU) */ ms5611_dev.prom.c[i] = (((uint16_t)prom_buf[0])<<8) | ((uint16_t)prom_buf[1]); if (retval != OK) { break; } } /* calculate CRC and return error if mismatch */ return ms5611_crc4(ms5611_dev.prom.c); } int ms5611_attach(struct i2c_dev_s *i2c) { int result = ERROR; ms5611_dev.i2c = i2c; MS5611_ADDRESS = MS5611_ADDRESS_1; /* write reset command */ uint8_t cmd_data = ADDR_RESET_CMD; struct i2c_msg_s reset_cmd[1] = { { .addr = MS5611_ADDRESS, .flags = 0, .buffer = &cmd_data, .length = 1 }, }; int ret = I2C_TRANSFER(ms5611_dev.i2c, reset_cmd, 1); if (ret == OK) { /* wait for PROM contents to be in the device (2.8 ms) */ up_udelay(3000); /* read PROM */ ret = ms5611_read_prom(); } /* check if the address was wrong */ if (ret != OK) { /* try second address */ MS5611_ADDRESS = MS5611_ADDRESS_2; /* write reset command */ cmd_data = ADDR_RESET_CMD; struct i2c_msg_s reset_cmd_2[1] = { { .addr = MS5611_ADDRESS, .flags = 0, .buffer = &cmd_data, .length = 1 }, }; ret = I2C_TRANSFER(ms5611_dev.i2c, reset_cmd_2, 1); /* wait for PROM contents to be in the device (2.8 ms) */ up_udelay(3000); /* read PROM */ ret = ms5611_read_prom(); } if (ret < 0) return -EIO; /* verify that the device is attached and functioning */ if (ret == OK) { if (MS5611_ADDRESS == MS5611_ADDRESS_1) { printf("[ms5611 driver] Attached MS5611 at addr #1 (0x76)\n"); } else { printf("[ms5611 driver] Attached MS5611 at addr #2 (0x77)\n"); } /* trigger temperature read */ (void)read_values(NULL); /* wait for conversion to complete */ up_udelay(9200); /* trigger pressure read */ (void)read_values(NULL); /* wait for conversion to complete */ up_udelay(9200); /* now a read_values call would obtain valid results */ /* make ourselves available */ register_driver("/dev/ms5611", &ms5611_fops, 0666, NULL); result = OK; } else { errno = EIO; } return result; }