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incubator-nuttx/drivers/sensors/lps25h.c

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/****************************************************************************
* drivers/sensors/lps25h.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/arch.h>
#include <nuttx/i2c/i2c_master.h>
#include <sys/types.h>
#include <assert.h>
#include <debug.h>
#include <stdio.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mutex.h>
#include <nuttx/random.h>
#include <nuttx/sensors/lps25h.h>
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
#ifdef CONFIG_DEBUG_LPS25H
# define lps25h_dbg(x, ...) _info(x, ##__VA_ARGS__)
#else
# define lps25h_dbg(x, ...) sninfo(x, ##__VA_ARGS__)
#endif
#ifndef CONFIG_LPS25H_I2C_FREQUENCY
# define CONFIG_LPS25H_I2C_FREQUENCY 400000
#endif
#define LPS25H_PRESSURE_INTERNAL_DIVIDER 4096
/* 'AN4450 - Hardware and software guidelines for use of LPS25H pressure
* sensors' - '6.2 One-shot mode conversion time estimation' gives estimates
* for conversion times:
*
* Typical conversion time ≈ 62*(Pavg+Tavg) + 975 μs
* ex: Tavg = 64; Pavg = 512; Typ. conversation time ≈ 36.7 ms
* (compatible with ODT=25 Hz)
* ex: Tavg = 32; Pavg = 128; Typ. conversation time ≈ 10.9 ms
* The formula is accurate within +/- 3% at room temperature
*
* Set timeout to 2 * max.conversation time (2*36.7*1.03 = 76 ms).
*/
#define LPS25H_RETRY_TIMEOUT_MSECS 76
#define LPS25H_MAX_RETRIES 5
#define LPS25H_I2C_RETRIES 10
/* Registers */
#define LPS25H_REF_P_XL 0x08
#define LPS25H_REF_P_L 0x09
#define LPS25H_REF_P_H 0x0a
#define LPS25H_WHO_AM_I 0x0f
#define LPS25H_RES_CONF 0x10
#define LPS25H_CTRL_REG1 0x20
#define LPS25H_CTRL_REG2 0x21
#define LPS25H_CTRL_REG3 0x22
#define LPS25H_CTRL_REG4 0x23
#define LPS25H_INT_CFG 0x24
#define LPS25H_INT_SOURCE 0x25
#define LPS25H_STATUS_REG 0x27
#define LPS25H_PRESS_POUT_XL 0x28
#define LPS25H_PRESS_OUT_L 0x29
#define LPS25H_PRESS_OUT_H 0x2a
#define LPS25H_TEMP_OUT_L 0x2b
#define LPS25H_TEMP_OUT_H 0x2c
#define LPS25H_FIFO_CTRL 0x2e
#define LPS25H_FIFO_STATUS 0x2f
#define LPS25H_THS_P_L 0x30
#define LPS25H_THS_P_H 0x31
#define LPS25H_RPDS_L 0x39
#define LPS25H_RPDS_H 0x3a
/* Bits in registers */
#define LPS25H_AUTO_ZERO (1 << 2)
#define LPS25H_BDU (1 << 2)
#define LPS25H_DIFF_EN (1 << 3)
#define LPS25H_FIFO_EN (1 << 6)
#define LPS25H_WTM_EN (1 << 5)
#define LPS25H_FIFO_MEAN_DEC (1 << 4)
#define LPS25H_PD (1 << 7)
#define LPS25H_ONE_SHOT (1 << 0)
#define LPS25H_INT_H_L (1 << 7)
#define LPS25H_PP_OD (1 << 6)
/****************************************************************************
* Private Types
****************************************************************************/
struct lps25h_dev_s
{
FAR struct i2c_master_s *i2c;
uint8_t addr;
bool irqenabled;
volatile bool int_pending;
mutex_t devlock;
sem_t waitsem;
FAR lps25h_config_t *config;
};
enum LPS25H_RES_CONF_AVG_PRES
{
PRES_AVG_8 = 0,
PRES_AVG_32,
PRES_AVG_128,
PRES_AVG_512
};
enum LPS25H_RES_CONF_AVG_TEMP
{
TEMP_AVG_8 = 0,
TEMP_AVG_16,
TEMP_AVG_32,
TEMP_AVG_64
};
enum LPS25H_CTRL_REG1_ODR
{
CTRL_REG1_ODR_ONE_SHOT = 0,
CTRL_REG1_ODR_1HZ,
CTRL_REG1_ODR_7HZ,
CTRL_REG1_ODR_12_5HZ,
CTRL_REG1_ODR_25HZ
};
enum LPS25H_CTRL_REG4_P1
{
P1_DRDY = 0x1,
P1_OVERRUN = 0x02,
P1_WTM = 0x04,
P1_EMPTY = 0x08
};
enum LPS25H_FIFO_CTRL_MODE
{
BYPASS_MODE = 0x0,
FIFO_STOP_WHEN_FULL,
STREAM_NEWEST_IN_FIFO,
STREAM_DEASSERTED,
BYPASS_DEASSERTED_STREAM,
FIFO_MEAN = 0x06,
BYPASS_DEASSERTED_FIFO
};
enum LPS25H_FIFO_CTRL_WTM
{
SAMPLE_2 = 0x01,
SAMPLE_4 = 0x03,
SAMPLE_8 = 0x07,
SAMPLE_16 = 0x0f,
SAMPLE_32 = 0x1f
};
enum LPS25H_INT_CFG_OP
{
PH_E = 0x1,
PL_E = 0x2,
LIR = 0x4
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int lps25h_open(FAR struct file *filep);
static int lps25h_close(FAR struct file *filep);
static ssize_t lps25h_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t lps25h_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int lps25h_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
static int lps25h_configure_dev(FAR struct lps25h_dev_s *dev);
static int lps25h_read_pressure(FAR struct lps25h_dev_s *dev,
FAR lps25h_pressure_data_t *pres);
static int lps25h_read_temper(FAR struct lps25h_dev_s *dev,
FAR lps25h_temper_data_t *temper);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_lps25hops =
{
lps25h_open, /* open */
lps25h_close, /* close */
lps25h_read, /* read */
lps25h_write, /* write */
NULL, /* seek */
lps25h_ioctl, /* ioctl */
};
/****************************************************************************
* Private Functions
****************************************************************************/
static int lps25h_do_transfer(FAR struct lps25h_dev_s *dev,
FAR struct i2c_msg_s *msgv,
size_t nmsg)
{
int ret = -EIO;
int retries;
for (retries = 0; retries < LPS25H_I2C_RETRIES; retries++)
{
ret = I2C_TRANSFER(dev->i2c, msgv, nmsg);
if (ret >= 0)
{
return 0;
}
else
{
/* Some error. Try to reset I2C bus and keep trying. */
#ifdef CONFIG_I2C_RESET
if (retries == LPS25H_I2C_RETRIES - 1)
{
break;
}
ret = I2C_RESET(dev->i2c);
if (ret < 0)
{
lps25h_dbg("I2C_RESET failed: %d\n", ret);
return ret;
}
#endif
}
}
lps25h_dbg("xfer failed: %d\n", ret);
return ret;
}
static int lps25h_write_reg8(FAR struct lps25h_dev_s *dev, uint8_t reg_addr,
const uint8_t value)
{
struct i2c_msg_s msgv[2] =
{
{
.frequency = CONFIG_LPS25H_I2C_FREQUENCY,
.addr = dev->addr,
.flags = 0,
.buffer = &reg_addr,
.length = 1
},
{
.frequency = CONFIG_LPS25H_I2C_FREQUENCY,
.addr = dev->addr,
.flags = I2C_M_NOSTART,
.buffer = (FAR void *)&value,
.length = 1
}
};
return lps25h_do_transfer(dev, msgv, 2);
}
static int lps25h_read_reg8(FAR struct lps25h_dev_s *dev,
FAR uint8_t *reg_addr,
FAR uint8_t *value)
{
struct i2c_msg_s msgv[2] =
{
{
.frequency = CONFIG_LPS25H_I2C_FREQUENCY,
.addr = dev->addr,
.flags = 0,
.buffer = reg_addr,
.length = 1
},
{
.frequency = CONFIG_LPS25H_I2C_FREQUENCY,
.addr = dev->addr,
.flags = I2C_M_READ,
.buffer = value,
.length = 1
}
};
return lps25h_do_transfer(dev, msgv, 2);
}
static int lps25h_power_on_off(FAR struct lps25h_dev_s *dev, bool on)
{
int ret;
uint8_t value;
value = on ? LPS25H_PD : 0;
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG1, value);
return ret;
}
static int lps25h_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lps25h_dev_s *dev = inode->i_private;
uint8_t value = 0;
uint8_t addr = LPS25H_WHO_AM_I;
int32_t ret;
/* Get exclusive access */
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
dev->config->set_power(dev->config, true);
ret = lps25h_read_reg8(dev, &addr, &value);
if (ret < 0)
{
lps25h_dbg("Cannot read device's ID\n");
dev->config->set_power(dev->config, false);
goto out;
}
lps25h_dbg("WHO_AM_I: 0x%2x\n", value);
dev->config->irq_enable(dev->config, true);
dev->irqenabled = true;
out:
nxmutex_unlock(&dev->devlock);
return ret;
}
static int lps25h_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lps25h_dev_s *dev = inode->i_private;
int ret;
/* Get exclusive access */
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
dev->config->irq_enable(dev->config, false);
dev->irqenabled = false;
ret = lps25h_power_on_off(dev, false);
dev->config->set_power(dev->config, false);
lps25h_dbg("CLOSED\n");
nxmutex_unlock(&dev->devlock);
return ret;
}
static ssize_t lps25h_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lps25h_dev_s *dev = inode->i_private;
lps25h_pressure_data_t data;
ssize_t length = 0;
int ret;
/* Get exclusive access */
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return (ssize_t)ret;
}
ret = lps25h_configure_dev(dev);
if (ret < 0)
{
lps25h_dbg("cannot configure sensor: %d\n", ret);
goto out;
}
ret = lps25h_read_pressure(dev, &data);
if (ret < 0)
{
lps25h_dbg("cannot read data: %d\n", ret);
}
else
{
/* This interface is mainly intended for easy debugging in nsh. */
length = snprintf(buffer, buflen, "%u\n", data.pressure_pa);
if (length > buflen)
{
length = buflen;
}
}
out:
nxmutex_unlock(&dev->devlock);
return length;
}
static ssize_t lps25h_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
ssize_t length = 0;
return length;
}
static void lps25h_notify(FAR struct lps25h_dev_s *dev)
{
DEBUGASSERT(dev != NULL);
dev->int_pending = true;
nxsem_post(&dev->waitsem);
}
static int lps25h_int_handler(int irq, FAR void *context, FAR void *arg)
{
FAR struct lps25h_dev_s *dev = (FAR struct lps25h_dev_s *)arg;
DEBUGASSERT(dev != NULL);
lps25h_notify(dev);
lps25h_dbg("lps25h interrupt\n");
return OK;
}
static int lps25h_configure_dev(FAR struct lps25h_dev_s *dev)
{
int ret = 0;
ret = lps25h_power_on_off(dev, false);
if (ret < 0)
{
return ret;
}
/* Enable FIFO */
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG2, LPS25H_FIFO_EN);
if (ret < 0)
{
return ret;
}
ret = lps25h_write_reg8(dev, LPS25H_FIFO_CTRL, (BYPASS_MODE << 5));
if (ret < 0)
{
return ret;
}
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG4, P1_DRDY);
if (ret < 0)
{
return ret;
}
/* Write CTRL_REG1 to turn device on */
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG1,
LPS25H_PD | (CTRL_REG1_ODR_1HZ << 4));
return ret;
}
static int lps25h_one_shot(FAR struct lps25h_dev_s *dev)
{
int ret = ERROR;
int retries;
irqstate_t flags;
if (!dev->irqenabled)
{
lps25h_dbg("IRQ disabled!\n");
}
/* Retry one-shot measurement multiple times. */
for (retries = 0; retries < LPS25H_MAX_RETRIES; retries++)
{
/* Power off so we start from a known state. */
ret = lps25h_power_on_off(dev, false);
if (ret < 0)
{
return ret;
}
/* Initiate a one shot mode measurement */
ret = lps25h_write_reg8(dev, LPS25H_CTRL_REG2, LPS25H_ONE_SHOT);
if (ret < 0)
{
return ret;
}
/* Power on to start measurement. */
ret = lps25h_power_on_off(dev, true);
if (ret < 0)
{
return ret;
}
ret = nxsem_tickwait_uninterruptible(&dev->waitsem,
MSEC2TICK(LPS25H_RETRY_TIMEOUT_MSECS));
if (ret == OK)
{
break;
}
else if (ret == -ETIMEDOUT)
{
uint8_t reg = LPS25H_CTRL_REG2;
uint8_t value;
/* In 'AN4450 - Hardware and software guidelines for use of
* LPS25H pressure sensors' - '4.3 One-shot mode measurement
* sequence', one-shot mode example is given where interrupt line
* is not used, but CTRL_REG2 is polled until ONE_SHOT bit is
* unset (as it is self-clearing). Check ONE_SHOT bit status here
* to see if we just missed interrupt.
*/
ret = lps25h_read_reg8(dev, &reg, &value);
if (ret == OK && (value & LPS25H_ONE_SHOT) == 0)
{
/* One-shot completed. */
break;
}
}
else
{
/* Some unknown mystery error */
DEBUGASSERT(ret == -ECANCELED);
return ret;
}
lps25h_dbg("Retrying one-shot measurement: retries=%d\n", retries);
}
if (ret != OK)
{
return -ETIMEDOUT;
}
flags = enter_critical_section();
dev->int_pending = false;
leave_critical_section(flags);
return ret;
}
static int lps25h_read_pressure(FAR struct lps25h_dev_s *dev,
FAR lps25h_pressure_data_t *pres)
{
int ret;
uint8_t pres_addr_h = LPS25H_PRESS_OUT_H;
uint8_t pres_addr_l = LPS25H_PRESS_OUT_L;
uint8_t pres_addr_xl = LPS25H_PRESS_POUT_XL;
uint8_t pres_value_h = 0;
uint8_t pres_value_l = 0;
uint8_t pres_value_xl = 0;
int32_t pres_res = 0;
ret = lps25h_one_shot(dev);
if (ret < 0)
{
return ret;
}
ret = lps25h_read_reg8(dev, &pres_addr_h, &pres_value_h);
if (ret < 0)
{
return ret;
}
ret = lps25h_read_reg8(dev, &pres_addr_l, &pres_value_l);
if (ret < 0)
{
return ret;
}
ret = lps25h_read_reg8(dev, &pres_addr_xl, &pres_value_xl);
if (ret < 0)
{
return ret;
}
pres_res = ((int32_t) pres_value_h << 16) |
((int16_t) pres_value_l << 8) |
pres_value_xl;
/* Add to entropy pool. */
add_sensor_randomness(pres_res);
/* Convert to more usable format. */
pres->pressure_int_hp =
pres_res / LPS25H_PRESSURE_INTERNAL_DIVIDER;
pres->pressure_pa = (uint64_t)
pres_res * 100000 / LPS25H_PRESSURE_INTERNAL_DIVIDER;
pres->raw_data = pres_res;
lps25h_dbg("Pressure: %u Pa\n", pres->pressure_pa);
return ret;
}
static int lps25h_read_temper(FAR struct lps25h_dev_s *dev,
FAR lps25h_temper_data_t *temper)
{
int ret;
uint8_t temper_addr_h = LPS25H_TEMP_OUT_H;
uint8_t temper_addr_l = LPS25H_TEMP_OUT_L;
uint8_t temper_value_h = 0;
uint8_t temper_value_l = 0;
int32_t temper_res;
int16_t raw_data;
ret = lps25h_read_reg8(dev, &temper_addr_h, &temper_value_h);
if (ret < 0)
{
return ret;
}
ret = lps25h_read_reg8(dev, &temper_addr_l, &temper_value_l);
if (ret < 0)
{
return ret;
}
raw_data = (temper_value_h << 8) | temper_value_l;
/* Add to entropy pool. */
add_sensor_randomness(raw_data);
/* T(⁰C) = 42.5 + (raw / 480)
* =>
* T(⁰C) * scale = (425 * 48 + raw) * scale / 480;
*/
temper_res = (425 * 48 + raw_data);
temper_res *= LPS25H_TEMPER_DIVIDER;
temper_res /= 480;
temper->int_temper = temper_res;
temper->raw_data = raw_data;
lps25h_dbg("Temperature: %d\n", temper_res);
return ret;
}
static int lps25h_who_am_i(FAR struct lps25h_dev_s *dev,
lps25h_who_am_i_data * who_am_i_data)
{
uint8_t who_addr = LPS25H_WHO_AM_I;
return lps25h_read_reg8(dev, &who_addr, &who_am_i_data->who_am_i);
}
static int lps25h_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lps25h_dev_s *dev = inode->i_private;
int ret;
/* Get exclusive access */
ret = nxmutex_lock(&dev->devlock);
if (ret < 0)
{
return ret;
}
switch (cmd)
{
case SNIOC_CFGR:
ret = lps25h_configure_dev(dev);
break;
case SNIOC_PRESSURE_OUT:
ret = lps25h_read_pressure(dev, (FAR lps25h_pressure_data_t *)arg);
break;
case SNIOC_TEMPERATURE_OUT:
/* NOTE: call SNIOC_PRESSURE_OUT before this one,
* or results are bogus.
*/
ret = lps25h_read_temper(dev, (FAR lps25h_temper_data_t *)arg);
break;
case SNIOC_SENSOR_OFF:
ret = lps25h_power_on_off(dev, false);
break;
case SNIOC_GET_DEV_ID:
ret = lps25h_who_am_i(dev, (FAR lps25h_who_am_i_data *)arg);
break;
default:
ret = -ENOTTY;
break;
}
nxmutex_unlock(&dev->devlock);
return ret;
}
int lps25h_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
uint8_t addr, FAR lps25h_config_t *config)
{
int ret = 0;
FAR struct lps25h_dev_s *dev;
dev = kmm_zalloc(sizeof(struct lps25h_dev_s));
if (!dev)
{
lps25h_dbg("Memory cannot be allocated for LPS25H sensor\n");
return -ENOMEM;
}
nxmutex_init(&dev->devlock);
nxsem_init(&dev->waitsem, 0, 0);
dev->addr = addr;
dev->i2c = i2c;
dev->config = config;
if (dev->config->irq_clear)
{
dev->config->irq_clear(dev->config);
}
ret = register_driver(devpath, &g_lps25hops, 0666, dev);
lps25h_dbg("Registered with %d\n", ret);
if (ret < 0)
{
nxmutex_destroy(&dev->devlock);
nxsem_destroy(&dev->waitsem);
kmm_free(dev);
lps25h_dbg("Error occurred during the driver registering\n");
return ret;
}
dev->config->irq_attach(config, lps25h_int_handler, dev);
dev->config->irq_enable(config, false);
dev->irqenabled = false;
return OK;
}
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