/****************************************************************************
* drivers/sensors/kxtj9.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 <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/signal.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/semaphore.h>
#include <nuttx/sensors/kxtj9.h>
#include <nuttx/random.h>
#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_KXTJ9)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_KXTJ9_I2C_BUS_SPEED
# define CONFIG_KXTJ9_I2C_BUS_SPEED 400000
#endif
/* Register Definitions *****************************************************/
/* Output registers */
#define XOUT_L 0x06
#define WHO_AM_I 0x0f
#define DCST_RESP 0x0c
/* Control registers */
#define INT_REL 0x1a
#define CTRL_REG1 0x1b
#define INT_CTRL1 0x1e
#define DATA_CTRL 0x21
#define CTRL_REG2 0x1d
/* Control register 1 bits */
#define PC1_OFF 0x7f
#define PC1_ON (1 << 7)
/* CTRL_REG1: set resolution, g-range, data ready enable */
/* Output resolution: 8-bit valid or 12-bit valid */
#define RES_8BIT 0
#define RES_12BIT (1 << 6)
/* Data ready function enable bit: set during probe if using irq mode */
#define DRDYE (1 << 5)
/* Output g-range: +/-2g, 4g, or 8g */
#define KXTJ9_G_2G 0
#define KXTJ9_G_4G (1 << 3)
#define KXTJ9_G_8G (1 << 4)
/* Interrupt control register 1 bits */
/* Set these during probe if using irq mode */
#define KXTJ9_IEL (1 << 3)
#define KXTJ9_IEA (1 << 4)
#define KXTJ9_IEN (1 << 5)
#define KXTJ9_SRST 0x80
#define WHO_AM_I_KXCJ9 0x0a
#define KXTJ9_CTRL1_CONFIG (RES_12BIT | KXTJ9_G_2G | DRDYE)
/* Misc. driver definitions *************************************************/
#define ACCEL_NUM_RETRIES 5
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes the state of one KXTJ9 device */
struct kxtj9_dev_s
{
FAR struct i2c_master_s *i2c;
sem_t exclsem;
bool enable;
bool power_enabled;
uint8_t address;
uint8_t shift;
uint8_t ctrl_reg1;
uint8_t data_ctrl;
uint8_t int_ctrl;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C helpers */
static int kxtj9_reg_read(FAR struct kxtj9_dev_s *priv, uint8_t regaddr,
FAR uint8_t *regval, unsigned int len);
static int kxtj9_reg_write(FAR struct kxtj9_dev_s *priv,
uint8_t regaddr, uint8_t regval);
/* KXTJ9 helpers */
static int kxtj9_configure(FAR struct kxtj9_dev_s *priv, uint8_t odr);
static int kxtj9_enable(FAR struct kxtj9_dev_s *priv, bool on);
static int kxtj9_read_sensor_data(FAR struct kxtj9_dev_s *priv,
FAR struct kxtj9_sensor_data *sensor_data);
static void kxtj9_soft_reset(FAR struct kxtj9_dev_s *priv);
static void kxtj9_set_mode_standby(FAR struct kxtj9_dev_s *priv);
/* Character driver methods */
static ssize_t kxtj9_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t kxtj9_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int kxtj9_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_fops =
{
NULL, /* open */
NULL, /* close */
kxtj9_read, /* read */
kxtj9_write, /* write */
NULL, /* seek */
kxtj9_ioctl, /* ioctl */
NULL /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: kxtj9_reg_read
*
* Description:
* Read from multiple KXTJ9 registers.
*
****************************************************************************/
static int kxtj9_reg_read(FAR struct kxtj9_dev_s *priv, uint8_t regaddr,
FAR uint8_t *regval, unsigned int len)
{
struct i2c_msg_s msg[2];
uint8_t buf[1];
int retries = ACCEL_NUM_RETRIES;
int ret;
do
{
/* Format two messages: The first is a write containing the register
* address
*/
buf[0] = regaddr;
msg[0].frequency = CONFIG_KXTJ9_I2C_BUS_SPEED,
msg[0].addr = priv->address;
msg[0].flags = 0;
msg[0].buffer = buf;
msg[0].length = 1;
/* The second is a read with a restart containing the register data */
msg[1].frequency = CONFIG_KXTJ9_I2C_BUS_SPEED,
msg[1].addr = priv->address;
msg[1].flags = I2C_M_READ;
msg[1].buffer = regval;
msg[1].length = len;
/* Then perform the transfer. */
ret = I2C_TRANSFER(priv->i2c, msg, 2);
}
while (ret < 0 && retries-- > 0);
return ret;
}
/****************************************************************************
* Name: kxtj9_reg_write
*
* Description:
* Write a value to a single KXTJ9 register
*
****************************************************************************/
static int kxtj9_reg_write(FAR struct kxtj9_dev_s *priv, uint8_t regaddr,
uint8_t regval)
{
struct i2c_msg_s msg;
uint8_t buf[2];
int ret;
int retries = ACCEL_NUM_RETRIES;
do
{
/* Setup for the transfer */
buf[0] = regaddr;
buf[1] = regval;
msg.frequency = CONFIG_KXTJ9_I2C_BUS_SPEED,
msg.addr = priv->address;
msg.flags = 0;
msg.buffer = buf;
msg.length = 2;
/* Then perform the transfer. */
ret = I2C_TRANSFER(priv->i2c, &msg, 1);
}
while (ret < 0 && retries-- > 0);
return ret;
}
/****************************************************************************
* Name: kxtj9_soft_reset
*
* Description:
* Configure the KXTJ9 device. Handler the SNIOC_CONFIGURE IOCTL command.
*
****************************************************************************/
static void kxtj9_soft_reset(FAR struct kxtj9_dev_s *priv)
{
uint8_t wbuf[1];
/* Set accel into standby and known state by disabling PC1 */
wbuf[0] = KXTJ9_CTRL1_CONFIG;
kxtj9_reg_write(priv, CTRL_REG1, wbuf[0]);
/* Send the reset command */
kxtj9_reg_read(priv, CTRL_REG2, &wbuf[0], 1);
wbuf[0] |= KXTJ9_SRST;
kxtj9_reg_write(priv, CTRL_REG2, wbuf[0]);
/* Delay 10ms for the accel parts to re-initialize */
nxsig_usleep(10000);
}
/****************************************************************************
* Name: kxtj9_set_mode_standby
*
* Description:
* Configure the KXTJ9 device. Handler the SNIOC_CONFIGURE IOCTL command.
*
****************************************************************************/
static void kxtj9_set_mode_standby(FAR struct kxtj9_dev_s *priv)
{
uint8_t wbuf[1];
/* Set Accel into standby and known state by disabling PC1 */
wbuf[0] = KXTJ9_CTRL1_CONFIG;
kxtj9_reg_write(priv, CTRL_REG1, wbuf[0]);
/* Clear interrupts */
wbuf[0] = 0;
kxtj9_reg_write(priv, INT_CTRL1, wbuf[0]);
}
/****************************************************************************
* Name: kxtj9_configure
*
* Description:
* Configure the KXTJ9 device. Handler the SNIOC_CONFIGURE IOCTL command.
*
****************************************************************************/
static int kxtj9_configure(FAR struct kxtj9_dev_s *priv, uint8_t odr)
{
uint8_t wbuf[0];
int ret;
ret = nxsem_wait_uninterruptible(&priv->exclsem);
if (ret < 0)
{
return ret;
}
kxtj9_soft_reset(priv);
kxtj9_set_mode_standby(priv);
/* Read WHO_AM_I register, should return 0x0a */
kxtj9_reg_read(priv, WHO_AM_I, &wbuf[0], 1);
if (wbuf[0] != WHO_AM_I_KXCJ9)
{
snerr("ERROR: Not KXCJ9 chipset, WHO_AM_I register is 0x%2x.\n",
wbuf[0]);
}
/* Ensure that PC1 is cleared before updating control registers */
kxtj9_reg_write(priv, CTRL_REG1, 0);
/* 12Bit Res and -2G~+2G range */
priv->ctrl_reg1 = KXTJ9_CTRL1_CONFIG;
kxtj9_reg_write(priv, CTRL_REG1, priv->ctrl_reg1);
priv->data_ctrl = odr;
kxtj9_reg_write(priv, DATA_CTRL, priv->data_ctrl);
/* In irq mode, populate INT_CTRL */
priv->int_ctrl = KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
kxtj9_reg_write(priv, INT_CTRL1, priv->int_ctrl);
nxsem_post(&priv->exclsem);
return 0;
}
/****************************************************************************
* Name: kxtj9_enable
*
* Description:
* Enable or disable the KXTJ9 device. Handler the SNIOC_ENABLE and
* SNIOC_DISABLE IOCTL commands.
*
****************************************************************************/
static int kxtj9_enable(FAR struct kxtj9_dev_s *priv, bool on)
{
uint8_t wbuf[1];
int ret;
ret = nxsem_wait_uninterruptible(&priv->exclsem);
if (ret < 0)
{
return ret;
}
if (!on && priv->power_enabled)
{
priv->ctrl_reg1 &= PC1_OFF;
kxtj9_reg_write(priv, CTRL_REG1, priv->ctrl_reg1);
priv->power_enabled = false;
sninfo("KXTJ9 in disabled mode\n");
}
else if (on && !priv->power_enabled)
{
/* Turn on outputs */
priv->ctrl_reg1 |= PC1_ON;
kxtj9_reg_write(priv, CTRL_REG1, priv->ctrl_reg1);
/* Clear initial interrupt if in irq mode */
kxtj9_reg_read(priv, INT_REL, wbuf, 1);
priv->power_enabled = true;
sninfo("KXTJ9 in operating mode\n");
}
nxsem_post(&priv->exclsem);
return OK;
}
/****************************************************************************
* Name: kxtj9_read_sensor_data
*
* Description:
* Read sensor data. This supports the standard driver read() method.
*
****************************************************************************/
static int kxtj9_read_sensor_data(FAR struct kxtj9_dev_s *priv,
FAR struct kxtj9_sensor_data *sensor_data)
{
int16_t acc_data[3];
uint8_t data;
int ret;
ret = nxsem_wait_uninterruptible(&priv->exclsem);
if (ret < 0)
{
return ret;
}
kxtj9_reg_read(priv, XOUT_L, (uint8_t *)acc_data, 6);
/* 12 bit resolution, get rid of the lowest 4 bits */
sensor_data->x = acc_data[0] >> 4;
sensor_data->y = acc_data[1] >> 4;
sensor_data->z = acc_data[2] >> 4;
/* Read INT_REL to clear interrupt status */
kxtj9_reg_read(priv, INT_REL, &data, 1);
nxsem_post(&priv->exclsem);
/* Feed sensor data to entropy pool */
add_sensor_randomness((acc_data[0] << 16) ^ (acc_data[1] << 8) ^
acc_data[2]);
return OK;
}
/****************************************************************************
* Name: kxtj9_read
*
* Description:
* The standard read method.
*
****************************************************************************/
static ssize_t kxtj9_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode;
FAR struct kxtj9_dev_s *priv;
size_t nsamples;
size_t i;
int ret;
/* How many samples will fit in the buffer? */
nsamples = buflen / sizeof(struct kxtj9_sensor_data);
/* If the provided buffer is not large enough to return a single sample,
* then return an error.
*/
if (nsamples < 1)
{
snerr("ERROR: Buffer too small %lu < %u\n",
buflen, sizeof(struct kxtj9_sensor_data));
return (ssize_t)-EINVAL;
}
DEBUGASSERT(filep != NULL && filep->f_inode != NULL && buffer != NULL);
inode = filep->f_inode;
priv = (FAR struct kxtj9_dev_s *)inode->i_private;
DEBUGASSERT(priv != NULL && priv->i2c != NULL);
/* Return all of the samples that will fit in the user-provided buffer */
for (i = 0; i < nsamples; i++)
{
/* Get the next sample data */
ret = kxtj9_read_sensor_data(priv,
(FAR struct kxtj9_sensor_data *)buffer);
if (ret < 0)
{
snerr("ERROR: kxtj9_read_sensor_data failed: %d\n", ret);
return (ssize_t)ret;
}
/* Set up for the next sample */
buffer += sizeof(struct kxtj9_sensor_data);
}
return (ssize_t)(nsamples * sizeof(struct kxtj9_sensor_data));
}
/****************************************************************************
* Name: kxtj9_write
*
* Description:
* A dummy write method.
*
****************************************************************************/
static ssize_t kxtj9_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Name: kxtj9_ioctl
*
* Description:
* The standard ioctl method.
*
****************************************************************************/
static int kxtj9_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct kxtj9_dev_s *priv;
int ret;
/* Sanity check */
DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
inode = filep->f_inode;
priv = (FAR struct kxtj9_dev_s *)inode->i_private;
DEBUGASSERT(priv != NULL && priv->i2c != NULL);
/* Handle ioctl commands */
switch (cmd)
{
/* Start converting. Arg: None. */
case SNIOC_ENABLE:
ret = kxtj9_enable(priv, true);
break;
/* Stop converting. Arg: None. */
case SNIOC_DISABLE:
ret = kxtj9_enable(priv, false);
break;
/* Configure the KXTJ9. Arg: enum kxtj9_odr_e value. */
case SNIOC_CONFIGURE:
{
DEBUGASSERT(arg <= UINT8_MAX);
ret = kxtj9_configure(priv, (uint8_t)arg);
sninfo("SNIOC_CONFIGURE: ODR=%u ret=%d\n",
(unsigned int)arg, ret);
}
break;
/* Unrecognized commands */
default:
snerr("ERROR: Unrecognized cmd: %d arg: %lu\n", cmd, arg);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: kxtj9_register
*
* Description:
* Register the KXTJ9 accelerometer device as 'devpath'.
*
* Input Parameters:
* devpath - The full path to the driver to register, e.g., "/dev/accel0".
* i2c - An I2C driver instance.
* addr - The I2C address of the KXTJ9 accelerometer, gyroscope or
* magnetometer.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int kxtj9_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
uint8_t address)
{
FAR struct kxtj9_dev_s *priv;
int ret;
/* Sanity check */
DEBUGASSERT(devpath != NULL && i2c != NULL);
/* Initialize the device's structure */
priv = (FAR struct kxtj9_dev_s *)kmm_zalloc(sizeof(struct kxtj9_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate driver instance\n");
return -ENOMEM;
}
priv->i2c = i2c;
priv->address = address;
nxsem_init(&priv->exclsem, 0, 1);
/* Register the character driver */
ret = register_driver(devpath, &g_fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
return ret;
}
return OK;
}
#endif /* CONFIG_I2C && CONFIG_SENSORS_KXTJ9 */