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incubator-nuttx/drivers/1wire/ds28e17.c

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/****************************************************************************
* drivers/1wire/ds28e17.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 <debug.h>
#include <string.h>
#include <nuttx/kmalloc.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/1wire/1wire_master.h>
#include <nuttx/1wire/1wire_crc.h>
#include <nuttx/1wire/1wire.h>
#include <nuttx/1wire/ds28e17.h>
#include "1wire_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_DS28E17_I2C_FREQUENCY
# define CONFIG_DS28E17_I2C_FREQUENCY 400000
#endif
/* DS28E17 device 1-Wire family ID */
#define DS_FAMILY 0x19
/* DS28E17 device I2C commands */
#define DS_WRITE_DATA_WITH_STOP 0x4b
#define DS_WRITE_DATA_NO_STOP 0x5a
#define DS_WRITE_DATA_ONLY 0x69
#define DS_WRITE_DATA_ONLY_WITH_STOP 0x78
#define DS_READ_DATA_WITH_STOP 0x87
#define DS_WRITE_READ_DATA_WITH_STOP 0x2d
#define DS_WRITE_CONFIGURATION 0xd2
#define DS_READ_CONFIGURATION 0xe1
#define DS_ENABLE_SLEEP_MODE 0x1e
#define DS_READ_DEVICE_REVISION 0xc4
/* DS28E17 status bits */
#define DS_STATUS_CRC 0x01
#define DS_STATUS_ADDRESS 0x02
#define DS_STATUS_START 0x08
/* Maximum number of I2C bytes to transfer within one CRC16 protected onewire
* command (same for either read and write).
*/
#define DS_DATA_LIMIT 255
/* Default I2C frequency to use when DS28E17 is detected. */
#define DS_DEFAULT_FREQUENCY CONFIG_DS28E17_I2C_FREQUENCY
/* Default I2C stretch value. */
#define DS_DEFAULT_STRETCH 1
/* How many times to retry check for chip busy condition vanishing. */
#define DS_BUSYWAIT_RETRIES 500
/****************************************************************************
* Private Types
****************************************************************************/
struct ds28e17_dev_s /* Must be cast-compatible with onewire_master_s */
{
FAR struct onewire_dev_s *dev; /* 1-wire interface */
};
/* I2C Device, Instance */
struct ds_i2c_inst_s /* Must be cast-compatible with i2c_master_s */
{
FAR const struct i2c_ops_s *ops; /* Standard I2C operations */
/* 1-wire data */
FAR struct onewire_master_s *master; /* 1-wire bus master */
FAR struct onewire_slave_s slave; /* Our slave data on 1-wire bus */
/* I2C data */
uint32_t frequency; /* Current I2C frequency */
uint8_t stretch; /* Current I2C stretch value */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
#ifdef CONFIG_I2C_RESET
static int ds_i2c_reset(FAR struct i2c_master_s *i2cdev);
#endif
static int ds_i2c_transfer(FAR struct i2c_master_s *i2cdev,
FAR struct i2c_msg_s *msgs, int count);
/****************************************************************************
* Private Data
****************************************************************************/
/* Device Structures, Instantiation */
static const struct i2c_ops_s ds_i2c_ops =
{
ds_i2c_transfer
#ifdef CONFIG_I2C_RESET
, ds_i2c_reset
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
static int ds_error(uint8_t buf[])
{
/* Warnings */
if (buf[0] & DS_STATUS_CRC)
{
i2cwarn("crc16 match failed\n");
}
if ((buf[0] & (DS_STATUS_CRC | DS_STATUS_ADDRESS)) == 0 && buf[1] != 0)
{
i2cwarn("I2C short write, no ack for %d bytes\n", buf[1]);
}
/* Error conditions */
if (buf[0] & DS_STATUS_ADDRESS)
{
i2cerr("I2C device not responding\n");
return -ENXIO;
}
if (buf[0] & DS_STATUS_START)
{
i2cerr("I2C status start\n");
return -EAGAIN;
}
if (buf[0] != 0 || buf[1] != 0)
{
i2cerr("I2C IO error\n");
return -EIO;
}
return OK;
}
static inline int ds_busywait_time(FAR struct ds_i2c_inst_s *inst)
{
int d;
/* Return busywait time (us) for I2C speeds 100 kHz, 400 kHz
* and 900 kHz, adjusted with current stretch value.
*/
switch (inst->frequency)
{
case 100000:
d = 90;
break;
case 400000:
default:
d = 23;
break;
case 900000:
d = 10;
break;
}
return d * inst->stretch;
}
static int ds_busywait(FAR struct ds_i2c_inst_s *inst, size_t length)
{
FAR struct onewire_master_s *master = inst->master;
int retries = DS_BUSYWAIT_RETRIES;
int delay;
int ret;
uint8_t bit = 1;
/* Calculate delay time from current I2C settings. */
delay = ds_busywait_time(inst);
do
{
ret = ONEWIRE_READBIT(master->dev, &bit);
if (ret < 0)
{
i2cerr("ERROR: ONEWIRE_READBIT failed\n");
return ret;
}
if (bit == 0)
{
return OK;
}
if (retries == DS_BUSYWAIT_RETRIES)
{
/* First time, after checking bit once, do a big delay
* for I2C to process all bytes in message.
*/
up_udelay(delay * length);
}
else
{
/* Otherwise, wait for one byte duration. */
up_udelay(delay);
}
}
while (retries-- > 0);
i2cwarn("busywait timeout\n");
return -ETIMEDOUT;
}
/****************************************************************************
* Name: ds_i2c_read
*
* Description:
* Read data from I2C slave.
*
****************************************************************************/
static int ds_i2c_read(FAR struct ds_i2c_inst_s *inst, uint16_t i2c_addr,
FAR uint8_t *buffer, ssize_t length)
{
FAR struct onewire_master_s *master = inst->master;
uint16_t crc;
int ret;
uint8_t buf[5];
if (length <= 0)
{
return -EINVAL;
}
if (length > DS_DATA_LIMIT)
{
i2cerr("ERROR: reading too many bytes!\n");
return -EINVAL;
}
/* Send command to DS28E17. */
buf[0] = DS_READ_DATA_WITH_STOP;
buf[1] = i2c_addr << 1 | 0x01;
buf[2] = length;
crc = onewire_crc16(buf, 3, 0);
buf[3] = ~(crc & 0xff);
buf[4] = ~((crc >> 8) & 0xff);
ret = ONEWIRE_WRITE(master->dev, buf, 5);
if (ret < 0)
{
return ret;
}
/* Wait busy indication to vanish. */
ret = ds_busywait(inst, length + 1);
if (ret < 0)
{
return ret;
}
/* Read status from DS28E17. */
ret = ONEWIRE_READ(master->dev, buf, 1);
buf[1] = 0;
/* Check error conditions. */
ret = ds_error(buf);
if (ret < 0)
{
return ret;
}
/* Read received I2C data from DS28E17. */
return ONEWIRE_READ(master->dev, buffer, length);
}
/****************************************************************************
* Name: ds_i2c_write
*
* Description:
* Write data to I2C slave.
*
****************************************************************************/
static int ds_i2c_write(FAR struct ds_i2c_inst_s *inst, uint16_t i2c_addr,
FAR const uint8_t *buffer, ssize_t length, bool stop)
{
FAR struct onewire_master_s *master = inst->master;
uint16_t crc;
int ret;
uint8_t buf[3];
if (length <= 0)
{
return -EINVAL;
}
if (length > DS_DATA_LIMIT)
{
/* TODO: split big writes into multiple chunks. */
i2cerr("ERROR: writing too many bytes!\n");
return -EINVAL;
}
/* Write command header. */
buf[0] = stop ? DS_WRITE_DATA_WITH_STOP : DS_WRITE_DATA_NO_STOP;
buf[1] = i2c_addr << 1;
buf[2] = length;
crc = onewire_crc16(buf, 3, 0);
ret = ONEWIRE_WRITE(master->dev, buf, 3);
if (ret < 0)
{
return ret;
}
/* Write payload I2C data to DS28E17. */
crc = onewire_crc16(buffer, length, crc);
ret = ONEWIRE_WRITE(master->dev, buffer, length);
if (ret < 0)
{
return ret;
}
/* Write checksum. */
buf[0] = ~(crc & 0xff);
buf[1] = ~((crc >> 8) & 0xff);
ret = ONEWIRE_WRITE(master->dev, buf, 2);
if (ret < 0)
{
return ret;
}
/* Wait busy indication to vanish. */
ret = ds_busywait(inst, length + 1);
if (ret < 0)
{
return ret;
}
/* Read status from DS28E17. */
ret = ONEWIRE_READ(master->dev, buf, 2);
if (ret < 0)
{
return ret;
}
/* Check error conditions. */
ret = ds_error(buf);
if (ret < 0)
{
return ret;
}
/* Return count of bytes written. */
return length;
}
/****************************************************************************
* Name: ds_i2c_write_read
*
* Description:
* Write data to I2C slave and read from same address.
*
****************************************************************************/
static int ds_i2c_write_read(FAR struct ds_i2c_inst_s *inst,
uint16_t i2c_addr,
FAR const uint8_t *wbuffer, ssize_t wlength,
FAR uint8_t *rbuffer, ssize_t rlength)
{
FAR struct onewire_master_s *master = inst->master;
uint16_t crc;
int ret;
uint8_t buf[3];
if (wlength <= 0 || rlength <= 0)
{
return -EINVAL;
}
if (wlength > DS_DATA_LIMIT)
{
i2cerr("ERROR: writing too many bytes!\n");
return -EINVAL;
}
if (rlength > DS_DATA_LIMIT)
{
i2cerr("ERROR: reading too many bytes!\n");
return -EINVAL;
}
/* Write command header. */
buf[0] = DS_WRITE_READ_DATA_WITH_STOP;
buf[1] = i2c_addr << 1;
buf[2] = wlength;
crc = onewire_crc16(buf, 3, 0);
ret = ONEWIRE_WRITE(master->dev, buf, 3);
if (ret < 0)
{
return ret;
}
/* Write payload I2C data to DS28E17. */
crc = onewire_crc16(wbuffer, wlength, crc);
ret = ONEWIRE_WRITE(master->dev, wbuffer, wlength);
if (ret < 0)
{
return ret;
}
/* Write read length and checksum. */
buf[0] = rlength;
crc = onewire_crc16(buf, 1, crc);
buf[1] = ~(crc & 0xff);
buf[2] = ~((crc >> 8) & 0xff);
ret = ONEWIRE_WRITE(master->dev, buf, 3);
if (ret < 0)
{
return ret;
}
/* Wait busy indication to vanish. */
ret = ds_busywait(inst, wlength + 1 + rlength + 1);
if (ret < 0)
{
return ret;
}
/* Read status from DS28E17. */
ret = ONEWIRE_READ(master->dev, buf, 2);
if (ret < 0)
{
return ret;
}
/* Check error conditions. */
ret = ds_error(buf);
if (ret < 0)
{
return ret;
}
/* Read received I2C data from DS28E17. */
return ONEWIRE_READ(master->dev, rbuffer, rlength);
}
static int ds_i2c_setfrequency(FAR struct ds_i2c_inst_s *inst,
uint32_t frequency)
{
FAR struct onewire_master_s *master = inst->master;
uint8_t buf[2];
int speed;
int ret;
switch (frequency)
{
case 100000:
speed = 0;
break;
case 400000:
speed = 1;
break;
case 900000:
speed = 2;
break;
default:
i2cerr("ERROR: bad I2C freq %" PRId32 "\n", frequency);
return -EINVAL;
}
i2cinfo("Changing I2C freq %" PRId32 " -> %" PRId32 "\n",
inst->frequency, frequency);
/* Select DS28E17 */
ret = onewire_reset_select(master, inst->slave.romcode);
if (ret < 0)
{
i2cerr("ERROR: cannot change I2C freq\n");
return ret;
}
/* Write new speed to device */
buf[0] = DS_WRITE_CONFIGURATION;
buf[1] = speed;
ret = ONEWIRE_WRITE(master->dev, buf, 2);
if (ret < 0)
{
i2cerr("ERROR: cannot change I2C freq\n");
return ret;
}
inst->frequency = frequency;
return ret;
}
/****************************************************************************
* Name: ds_i2c_process
*
* Description:
* Common I2C transfer logic
*
* Initiates a master mode transaction on the I2C bus to transfer the
* provided messages to and from the slave devices.
*
****************************************************************************/
static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
FAR struct i2c_msg_s *msgs, int count)
{
FAR struct ds_i2c_inst_s *inst = (FAR struct ds_i2c_inst_s *)i2cdev;
FAR struct onewire_master_s *master = inst->master;
int ret;
int i;
/* Check from first message only, if we want to change I2C frequency. */
if (inst->frequency != msgs[0].frequency)
{
ds_i2c_setfrequency(inst, msgs[0].frequency);
}
/* Select DS28E17 */
i = onewire_reset_select(master, inst->slave.romcode);
if (i < 0)
{
goto errout;
}
while (i < count)
{
/* First we try to use DS_WRITE_READ_DATA_WITH_STOP to optimize
* the common case of write followed by read to a same address.
*/
if (i < count - 1 && msgs[i].addr == msgs[i + 1].addr &&
(msgs[i].flags & I2C_M_READ) == 0 &&
(msgs[i + 1].flags & I2C_M_READ))
{
/* Write-read combined transfer. */
ret = ds_i2c_write_read(inst, msgs[i].addr,
msgs[i].buffer, msgs[i].length,
msgs[i + 1].buffer, msgs[i + 1].length);
if (ret < 0)
{
i = ret;
goto errout;
}
/* We processed two messages here. */
i += 2;
}
else if (msgs[i].flags & I2C_M_READ)
{
/* Read transfer. */
ret = ds_i2c_read(inst, msgs[i].addr, msgs[i].buffer,
msgs[i].length);
if (ret < 0)
{
i = ret;
goto errout;
}
i++;
}
else
{
/* Write transfer. Stop condition only for last transfer. */
ret = ds_i2c_write(inst, msgs[i].addr, msgs[i].buffer,
msgs[i].length, i == (count - 1));
if (ret < 0)
{
i = ret;
goto errout;
}
i++;
}
/* Any more messages to process? */
if (i < count)
{
/* Yes. Resume to same DS28E17.
* Oddness: Skip-ROM does not set RS-bit needed by resume.
*/
if (master->nslaves > 1)
{
ret = onewire_reset_resume(master);
}
else
{
ret = onewire_reset_select(master, inst->slave.romcode);
}
if (ret < 0)
{
i = ret;
goto errout;
}
}
}
errout:
return i;
}
/****************************************************************************
* Name: ds_i2c_reset
*
* Description:
* Reset an I2C bus
*
****************************************************************************/
#ifdef CONFIG_I2C_RESET
static int ds_i2c_reset(FAR struct i2c_master_s *i2cdev)
{
FAR struct ds_i2c_inst_s *inst = (FAR struct ds_i2c_inst_s *)i2cdev;
FAR struct onewire_master_s *master = inst->master;
int ret;
ret = nxrmutex_lock(&master->devlock);
if (ret < 0)
{
return ret;
}
ret = ONEWIRE_RESET(master->dev);
nxrmutex_unlock(&master->devlock);
return ret;
}
#endif
/****************************************************************************
* Name: ds_i2c_transfer
*
* Description:
* Generic I2C transfer function
*
****************************************************************************/
static int ds_i2c_transfer(FAR struct i2c_master_s *i2cdev,
FAR struct i2c_msg_s *msgs,
int count)
{
FAR struct ds_i2c_inst_s *inst = (FAR struct ds_i2c_inst_s *)i2cdev;
FAR struct onewire_master_s *master = inst->master;
int ret;
ret = nxrmutex_lock(&master->devlock);
if (ret < 0)
{
return ret;
}
ret = ds_i2c_process(i2cdev, msgs, count);
nxrmutex_unlock(&master->devlock);
return ret;
}
/****************************************************************************
* Name: ds28e17_selftest
*
* Description:
*
****************************************************************************/
static int ds28e17_selftest(FAR struct ds_i2c_inst_s *inst)
{
FAR struct onewire_master_s *master = inst->master;
uint8_t txbuf[] =
{
ONEWIRE_CMD_READ_ROM
};
uint8_t rxbuf[8] =
{
0
};
uint64_t rom;
uint8_t crc;
int ret;
/* Read ROM-code of single connected slave and
* check its checksum.
*/
ret = ONEWIRE_RESET(master->dev);
if (ret < 0)
{
i2cerr("ERROR: ONEWIRE_RESET failed: %d\n", ret);
return ret;
}
ret = ONEWIRE_WRITE(master->dev, txbuf, sizeof(txbuf));
if (ret < 0)
{
i2cerr("ERROR: ONEWIRE_WRITE failed: %d\n", ret);
return ret;
}
ret = ONEWIRE_READ(master->dev, rxbuf, sizeof(rxbuf));
if (ret < 0)
{
i2cerr("ERROR: ONEWIRE_READ failed: %d\n", ret);
return ret;
}
#ifdef CONFIG_DEBUG_I2C_INFO
lib_dumpbuffer("ds28e17_selftest: rxbuf", rxbuf, sizeof(rxbuf));
#endif
memcpy(&rom, rxbuf, 8);
i2cinfo("recv rom: 0x%" PRIx64 "\n", rom);
crc = onewire_crc8(rxbuf, sizeof(rxbuf)-1);
i2cinfo("crc8=%d, recv crc8=%d\n", crc, (int)rxbuf[7]);
if (crc != rxbuf[7])
{
i2cerr("ERROR: crc8 does not match!\n");
ret = -EIO;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ds28e17_search
*
* Description:
* Search all DS28E17 devices from a 1-wire network.
*
* Input Parameters:
* priv - Pointer to the associated DS28E17
* cb_search - Callback to call on each device found
* arg - Argument passed to cb_search
*
* Return Value:
* Number of DS28E17 devices present.
*
****************************************************************************/
int ds28e17_search(FAR struct ds28e17_dev_s *priv,
void (*cb_search)(int family,
uint64_t romcode,
void *arg),
void *arg)
{
FAR struct onewire_master_s *master = (FAR struct onewire_master_s *)priv;
DEBUGASSERT(master != NULL && cb_search != NULL);
return onewire_search(master, DS_FAMILY, false, cb_search, arg);
}
/****************************************************************************
* Name: ds28e17_lower_half
*
* Description:
* Initialize the lower half of the DS28E17 by creating a i2c_master_s
* for the virtual i2c master and link it to the associated DS28E17 and
* its port.
*
* Input Parameters:
* dev - Pointer to the associated DS28E17
* romcode - The unique 64-bit address in 1-wire network.
* Use zero for skip-ROM mode.
*
* Returned Value:
* i2c device instance; NULL on failure.
*
****************************************************************************/
FAR struct i2c_master_s *
ds28e17_lower_half(FAR struct ds28e17_dev_s *priv, uint64_t romcode)
{
FAR struct ds_i2c_inst_s *inst; /* device, single instance */
FAR struct onewire_master_s *master = (FAR struct onewire_master_s *)priv;
int ret;
DEBUGASSERT(master != NULL);
/* Allocate instance */
inst = kmm_zalloc(sizeof(struct ds_i2c_inst_s));
if (inst == NULL)
{
i2cerr("ERROR: Failed to allocate instance\n");
return NULL;
}
/* Initialize instance */
inst->ops = &ds_i2c_ops;
inst->master = master;
inst->frequency = 400000; /* power-on frequency */
inst->stretch = DS_DEFAULT_STRETCH;
inst->slave.romcode = romcode;
/* We need a recursive lock as this may be called from a search callback. */
ret = nxrmutex_lock(&master->devlock);
if (ret < 0)
{
kmm_free(inst);
i2cerr("ERROR: Failed to acquire lock\n");
return NULL;
}
if (onewire_addslave(master, &inst->slave) < 0)
{
kmm_free(inst);
i2cerr("ERROR: Failed to add slave\n");
nxrmutex_unlock(&master->devlock);
return NULL;
}
/* Should default speed be different from DS28E17 power-on frequency? */
if (inst->frequency != DS_DEFAULT_FREQUENCY)
{
ds_i2c_setfrequency(inst, DS_DEFAULT_FREQUENCY);
}
/* TODO: better selftest */
if (master->maxslaves == 1)
{
ds28e17_selftest(inst);
}
nxrmutex_unlock(&master->devlock);
return (FAR struct i2c_master_s *)inst;
}
/****************************************************************************
* Name: ds28e17_lower_half_unregister
*
* Description:
* Put back the lower half of the DS28E17.
*
* Input Parameters:
* priv - Pointer to the associated DS28E17
* i2cdev - i2c device instance from ds28e17_lower_half()
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int ds28e17_lower_half_unregister(FAR struct ds28e17_dev_s *priv,
FAR struct i2c_master_s *i2cdev)
{
FAR struct ds_i2c_inst_s *inst = (FAR struct ds_i2c_inst_s *)i2cdev;
FAR struct onewire_master_s *master = inst->master;
int ret;
ret = nxrmutex_lock(&master->devlock);
if (ret < 0)
{
return ret;
}
ret = onewire_removeslave(master, &inst->slave);
if (ret < 0)
{
kmm_free(inst);
i2cerr("ERROR: Failed to remove slave\n");
nxrmutex_unlock(&master->devlock);
return ret;
}
kmm_free(inst);
nxrmutex_unlock(&master->devlock);
return OK;
}
/****************************************************************************
* Name: ds28e17_initialize
*
* Description:
* Returns a common DS28E17 device from 1-wire lower half device
*
* Input Parameters:
* dev - The allocated 1-wire lower half
*
****************************************************************************/
FAR struct ds28e17_dev_s *ds28e17_initialize(FAR struct onewire_dev_s *dev)
{
FAR struct onewire_master_s *priv;
priv = onewire_initialize(dev, DS_DEFAULT_MAXSLAVES);
/* We do not have our own data fields so just cast it. */
return (FAR struct ds28e17_dev_s *)priv;
}
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