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incubator-nuttx/drivers/ioexpander/mcp23x17.c

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/****************************************************************************
* drivers/ioexpander/mcp23x17.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 <nuttx/irq.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/kmalloc.h>
#include <nuttx/ioexpander/ioexpander.h>
#include "mcp23x17.h"
#if defined(CONFIG_IOEXPANDER_MCP23X17)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_I2C
# warning I2C support is required (CONFIG_I2C)
#endif
#if (!defined CONFIG_SCHED_WORKQUEUE) && (defined CONFIG_MCP23X17_INT_ENABLE)
# error Work queue support is required (CONFIG_SCHED_WORKQUEUE)
#endif
#if (!defined CONFIG_SCHED_HPWORK) && (defined CONFIG_MCP23X17_INT_ENABLE)
# error High-Priority Work support is required (CONFIG_SCHED_HPWORK)
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static inline int mcp23x17_write(FAR struct mcp23x17_dev_s *priv,
FAR const uint8_t *wbuffer, int wbuflen);
static inline int mcp23x17_writeread(FAR struct mcp23x17_dev_s *priv,
FAR const uint8_t *wbuffer, int wbuflen, FAR uint8_t *rbuffer,
int rbuflen);
static int mcp23x17_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int dir);
static int mcp23x17_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int opt, void *val);
static int mcp23x17_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
bool value);
static int mcp23x17_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value);
static int mcp23x17_readbuf(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value);
#ifdef CONFIG_IOEXPANDER_MULTIPIN
static int mcp23x17_multiwritepin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values, int count);
static int mcp23x17_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values, int count);
static int mcp23x17_multireadbuf(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values, int count);
#endif
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
static FAR void *mcp23x17_attach(FAR struct ioexpander_dev_s *dev,
ioe_pinset_t pinset, ioe_callback_t callback, FAR void *arg);
static int mcp23x17_detach(FAR struct ioexpander_dev_s *dev,
FAR void *handle);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
#ifndef CONFIG_MCP23X17_MULTIPLE
/* If only a single MCP23X17 device is supported, then the driver state
* structure may as well be pre-allocated.
*/
static struct mcp23x17_dev_s g_mcp23x17;
/* Otherwise, we will need to maintain allocated driver instances in a list */
#else
static struct mcp23x17_dev_s *g_mcp23x17list;
#endif
/* I/O expander vtable */
static const struct ioexpander_ops_s g_mcp23x17_ops =
{
mcp23x17_direction,
mcp23x17_option,
mcp23x17_writepin,
mcp23x17_readpin,
mcp23x17_readbuf
#ifdef CONFIG_IOEXPANDER_MULTIPIN
, mcp23x17_multiwritepin
, mcp23x17_multireadpin
, mcp23x17_multireadbuf
#endif
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
, mcp23x17_attach
, mcp23x17_detach
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mcp23x17_write
*
* Description:
* Write to the I2C device.
*
****************************************************************************/
static inline int mcp23x17_write(FAR struct mcp23x17_dev_s *priv,
FAR const uint8_t *wbuffer, int wbuflen)
{
struct i2c_msg_s msg;
int ret;
/* Setup for the transfer */
msg.frequency = priv->config->frequency;
msg.addr = priv->config->address;
msg.flags = 0;
msg.buffer = (FAR uint8_t *)wbuffer; /* Override const */
msg.length = wbuflen;
/* Then perform the transfer. */
ret = I2C_TRANSFER(priv->i2c, &msg, 1);
return (ret >= 0) ? OK : ret;
}
/****************************************************************************
* Name: mcp23x17_writeread
*
* Description:
* Write to then read from the I2C device.
*
****************************************************************************/
static inline int mcp23x17_writeread(FAR struct mcp23x17_dev_s *priv,
FAR const uint8_t *wbuffer, int wbuflen,
FAR uint8_t *rbuffer, int rbuflen)
{
struct i2c_config_s config;
/* Set up the configuration and perform the write-read operation */
config.frequency = priv->config->frequency;
config.address = priv->config->address;
config.addrlen = 7;
return i2c_writeread(priv->i2c, &config, wbuffer, wbuflen,
rbuffer, rbuflen);
}
/****************************************************************************
* Name: mcp23x17_setbit
*
* Description:
* Write a bit in a register pair
*
****************************************************************************/
static int mcp23x17_setbit(FAR struct mcp23x17_dev_s *priv, uint8_t addr,
uint8_t pin, bool bitval)
{
uint8_t buf[2];
int ret;
if (pin > 15)
{
return -ENXIO;
}
else if (pin > 7)
{
addr += 1;
pin -= 8;
}
buf[0] = addr;
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Get the shadowed register value */
buf[1] = priv->sreg[addr];
#else
/* Get the register value from the IO-Expander */
ret = mcp23x17_writeread(priv, &buf[0], 1, &buf[1], 1);
if (ret < 0)
{
return ret;
}
#endif
if (bitval)
{
buf[1] |= (1 << pin);
}
else
{
buf[1] &= ~(1 << pin);
}
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Save the new register value in the shadow register */
priv->sreg[addr] = buf[1];
#endif
ret = mcp23x17_write(priv, buf, 2);
#ifdef CONFIG_MCP23X17_RETRY
if (ret != OK)
{
/* Try again (only once) */
ret = mcp23x17_write(priv, buf, 2);
}
#endif
return ret;
}
/****************************************************************************
* Name: mcp23x17_getbit
*
* Description:
* Get a bit from a register pair
*
****************************************************************************/
static int mcp23x17_getbit(FAR struct mcp23x17_dev_s *priv, uint8_t addr,
uint8_t pin, FAR bool *val)
{
uint8_t buf;
int ret;
if (pin > 15)
{
return -ENXIO;
}
else if (pin > 7)
{
addr += 1;
pin -= 8;
}
ret = mcp23x17_writeread(priv, &addr, 1, &buf, 1);
if (ret < 0)
{
return ret;
}
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Save the new register value in the shadow register */
priv->sreg[addr] = buf;
#endif
*val = (buf >> pin) & 1;
return OK;
}
/****************************************************************************
* Name: mcp23x17_direction
*
* Description:
* Set the direction of an ioexpander pin. Required.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin to alter in this call
* dir - One of the IOEXPANDER_DIRECTION_ macros
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int direction)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
if (direction != IOEXPANDER_DIRECTION_IN &&
direction != IOEXPANDER_DIRECTION_IN_PULLUP &&
direction != IOEXPANDER_DIRECTION_OUT)
{
return -EINVAL;
}
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_setbit(priv, MCP23X17_IODIRA, pin,
(direction == IOEXPANDER_DIRECTION_IN) ||
(direction == IOEXPANDER_DIRECTION_IN_PULLUP));
if (ret < 0)
{
nxmutex_unlock(&priv->lock);
return ret;
}
ret = mcp23x17_setbit(priv, MCP23X17_GPPUA, pin,
(direction == IOEXPANDER_DIRECTION_IN_PULLUP));
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* Name: mcp23x17_option
*
* Description:
* Set pin options. Required.
* Since all IO expanders have various pin options, this API allows setting
* pin options in a flexible way.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin to alter in this call
* opt - One of the IOEXPANDER_OPTION_ macros
* val - The option's value
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int opt, FAR void *value)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret = -EINVAL;
if (opt == IOEXPANDER_OPTION_INVERT)
{
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_setbit(priv, MCP23X17_IPOLA, pin,
((uintptr_t)value == IOEXPANDER_VAL_INVERT));
nxmutex_unlock(&priv->lock);
}
return ret;
}
/****************************************************************************
* Name: mcp23x17_writepin
*
* Description:
* Set the pin level. Required.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin to alter in this call
* val - The pin level. Usually TRUE will set the pin high,
* except if OPTION_INVERT has been set on this pin.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
bool value)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_setbit(priv, MCP23X17_GPIOA, pin, value);
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* Name: mcp23x17_readpin
*
* Description:
* Read the actual PIN level. This can be different from the last value
* written to this pin. Required.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin
* valptr - Pointer to a buffer where the pin level is stored. Usually TRUE
* if the pin is high, except if OPTION_INVERT has been set on
* this pin.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_getbit(priv, MCP23X17_GPIOA, pin, value);
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* Name: mcp23x17_readbuf
*
* Description:
* Read the buffered pin level.
* This can be different from the actual pin state. Required.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin
* valptr - Pointer to a buffer where the level is stored.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_readbuf(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_getbit(priv, MCP23X17_GPIOA, pin, value);
nxmutex_unlock(&priv->lock);
return ret;
}
#ifdef CONFIG_IOEXPANDER_MULTIPIN
/****************************************************************************
* Name: mcp23x17_getmultibits
*
* Description:
* Read multiple bits from MCP23X17 registers.
*
****************************************************************************/
static int mcp23x17_getmultibits(FAR struct mcp23x17_dev_s *priv,
uint8_t addr,
FAR uint8_t *pins,
FAR bool *values,
int count)
{
uint8_t buf[2];
int ret = OK;
int i;
int index;
int pin;
ret = mcp23x17_writeread(priv, &addr, 1, buf, 2);
if (ret < 0)
{
return ret;
}
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Save the new register value in the shadow register */
priv->sreg[addr] = buf[0];
priv->sreg[addr + 1] = buf[1];
#endif
/* Read the requested bits */
for (i = 0; i < count; i++)
{
index = 0;
pin = pins[i];
if (pin > 15)
{
return -ENXIO;
}
else if (pin > 7)
{
index = 1;
pin -= 8;
}
values[i] = (buf[index] >> pin) & 1;
}
return OK;
}
/****************************************************************************
* Name: mcp23x17_multiwritepin
*
* Description:
* Set the pin level for multiple pins. This routine may be faster than
* individual pin accesses. Optional.
*
* Input Parameters:
* dev - Device-specific state data
* pins - The list of pin indexes to alter in this call
* val - The list of pin levels.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_multiwritepin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
uint8_t addr = MCP23X17_GPIOA;
uint8_t buf[3];
int ret;
int i;
int index;
int pin;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
/* Start by reading both registers, whatever the pins to change. We could
* attempt to read one port only if all pins were on the same port, but
* this would not save much.
*/
#ifndef CONFIG_MCP23X17_SHADOW_MODE
ret = mcp23x17_writeread(priv, &addr, 1, &buf[1], 2);
if (ret < 0)
{
nxmutex_unlock(&priv->lock);
return ret;
}
#else
/* In Shadow-Mode we "read" the pin status from the shadow registers */
buf[1] = priv->sreg[addr];
buf[2] = priv->sreg[addr + 1];
#endif
/* Apply the user defined changes */
for (i = 0; i < count; i++)
{
index = 1;
pin = pins[i];
if (pin > 15)
{
nxmutex_unlock(&priv->lock);
return -ENXIO;
}
else if (pin > 7)
{
index = 2;
pin -= 8;
}
if (values[i])
{
buf[index] |= (1 << pin);
}
else
{
buf[index] &= ~(1 << pin);
}
}
/* Now write back the new pins states */
buf[0] = addr;
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Save the new register values in the shadow register */
priv->sreg[addr] = buf[1];
priv->sreg[addr + 1] = buf[2];
#endif
ret = mcp23x17_write(priv, buf, 3);
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* Name: mcp23x17_multireadpin
*
* Description:
* Read the actual level for multiple pins. This routine may be faster than
* individual pin accesses. Optional.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The list of pin indexes to read
* valptr - Pointer to a buffer where the pin levels are stored.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_getmultibits(priv, MCP23X17_GPIOA,
pins, values, count);
nxmutex_unlock(&priv->lock);
return ret;
}
/****************************************************************************
* Name: mcp23x17_multireadbuf
*
* Description:
* Read the buffered level of multiple pins. This routine may be faster
* than individual pin accesses. Optional.
*
* Input Parameters:
* dev - Device-specific state data
* pin - The index of the pin
* valptr - Pointer to a buffer where the buffered levels are stored.
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_multireadbuf(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return ret;
}
ret = mcp23x17_getmultibits(priv, MCP23X17_GPIOA,
pins, values, count);
nxmutex_unlock(&priv->lock);
return ret;
}
#endif
#ifdef CONFIG_MCP23X17_INT_ENABLE
/****************************************************************************
* Name: mcp23x17_attach
*
* Description:
* Attach and enable a pin interrupt callback function.
*
* Input Parameters:
* dev - Device-specific state data
* pinset - The set of pin events that will generate the callback
* callback - The pointer to callback function. NULL will detach the
* callback.
* arg - User-provided callback argument
*
* Returned Value:
* A non-NULL handle value is returned on success. This handle may be
* used later to detach and disable the pin interrupt.
*
****************************************************************************/
static FAR void *mcp23x17_attach(FAR struct ioexpander_dev_s *dev,
ioe_pinset_t pinset,
ioe_callback_t callback,
FAR void *arg)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
FAR void *handle = NULL;
uint8_t addr = MCP23X17_GPINTENA;
uint8_t buf[3];
int i;
int ret;
/* Get exclusive access to the MCP23X17 */
ret = nxmutex_lock(&priv->lock);
if (ret < 0)
{
return NULL;
}
ret = mcp23x17_writeread(priv, &addr, 1, &buf[1], 2);
if (ret < 0)
{
nxmutex_unlock(&priv->lock);
return NULL;
}
buf[0] = addr;
buf[1] |= (uint8_t)(pinset & 0x00ff);
buf[2] |= (uint8_t)((pinset & 0xff00) >> 8);
ret = mcp23x17_write(priv, buf, 3);
if (ret < 0)
{
nxmutex_unlock(&priv->lock);
return NULL;
}
/* Find and available in entry in the callback table */
for (i = 0; i < CONFIG_MCP23X17_INT_NCALLBACKS; i++)
{
/* Is this entry available (i.e., no callback attached) */
if (priv->cb[i].cbfunc == NULL)
{
/* Yes.. use this entry */
priv->cb[i].pinset = pinset;
priv->cb[i].cbfunc = callback;
priv->cb[i].cbarg = arg;
handle = &priv->cb[i];
break;
}
}
/* Add this callback to the table */
nxmutex_unlock(&priv->lock);
return handle;
}
/****************************************************************************
* Name: mcp23x17_detach
*
* Description:
* Detach and disable a pin interrupt callback function.
*
* Input Parameters:
* dev - Device-specific state data
* handle - The non-NULL opaque value return by mcp23x17_attch()
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int mcp23x17_detach(FAR struct ioexpander_dev_s *dev,
FAR void *handle)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)dev;
FAR struct mcp23x17_callback_s *cb =
(FAR struct mcp23x17_callback_s *)handle;
DEBUGASSERT(priv != NULL && cb != NULL);
DEBUGASSERT((uintptr_t)cb >= (uintptr_t)&priv->cb[0] &&
(uintptr_t)cb <=
(uintptr_t)&priv->cb[CONFIG_MCP23X17_INT_NCALLBACKS - 1]);
UNUSED(priv);
cb->pinset = 0;
cb->cbfunc = NULL;
cb->cbarg = NULL;
return OK;
}
/****************************************************************************
* Name: mcp23x17_irqworker
*
* Description:
* Handle GPIO interrupt events (this function actually executes in the
* context of the worker thread).
*
****************************************************************************/
static void mcp23x17_irqworker(void *arg)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)arg;
uint8_t addr = MCP23X17_INTFA;
uint8_t buf[2];
ioe_pinset_t pinset;
int ret;
int i;
/* Read interrupt flags */
ret = mcp23x17_writeread(priv, &addr, 1, buf, 2);
if (ret == OK)
{
/* Create a 16-bit pinset */
pinset = ((unsigned int)buf[1] << 8) | buf[0];
/* Perform pin interrupt callbacks */
for (i = 0; i < CONFIG_MCP23X17_INT_NCALLBACKS; i++)
{
/* Is this entry valid (i.e., callback attached)? If so, did
* any of the requested pin interrupts occur?
*/
if (priv->cb[i].cbfunc != NULL)
{
/* Did any of the requested pin interrupts occur? */
ioe_pinset_t match = pinset & priv->cb[i].pinset;
if (match != 0)
{
/* Yes.. perform the callback */
priv->cb[i].cbfunc(&priv->dev, match,
priv->cb[i].cbarg);
}
}
}
/* Read GPIOs to clear interrupt condition */
addr = MCP23X17_INTCAPA;
mcp23x17_writeread(priv, &addr, 1, buf, 2);
#ifdef CONFIG_MCP23X17_SHADOW_MODE
/* Don't forget to update the shadow registers at this point */
priv->sreg[addr] = buf[0];
priv->sreg[addr + 1] = buf[1];
#endif
}
/* Re-enable interrupts */
priv->config->enable(priv->config, TRUE);
}
/****************************************************************************
* Name: mcp23x17_interrupt
*
* Description:
* Handle GPIO interrupt events (this function executes in the
* context of the interrupt).
*
****************************************************************************/
static int mcp23x17_interrupt(int irq, FAR void *context, FAR void *arg)
{
FAR struct mcp23x17_dev_s *priv = (FAR struct mcp23x17_dev_s *)arg;
/* In complex environments, we cannot do I2C transfers from the interrupt
* handler because semaphores are probably used to lock the I2C bus. In
* this case, we will defer processing to the worker thread. This is also
* much kinder in the use of system resources and is, therefore, probably
* a good thing to do in any event.
*/
/* Notice that further GPIO interrupts are disabled until the work is
* actually performed. This is to prevent overrun of the worker thread.
* Interrupts are re-enabled in mcp23x17_irqworker() when the work is
* completed.
*/
if (work_available(&priv->work))
{
priv->config->enable(priv->config, FALSE);
work_queue(HPWORK, &priv->work, mcp23x17_irqworker,
(FAR void *)priv, 0);
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mcp23x17_initialize
*
* Description:
* Initialize a MCP23X17 I2C device.
*
* TODO: Add support for more than one device.
*
****************************************************************************/
FAR struct ioexpander_dev_s *mcp23x17_initialize(
FAR struct i2c_master_s *i2cdev,
FAR struct mcp23x17_config_s *config)
{
FAR struct mcp23x17_dev_s *priv;
#ifdef CONFIG_MCP23X17_INT_MIRROR
uint8_t buf[3];
#endif
DEBUGASSERT(i2cdev != NULL && config != NULL);
#ifdef CONFIG_MCP23X17_MULTIPLE
/* Allocate the device state structure */
priv = (FAR struct mcp23x17_dev_s *)
kmm_zalloc(sizeof(struct mcp23x17_dev_s));
if (!priv)
{
return NULL;
}
/* And save the device structure in the list of MCP23X17 so that we can
* find it later.
*/
priv->flink = g_mcp23x17list;
g_mcp23x17list = priv;
#else
/* Use the global MCP23X17 driver instance */
priv = &g_mcp23x17;
#endif
/* Initialize the device state structure */
priv->i2c = i2cdev;
priv->dev.ops = &g_mcp23x17_ops;
priv->config = config;
#ifdef CONFIG_MCP23X17_INT_ENABLE
#ifdef CONFIG_MCP23X17_INT_MIRROR
buf[0] = MCP23X17_IOCON;
buf[1] = 0x40;
buf[2] = 0x40;
mcp23x17_write(priv, buf, 3);
#endif
priv->config->attach(priv->config, mcp23x17_interrupt, priv);
priv->config->enable(priv->config, TRUE);
#endif
nxmutex_init(&priv->lock);
return &priv->dev;
}
#endif /* CONFIG_IOEXPANDER_MCP23X17 */
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