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incubator-nuttx/drivers/ioexpander/pca9538.c

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/****************************************************************************
* drivers/ioexpander/pca9538.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 <stdbool.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 "pca9538.h"
#if defined(CONFIG_IOEXPANDER_PCA9538)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_I2C
# warning I2C support is required (CONFIG_I2C)
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static inline int pca9538_write(FAR struct pca9538_dev_s *pca,
FAR const uint8_t *wbuffer, int wbuflen);
static inline int pca9538_writeread(FAR struct pca9538_dev_s *pca,
FAR const uint8_t *wbuffer, int wbuflen, FAR uint8_t *rbuffer,
int rbuflen);
static int pca9538_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int dir);
static int pca9538_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int opt, void *val);
static int pca9538_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
bool value);
static int pca9538_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value);
static int pca9538_readbuf(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value);
#ifdef CONFIG_IOEXPANDER_MULTIPIN
static int pca9538_multiwritepin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values, int count);
static int pca9538_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values, int count);
static int pca9538_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 *pca9538_attach(FAR struct ioexpander_dev_s *dev,
ioe_pinset_t pinset, ioe_callback_t callback, FAR void *arg);
static int pca9538_detach(FAR struct ioexpander_dev_s *dev,
FAR void *handle);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
#ifndef CONFIG_PCA9538_MULTIPLE
/* If only a single PCA9538 device is supported, then the driver state
* structure may as well be pre-allocated.
*/
static struct pca9538_dev_s g_pca9538;
/* Otherwise, we will need to maintain allocated driver instances in a list */
#else
static struct pca9538_dev_s *g_pca9538list;
#endif
/* I/O expander vtable */
static const struct ioexpander_ops_s g_pca9538_ops =
{
pca9538_direction,
pca9538_option,
pca9538_writepin,
pca9538_readpin,
pca9538_readbuf
#ifdef CONFIG_IOEXPANDER_MULTIPIN
, pca9538_multiwritepin
, pca9538_multireadpin
, pca9538_multireadbuf
#endif
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
, pca9538_attach
, pca9538_detach
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pca9538_write
*
* Description:
* Write to the I2C device.
*
****************************************************************************/
static inline int pca9538_write(FAR struct pca9538_dev_s *pca,
FAR const uint8_t *wbuffer, int wbuflen)
{
struct i2c_msg_s msg;
int ret;
/* Setup for the transfer */
msg.frequency = pca->config->frequency;
msg.addr = pca->config->address;
msg.flags = 0;
msg.buffer = (FAR uint8_t *)wbuffer; /* Override const */
msg.length = wbuflen;
/* Then perform the transfer. */
ret = I2C_TRANSFER(pca->i2c, &msg, 1);
return (ret >= 0) ? OK : ret;
}
/****************************************************************************
* Name: pca9538_writeread
*
* Description:
* Write to then read from the I2C device.
*
****************************************************************************/
static inline int pca9538_writeread(FAR struct pca9538_dev_s *pca,
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 = pca->config->frequency;
config.address = pca->config->address;
config.addrlen = 7;
return i2c_writeread(pca->i2c, &config, wbuffer,
wbuflen, rbuffer, rbuflen);
}
/****************************************************************************
* Name: pca9538_setbit
*
* Description:
* Write a bit in a register pair
*
****************************************************************************/
static int pca9538_setbit(FAR struct pca9538_dev_s *pca, uint8_t addr,
uint8_t pin, bool bitval)
{
uint8_t buf[2];
int ret;
if (pin >= PCA9538_GPIO_NPINS)
{
return -ENXIO;
}
buf[0] = addr;
#ifdef CONFIG_PCA9538_SHADOW_MODE
/* Get the shadowed register value */
buf[1] = pca->sreg[addr];
#else
/* Get the register value from the IO-Expander */
ret = pca9538_writeread(pca, &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_PCA9538_SHADOW_MODE
/* Save the new register value in the shadow register */
pca->sreg[addr] = buf[1];
#endif
ret = pca9538_write(pca, buf, 2);
#ifdef CONFIG_PCA9538_RETRY
if (ret != OK)
{
/* Try again (only once) */
ret = pca9538_write(pca, buf, 2);
}
#endif
return ret;
}
/****************************************************************************
* Name: pca9538_getbit
*
* Description:
* Get a bit from a register pair
*
****************************************************************************/
static int pca9538_getbit(FAR struct pca9538_dev_s *pca, uint8_t addr,
uint8_t pin, FAR bool *val)
{
uint8_t buf;
int ret;
if (pin >= PCA9538_GPIO_NPINS)
{
return -ENXIO;
}
ret = pca9538_writeread(pca, &addr, 1, &buf, 1);
if (ret < 0)
{
return ret;
}
#ifdef CONFIG_PCA9538_SHADOW_MODE
/* Save the new register value in the shadow register */
pca->sreg[addr] = buf;
#endif
*val = (buf >> pin) & 1;
return OK;
}
/****************************************************************************
* Name: pca9538_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 pca9538_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int direction)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
if (direction != IOEXPANDER_DIRECTION_IN &&
direction != IOEXPANDER_DIRECTION_OUT)
{
return -EINVAL;
}
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_setbit(pca, PCA9538_REG_CONFIG, pin,
(direction == IOEXPANDER_DIRECTION_IN));
nxmutex_unlock(&pca->lock);
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int opt, FAR void *value)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret = -EINVAL;
if (opt == IOEXPANDER_OPTION_INVERT)
{
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_setbit(pca, PCA9538_REG_POLINV, pin,
((uintptr_t)value == IOEXPANDER_VAL_INVERT));
nxmutex_unlock(&pca->lock);
}
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_writepin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
bool value)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_setbit(pca, PCA9538_REG_OUTPUT, pin, value);
nxmutex_unlock(&pca->lock);
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_getbit(pca, PCA9538_REG_INPUT, pin, value);
nxmutex_unlock(&pca->lock);
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_readbuf(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_getbit(pca, PCA9538_REG_OUTPUT, pin, value);
nxmutex_unlock(&pca->lock);
return ret;
}
#ifdef CONFIG_IOEXPANDER_MULTIPIN
/****************************************************************************
* Name: pca9538_getmultibits
*
* Description:
* Read multiple bits from PCA9538 registers.
*
****************************************************************************/
static int pca9538_getmultibits(FAR struct pca9538_dev_s *pca, 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 = pca9538_writeread(pca, &addr, 1, buf, 2);
if (ret < 0)
{
return ret;
}
#ifdef CONFIG_PCA9538_SHADOW_MODE
/* Save the new register value in the shadow register */
pca->sreg[addr] = buf[0];
pca->sreg[addr + 1] = buf[1];
#endif
/* Read the requested bits */
for (i = 0; i < count; i++)
{
index = 0;
pin = pins[i];
if (pin >= PCA9538_GPIO_NPINS)
{
return -ENXIO;
}
values[i] = (buf[index] >> pin) & 1;
}
return OK;
}
/****************************************************************************
* Name: pca9538_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 pca9538_multiwritepin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
uint8_t addr = PCA9538_REG_OUTPUT;
uint8_t buf[3];
int ret;
int i;
int index;
int pin;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->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_PCA9538_SHADOW_MODE
ret = pca9538_writeread(pca, &addr, 1, &buf[1], 2);
if (ret < 0)
{
nxmutex_unlock(&pca->lock);
return ret;
}
#else
/* In Shadow-Mode we "read" the pin status from the shadow registers */
buf[1] = pca->sreg[addr];
buf[2] = pca->sreg[addr + 1];
#endif
/* Apply the user defined changes */
for (i = 0; i < count; i++)
{
index = 1;
pin = pins[i];
if (pin >= PCA9538_GPIO_NPINS)
{
nxmutex_unlock(&pca->lock);
return -ENXIO;
}
if (values[i])
{
buf[index] |= (1 << pin);
}
else
{
buf[index] &= ~(1 << pin);
}
}
/* Now write back the new pins states */
buf[0] = addr;
#ifdef CONFIG_PCA9538_SHADOW_MODE
/* Save the new register values in the shadow register */
pca->sreg[addr] = buf[1];
pca->sreg[addr + 1] = buf[2];
#endif
ret = pca9538_write(pca, buf, 3);
nxmutex_unlock(&pca->lock);
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_getmultibits(pca, PCA9538_REG_INPUT,
pins, values, count);
nxmutex_unlock(&pca->lock);
return ret;
}
/****************************************************************************
* Name: pca9538_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 pca9538_multireadbuf(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
ret = pca9538_getmultibits(pca, PCA9538_REG_OUTPUT,
pins, values, count);
nxmutex_unlock(&pca->lock);
return ret;
}
#endif
#ifdef CONFIG_PCA9538_INT_ENABLE
/****************************************************************************
* Name: pca9538_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 *pca9538_attach(FAR struct ioexpander_dev_s *dev,
ioe_pinset_t pinset, ioe_callback_t callback,
FAR void *arg)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
FAR void *handle = NULL;
int i;
int ret;
/* Get exclusive access to the PCA555 */
ret = nxmutex_lock(&pca->lock);
if (ret < 0)
{
return ret;
}
/* Find and available in entry in the callback table */
for (i = 0; i < CONFIG_PCA9538_INT_NCALLBACKS; i++)
{
/* Is this entry available (i.e., no callback attached) */
if (pca->cb[i].cbfunc == NULL)
{
/* Yes.. use this entry */
pca->cb[i].pinset = pinset;
pca->cb[i].cbfunc = callback;
pca->cb[i].cbarg = arg;
handle = &pca->cb[i];
break;
}
}
/* Add this callback to the table */
nxmutex_unlock(&pca->lock);
return handle;
}
/****************************************************************************
* Name: pca9538_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 pca9538_attch()
*
* Returned Value:
* 0 on success, else a negative error code
*
****************************************************************************/
static int pca9538_detach(FAR struct ioexpander_dev_s *dev, FAR void *handle)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)dev;
FAR struct pca9538_callback_s *cb =
(FAR struct pca9538_callback_s *)handle;
DEBUGASSERT(pca != NULL && cb != NULL);
DEBUGASSERT((uintptr_t)cb >= (uintptr_t)&pca->cb[0] &&
(uintptr_t)cb <= (uintptr_t)&pca->cb[CONFIG_TCA64XX_INT_NCALLBACKS - 1]);
UNUSED(pca);
cb->pinset = 0;
cb->cbfunc = NULL;
cb->cbarg = NULL;
return OK;
}
/****************************************************************************
* Name: pca9538_irqworker
*
* Description:
* Handle GPIO interrupt events (this function actually executes in the
* context of the worker thread).
*
****************************************************************************/
static void pca9538_irqworker(void *arg)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_dev_s *)arg;
uint8_t addr = PCA9538_REG_INPUT;
uint8_t buf[2];
ioe_pinset_t pinset;
int ret;
int i;
/* Read inputs */
ret = pca9538_writeread(pca, &addr, 1, buf, 2);
if (ret == OK)
{
#ifdef CONFIG_PCA9538_SHADOW_MODE
/* Don't forget to update the shadow registers at this point */
pca->sreg[addr] = buf[0];
pca->sreg[addr + 1] = buf[1];
#endif
/* Create a 16-bit pinset */
pinset = ((unsigned int)buf[0] << 8) | buf[1];
/* Perform pin interrupt callbacks */
for (i = 0; i < CONFIG_PCA9538_INT_NCALLBACKS; i++)
{
/* Is this entry valid (i.e., callback attached)? If so, did
* any of the requested pin interrupts occur?
*/
if (pca->cb[i].cbfunc != NULL)
{
/* Did any of the requested pin interrupts occur? */
ioe_pinset_t match = pinset & pca->cb[i].pinset;
if (match != 0)
{
/* Yes.. perform the callback */
pca->cb[i].cbfunc(&pca->dev, match,
pca->cb[i].cbarg);
}
}
}
}
/* Re-enable interrupts */
pca->config->enable(pca->config, TRUE);
}
/****************************************************************************
* Name: pca9538_interrupt
*
* Description:
* Handle GPIO interrupt events (this function executes in the
* context of the interrupt).
*
****************************************************************************/
static int pca9538_interrupt(int irq, FAR void *context, FAR void *arg)
{
FAR struct pca9538_dev_s *pca = (FAR struct pca9538_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 pca9538_irqworker() when the work is
* completed.
*/
if (work_available(&pca->work))
{
pca->config->enable(pca->config, FALSE);
work_queue(HPWORK, &pca->work, pca9538_irqworker,
(FAR void *)pca, 0);
}
return OK;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pca9538_initialize
*
* Description:
* Initialize a PCA9538 I2C device.
*
****************************************************************************/
FAR struct ioexpander_dev_s *pca9538_initialize
(FAR struct i2c_master_s *i2cdev, FAR struct pca9538_config_s *config)
{
FAR struct pca9538_dev_s *pcadev;
DEBUGASSERT(i2cdev != NULL && config != NULL &&
config->set_nreset_pin != NULL);
config->set_nreset_pin(true);
#ifdef CONFIG_PCA9538_MULTIPLE
/* Allocate the device state structure */
pcadev = (FAR struct pca9538_dev_s *)kmm_zalloc
(sizeof(struct pca9538_dev_s));
if (!pcadev)
{
return NULL;
}
/* And save the device structure in the list of PCA9538 so that we can
* find it later.
*/
pcadev->flink = g_pca9538list;
g_pca9538list = pcadev;
#else
/* Use the one-and-only PCA9538 driver instance */
pcadev = &g_pca9538;
#endif
/* Initialize the device state structure */
pcadev->i2c = i2cdev;
pcadev->dev.ops = &g_pca9538_ops;
pcadev->config = config;
#ifdef CONFIG_PCA9538_INT_ENABLE
DEBUGASSERT(pcadev->config->attach != NULL &&
pcadev->config->enable != NULL);
pcadev->config->attach(pcadev->config, pca9538_interrupt, pcadev);
pcadev->config->enable(pcadev->config, TRUE);
#endif
nxmutex_init(&pcadev->lock);
return &pcadev->dev;
}
#endif /* CONFIG_IOEXPANDER_PCA9538 */
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