nuttx/drivers/ioexpander/pca9555.c
2015-10-10 10:41:00 -06:00

552 lines
16 KiB
C

/****************************************************************************
* drivers/ioexpander/pca9555.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Sebastien Lorquet <sebastien@lorquet.fr>
*
* References:
* "16-bit I2C-bus and SMBus I/O port with interrupt product datasheet",
* Rev. 08 - 22 October 2009, NXP
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/i2c.h>
#include <nuttx/ioexpander/ioexpander.h>
#include "pca9555.h"
#if defined(CONFIG_IOEXPANDER_PCA9555)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_I2C
# warning I2C support is required (CONFIG_I2C)
#endif
#ifndef CONFIG_I2C_WRITEREAD
# warning Support of the I2C writeread() method is required (CONFIG_I2C_WRITEREAD)
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int pca9555_direction (FAR struct ioexpander_dev_s *dev,
uint8_t pin, int dir);
static int pca9555_option (FAR struct ioexpander_dev_s *dev,
uint8_t pin, int opt, void *val);
static int pca9555_write (FAR struct ioexpander_dev_s *dev,
uint8_t pin, bool value);
static int pca9555_readpin (FAR struct ioexpander_dev_s *dev,
uint8_t pin, FAR bool *value);
static int pca9555_readbuf (FAR struct ioexpander_dev_s *dev,
uint8_t pin, FAR bool *value);
#ifdef CONFIG_IOEXPANDER_MULTIPIN
static int pca9555_multiwrite (FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count);
static int pca9555_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count);
static int pca9555_multireadbuf(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
#ifndef CONFIG_PCA9555_MULTIPLE
/* If only a single PCA9555 device is supported, then the driver state
* structure may as well be pre-allocated.
*/
static struct pca9555_dev_s g_pca9555;
/* Otherwise, we will need to maintain allocated driver instances in a list */
#else
static struct pca9555_dev_s *g_pca9555list;
#endif
static const struct ioexpander_ops_s g_pca9555_ops =
{
pca9555_direction,
pca9555_option,
pca9555_write,
pca9555_readpin,
pca9555_readbuf,
#ifdef CONFIG_IOEXPANDER_MULTIPIN
pca9555_multiwrite,
pca9555_multireadpin,
pca9555_multireadbuf,
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pca9555_setbit
*
* Description:
* Write a bit in a register pair
*
****************************************************************************/
static int pca9555_setbit(FAR struct i2c_dev_s *i2c, uint8_t addr,
uint8_t pin, int bitval)
{
int ret;
uint8_t buf[2];
buf[0] = addr;
if (pin > 15)
{
return -ENXIO;
}
else if (pin > 7)
{
addr += 1;
pin -= 8;
}
ret = I2C_WRITEREAD(i2c, &addr, 1, &buf[1], 1);
if (ret < 0)
{
return ret;
}
if (bitval)
{
buf[1] |= (1 << pin);
}
else
{
buf[1] &= ~(1 << pin);
}
return I2C_WRITE(i2c, buf, 2);
}
/****************************************************************************
* Name: pca9555_getbit
*
* Description:
* Get a bit from a register pair
*
****************************************************************************/
static int pca9555_getbit(FAR struct i2c_dev_s *i2c, 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 = I2C_WRITEREAD(i2c, &addr, 1, &buf, 1);
if (ret < 0)
{
return ret;
}
*val = (buf >> pin) & 1;
return OK;
}
/****************************************************************************
* Name: pca9555_direction
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_direction(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int direction)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_setbit(pca->i2c, PCA9555_REG_CONFIG, pin,
(direction == IOEXPANDER_DIRECTION_IN));
}
/****************************************************************************
* Name: pca9555_option
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_option(FAR struct ioexpander_dev_s *dev, uint8_t pin,
int opt, void *val)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
int ival = (int)val;
if (opt == IOEXPANDER_OPTION_INVERT)
{
return pca9555_setbit(pca->i2c, PCA9555_REG_POLINV, pin, ival);
}
return -EINVAL;
}
/****************************************************************************
* Name: pca9555_write
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_write(FAR struct ioexpander_dev_s *dev, uint8_t pin,
bool value)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_setbit(pca->i2c, PCA9555_REG_OUTPUT, pin, value);
}
/****************************************************************************
* Name: pca9555_readpin
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_readpin(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_getbit(pca->i2c, PCA9555_REG_INPUT, pin, value);
}
/****************************************************************************
* Name: pca9555_readbuf
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_readbuf(FAR struct ioexpander_dev_s *dev, uint8_t pin,
FAR bool *value)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_getbit(pca->i2c, PCA9555_REG_OUTPUT, pin, value);
}
#ifdef CONFIG_IOEXPANDER_MULTIPIN
/****************************************************************************
* Name: pca9555_getmultibits
*
* Description:
* Read multiple bits from PCA9555 registers.
*
****************************************************************************/
static int pca9555_getmultibits(FAR struct i2c_dev_s *i2c, 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 = I2C_WRITEREAD(i2c, &addr, 1, buf, 2);
if (ret < 0)
{
return ret;
}
/* 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: pca9555_multiwrite
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_multiwrite(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
uint8_t addr = PCA9555_REG_OUTPUT;
uint8_t buf[3];
int ret;
int i;
int index;
int pin;
/* 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. */
ret = I2C_WRITEREAD(pca->i2c, &addr, 1, &buf[1], 2);
if (ret < 0)
{
return ret;
}
/* Apply the user defined changes */
for (i = 0; i < count; i++)
{
index = 1;
pin = pins[i];
if (pin > 15)
{
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;
return I2C_WRITE(pca->i2c, buf, 3);
}
/****************************************************************************
* Name: pca9555_multireadpin
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_multireadpin(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_getmultibits(pca->i2c, PCA9555_REG_INPUT,
pins, values, count);
}
/****************************************************************************
* Name: pca9555_multireadbuf
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_multireadbuf(FAR struct ioexpander_dev_s *dev,
FAR uint8_t *pins, FAR bool *values,
int count)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return pca9555_getmultibits(pca->i2c, PCA9555_REG_OUTPUT,
pins, values, count);
}
#endif
#ifndef CONFIG_PCA9555_INT_DISABLE
/****************************************************************************
* Name: pca9555_gpioworker
*
* Description:
* See include/nuttx/ioexpander/ioexpander.h
*
****************************************************************************/
static int pca9555_attach(FAR struct ioexpander_dev_s *dev, uint8_t pin,
ioexpander_handler_t handler)
{
FAR struct pca9555_dev_s *pca = (FAR struct pca9555_dev_s *)dev;
return 0;
}
/****************************************************************************
* Name: pca9555_irqworker
*
* Description:
* Handle GPIO interrupt events (this function actually executes in the
* context of the worker thread).
*
****************************************************************************/
static void pca9555_irqworker(FAR struct pca9555_dev_s *priv)
{
uint8_t regval;
uint8_t pinmask;
int pin;
/* Get the set of pending GPIO interrupts */
/* Look at each pin */
for (pin = 0; pin < PCA9555_GPIO_NPINS; pin++)
{
/* Check if we have a handler for this interrupt (there should
* be one)
*/
/* Interrupt is pending... dispatch the interrupt to the
* callback
*/
/* Clear the pending GPIO interrupt by writing a '1' to the
* pin position in the status register.
*/
}
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pca9555_initialize
*
* Description:
* Initialize a PCA9555 I2C device.
*
* TODO: Actually support more than one device.
*
****************************************************************************/
FAR struct ioexpander_dev_s *pca9555_initialize(FAR struct i2c_dev_s *i2cdev,
FAR struct pca9555_config_s *config)
{
FAR struct pca9555_dev_s *pcadev;
DEBUGASSERT(i2cdev != NULL && config != NULL);
#ifdef CONFIG_PCA9555_MULTIPLE
/* Allocate the device state structure */
pcadev = (FAR struct pca9555_dev_s *)kmm_zalloc(sizeof(struct pca9555_dev_s));
if (!pcadev)
{
return NULL;
}
/* And save the device structure in the list of PCA9555 so that we can
* find it later.
*/
pcadev->flink = g_pca9555list;
g_pca9555list = pcadev;
#else
/* Use the one-and-only PCA9555 driver instance */
pcadev = &g_pca9555;
#endif
/* Initialize the device state structure */
pcadev->i2c = i2cdev;
pcadev->dev.ops = &g_pca9555_ops;
/* Set the I2C address and frequency. REVISIT: This logic would be
* insufficient if we share the I2C bus with any other devices that also
* modify the address and frequency.
*/
I2C_SETADDRESS(i2cdev, config->address, 7);
I2C_SETFREQUENCY(i2cdev, config->frequency);
return &pcadev->dev;
}
#endif /* CONFIG_IOEXPANDER_PCA9555 */