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incubator-nuttx/drivers/i2c/pca9540bdp.c

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/****************************************************************************
* drivers/i2c/pca9540bdp.c
* Driver for the PCA9540BDP i2c multiplexer
*
* Copyright (C) 2018 Giorgio Groß. All rights reserved.
* Author: Giorgio Groß <giorgio.gross@robodev.eu>
*
* 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 <stdlib.h>
#include <fixedmath.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c/i2c_master.h>
#include "pca9540bdp.h"
#include <nuttx/i2c/pca9540bdp.h>
#ifdef CONFIG_I2CMULTIPLEXER_PCA9540BDP
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C Helpers */
static int pca9540bdp_write_config(FAR struct pca9540bdp_dev_s *priv,
FAR uint8_t regvalue);
static int pca9540bdp_read_config(FAR struct pca9540bdp_dev_s *priv,
FAR uint8_t *regvalue);
/* Other helpers */
static int pca9540bdp_select_port(FAR struct pca9540bdp_dev_s *priv,
uint8_t val);
/* I2C multiplexer vtable */
static int pca9540bdp_transfer_on_port (FAR struct i2c_master_s *dev,
FAR struct i2c_msg_s *msgs, int count);
#ifdef CONFIG_I2C_RESET
static int pca9540bdp_reset_on_port (FAR struct i2c_master_s *dev);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static const struct i2c_ops_s g_i2cmux_ops =
{
pca9540bdp_transfer_on_port
#ifdef CONFIG_I2C_RESET
, pca9540bdp_reset_on_port
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
static int pca9540bdp_write_config(FAR struct pca9540bdp_dev_s *priv,
FAR uint8_t regvalue)
{
struct i2c_config_s iconf;
int ret;
iconf.frequency = CONFIG_PCA9549BDP_I2C_FREQUENCY;
iconf.address = priv->addr;
iconf.addrlen = 7;
ret = i2c_write(priv->i2c, &iconf, &regvalue, 1);
i2cinfo("Write to address 0x%02X; register value: 0x%02x ret: %d\n",
priv->addr, regvalue, ret);
return ret;
}
static int pca9540bdp_read_config(FAR struct pca9540bdp_dev_s *priv,
FAR uint8_t *regvalue)
{
struct i2c_config_s iconf;
int ret;
iconf.frequency = CONFIG_PCA9549BDP_I2C_FREQUENCY;
iconf.address = priv->addr;
iconf.addrlen = 7;
ret = i2c_read(priv->i2c, &iconf, regvalue, 1);
i2cinfo("Read from address: 0x%02X; register value: 0x%02x ret: %d\n",
priv->addr, *regvalue, ret);
return ret;
}
static int pca9540bdp_select_port(FAR struct pca9540bdp_dev_s *priv,
uint8_t val)
{
if (val != PCA9540BDP_SEL_PORT0 && val != PCA9540BDP_SEL_PORT1)
{
/* port not supported */
return -EINVAL;
}
if ((PCA9540BDP_ENABLE | val) == priv->state)
{
/* port already selected */
return OK;
}
/* Modify state and write it to the mux. Selecting a port always enables
* the device
*/
priv->state = PCA9540BDP_ENABLE | val;
return (pca9540bdp_write_config(priv, priv->state) == 0) ? OK : -ECOMM;
}
static int pca9540bdp_transfer_on_port(FAR struct i2c_master_s *dev,
FAR struct i2c_msg_s *msgs, int count)
{
FAR struct i2c_port_dev_s *port_dev = (FAR struct i2c_port_dev_s *)dev;
FAR struct pca9540bdp_dev_s *priv = port_dev->dev;
int ret;
/* select the mux port */
if (pca9540bdp_select_port(priv, port_dev->port) != OK)
{
i2cerr("Could not select proper mux port\n");
return -ECOMM; /* Signal error condition */
}
/* Resume the i2c transfer to the device connected to the mux port */
ret = I2C_TRANSFER(priv->i2c, msgs, count);
i2cinfo("Selected port %d and resumed transfer. Result: %d\n",
port_dev->port, ret);
return ret;
}
#ifdef CONFIG_I2C_RESET
static int pca9540bdp_reset_on_port (FAR struct i2c_master_s *dev)
{
FAR struct i2c_port_dev_s *port_dev = (struct i2c_port_dev_s *)dev;
FAR struct pca9540bdp_dev_s *priv = port_dev->dev;
int port = port_dev->port;
int ret;
/* select the mux port */
if (pca9540bdp_select_port(priv, port) != OK)
{
i2cerr("Could not select proper mux port\n");
return -ECOMM; /* signal error condition */
}
/* resume the i2c reset for the device connected to the mux port */
ret = I2C_RESET(priv->i2c);
return ret;
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pca9540bdp_lower_half
*
* Description:
* Initialize the lower half of the PCA9540BDP by creating a i2c_master_s
* for the virtual i2c master and link it to the associated PCA9540BDP and
* its port.
*
* Input Parameters:
* dev - Pointer to the associated PCA9540BDP
* port - The port number as defined in pca9540bdp.h
*
* Returned Value:
* Common i2c multiplexer device instance; NULL on failure.
*
****************************************************************************/
FAR struct i2c_master_s *
pca9540bdp_lower_half(FAR struct pca9540bdp_dev_s *dev, uint8_t port)
{
FAR struct i2c_port_dev_s *port_dev;
/* Sanity check */
DEBUGASSERT(dev != NULL);
/* Initialize the i2c_port_dev_s device structure */
port_dev = (FAR struct i2c_port_dev_s *)
kmm_malloc(sizeof(struct i2c_port_dev_s));
if (port_dev == NULL)
{
i2cerr("ERROR: Failed to allocate i2c port lower half instance\n");
return NULL;
}
/* set vi2c ops to their implementations */
port_dev->vi2c.ops = &g_i2cmux_ops;
/* save state variables */
port_dev->dev = dev;
port_dev->port = port;
return &port_dev->vi2c;
}
/****************************************************************************
* Name: pca9540bdp_initialize
*
* Description:
* Initialize the PCA9540BDP device.
*
* Input Parameters:
* i2c - An instance of the I2C interface to use to communicate with
* PCA9540BDP
* addr - The I2C address of the PCA9540BDP. The base I2C address of the
* PCA9540BDP is 0x70.
*
* Returned Value:
* Common i2c multiplexer device instance; NULL on failure.
*
****************************************************************************/
FAR struct pca9540bdp_dev_s *
pca9540bdp_initialize(FAR struct i2c_master_s *i2c, uint8_t addr)
{
FAR struct pca9540bdp_dev_s *priv;
/* Sanity check */
DEBUGASSERT(i2c != NULL);
/* Initialize the PCA9549BDP device structure */
priv = (FAR struct pca9540bdp_dev_s *)
kmm_malloc(sizeof(struct pca9540bdp_dev_s));
if (priv == NULL)
{
i2cerr("ERROR: Failed to allocate instance\n");
return NULL;
}
priv->i2c = i2c;
priv->addr = addr;
priv->state = 0x00;
if (pca9540bdp_read_config(priv, &priv->state) != OK)
{
i2cerr("Could not read initial state from the device\n");
kmm_free(priv);
return NULL; /* signal error condition */
}
i2cinfo("Initial device state: %d\n", priv->state);
if (pca9540bdp_select_port(priv, PCA9540BDP_SEL_PORT0) != OK)
{
i2cerr("Could not select mux port 0\n");
kmm_free(priv);
return NULL; /* signal error condition */
}
i2cinfo("PCA9549BDP (addr=0x%02x) set up with port %d\n", priv->addr,
PCA9540BDP_SEL_PORT0);
return priv;
}
#endif /* CONFIG_I2CMULTIPLEXER_PCA9540BDP */
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