i2c: Add support to TCA9548A multiplexer
This commit is contained in:
Alan C. Assis
Petro Karashchenko
parent
2c3020ddaf
commit
0b23257ef1
@ -7,6 +7,10 @@ config ARCH_HAVE_I2CRESET
|
||||
bool
|
||||
default n
|
||||
|
||||
config BOARD_HAVE_I2CMUX
|
||||
bool
|
||||
default n
|
||||
|
||||
menuconfig I2C
|
||||
bool "I2C Driver Support"
|
||||
default n
|
||||
@ -94,9 +98,18 @@ config I2CMULTIPLEXER_PCA9540BDP
|
||||
bool "PCA9540BDP NXP multiplexer"
|
||||
default n
|
||||
depends on I2C
|
||||
select BOARD_HAVE_I2CMUX
|
||||
---help---
|
||||
Enable support for the NXP PCA9540BDP i2c multiplexer
|
||||
|
||||
config I2CMULTIPLEXER_TCA9548A
|
||||
bool "TCA9548A TI multiplexer"
|
||||
default n
|
||||
depends on I2C
|
||||
select BOARD_HAVE_I2CMUX
|
||||
---help---
|
||||
Enable support for the TI TCA9548A i2c multiplexer
|
||||
|
||||
# put more i2c mux devices here
|
||||
|
||||
endmenu # I2C Multiplexer Support
|
||||
|
||||
@ -38,6 +38,10 @@ ifeq ($(CONFIG_I2CMULTIPLEXER_PCA9540BDP),y)
|
||||
CSRCS += pca9540bdp.c
|
||||
endif
|
||||
|
||||
ifeq ($(CONFIG_I2CMULTIPLEXER_TCA9548A),y)
|
||||
CSRCS += tca9548a.c
|
||||
endif
|
||||
|
||||
# Include I2C device driver build support
|
||||
|
||||
DEPPATH += --dep-path i2c
|
||||
|
||||
412
drivers/i2c/tca9548a.c
Normal file
412
drivers/i2c/tca9548a.c
Normal file
@ -0,0 +1,412 @@
|
||||
/****************************************************************************
|
||||
* drivers/i2c/tca9548a.c
|
||||
* Driver for the TCA9448A i2c multiplexer
|
||||
*
|
||||
* 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 <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 <nuttx/i2c/tca9548a.h>
|
||||
|
||||
#ifdef CONFIG_I2CMULTIPLEXER_TCA9548A
|
||||
|
||||
#ifndef CONFIG_TCA9548A_I2C_FREQUENCY
|
||||
# define CONFIG_TCA9548A_I2C_FREQUENCY 400000
|
||||
#endif
|
||||
|
||||
/****************************************************************************
|
||||
* Private Function Prototypes
|
||||
****************************************************************************/
|
||||
|
||||
/* I2C Helpers */
|
||||
|
||||
static int tca9548a_write_config(FAR struct tca9548a_dev_s *priv,
|
||||
uint8_t regvalue);
|
||||
static int tca9548a_read_config(FAR struct tca9548a_dev_s *priv,
|
||||
FAR uint8_t *regvalue);
|
||||
|
||||
/* Other helpers */
|
||||
|
||||
static int tca9548a_select_channel(FAR struct tca9548a_dev_s *priv,
|
||||
uint8_t val);
|
||||
|
||||
/* I2C multiplexer vtable */
|
||||
|
||||
static int tca9548a_transfer_on_channel (FAR struct i2c_master_s *dev,
|
||||
FAR struct i2c_msg_s *msgs,
|
||||
int count);
|
||||
#ifdef CONFIG_I2C_RESET
|
||||
static int tca9548a_reset_on_channel (FAR struct i2c_master_s *dev);
|
||||
#endif
|
||||
|
||||
/****************************************************************************
|
||||
* Private Data
|
||||
****************************************************************************/
|
||||
|
||||
static const struct i2c_ops_s g_i2cmux_ops =
|
||||
{
|
||||
tca9548a_transfer_on_channel
|
||||
#ifdef CONFIG_I2C_RESET
|
||||
, tca9548a_reset_on_channel
|
||||
#endif
|
||||
};
|
||||
|
||||
/****************************************************************************
|
||||
* Private Types
|
||||
****************************************************************************/
|
||||
|
||||
struct i2c_channel_dev_s
|
||||
{
|
||||
FAR struct i2c_master_s vi2c; /* Nested structure to allow casting as
|
||||
* public i2c master */
|
||||
uint8_t channel; /* Associated channel on the mux */
|
||||
FAR struct tca9548a_dev_s *dev; /* Associated device */
|
||||
};
|
||||
|
||||
/****************************************************************************
|
||||
* Private Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_write_config
|
||||
*
|
||||
* Description:
|
||||
* Write to the mux register of TCA9548A.
|
||||
*
|
||||
* Input Parameters:
|
||||
* priv - A pointer to the TCA9548A device structure.
|
||||
* regvalue - The value that will be written.
|
||||
*
|
||||
* Returned Value:
|
||||
* OK on success or a negative error.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
static int tca9548a_write_config(FAR struct tca9548a_dev_s *priv,
|
||||
uint8_t regvalue)
|
||||
{
|
||||
struct i2c_config_s iconf;
|
||||
int ret;
|
||||
|
||||
iconf.frequency = CONFIG_TCA9548A_I2C_FREQUENCY;
|
||||
iconf.address = priv->addr;
|
||||
iconf.addrlen = 7;
|
||||
|
||||
ret = i2c_write(priv->i2c, &iconf, ®value, 1);
|
||||
|
||||
i2cinfo("Write to address 0x%02X; register value: 0x%02x ret: %d\n",
|
||||
priv->addr, regvalue, ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_read_config
|
||||
*
|
||||
* Description:
|
||||
* Read the mux register from TCA9548A.
|
||||
*
|
||||
* Input Parameters:
|
||||
* priv - A pointer to the TCA9548A device structure.
|
||||
* regvalue - A pointer to a buffer into which data will be received.
|
||||
*
|
||||
* Returned Value:
|
||||
* OK on success or a negative error.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
static int tca9548a_read_config(FAR struct tca9548a_dev_s *priv,
|
||||
FAR uint8_t *regvalue)
|
||||
{
|
||||
struct i2c_config_s iconf;
|
||||
int ret;
|
||||
|
||||
iconf.frequency = CONFIG_TCA9548A_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;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_select_channel
|
||||
*
|
||||
* Description:
|
||||
* Helper function to select a channel in the TCA9548A. The TCA9548A allows
|
||||
* to select more than 1 channel at same time, but here we are forcing it
|
||||
* to only enable a single channel by time. It will avoid collision in case
|
||||
* where two devices with same address are connected to two channels.
|
||||
*
|
||||
* Input Parameters:
|
||||
* dev - Pointer to the (virtual) i2c_master_s.
|
||||
* val - The channel to be selected.
|
||||
*
|
||||
* Returned Value:
|
||||
* OK on success or a negative error.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
static int tca9548a_select_channel(FAR struct tca9548a_dev_s *priv,
|
||||
uint8_t val)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (val > TCA9548A_SEL_CH7)
|
||||
{
|
||||
/* channel not existent/supported */
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if ((priv->state & (1 << val)) != 0)
|
||||
{
|
||||
/* channel already selected */
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
/* Try to setup the new channel */
|
||||
|
||||
ret = tca9548a_write_config(priv, 1 << val);
|
||||
if (ret < 0)
|
||||
{
|
||||
return -ECOMM;
|
||||
}
|
||||
|
||||
/* Modify state. Selecting a channel always enables the device */
|
||||
|
||||
priv->state = 1 << val;
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_transfer_on_channel
|
||||
*
|
||||
* Description:
|
||||
* Transfer an I2C message over the TCA9548A multiplexer. This function is
|
||||
* attached to the virtual i2c_master ".transfer()" pointer. This way every
|
||||
* time an I2C message is sent it is called and it starts sending a command
|
||||
* to TCA9548A setup the right channel defined to this i2c_master. All the
|
||||
* expected messages are then transfered to the I2C device connected the
|
||||
* this selected channel.
|
||||
*
|
||||
* Input Parameters:
|
||||
* dev - Pointer to the (virtual) i2c_master_s.
|
||||
* msgs - the i2c message to be send to a device connected on TCA9548A.
|
||||
* count - Number of messages to be send.
|
||||
*
|
||||
* Returned Value:
|
||||
* OK on success or a negative error.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
static int tca9548a_transfer_on_channel(FAR struct i2c_master_s *dev,
|
||||
FAR struct i2c_msg_s *msgs,
|
||||
int count)
|
||||
{
|
||||
FAR struct i2c_channel_dev_s *ch_dev = (FAR struct i2c_channel_dev_s *)dev;
|
||||
FAR struct tca9548a_dev_s *priv = ch_dev->dev;
|
||||
int ret;
|
||||
|
||||
/* select the mux channel */
|
||||
|
||||
if (tca9548a_select_channel(priv, ch_dev->channel) != OK)
|
||||
{
|
||||
i2cerr("Could not select proper mux channel\n");
|
||||
return -ECOMM; /* Signal error condition */
|
||||
}
|
||||
|
||||
/* Resume the i2c transfer to the device connected to the mux channel */
|
||||
|
||||
ret = I2C_TRANSFER(priv->i2c, msgs, count);
|
||||
i2cinfo("Selected channel %d and resumed transfer. Result: %d\n",
|
||||
ch_dev->channel, ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_reset_on_channel
|
||||
*
|
||||
* Description:
|
||||
* Reset the I2C device connected to the current channel
|
||||
*
|
||||
* Input Parameters:
|
||||
* dev - Pointer to the (virtual) i2c_master_s.
|
||||
*
|
||||
* Returned Value:
|
||||
* OK on success or a negative error.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
#ifdef CONFIG_I2C_RESET
|
||||
static int tca9548a_reset_on_channel(FAR struct i2c_master_s *dev)
|
||||
{
|
||||
FAR struct i2c_channel_dev_s *ch_dev = (struct i2c_channel_dev_s *)dev;
|
||||
FAR struct tca9548a_dev_s *priv = ch_dev->dev;
|
||||
int channel = ch_dev->channel;
|
||||
int ret;
|
||||
|
||||
/* select the mux channel */
|
||||
|
||||
if (tca9548a_select_channel(priv, channel) != OK)
|
||||
{
|
||||
i2cerr("Could not select proper mux channel\n");
|
||||
return -ECOMM; /* signal error condition */
|
||||
}
|
||||
|
||||
/* resume the i2c reset for the device connected to the mux channel */
|
||||
|
||||
ret = I2C_RESET(priv->i2c);
|
||||
return ret;
|
||||
}
|
||||
#endif
|
||||
|
||||
/****************************************************************************
|
||||
* Public Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_lower_half
|
||||
*
|
||||
* Description:
|
||||
* Initialize the lower half of the TCA9548A by creating an i2c_master_s
|
||||
* for the virtual i2c master and link it to the associated TCA9548A and
|
||||
* its channel.
|
||||
*
|
||||
* Input Parameters:
|
||||
* dev - Pointer to the associated TCA9548A
|
||||
* channel - The channel number as defined in tca9548a.h
|
||||
*
|
||||
* Returned Value:
|
||||
* Common i2c multiplexer device instance; NULL on failure.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
FAR struct i2c_master_s *
|
||||
tca9548a_lower_half(FAR struct tca9548a_dev_s *dev, uint8_t channel)
|
||||
{
|
||||
FAR struct i2c_channel_dev_s *channel_dev;
|
||||
|
||||
/* Sanity check */
|
||||
|
||||
DEBUGASSERT(dev != NULL);
|
||||
|
||||
/* Initialize the i2c_channel_dev_s device structure */
|
||||
|
||||
channel_dev = (FAR struct i2c_channel_dev_s *)
|
||||
kmm_malloc(sizeof(struct i2c_channel_dev_s));
|
||||
|
||||
if (channel_dev == NULL)
|
||||
{
|
||||
i2cerr("ERROR: Failed to allocate i2c channel lower half instance\n");
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/* set vi2c ops to their implementations */
|
||||
|
||||
channel_dev->vi2c.ops = &g_i2cmux_ops;
|
||||
|
||||
/* save state variables */
|
||||
|
||||
channel_dev->dev = dev;
|
||||
channel_dev->channel = channel;
|
||||
|
||||
return &channel_dev->vi2c;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_initialize
|
||||
*
|
||||
* Description:
|
||||
* Initialize the TCA9548A device.
|
||||
*
|
||||
* Input Parameters:
|
||||
* i2c - An instance of the I2C interface to use to communicate with
|
||||
* TCA9548A
|
||||
* addr - The I2C address of the TCA9548A. The base I2C address of the
|
||||
* TCA9548A is 0x70.
|
||||
*
|
||||
* Returned Value:
|
||||
* Common i2c multiplexer device instance; NULL on failure.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
FAR struct tca9548a_dev_s *
|
||||
tca9548a_initialize(FAR struct i2c_master_s *i2c, uint8_t addr)
|
||||
{
|
||||
FAR struct tca9548a_dev_s *priv;
|
||||
|
||||
/* Sanity check */
|
||||
|
||||
DEBUGASSERT(i2c != NULL);
|
||||
|
||||
/* Initialize the TCA9548A device structure */
|
||||
|
||||
priv = (FAR struct tca9548a_dev_s *)
|
||||
kmm_malloc(sizeof(struct tca9548a_dev_s));
|
||||
|
||||
if (priv == NULL)
|
||||
{
|
||||
i2cerr("ERROR: Failed to allocate instance\n");
|
||||
return NULL;
|
||||
}
|
||||
|
||||
priv->i2c = i2c;
|
||||
priv->addr = addr;
|
||||
priv->state = 0x00;
|
||||
|
||||
if (tca9548a_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 (tca9548a_select_channel(priv, TCA9548A_SEL_CH0) != OK)
|
||||
{
|
||||
i2cerr("Could not select mux channel 0\n");
|
||||
kmm_free(priv);
|
||||
return NULL; /* signal error condition */
|
||||
}
|
||||
|
||||
i2cinfo("TCA9548A (addr=0x%02x) set up with channel %d\n", priv->addr,
|
||||
TCA9548A_SEL_CH0);
|
||||
|
||||
return priv;
|
||||
}
|
||||
|
||||
#endif /* CONFIG_I2CMULTIPLEXER_TCA9548A */
|
||||
126
include/nuttx/i2c/tca9548a.h
Normal file
126
include/nuttx/i2c/tca9548a.h
Normal file
@ -0,0 +1,126 @@
|
||||
/****************************************************************************
|
||||
* include/nuttx/i2c/tca9548a.h
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
#ifndef __INCLUDE_NUTTX_I2C_TCA9548A_H
|
||||
#define __INCLUDE_NUTTX_I2C_TCA9548A_H
|
||||
|
||||
/****************************************************************************
|
||||
* Included Files
|
||||
****************************************************************************/
|
||||
|
||||
#include <nuttx/config.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <nuttx/i2c/i2c_master.h>
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
/* It is possible to config. TCA9548A to communicate from 0x70-0x77 */
|
||||
|
||||
#define TCA9548A_BASEADDR0 0x70
|
||||
#define TCA9548A_BASEADDR1 0x71
|
||||
#define TCA9548A_BASEADDR2 0x72
|
||||
#define TCA9548A_BASEADDR3 0x73
|
||||
#define TCA9548A_BASEADDR4 0x74
|
||||
#define TCA9548A_BASEADDR5 0x75
|
||||
#define TCA9548A_BASEADDR6 0x76
|
||||
#define TCA9548A_BASEADDR7 0x77
|
||||
|
||||
/* The TCA9548A can multiplex up to 8 channels */
|
||||
|
||||
#define TCA9548A_SEL_CH0 0x0
|
||||
#define TCA9548A_SEL_CH1 0x1
|
||||
#define TCA9548A_SEL_CH2 0x2
|
||||
#define TCA9548A_SEL_CH3 0x3
|
||||
#define TCA9548A_SEL_CH4 0x4
|
||||
#define TCA9548A_SEL_CH5 0x5
|
||||
#define TCA9548A_SEL_CH6 0x6
|
||||
#define TCA9548A_SEL_CH7 0x7
|
||||
|
||||
/****************************************************************************
|
||||
* Public Types
|
||||
****************************************************************************/
|
||||
|
||||
struct tca9548a_dev_s
|
||||
{
|
||||
FAR struct i2c_master_s *i2c; /* I2C interface */
|
||||
uint8_t addr;
|
||||
uint8_t state; /* Control register state */
|
||||
};
|
||||
|
||||
/****************************************************************************
|
||||
* Public Function Prototypes
|
||||
****************************************************************************/
|
||||
|
||||
#ifdef __cplusplus
|
||||
#define EXTERN extern "C"
|
||||
extern "C"
|
||||
{
|
||||
#else
|
||||
#define EXTERN extern
|
||||
#endif
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_lower_half
|
||||
*
|
||||
* Description:
|
||||
* Initialize the lower half of the TCA9548A by creating a i2c_master_s
|
||||
* for the virtual i2c master and link it to the associated TCA9548A and
|
||||
* its port.
|
||||
*
|
||||
* Input Parameters:
|
||||
* dev - Pointer to the associated TCA9548A
|
||||
* channel - The channel number to be selected to communicate
|
||||
*
|
||||
* Returned Value:
|
||||
* Common i2c multiplexer device instance; NULL on failure.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
FAR struct i2c_master_s *
|
||||
tca9548a_lower_half(FAR struct tca9548a_dev_s *dev, uint8_t channel);
|
||||
|
||||
/****************************************************************************
|
||||
* Name: tca9548a_initialize
|
||||
*
|
||||
* Description:
|
||||
* Initialize the TCA9548A device.
|
||||
*
|
||||
* Input Parameters:
|
||||
* i2c - An instance of the I2C interface to use to communicate with
|
||||
* TCA9548A
|
||||
* addr - The I2C address of the TCA9548A. The base I2C address of the
|
||||
* TCA9548A is 0x70.
|
||||
*
|
||||
* Returned Value:
|
||||
* Common i2c multiplexer device instance; NULL on failure.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
FAR struct tca9548a_dev_s *tca9548a_initialize(FAR struct i2c_master_s *i2c,
|
||||
uint8_t addr);
|
||||
|
||||
#undef EXTERN
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* __INCLUDE_NUTTX_I2C_TCA9548A_H */
|
||||
Loading…
Reference in New Issue
Block a user