diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 37386aed3e..23fa520eae 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -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 diff --git a/drivers/i2c/Make.defs b/drivers/i2c/Make.defs index 475b533ea0..2a5c8248d8 100644 --- a/drivers/i2c/Make.defs +++ b/drivers/i2c/Make.defs @@ -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 diff --git a/drivers/i2c/tca9548a.c b/drivers/i2c/tca9548a.c new file mode 100644 index 0000000000..ebfd6ee75c --- /dev/null +++ b/drivers/i2c/tca9548a.c @@ -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 + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#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 */ diff --git a/include/nuttx/i2c/tca9548a.h b/include/nuttx/i2c/tca9548a.h new file mode 100644 index 0000000000..74de6a6844 --- /dev/null +++ b/include/nuttx/i2c/tca9548a.h @@ -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 +#include +#include + +/**************************************************************************** + * 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 */