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nuttx/drivers/ioexpander/mcp23x17.h
Alan C. Assis 4c74f46afe Add basic support for MCP23017 I/O Expander
2021-05-16 12:48:52 -05:00

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/****************************************************************************
* drivers/ioexpander/mcp23x17.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 __DRIVERS_IOEXPANDER_MCP23X17_H
#define __DRIVERS_IOEXPANDER_MCP23X17_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/wdog.h>
#include <nuttx/clock.h>
#include <nuttx/semaphore.h>
#include <nuttx/wqueue.h>
#include <nuttx/ioexpander/ioexpander.h>
#include <nuttx/ioexpander/mcp23x17.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/irq.h>
#if defined(CONFIG_IOEXPANDER) && defined(CONFIG_IOEXPANDER_MCP23X17)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Prerequisites:
* CONFIG_I2C
* I2C support is required
* CONFIG_IOEXPANDER
* Enables I/O expander support
*
* CONFIG_IOEXPANDER_MCP23X17
* Enables support for the MCP23X17 driver (Needs CONFIG_INPUT)
* CONFIG_MCP23X17_MULTIPLE
* Can be defined to support multiple MCP23X17 devices on board.
* CONFIG_MCP23X17_INT_NCALLBACKS
* Maximum number of supported pin interrupt callbacks.
* CONFIG_MCP23X17_INT_POLL
* Enables a poll for missed interrupts
* CONFIG_MCP23X17_INT_POLLDELAY
* If CONFIG_MCP23X17_INT_POLL=y, then this is the delay in microseconds
* between polls for missed interrupts.
*/
#ifndef CONFIG_I2C
# error "CONFIG_I2C is required by MCP23X17"
#endif
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
# ifndef CONFIG_MCP23X17_INT_NCALLBACKS
# define CONFIG_MCP23X17_INT_NCALLBACKS 4
# endif
#endif
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
# ifndef CONFIG_SCHED_WORKQUEUE
# error Work queue support required. CONFIG_SCHED_WORKQUEUE must be selected.
# endif
#endif
#ifndef CONFIG_MCP23X17_INT_POLLDELAY
# define CONFIG_MCP23X17_INT_POLLDELAY 500000
#endif
/* MCP23X17 Definitions *****************************************************/
/* I2C frequency */
#define MCP23X17_I2C_MAXFREQUENCY 400000 /* 400KHz */
/* MCP23X17 *****************************************************************/
/* If IOCON.BANK = 0 Addressing Mode */
#define MCP23X17_IODIRA 0x00
#define MCP23X17_IODIRB 0x01
#define MCP23X17_IPOLA 0x02
#define MCP23X17_IPOLB 0x03
#define MCP23X17_GPINTENA 0x04
#define MCP23X17_GPINTENB 0x05
#define MCP23X17_DEFVALA 0x06
#define MCP23X17_DEFVALB 0x07
#define MCP23X17_INTCONA 0x08
#define MCP23X17_INTCONB 0x09
#define MCP23X17_IOCON 0x0a
#define MCP23X17_IOCON_2 0x0b
#define MCP23X17_GPPUA 0x0c
#define MCP23X17_GPPUB 0x0d
#define MCP23X17_INTFA 0x0e
#define MCP23X17_INTFB 0x0f
#define MCP23X17_INTCAPA 0x10
#define MCP23X17_INTCAPB 0x11
#define MCP23X17_GPIOA 0x12
#define MCP23X17_GPIOB 0x13
#define MCP23X17_OLATA 0x14
#define MCP23X17_OLATB 0x15
#define MCP23X17_IOCON_INTPOL (1 << 1) /* Polarity of INT output pin */
#define MCP23X17_IOCON_ODR (1 << 2) /* Config INT pin as open-drain */
#define MCP23X17_IOCON_HAEN (1 << 3) /* HW Address enable bit */
#define MCP23X17_IOCON_DISSLW (1 << 4) /* Disable Slew Rate for SDA output */
#define MCP23X17_IOCON_SEQOP (1 << 5) /* Disable Sequencial Operation */
#define MCP23X17_IOCON_MIRROR (1 << 6) /* Mirror INT pins */
#define MCP23X17_IOCON_BANK (1 << 7) /* Configure how to address register */
#define MCP23X17_NR_GPIO_MAX 16
#define MCP23X17_POLLDELAY (CONFIG_MCP23X17_INT_POLLDELAY / USEC_PER_TICK)
/****************************************************************************
* Public Types
****************************************************************************/
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
/* This type represents on registered pin interrupt callback */
struct mcp23x17_callback_s
{
ioe_pinset_t pinset; /* Set of pin interrupts that will generate
* the callback. */
ioe_callback_t cbfunc; /* The saved callback function pointer */
FAR void *cbarg; /* Callback argument */
};
#endif
/* This structure represents the state of the MCP23X17 driver */
struct mcp23x17_dev_s
{
struct ioexpander_dev_s dev; /* Nested structure to allow casting
* as public gpio expander.
*/
FAR struct mcp23x17_config_s *config; /* Board configuration data */
FAR struct i2c_master_s *i2c; /* Saved I2C driver instance */
sem_t exclsem; /* Mutual exclusion */
#ifdef CONFIG_IOEXPANDER_INT_ENABLE
#ifdef CONFIG_MCP23X17_INT_POLL
struct wdog_s wdog; /* Timer used to poll for missed interrupts */
#endif
ioe_pinset_t input; /* Last input registers */
ioe_pinset_t intstat; /* Pending interrupts */
struct work_s work; /* Supports the interrupt handling "bottom half" */
/* Saved callback information for each I/O expander client */
struct mcp23x17_callback_s cb[CONFIG_MCP23X17_INT_NCALLBACKS];
#endif
};
#endif /* CONFIG_IOEXPANDER && CONFIG_IOEXPANDER_MCP23X17 */
#endif /* __DRIVERS_IOEXPANDER_MCP23X17_H */
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