155 lines
5.6 KiB
C
155 lines
5.6 KiB
C
/****************************************************************************
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* drivers/ioexpander/pcf8574.h
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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#ifndef __DRIVERS_IOEXPANDER_PCF8574_H
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#define __DRIVERS_IOEXPANDER_PCF8574_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <nuttx/wdog.h>
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#include <nuttx/clock.h>
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#include <nuttx/semaphore.h>
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#include <nuttx/wqueue.h>
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#include <nuttx/ioexpander/ioexpander.h>
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#include <nuttx/ioexpander/pcf8574.h>
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#include <nuttx/i2c/i2c_master.h>
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#include <nuttx/irq.h>
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#if defined(CONFIG_IOEXPANDER) && defined(CONFIG_IOEXPANDER_PCF8574)
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Configuration ************************************************************/
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/* Prerequisites:
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* CONFIG_I2C
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* I2C support is required
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* CONFIG_IOEXPANDER
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* Enables I/O expander support
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*
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* CONFIG_IOEXPANDER_PCF8574
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* Enables support for the PCF8574 driver (Needs CONFIG_INPUT)
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* CONFIG_PCF8574_MULTIPLE
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* Can be defined to support multiple PCF8574 devices on board.
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* CONFIG_PCF8574_INT_NCALLBACKS
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* Maximum number of supported pin interrupt callbacks.
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* CONFIG_PCF8574_INT_POLL
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* Enables a poll for missed interrupts
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* CONFIG_PCF8574_INT_POLLDELAY
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* If CONFIG_PCF8574_INT_POLL=y, then this is the delay in microseconds
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* between polls for missed interrupts.
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*/
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#ifndef CONFIG_I2C
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# error "CONFIG_I2C is required by PCF8574"
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#endif
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#ifdef CONFIG_IOEXPANDER_INT_ENABLE
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# ifndef CONFIG_PCF8574_INT_NCALLBACKS
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# define CONFIG_PCF8574_INT_NCALLBACKS 4
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# endif
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#endif
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#ifdef CONFIG_IOEXPANDER_INT_ENABLE
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# ifndef CONFIG_SCHED_WORKQUEUE
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# error Work queue support required. CONFIG_SCHED_WORKQUEUE must be selected.
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# endif
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#endif
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#ifndef CONFIG_PCF8574_INT_POLLDELAY
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# define CONFIG_PCF8574_INT_POLLDELAY 500000
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#endif
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/* PCF8574 Definitions ******************************************************/
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#define PCF8574_I2C_MAXFREQUENCY 400000 /* 400KHz */
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#define PCF8574_POLLDELAY (CONFIG_PCF8574_INT_POLLDELAY / USEC_PER_TICK)
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#define PCF8574_LEVEL_SENSITIVE(d,p) \
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(((d)->trigger & ((ioe_pinset_t)1 << (p))) == 0)
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#define PCF8574_LEVEL_HIGH(d,p) \
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(((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0)
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#define PCF8574_LEVEL_LOW(d,p) \
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(((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0)
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#define PCF8574_EDGE_SENSITIVE(d,p) \
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(((d)->trigger & ((ioe_pinset_t)1 << (p))) != 0)
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#define PCF8574_EDGE_RISING(d,p) \
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(((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0)
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#define PCF8574_EDGE_FALLING(d,p) \
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(((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0)
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#define PCF8574_EDGE_BOTH(d,p) \
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(PCF8574_LEVEL_RISING(d,p) && PCF8574_LEVEL_FALLING(d,p))
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/****************************************************************************
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* Public Types
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****************************************************************************/
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#ifdef CONFIG_IOEXPANDER_INT_ENABLE
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/* This type represents on registered pin interrupt callback */
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struct pcf8574_callback_s
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{
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ioe_pinset_t pinset; /* Set of pin interrupts that will generate
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* the callback. */
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ioe_callback_t cbfunc; /* The saved callback function pointer */
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FAR void *cbarg; /* Callback argument */
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};
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#endif
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/* This structure represents the state of the PCF8574 driver */
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struct pcf8574_dev_s
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{
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struct ioexpander_dev_s dev; /* Nested structure to allow casting as public gpio
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* expander. */
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FAR struct pcf8574_config_s *config; /* Board configuration data */
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FAR struct i2c_master_s *i2c; /* Saved I2C driver instance */
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sem_t exclsem; /* Mutual exclusion */
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uint8_t inpins; /* Set of input pins */
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uint8_t outstate; /* State of all output pins */
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#ifdef CONFIG_IOEXPANDER_INT_ENABLE
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#ifdef CONFIG_PCF8574_INT_POLL
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struct wdog_s wdog; /* Timer used to poll for missed interrupts */
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#endif
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uint8_t input; /* Last input registers */
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uint8_t intstat; /* Pending interrupts */
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uint8_t trigger; /* Bit encoded: 0=level 1=edge */
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uint8_t level[2]; /* Bit encoded: 01=high/rising, 10 low/falling, 11 both */
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struct work_s work; /* Supports the interrupt handling "bottom half" */
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/* Saved callback information for each I/O expander client */
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struct pcf8574_callback_s cb[CONFIG_PCF8574_INT_NCALLBACKS];
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#endif
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};
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#endif /* CONFIG_IOEXPANDER && CONFIG_IOEXPANDER_PCF8574 */
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#endif /* __DRIVERS_IOEXPANDER_PCF8574_H */
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