/******************************************************************************************** * drivers/ioexpander/pcf8574.h * * Copyright (C) 2016 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. * ********************************************************************************************/ #ifndef __DRIVERS_IOEXPANDER_PCF8574_H #define __DRIVERS_IOEXPANDER_PCF8574_H /******************************************************************************************** * Included Files ********************************************************************************************/ #include #include #include #include #include #include #include #include #include #if defined(CONFIG_IOEXPANDER) && defined(CONFIG_IOEXPANDER_PCF8574) /******************************************************************************************** * Pre-processor Definitions ********************************************************************************************/ /* Configuration ****************************************************************************/ /* Prerequisites: * CONFIG_I2C * I2C support is required * CONFIG_IOEXPANDER * Enables I/O expander support * * Other settings that effect the driver: CONFIG_DISABLE_POLL * * CONFIG_IOEXPANDER_PCF8574 * Enables support for the PCF8574 driver (Needs CONFIG_INPUT) * CONFIG_PCF8574_MULTIPLE * Can be defined to support multiple PCF8574 devices on board. * CONFIG_PCF8574_INT_NCALLBACKS * Maximum number of supported pin interrupt callbacks. * CONFIG_PCF8574_INT_POLL * Enables a poll for missed interrupts * CONFIG_PCF8574_INT_POLLDELAY * If CONFIG_PCF8574_INT_POLL=y, then this is the delay in microseconds * between polls for missed interrupts. */ #ifndef CONFIG_I2C # error "CONFIG_I2C is required by PCF8574" #endif #ifdef CONFIG_IOEXPANDER_INT_ENABLE # ifndef CONFIG_PCF8574_INT_NCALLBACKS # define CONFIG_PCF8574_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_PCF8574_INT_POLLDELAY # define CONFIG_PCF8574_INT_POLLDELAY 500000 #endif /* PCF8574 Definitions **********************************************************************/ #define PCF8574_I2C_MAXFREQUENCY 400000 /* 400KHz */ #define PCF8574_POLLDELAY (CONFIG_PCF8574_INT_POLLDELAY / USEC_PER_TICK) #define PCF8574_LEVEL_SENSITIVE(d,p) \ (((d)->trigger & ((ioe_pinset_t)1 << (p))) == 0) #define PCF8574_LEVEL_HIGH(d,p) \ (((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0) #define PCF8574_LEVEL_LOW(d,p) \ (((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0) #define PCF8574_EDGE_SENSITIVE(d,p) \ (((d)->trigger & ((ioe_pinset_t)1 << (p))) != 0) #define PCF8574_EDGE_RISING(d,p) \ (((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0) #define PCF8574_EDGE_FALLING(d,p) \ (((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0) #define PCF8574_EDGE_BOTH(d,p) \ (PCF8574_LEVEL_RISING(d,p) && PCF8574_LEVEL_FALLING(d,p)) /******************************************************************************************** * Public Types ********************************************************************************************/ #ifdef CONFIG_IOEXPANDER_INT_ENABLE /* This type represents on registered pin interrupt callback */ struct pcf8574_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 PCF8574 driver */ struct pcf8574_dev_s { struct ioexpander_dev_s dev; /* Nested structure to allow casting as public gpio * expander. */ FAR struct pcf8574_config_s *config; /* Board configuration data */ FAR struct i2c_master_s *i2c; /* Saved I2C driver instance */ sem_t exclsem; /* Mutual exclusion */ uint8_t inpins; /* Set of input pins */ uint8_t outstate; /* State of all output pins */ #ifdef CONFIG_IOEXPANDER_INT_ENABLE #ifdef CONFIG_PCF8574_INT_POLL WDOG_ID wdog; /* Timer used to poll for missed interrupts */ #endif uint8_t input; /* Last input registeres */ uint8_t intstat; /* Pending interrupts */ uint8_t trigger; /* Bit encoded: 0=level 1=edge */ uint8_t level[2]; /* Bit encoded: 01=high/rising, 10 low/falling, 11 both */ struct work_s work; /* Supports the interrupt handling "bottom half" */ /* Saved callback information for each I/O expander client */ struct pcf8574_callback_s cb[CONFIG_PCF8574_INT_NCALLBACKS]; #endif }; #endif /* CONFIG_IOEXPANDER && CONFIG_IOEXPANDER_PCF8574 */ #endif /* __DRIVERS_IOEXPANDER_PCF8574_H */