GPIO.h

Go to the documentation of this file.

/*
 * Copyright (c) 2015-2019, Texas Instruments Incorporated
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * *  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * *  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.
 *
 * *  Neither the name of Texas Instruments Incorporated 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.
 */
/*!****************************************************************************
 *  @file       GPIO.h
 *
 *  @brief      General Purpose I/O driver interface.
 *
 *  The GPIO header file should be included in an application as follows:
 *  @code
 *  #include <ti/drivers/GPIO.h>
 *  @endcode
 *
 *  # Overview #
 *  The GPIO module allows you to manage General Purpose I/O pins via simple
 *  and portable APIs. GPIO pin behavior is usually configured statically,
 *  but can also be configured or reconfigured at runtime.
 *
 *  Because of its simplicity, the GPIO driver does not follow the model of
 *  other TI-RTOS drivers in which a driver application interface has
 *  separate device-specific implementations. This difference is most
 *  apparent in the GPIOxxx_Config structure, which does not require you to
 *  specify a particular function table or object.
 *
 *  # Usage #
 *  This section provides a basic \ref ti_drivers_GPIO_Synopsis
 *  "usage summary" and a set of \ref ti_drivers_GPIO_Examples "examples"
 *  in the form of commented code fragments.  Detailed descriptions of the
 *  GPIO APIs and their effect are provided in subsequent sections.
 *
 *  @anchor ti_drivers_GPIO_Synopsis
 *  ### Synopsis #
 *  @anchor ti_drivers_GPIO_Synopsis_Code
 *  @code
 *  // Import GPIO Driver definitions
 *  #include <ti/drivers/GPIO.h>
 *
 *  // Define names for GPIO pin indexes
 *  #define BUTTON 0
 *  #define LED    1
 *
 *  // One-time init of GPIO driver
 *  GPIO_init();
 *
 *  // Read GPIO pin
 *  unsigned int state = GPIO_read(BUTTON);
 *
 *  // Write to GPIO pin
 *  GPIO_write(LED, state);
 *  @endcode
 *
 *  @anchor ti_drivers_GPIO_Examples
 *  ### Examples #
 *  * @ref ti_drivers_GPIO_Example_callback "Creating an input callback"
 *  * @ref ti_drivers_GPIO_Example_reconfigure "Runtime pin configuration"
 *
 *  @anchor ti_drivers_GPIO_Example_callback
 *  **Creating an input callback**: The following example demonstrates how
 *  to configure a GPIO pin to generate an interrupt and how to toggle an
 *  an LED on and off within the registered interrupt callback function.
 *  @code
 *  // Driver header file
 *  #include <ti/drivers/GPIO.h>
 *
 *  // TI Drivers Configuration
 *  #include "ti_drivers_config.h"
 *  // Board file
 *  #include <ti/drivers/Board.h>
 *
 *  // GPIO button call back function
 *  void gpioButton0Fxn(uint_least8_t index);
 *
 *  main()
 *  {
 *      // One-time Board initialization
 *      Board_init();
 *
 *      // One-time init of GPIO driver
 *      GPIO_init();
 *
 *      // Turn on user LED
 *      GPIO_write(CONFIG_GPIO_LED0, CONFIG_GPIO_LED_ON);
 *
 *      // install Button callback
 *      GPIO_setCallback(CONFIG_GPIO_BUTTON0, gpioButton0Fxn);
 *
 *      // Enable interrupts
 *      GPIO_enableInt(CONFIG_GPIO_BUTTON0);
 *  }
 *
 *  //
 *  //  ======== gpioButton0Fxn ========
 *  //  Callback function for the GPIO interrupt on CONFIG_GPIO_BUTTON0
 *  //
 *  //  Note: index is the GPIO id for the button which is not used here
 *  //
 *  void gpioButton0Fxn(uint_least8_t index)
 *  {
 *      // Toggle the LED
 *      GPIO_toggle(CONFIG_GPIO_LED0);
 *  }
 *  @endcode
 *
 *  @anchor ti_drivers_GPIO_Example_reconfigure
 *  **Runtime pin configuration**: The following example demonstrates how
 *  to (re)configure GPIO pins.
 *  @code
 *  // Driver header file
 *  #include <ti/drivers/GPIO.h>
 *
 *  // TI Driver configuration
 *  #include "ti_drivers_config.h"
 *
 *  #define LED    CONFIG_GPIO_LED0
 *  #define BUTTON CONFIG_GPIO_BUTTON0
 *
 *  void main()
 *  {
 *      // One-time init of GPIO driver
 *      GPIO_init();
 *
 *      // Configure a button input pin
 *      GPIO_setConfig(BUTTON, GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_FALLING);
 *
 *      // Configure an LED output pin
 *      GPIO_setConfig(LED, GPIO_CFG_OUT_STD | GPIO_CFG_OUT_LOW);
 *  }
 *  @endcode
 *
 *  ### GPIO Driver Configuration #
 *
 *  In order to use the GPIO APIs, the application is required
 *  to provide 3 structures in the ti_drivers_config.c file:
 *  1.  An array of @ref GPIO_PinConfig elements that defines the
 *  initial configuration of each pin used by the application. A
 *  pin is referenced in the application by its corresponding index in this
 *  array. The pin type (that is, INPUT/OUTPUT), its initial state (that is
 *  OUTPUT_HIGH or LOW), interrupt behavior (RISING/FALLING edge, etc.), and
 *  device specific pin identification are configured in each element
 *  of this array (see @ref GPIO_PinConfigSettings).
 *  Below is an MSP432 device specific example of the GPIO_PinConfig array:
 *  @code
 *  //
 *  // Array of Pin configurations
 *  //
 *  GPIO_PinConfig gpioPinConfigs[] = {
 *      // Input pins
 *      // MSP_EXP432P401R_GPIO_S1
 *      GPIOMSP432_P1_1 | GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_FALLING,
 *      // MSP_EXP432P401R_GPIO_S2
 *      GPIOMSP432_P1_4 | GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_FALLING,
 *
 *      // Output pins
 *      // MSP_EXP432P401R_GPIO_LED1
 *      GPIOMSP432_P1_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,
 *      // MSP_EXP432P401R_GPIO_LED_RED
 *      GPIOMSP432_P2_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,
 *  };
 *  @endcode
 *
 *  2.  An array of @ref GPIO_CallbackFxn elements that is used to store
 *  callback function pointers for GPIO pins configured with interrupts.
 *  The indexes for these array elements correspond to the pins defined
 *  in the GPIO_pinConfig array. These function pointers can be defined
 *  statically by referencing the callback function name in the array
 *  element, or dynamically, by setting the array element to NULL and using
 *  GPIO_setCallback() at runtime to plug the callback entry.
 *  Pins not used for interrupts can be omitted from the callback array to
 *  reduce memory usage (if they are placed at the end of GPIO_pinConfig
 *  array). The callback function syntax should match the following:
 *  @code
 *  void (*GPIO_CallbackFxn)(uint_least8_t index);
 *  @endcode
 *  The index parameter is the same index that was passed to
 *  GPIO_setCallback(). This allows the same callback function to be used
 *  for multiple GPIO interrupts, by using the index to identify the GPIO
 *  that caused the interrupt.
 *  @remark Callback functions are called in the context of an interrupt
 *  service routine and should be designed accordingly.
 *
 *  When an interrupt is triggered, the interrupt status of all
 *  (interrupt enabled) pins on a port will be read, cleared, and the
 *  respective callbacks will be executed. Callbacks will be called in order
 *  from least significant bit to most significant bit.
 *  Below is an MSP432 device specific example of the GPIO_CallbackFxn array:
 *  @code
 *  //
 *  // Array of callback function pointers
 *  //
 *  GPIO_CallbackFxn gpioCallbackFunctions[] = {
 *      // MSP_EXP432P401R_GPIO_S1
 *      NULL,
 *      // MSP_EXP432P401R_GPIO_S2
 *      NULL
 *  };
 *  @endcode
 *
 *  3.  A device specific GPIOxxx_Config structure that tells the GPIO
 *  driver where the two aforementioned arrays are and the number of elements
 *  in each. The interrupt priority of all pins configured to generate
 *  interrupts is also specified here. Values for the interrupt priority are
 *  device-specific. You should be well-acquainted with the interrupt
 *  controller used in your device before setting this parameter to a
 *  non-default value. The sentinel value of (~0) (the default value) is
 *  used to indicate that the lowest possible priority should be used.
 *  Below is an MSP432 device specific example of a GPIOxxx_Config
 *  structure:
 *  @code
 *  //
 *  // MSP432 specific GPIOxxx_Config structure
 *  //
 *  const GPIOMSP432_Config GPIOMSP432_config = {
 *      .pinConfigs = (GPIO_PinConfig *)gpioPinConfigs,
 *      .callbacks = (GPIO_CallbackFxn *)gpioCallbackFunctions,
 *      .numberOfPinConfigs = sizeof(gpioPinConfigs)/sizeof(GPIO_PinConfig),
 *      .numberOfCallbacks = sizeof(gpioCallbackFunctions)/sizeof(GPIO_CallbackFxn),
 *      .intPriority = (~0)
 *  };
 *  @endcode
 *
 *  ### Initializing the GPIO Driver #
 *
 *  GPIO_init() must be called before any other GPIO APIs.  This function
 *  configures each GPIO pin in the user-provided @ref GPIO_PinConfig
 *  array according to the defined settings. The user can also reconfigure
 *  a pin dynamically after GPIO_init() is called by using the
 *  GPIO_setConfig(), and GPIO_setCallback() APIs.
 *
 *  # Implementation #
 *
 *  Unlike most other TI-RTOS drivers, the GPIO driver has no generic function
 *  table with pointers to device-specific API implementations. All the generic
 *  GPIO APIs are implemented by the device-specific GPIO driver module.
 *  Additionally, there is no notion of an instance 'handle' with the GPIO
 *  driver.
 *
 *  GPIO pins are referenced by their numeric index in the GPIO_PinConfig
 *  array.  This design approach was used to enhance runtime and memory
 *  efficiency.
 *
 ******************************************************************************
 */

#ifndef ti_drivers_GPIO__include
#define ti_drivers_GPIO__include

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

#define GPIO_STATUS_RESERVED        (-32)

#define GPIO_STATUS_SUCCESS         (0)

#define GPIO_STATUS_ERROR           (-1)

typedef uint32_t GPIO_PinConfig;

#define GPIO_CFG_IO_MASK           0x00ff0000
#define GPIO_CFG_IO_LSB            16
#define GPIO_CFG_OUT_TYPE_MASK     0x00060000
#define GPIO_CFG_OUT_TYPE_LSB      17
#define GPIO_CFG_IN_TYPE_MASK      0x00060000
#define GPIO_CFG_IN_TYPE_LSB       17
#define GPIO_CFG_OUT_STRENGTH_MASK 0x00f00000
#define GPIO_CFG_OUT_STRENGTH_LSB  20
#define GPIO_CFG_INT_MASK          0x07000000
#define GPIO_CFG_INT_LSB           24
#define GPIO_CFG_OUT_BIT           19

#define GPIO_CFG_OUTPUT            (((uint32_t) 0) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_OUT_STD           (((uint32_t) 0) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_OUT_OD_NOPULL     (((uint32_t) 2) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_OUT_OD_PU         (((uint32_t) 4) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_OUT_OD_PD         (((uint32_t) 6) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_OUT_STR_LOW       (((uint32_t) 0) << GPIO_CFG_OUT_STRENGTH_LSB) 
#define GPIO_CFG_OUT_STR_MED       (((uint32_t) 1) << GPIO_CFG_OUT_STRENGTH_LSB) 
#define GPIO_CFG_OUT_STR_HIGH      (((uint32_t) 2) << GPIO_CFG_OUT_STRENGTH_LSB) 
#define GPIO_CFG_OUT_HIGH          (((uint32_t) 1) << GPIO_CFG_OUT_BIT) 
#define GPIO_CFG_OUT_LOW           (((uint32_t) 0) << GPIO_CFG_OUT_BIT) 
#define GPIO_CFG_INPUT             (((uint32_t) 1) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_IN_NOPULL         (((uint32_t) 1) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_IN_PU             (((uint32_t) 3) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_IN_PD             (((uint32_t) 5) << GPIO_CFG_IO_LSB) 
#define GPIO_CFG_IN_INT_NONE       (((uint32_t) 0) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_FALLING    (((uint32_t) 1) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_RISING     (((uint32_t) 2) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_BOTH_EDGES (((uint32_t) 3) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_LOW        (((uint32_t) 4) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_HIGH       (((uint32_t) 5) << GPIO_CFG_INT_LSB)    
#define GPIO_CFG_IN_INT_ONLY       (((uint32_t) 1) << 27)                  
#define GPIO_DO_NOT_CONFIG         0x40000000                              
typedef void (*GPIO_CallbackFxn)(uint_least8_t index);

extern void GPIO_clearInt(uint_least8_t index);

extern void GPIO_disableInt(uint_least8_t index);

extern void GPIO_enableInt(uint_least8_t index);

extern void GPIO_getConfig(uint_least8_t index, GPIO_PinConfig *pinConfig);

extern void GPIO_init();

extern uint_fast8_t GPIO_read(uint_least8_t index);

extern void GPIO_setCallback(uint_least8_t index, GPIO_CallbackFxn callback);

extern int_fast16_t GPIO_setConfig(uint_least8_t index,
    GPIO_PinConfig pinConfig);

extern void GPIO_toggle(uint_least8_t index);

extern void GPIO_write(uint_least8_t index, unsigned int value);

#ifdef __cplusplus
}
#endif

#endif /* ti_drivers_GPIO__include */