path: root/os/hal/include/pal.h

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    pal.h
 * @brief   I/O Ports Abstraction Layer macros, types and structures.
 *
 * @addtogroup PAL
 * @{
 */

#ifndef _PAL_H_
#define _PAL_H_

#if CH_HAL_USE_PAL || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

/**
 * @brief   Bits in a mode word dedicated as mode selector.
 * @details The other bits are not defined and may be used as device-specific
 *          option bits.
 */
#define PAL_MODE_MASK                   0xF

/**
 * @brief   After reset state.
 * @details The state itself is not specified and is architecture dependent,
 *          it is guaranteed to be equal to the after-reset state. It is
 *          usually an input state.
 */
#define PAL_MODE_RESET                  0

/**
 * @brief   Safe state for <b>unconnected</b> pads.
 * @details The state itself is not specified and is architecture dependent,
 *          it may be mapped on @p PAL_MODE_INPUT_PULLUP,
 *          @p PAL_MODE_INPUT_PULLDOWN or @p PAL_MODE_OUTPUT_PUSHPULL as
 *          example.
 */
#define PAL_MODE_UNCONNECTED            1

/**
 * @brief   Regular input high-Z pad.
 */
#define PAL_MODE_INPUT                  2

/**
 * @brief   Input pad with weak pull up resistor.
 */
#define PAL_MODE_INPUT_PULLUP           3

/**
 * @brief   Input pad with weak pull down resistor.
 */
#define PAL_MODE_INPUT_PULLDOWN         4

/**
 * @brief   Analog input mode.
 */
#define PAL_MODE_INPUT_ANALOG           5

/**
 * @brief   Push-pull output pad.
 */
#define PAL_MODE_OUTPUT_PUSHPULL        6

/**
 * @brief   Open-drain output pad.
 */
#define PAL_MODE_OUTPUT_OPENDRAIN       7

/**
 * @brief   Logical low state.
 */
#define PAL_LOW 0

/**
 * @brief   Logical high state.
 */
#define PAL_HIGH 1

/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/

/*===========================================================================*/
/* Driver data structures and types.                                         */
/*===========================================================================*/

#include "pal_lld.h"

/**
 * @brief   I/O bus descriptor.
 * @details This structure describes a group of contiguous digital I/O lines
 *          that have to be handled as bus.
 * @note    I/O operations on a bus do not affect I/O lines on the same port but
 *          not belonging to the bus.
 */
typedef struct {
  /**
   * @brief Port identifier.
   */
  ioportid_t            bus_portid;
  /**
   * @brief Bus mask aligned to port bit 0.
   * @note  The bus mask implicitly define the bus width. A logical AND is
   *        performed on the bus data.
   */
  ioportmask_t          bus_mask;
  /**
   * @brief Offset, within the port, of the least significant bit of the bus.
   */
  uint_fast8_t          bus_offset;
} IOBus;

/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/

/**
 * @brief   Port bit helper macro.
 * @details This macro calculates the mask of a bit within a port.
 *
 * @param[in] n         bit position within the port
 * @return              The bit mask.
 */
#define PAL_PORT_BIT(n) ((ioportmask_t)(1 << (n)))


/**
 * @brief   Bits group mask helper.
 * @details This macro calculates the mask of a bits group.
 *
 * @param[in] width         group width
 * @return                  The group mask.
 */
#define PAL_GROUP_MASK(width) ((ioportmask_t)(1 << (width)) - 1)

/**
 * @brief   Data part of a static I/O bus initializer.
 * @details This macro should be used when statically initializing an I/O bus
 *          that is part of a bigger structure.
 *
 * @param[in] name      name of the IOBus variable
 * @param[in] port      I/O port descriptor
 * @param[in] width     bus width in bits
 * @param[in] offset     bus bit offset within the port
 */
#define _IOBUS_DATA(name, port, width, offset)                          \
  {port, PAL_GROUP_MASK(width), offset}

/**
 * @brief   Static I/O bus initializer.
 *
 * @param[in] name      name of the IOBus variable
 * @param[in] port      I/O port descriptor
 * @param[in] width     bus width in bits
 * @param[in] offset    bus bit offset within the port
 */
#define IOBUS_DECL(name, port, width, offset)                           \
  IOBus name = _IOBUS_DATA(name, port, width, offset)

/**
 * @brief   PAL subsystem initialization.
 *
 * @param[in] config pointer to an architecture specific configuration
 *            structure. This structure is defined in the low level driver
 *            header.
 */
#define palInit(config) pal_lld_init(config)

/**
 * @brief   Reads the physical I/O port states.
 * @note    The default implementation always return zero and computes the
 *          parameter eventual side effects.
 *
 * @param[in] port      port identifier
 * @return              The port logical states.
 */
#if !defined(pal_lld_readport) || defined(__DOXYGEN__)
#define palReadPort(port) ((void)(port), 0)
#else
#define palReadPort(port) pal_lld_readport(port)
#endif

/**
 * @brief   Reads the output latch.
 * @details The purpose of this function is to read back the latched output
 *          value.
 * @note    The default implementation always return zero and computes the
 *          parameter eventual side effects.
 *
 * @param[in] port      port identifier
 * @return              The latched logical states.
 */
#if !defined(pal_lld_readlatch) || defined(__DOXYGEN__)
#define palReadLatch(port) ((void)(port), 0)
#else
#define palReadLatch(port) pal_lld_readlatch(port)
#endif

/**
 * @brief   Writes a bits mask on a I/O port.
 * @note    The default implementation does nothing except computing the
 *          parameters eventual side effects.
 *
 * @param[in] port      port identifier
 * @param[in] bits      bits to be written on the specified port
 */
#if !defined(pal_lld_writeport) || defined(__DOXYGEN__)
#define palWritePort(port, bits) ((void)(port), (void)(bits))
#else
#define palWritePort(port, bits) pal_lld_writeport(port, bits)
#endif

/**
 * @brief   Sets a bits mask on a I/O port.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 *
 * @param[in] port      port identifier
 * @param[in] bits      bits to be ORed on the specified port
 */
#if !defined(pal_lld_setport) || defined(__DOXYGEN__)
#define palSetPort(port, bits) {                                        \
  palWritePort(port, palReadLatch(port) | (bits));                      \
}
#else
#define palSetPort(port, bits) pal_lld_setport(port, bits)
#endif

/**
 * @brief   Clears a bits mask on a I/O port.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures,  for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 *
 * @param[in] port      port identifier
 * @param[in] bits      bits to be cleared on the specified port
 *
 */
#if !defined(pal_lld_clearport) || defined(__DOXYGEN__)
#define palClearPort(port, bits) {                                      \
  palWritePort(port, palReadLatch(port) & ~(bits));                     \
}
#else
#define palClearPort(port, bits) pal_lld_clearport(port, bits)
#endif

/**
 * @brief   Toggles a bits mask on a I/O port.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 *
 * @param[in] port      port identifier
 * @param[in] bits      bits to be XORed on the specified port
 */
#if !defined(pal_lld_toggleport) || defined(__DOXYGEN__)
#define palTogglePort(port, bits) {                                     \
  palWritePort(port, palReadLatch(port) ^ (bits));                      \
}
#else
#define palTogglePort(port, bits) pal_lld_toggleport(port, bits)
#endif

/**
 * @brief   Reads a group of bits.
 *
 * @param[in] port      port identifier
 * @param[in] mask      group mask, a logical AND is performed on the input
 *                      data
 * @param[in] offset    group bit offset within the port
 * @return              The group logical states.
 */
#if !defined(pal_lld_readgroup) || defined(__DOXYGEN__)
#define palReadGroup(port, mask, offset)                               \
  ((palReadPort(port) >> (offset)) & (mask))
#else
#define palReadGroup(port, mask, offset) pal_lld_readgroup(port, mask, offset)
#endif

/**
 * @brief   Writes a group of bits.
 *
 * @param[in] port      port identifier
 * @param[in] mask      group mask, a logical AND is performed on the
 *                      output  data
 * @param[in] offset    group bit offset within the port
 * @param[in] bits      bits to be written. Values exceeding the group
 *                      width are masked.
 */
#if !defined(pal_lld_writegroup) || defined(__DOXYGEN__)
#define palWriteGroup(port, mask, offset, bits) {                       \
  palWritePort(port, (palReadLatch(port) & ~((mask) << (offset))) |     \
                     (((bits) & (mask)) << (offset)));                  \
}
#else
#define palWriteGroup(port, mask, offset, bits)                         \
  pal_lld_writegroup(port, mask, offset, bits)
#endif


/**
 * @brief   Pads group mode setup.
 * @details This function programs a pads group belonging to the same port
 *          with the specified mode.
 * @note    Programming an unknown or unsupported mode is silently ignored.
 *
 * @param[in] port      port identifier
 * @param[in] mask      group mask
 * @param[in] mode      group mode
 *
 */
#if !defined(pal_lld_setgroupmode) || defined(__DOXYGEN__)
#define palSetGroupMode(port, mask, mode)
#else
#define palSetGroupMode(port, mask, mode) pal_lld_setgroupmode(port, mask, mode)
#endif

/**
 * @brief   Reads an input pad logical state.
 * @note    The default implementation not necessarily optimal. Low level
 *          drivers may  optimize the function by using specific hardware
 *          or coding.
 * @note    The default implementation internally uses the @p palReadPort().
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 * @return              The logical state.
 * @retval PAL_LOW      low logical state.
 * @retval PAL_HIGH     high logical state.
 *
 */
#if !defined(pal_lld_readpad) || defined(__DOXYGEN__)
#define palReadPad(port, pad) ((palReadPort(port) >> (pad)) & 1)
#else
#define palReadPad(port, pad) pal_lld_readpad(port, pad)
#endif

/**
 * @brief   Writes a logical state on an output pad.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 * @note    The default implementation internally uses the @p palReadLatch()
 *          and @p palWritePort().
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 * @param[in] bit       logical value, the value must be @p PAL_LOW or
 *                      @p PAL_HIGH
 */
#if !defined(pal_lld_writepad) || defined(__DOXYGEN__)
#define palWritePad(port, pad, bit) {                                   \
  palWritePort(port, (palReadLatch(port) & ~PAL_PORT_BIT(pad)) |        \
                     (((bit) & 1) << pad));                             \
}
#else
#define palWritePad(port, pad, bit) pal_lld_writepad(port, pad, bit)
#endif

/**
 * @brief   Sets a pad logical state to @p PAL_HIGH.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 * @note    The default implementation internally uses the @p palSetPort().
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 */
#if !defined(pal_lld_setpad) || defined(__DOXYGEN__)
#define palSetPad(port, pad) palSetPort(port, PAL_PORT_BIT(pad))
#else
#define palSetPad(port, pad) pal_lld_setpad(port, pad)
#endif

/**
 * @brief   Clears a pad logical state to @p PAL_LOW.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 * @note    The default implementation internally uses the @p palClearPort().
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 */
#if !defined(pal_lld_clearpad) || defined(__DOXYGEN__)
#define palClearPad(port, pad) palClearPort(port, PAL_PORT_BIT(pad))
#else
#define palClearPad(port, pad) pal_lld_clearpad(port, pad)
#endif

/**
 * @brief   Toggles a pad logical state.
 * @note    The operation is not guaranteed to be atomic on all the
 *          architectures, for atomicity and/or portability reasons you may
 *          need to enclose port I/O operations between @p chSysLock() and
 *          @p chSysUnlock().
 * @note    The default implementation is non atomic and not necessarily
 *          optimal. Low level drivers may  optimize the function by using
 *          specific hardware or coding.
 * @note    The default implementation internally uses the @p palTogglePort().
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 */
#if !defined(pal_lld_togglepad) || defined(__DOXYGEN__)
#define palTogglePad(port, pad) palTogglePort(port, PAL_PORT_BIT(pad))
#else
#define palTogglePad(port, pad) pal_lld_togglepad(port, pad)
#endif


/**
 * @brief   Pad mode setup.
 * @details This function programs a pad with the specified mode.
 * @note    The default implementation not necessarily optimal. Low level
 *          drivers may  optimize the function by using specific hardware
 *          or coding.
 * @note    Programming an unknown or unsupported mode is silently ignored.
 *
 * @param[in] port      port identifier
 * @param[in] pad       pad number within the port
 * @param[in] mode      pad mode
 */
#if !defined(pal_lld_setpadmode) || defined(__DOXYGEN__)
#define palSetPadMode(port, pad, mode)                                  \
  palSetGroupMode(port, PAL_PORT_BIT(pad), mode)
#else
#define palSetPadMode(port, pad, mode) pal_lld_setpadmode(port, pad, mode)
#endif

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#ifdef __cplusplus
extern "C" {
#endif
  ioportmask_t palReadBus(IOBus *bus);
  void palWriteBus(IOBus *bus, ioportmask_t bits);
  void palSetBusMode(IOBus *bus, uint_fast8_t mode);
#ifdef __cplusplus
}
#endif

#endif /* _PAL_H_ */

#endif /* CH_HAL_USE_PAL */

/** @} */