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- /*!
- * \file /utl/com/spi.h
- * \brief An Abstract base class interface for the spi bus
- *
- * Copyright (C) 2018 Christos Choutouridis
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as
- * published by the Free Software Foundation, either version 3
- * of the License, or (at your option) any later version.
- *
- * This program 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 Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
- #ifndef _utl_com_spi_h__
- #define _utl_com_spi_h__
-
- #include <utl/core/impl.h>
- #include <utl/core/crtp.h>
- #include <utl/meta/meta.h>
-
- namespace utl {
-
- /*!
- * \ingroup Communication
- * \brief Abstract base class for spi bus
- */
- //!@{
-
- namespace spi {
- /*!
- * SPI implementation bit order
- */
- enum class bitOrder {
- LSB_First =0x01, //!< Most significant first
- MSB_First =0x80 //!< Less significant first
- };
- /*!
- * SPI implementation Clock Polarity
- */
- enum class cpol {
- LOW =0, //!< LOW
- HIGH //!< HIGH
- };
- /*!
- * SPI implementation Clock Phase
- */
- enum class cpha {
- LOW =0, //!< LOW
- HIGH //!< HIGH
- };
- }
-
- /*!
- * Template base class for SPI communication interface using CRTP
- * This class force a common interface for SPI communication
- * protocol implementations.
- * \param impl_t The CRTP type (the derived/implementation class typename).
- */
- template <typename impl_t>
- class spi_i {
- _CRTP_IMPL(impl_t); //! \brief Syntactic sugar to CRTP casting
-
- public:
- using type = spi_i<impl_t>; //!< Export type as identity meta-function
-
- /*!
- * \name Object lifetime
- */
- //!@{
- protected:
- spi_i () = default; //!< Allow constructor from derived only
- ~spi_i () = default; //!< Allow destructor from derived only
- spi_i (const type&) = delete; //!< No copies
- type& operator= (const type&) = delete;
- //!@}
-
- /*!
- * \name Implementation requirements
- * \note
- * In order for the implementation to have the following as private members
- * it also need to declare this class as friend
- */
- //! @{
- private:
- uint32_t _clock () const { return impl()._clock (); } //!< clock frequency of the bus [Hz]
- void _clock (uint32_t c) { impl()._clock (c); } //!< set clock frequency of the bus [Hz]
- byte_t _tx_data (byte_t b) { return impl()._tx_data (b); } //!< Transmit a byte on the bus and return the response
- //! @}
-
- /*!
- * \name Get/Set functions provided by the interface
- */
- //!@{
- public:
- uint32_t clock () const { return _clock (); } //!< \return clock frequency of the bus
- void clock (uint32_t c) { _clock (c); } //!< \brief set clock frequency of the bus
- //!@}
-
- /*!
- * \name I/O functions provided by the interface
- */
- //!@{
- public:
- /*!
- * Transmit a byte to spi bus and return the response
- */
- byte_t tx_data (byte_t out) {
- return _tx_data (out);
- }
- /*!
- * \brief
- * Transmit a number of bytes to the spi bus and read the response.
- * \param out Pointer to data to send to the bus
- * \param in Pointer to buffer to store the data from the bus
- * \param n The number of bytes to transmit/receive
- * \return The number of bytes.
- */
- size_t tx_data (const byte_t *out, byte_t *in, size_t n);
- /*!
- * Receive a byte from spi bus while transmitting 0xFF
- */
- byte_t rx_data () {
- return _tx_data(0xFF);
- }
- /*!
- * \brief
- * Receive a number of bytes from the spi bus while transmitting 0xFFs.
- * \param in Pointer to buffer to store the data
- * \param n The number of bytes to read
- * \return The number of received bytes.
- */
- size_t rx_data (byte_t *in, size_t n);
- //!@}
- };
-
- /*!
- * \brief
- * Transmit a number of bytes to the spi bus and read the response.
- * \param out Pointer to data to send to the bus
- * \param in Pointer to buffer to store the data from the bus
- * \param n The number of bytes to transmit/receive
- * \return The number of bytes.
- */
- template<typename _I>
- size_t spi_i<_I>::tx_data (const byte_t *out, byte_t *in, size_t n) {
- for (size_t nn {n} ; nn ; --nn)
- *in++ = _tx_data (*out++);
- return n;
- }
- /*!
- * \brief
- * Receive a number of bytes from the spi bus while transmitting 0xFFs.
- * \param in Pointer to buffer to store the data
- * \param n The number of bytes to read
- * \return The number of received bytes.
- */
- template<typename _I>
- size_t spi_i<_I>::rx_data (byte_t *in, size_t n) {
- for (size_t nn {n} ; nn ; --nn)
- *in++ = _tx_data (0xFF);
- return n;
- }
-
- /*!
- * \brief
- * A virtual base class implementation
- * \param none
- */
- template <>
- class spi_i <virtual_tag> {
- public:
- using type = spi_i<virtual_tag>; //!< Export type as identity meta-function
-
- /*!
- * \name Object lifetime
- */
- //!@{
- protected:
- spi_i () = default; //!< Allow constructor from derived only
- spi_i (const type&) = delete; //!< No copies
- type& operator= (const type&) = delete;
- public:
- virtual ~spi_i () = default; //!< Virtual default destructor
- //!@}
-
- /*!
- * \name Implementation requirements
- */
- //! @{
- private:
- virtual uint32_t _clock () const =0; //!< Read the clock frequency of the bus
- virtual void _clock (uint32_t) =0; //!< Set the clock frequency of the bus
- virtual byte_t _tx_data (byte_t) =0; //!< Transmit a byte on the bus and return the response
- //! @}
-
- /*!
- * \name Get/Set functions provided by the interface
- */
- //!@{
- public:
- uint32_t clock () const { return _clock (); } //!< \return clock frequency of the bus
- void clock (uint32_t c) { _clock (c); } //!< \brief set clock frequency of the bus
- //!@}
-
- /*!
- * \name I/O functions provided by the interface
- */
- //!@{
- public:
- /*!
- * Transmit a byte to spi bus and return the response
- */
- byte_t tx_data (byte_t out) {
- return _tx_data (out);
- }
- /*!
- * \brief
- * Transmit a number of bytes to the spi bus and read the response.
- * \param out Pointer to data to send to the bus
- * \param in Pointer to buffer to store the data from the bus
- * \param n The number of bytes to transmit/receive
- * \return The number of bytes.
- */
- size_t tx_data (const byte_t *out, byte_t *in, size_t n);
- /*!
- * Receive a byte from spi bus while transmitting 0xFF
- */
- byte_t rx_data () {
- return _tx_data (0xFF);
- }
- /*!
- * \brief
- * Receive a number of bytes from the spi bus while transmitting 0xFFs.
- * \param in Pointer to buffer to store the data
- * \param n The number of bytes to read
- * \return The number of received bytes.
- */
- size_t rx_data (byte_t *in, size_t n);
- //!@}
-
- };
-
- /*!
- * \brief
- * Transmit a number of bytes to the spi bus and read the response.
- * \param out Pointer to data to send to the bus
- * \param in Pointer to buffer to store the data from the bus
- * \param n The number of bytes to transmit/receive
- * \return The number of bytes.
- */
- size_t spi_i<virtual_tag>::tx_data (const byte_t *out, byte_t *in, size_t n) {
- for (size_t nn {n} ; nn ; --nn)
- *in++ = _tx_data (*out++);
- return n;
- }
- /*!
- * \brief
- * Receive a number of bytes from the spi bus while transmitting 0xFFs.
- * \param in Pointer to buffer to store the data
- * \param n The number of bytes to read
- * \return The number of received bytes.
- */
- size_t spi_i<virtual_tag>::rx_data (byte_t *in, size_t n) {
- for (size_t nn {n} ; nn ; --nn)
- *in++ = _tx_data (0xFF);
- return n;
- }
-
-
-
- /*!
- * i2c interface concept
- */
- //! @{
- #if defined _utl_have_concepts
- template <typename T>
- concept bool Spi_i = requires (T t, const T ct, typename T::Sequence s) {
- // Object type
- requires not_<std::is_copy_constructible<T>::value>::value;
- requires not_<std::is_copy_assignable<T>::value>::value;
- // Methods
- {ct.clock()} -> uint32_t;
- {t.clock(0)} -> void;
- {t.tx_data(1)} -> byte_t;
- {t.rx_data()} -> byte_t;
- };
- #else
- namespace spi_i_details {
- using std::declval;
-
- template <class _Tp> using try_cclock_t= decltype (declval<const _Tp>().clock());
- template <class _Tp> using try_clock_t = decltype (declval<_Tp>().clock(declval<uint32_t>()));
- template <class _Tp> using try_tx_t = decltype (declval<_Tp>().tx_data(declval<byte_t>()));
- template <class _Tp> using try_rx_t = decltype (declval<_Tp>().rx_data());
-
- //! Primary template to catch any non SPI interface types
- template <typename _Tp, typename =void>
- struct is_spi_ : meta::false_ {};
-
- //! template to catch a proper SPI interface type
- template <typename _Tp>
- struct is_spi_ <
- _Tp,
- meta::void_t <
- meta::use_if_same_t <try_cclock_t<_Tp>, uint32_t>,
- meta::use_if_same_t <try_clock_t<_Tp>, void>,
- meta::use_if_same_t <try_tx_t<_Tp>, byte_t>,
- meta::use_if_same_t <try_rx_t<_Tp>, byte_t>
- >
- > : meta::true_ {};
- }
- /*!
- * Value meta-programming function for SPI interface checking
- * \param _Tp Type to check
- * \return True if _Tp is a spi interface
- */
- // template <typename _Tp>
- // constexpr bool Spi_i = spi_i_details::is_spi_<_Tp>::value;
- #endif
- //! @}
-
- //! @}
-
- } // namespace utl
-
- #endif /* #ifndef _utl_com_spi_h__ */
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