px4io_serial.h

/****************************************************************************
 *
 *   Copyright (c) 2015 PX4 Development Team. All rights reserved.
 *
 * 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 PX4 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
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 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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 ****************************************************************************/

#pragma once

/* XXX trim includes */
#include <px4_config.h>
#include <px4_posix.h>

#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <assert.h>
#include <debug.h>
#include <time.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>

#include <arch/board/board.h>
#include <perf/perf_counter.h>

#include <board_config.h>

#include <drivers/device/device.h>
#include <modules/px4iofirmware/protocol.h>

class PX4IO_serial : public device::Device
{
public:
    PX4IO_serial();
    virtual ~PX4IO_serial();

    virtual int init() = 0;
    virtual int read(unsigned offset, void *data, unsigned count = 1);
    virtual int write(unsigned address, void *data, unsigned count = 1);

protected:
    int     init(IOPacket *io_buffer);

    virtual int _bus_exchange(IOPacket *_packet) = 0;

    perf_counter_t      _pc_txns;
    perf_counter_t      _pc_retries;
    perf_counter_t      _pc_timeouts;
    perf_counter_t      _pc_crcerrs;
    perf_counter_t      _pc_protoerrs;
    perf_counter_t      _pc_uerrs;
    perf_counter_t      _pc_idle;
    perf_counter_t      _pc_badidle;
private:
    /*
     * XXX tune this value
     *
     * At 1.5Mbps each register takes 13.3µs, and we always transfer a full packet.
     * Packet overhead is 26µs for the four-byte header.
     *
     * 32 registers = 451µs
     *
     * Maybe we can just send smaller packets (e.g. 8 regs) and loop for larger (less common)
     * transfers? Could cause issues with any regs expecting to be written atomically...
     */
    IOPacket        *_io_buffer_ptr;

    px4_sem_t           _bus_semaphore;

    /* do not allow top copying this class */
    PX4IO_serial(PX4IO_serial &);
    PX4IO_serial &operator = (const PX4IO_serial &);
};

#if defined(CONFIG_STM32_STM32F10XX) || defined(CONFIG_STM32_STM32F4XXX)

#define PX4IO_INTERFACE_CLASS PX4IO_serial_f4
#define PX4IO_INTERFACE_F4

class PX4IO_serial_f4 : public PX4IO_serial
{
public:
    PX4IO_serial_f4();
    ~PX4IO_serial_f4();

    virtual int init();
    virtual int ioctl(unsigned operation, unsigned &arg);

protected:
    int     _bus_exchange(IOPacket *_packet);

private:
    DMA_HANDLE      _tx_dma;
    DMA_HANDLE      _rx_dma;

    IOPacket *_current_packet;

    static const unsigned   _dma_status_inactive = 0x80000000;  // low bits overlap DMA_STATUS_* values
    static const unsigned   _dma_status_waiting  = 0x00000000;
    volatile unsigned   _rx_dma_status;

    px4_sem_t           _completion_semaphore;

    static void     _dma_callback(DMA_HANDLE handle, uint8_t status, void *arg);
    void            _do_rx_dma_callback(unsigned status);

    static int      _interrupt(int vector, void *context, void *arg);
    void            _do_interrupt();

    void            _abort_dma();

    perf_counter_t      _pc_dmasetup;
    perf_counter_t      _pc_dmaerrs;

    /* do not allow top copying this class */
    PX4IO_serial_f4(PX4IO_serial_f4 &);
    PX4IO_serial_f4 &operator = (const PX4IO_serial_f4 &);

    static IOPacket     _io_buffer_storage;     // XXX static to ensure DMA-able memory
};

#elif defined(CONFIG_ARCH_CHIP_STM32F7)

#define PX4IO_INTERFACE_CLASS PX4IO_serial_f7
#define PX4IO_INTERFACE_F7

#include <stm32_dma.h>


class PX4IO_serial_f7 : public PX4IO_serial
{
public:
    PX4IO_serial_f7();
    ~PX4IO_serial_f7();

    virtual int init();
    virtual int ioctl(unsigned operation, unsigned &arg);

protected:
    int     _bus_exchange(IOPacket *_packet);

private:
    DMA_HANDLE      _tx_dma;
    DMA_HANDLE      _rx_dma;

    IOPacket *_current_packet;

    static const unsigned   _dma_status_inactive = 0x80000000;  // low bits overlap DMA_STATUS_* values
    static const unsigned   _dma_status_waiting  = 0x00000000;
    volatile unsigned   _rx_dma_status;

    px4_sem_t           _completion_semaphore;

    static void     _dma_callback(DMA_HANDLE handle, uint8_t status, void *arg);
    void            _do_rx_dma_callback(unsigned status);

    static int      _interrupt(int vector, void *context, void *arg);
    void            _do_interrupt();

    void            _abort_dma();

    perf_counter_t      _pc_dmasetup;
    perf_counter_t      _pc_dmaerrs;

    /* do not allow top copying this class */
    PX4IO_serial_f7(PX4IO_serial_f7 &);
    PX4IO_serial_f7 &operator = (const PX4IO_serial_f7 &);

    static uint8_t _io_buffer_storage[];
};

#else
#error "Interface not implemented for this chip"
#endif