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//==========================================================================
//
// spi.c
//
// Generic API for accessing devices attached to an SPI bus
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 2004 Free Software Foundation, Inc.
//
// eCos 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 2 or (at your option) any later
// version.
//
// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// As a special exception, if other files instantiate templates or use
// macros or inline functions from this file, or you compile this file
// and link it with other works to produce a work based on this file,
// this file does not by itself cause the resulting work to be covered by
// the GNU General Public License. However the source code for this file
// must still be made available in accordance with section (3) of the GNU
// General Public License v2.
//
// This exception does not invalidate any other reasons why a work based
// on this file might be covered by the GNU General Public License.
// -------------------------------------------
// ####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//###DESCRIPTIONBEGIN####
//
// Author(s): bartv
// Date: 2004-04-23
//
//###DESCRIPTIONEND####
//========================================================================
#include <pkgconf/infra.h>
#include <pkgconf/io_spi.h>
#include <cyg/infra/cyg_ass.h>
#include <cyg/io/spi.h>
// The simple transfer function just calls the transaction functions
// in order. The chip select should be dropped at the end of this
// transfer.
void
cyg_spi_transfer(cyg_spi_device* device, cyg_bool polled, cyg_uint32 count, const cyg_uint8* tx_data, cyg_uint8* rx_data)
{
cyg_spi_transaction_begin(device);
cyg_spi_transaction_transfer(device, polled, count, tx_data, rx_data, 1);
cyg_spi_transaction_end(device);
}
// Tick is similarly simple.
void
cyg_spi_tick(cyg_spi_device* device, cyg_bool polled, cyg_uint32 count)
{
cyg_spi_transaction_begin(device);
cyg_spi_transaction_tick(device, polled, count);
cyg_spi_transaction_end(device);
}
// get_config() and set_config() requires locking the bus, then accessing the
// bus-specific function via the bus structure. Only locking is needed, not
// setting up the bus for a transfer to this device, so the transaction begin
// function is inappropriate.
int
cyg_spi_get_config(cyg_spi_device* device, cyg_uint32 key, void* buf, cyg_uint32* len)
{
int result;
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_CHECK_FUNC_PTR(bus->spi_get_config, "SPI bus driver has not provided a get_config function");
while (!cyg_drv_mutex_lock(&(bus->spi_lock)));
result = (*(bus->spi_get_config))(device, key, buf, len);
cyg_drv_mutex_unlock(&(bus->spi_lock));
return result;
}
// set_config is basically just a clone of the above, but using a different
// bus-specific operation.
int
cyg_spi_set_config(cyg_spi_device* device, cyg_uint32 key, const void* buf, cyg_uint32* len)
{
int result;
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_CHECK_FUNC_PTR(bus->spi_set_config, "SPI bus driver has not provided a set_config function");
while (!cyg_drv_mutex_lock(&(bus->spi_lock)));
result = (*(bus->spi_set_config))(device, key, buf, len);
cyg_drv_mutex_unlock(&(bus->spi_lock));
return result;
}
// transaction-begin involves getting sole access to the bus, then calling
// the bus driver's begin function to set up the hardware appropriately for
// the target device.
void
cyg_spi_transaction_begin(cyg_spi_device* device)
{
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_CHECK_FUNC_PTR(bus->spi_transaction_begin, "SPI device has not provided a transaction_begin function");
while (!cyg_drv_mutex_lock(&(bus->spi_lock)));
#ifdef CYGDBG_USE_ASSERTS
bus->spi_current_device = device;
#endif
// This thread now has exclusive access to the bus
(*(bus->spi_transaction_begin))(device);
// All done. Return with the bus still locked.
}
// A variant of the above which returns immediately if some other thread
// is using the bus.
cyg_bool
cyg_spi_transaction_begin_nb(cyg_spi_device* device)
{
cyg_bool result = false;
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_CHECK_FUNC_PTR(bus->spi_transaction_begin, "SPI device has not provided a transaction_begin function");
if (cyg_drv_mutex_trylock(&(bus->spi_lock))) {
#ifdef CYGDBG_USE_ASSERTS
bus->spi_current_device = device;
#endif
(*(bus->spi_transaction_begin))(device);
result = true;
}
return result;
}
void
cyg_spi_transaction_transfer(cyg_spi_device* device, cyg_bool polled,
cyg_uint32 count, const cyg_uint8* tx_data, cyg_uint8* rx_data,
cyg_bool drop_cs)
{
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_ASSERT(bus->spi_current_device == device, "SPI transfer requested without claiming the bus");
CYG_CHECK_FUNC_PTR(bus->spi_transaction_transfer, "SPI device has not provided a transfer function");
(*(bus->spi_transaction_transfer))(device, polled, count, tx_data, rx_data, drop_cs);
}
void
cyg_spi_transaction_tick(cyg_spi_device* device, cyg_bool polled, cyg_uint32 count)
{
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_ASSERT(bus->spi_current_device == device, "SPI ticks requested without claiming the bus");
CYG_CHECK_FUNC_PTR(bus->spi_transaction_tick, "SPI device has not provided a tick function");
(*(bus->spi_transaction_tick))(device, polled, count);
}
void
cyg_spi_transaction_end(cyg_spi_device* device)
{
cyg_spi_bus* bus;
CYG_CHECK_DATA_PTR(device, "valid SPI device pointer required");
bus = device->spi_bus;
CYG_CHECK_DATA_PTR(bus, "SPI device does not point at a valid bus structure");
CYG_ASSERT(bus->spi_current_device == device, "SPI transfer requested without claiming the bus");
CYG_CHECK_FUNC_PTR(bus->spi_transaction_end, "SPI device has not provided an end function");
// First, call the bus' end function.
(*(bus->spi_transaction_end))(device);
// Then release the SPI bus for other threads.
cyg_drv_mutex_unlock(&(bus->spi_lock));
}
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