Add AVR32 port and demo files.

Demo/lwIP_AVR32_UC3/DRIVERS/INTC/intc.c

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+/*This file is prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief INTC driver for AVR32 UC3.
+ *
+ * AVR32 Interrupt Controller driver module.
+ *
+ * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
+ * - Supported devices:  All AVR32 devices with an INTC module can be used.
+ * - AppNote:
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support email: avr32@atmel.com
+ *
+ ******************************************************************************/
+
+/* Copyright (c) 2007, Atmel Corporation 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. The name of ATMEL may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL ``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 EXPRESSLY AND
+ * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
+ */
+
+
+#if __GNUC__
+#  include <avr32/io.h>
+#elif __ICCAVR32__
+#  include <avr32/iouc3a0512.h>
+#else
+#  error Unknown compiler
+#endif
+
+#include "compiler.h"
+#include "preprocessor.h"
+#include "intc.h"
+
+
+//! Values to store in the interrupt priority registers for the various interrupt priority levels.
+extern const unsigned int ipr_val[AVR32_INTC_NUM_INT_LEVELS];
+
+//! Creates a table of interrupt line handlers per interrupt group in order to optimize RAM space.
+//! Each line handler table contains a set of pointers to interrupt handlers.
+#define DECL_INT_LINE_HANDLER_TABLE(GRP, unused) \
+static volatile __int_handler _int_line_handler_table_##GRP[AVR32_INTC_NUM_IRQS_PER_GRP##GRP];
+MREPEAT(AVR32_INTC_NUM_INT_GRPS, DECL_INT_LINE_HANDLER_TABLE, ~);
+#undef DECL_INT_LINE_HANDLER_TABLE
+
+//! Table containing for each interrupt group the number of interrupt request
+//! lines and a pointer to the table of interrupt line handlers.
+static const struct
+{
+  unsigned int num_irqs;
+  volatile __int_handler *_int_line_handler_table;
+} _int_handler_table[AVR32_INTC_NUM_INT_GRPS] =
+{
+#define INSERT_INT_LINE_HANDLER_TABLE(GRP, unused) \
+  {AVR32_INTC_NUM_IRQS_PER_GRP##GRP, _int_line_handler_table_##GRP},
+  MREPEAT(AVR32_INTC_NUM_INT_GRPS, INSERT_INT_LINE_HANDLER_TABLE, ~)
+#undef INSERT_INT_LINE_HANDLER_TABLE
+};
+
+
+/*! \brief Default interrupt handler.
+ *
+ * \note Taken and adapted from Newlib.
+ */
+#if __GNUC__
+__attribute__((__interrupt__))
+#elif __ICCAVR32__
+__interrupt
+#endif
+static void _unhandled_interrupt(void)
+{
+  // Catch unregistered interrupts.
+  while (TRUE);
+}
+
+
+/*! \brief Gets the interrupt handler of the current event at the \a int_lev
+ *         interrupt priority level (called from exception.S).
+ *
+ * \param int_lev Interrupt priority level to handle.
+ *
+ * \return Interrupt handler to execute.
+ *
+ * \note Taken and adapted from Newlib.
+ */
+__int_handler _get_interrupt_handler(unsigned int int_lev)
+{
+  // ICR3 is mapped first, ICR0 last.
+  // Code in exception.S puts int_lev in R12 which is used by AVR32-GCC to pass
+  // a single argument to a function.
+  unsigned int int_grp = (&AVR32_INTC.icr3)[INT3 - int_lev];
+  unsigned int int_req = AVR32_INTC.irr[int_grp];
+
+  // As an interrupt may disappear while it is being fetched by the CPU
+  // (spurious interrupt caused by a delayed response from an MCU peripheral to
+  // an interrupt flag clear or interrupt disable instruction), check if there
+  // are remaining interrupt lines to process.
+  // If a spurious interrupt occurs, the status register (SR) contains an
+  // execution mode and interrupt level masks corresponding to a level 0
+  // interrupt, whatever the interrupt priority level causing the spurious
+  // event. This behavior has been chosen because a spurious interrupt has not
+  // to be a priority one and because it may not cause any trouble to other
+  // interrupts.
+  // However, these spurious interrupts place the hardware in an unstable state
+  // and could give problems in other/future versions of the CPU, so the
+  // software has to be written so that they never occur. The only safe way of
+  // achieving this is to always clear or disable peripheral interrupts with the
+  // following sequence:
+  // 1: Mask the interrupt in the CPU by setting GM (or IxM) in SR.
+  // 2: Perform the bus access to the peripheral register that clears or
+  //    disables the interrupt.
+  // 3: Wait until the interrupt has actually been cleared or disabled by the
+  //    peripheral. This is usually performed by reading from a register in the
+  //    same peripheral (it DOES NOT have to be the same register that was
+  //    accessed in step 2, but it MUST be in the same peripheral), what takes
+  //    bus system latencies into account, but peripheral internal latencies
+  //    (generally 0 cycle) also have to be considered.
+  // 4: Unmask the interrupt in the CPU by clearing GM (or IxM) in SR.
+  // Note that steps 1 and 4 are useless inside interrupt handlers as the
+  // corresponding interrupt level is automatically masked by IxM (unless IxM is
+  // explicitly cleared by the software).
+  //
+  // Get the right IRQ handler.
+  //
+  // If several interrupt lines are active in the group, the interrupt line with
+  // the highest number is selected. This is to be coherent with the
+  // prioritization of interrupt groups performed by the hardware interrupt
+  // controller.
+  //
+  // If no handler has been registered for the pending interrupt,
+  // _unhandled_interrupt will be selected thanks to the initialization of
+  // _int_line_handler_table_x by INTC_init_interrupts.
+  //
+  // exception.S will provide the interrupt handler with a clean interrupt stack
+  // frame, with nothing more pushed onto the stack. The interrupt handler must
+  // manage the `rete' instruction, what can be done thanks to pure assembly,
+  // inline assembly or the `__attribute__((__interrupt__))' C function
+  // attribute.
+  return (int_req) ? _int_handler_table[int_grp]._int_line_handler_table[32 - clz(int_req) - 1] : NULL;
+}
+
+
+void INTC_init_interrupts(void)
+{
+  unsigned int int_grp, int_req;
+
+  // For all interrupt groups,
+  for (int_grp = 0; int_grp < AVR32_INTC_NUM_INT_GRPS; int_grp++)
+  {
+    // For all interrupt request lines of each group,
+    for (int_req = 0; int_req < _int_handler_table[int_grp].num_irqs; int_req++)
+    {
+      // Assign _unhandled_interrupt as default interrupt handler.
+      _int_handler_table[int_grp]._int_line_handler_table[int_req] = &_unhandled_interrupt;
+    }
+
+    // Set the interrupt group priority register to its default value.
+    // By default, all interrupt groups are linked to the interrupt priority
+    // level 0 and to the interrupt vector _int0.
+    AVR32_INTC.ipr[int_grp] = ipr_val[INT0];
+  }
+}
+
+
+void INTC_register_interrupt(__int_handler handler, unsigned int irq, unsigned int int_lev)
+{
+  unsigned int int_grp = irq / AVR32_INTC_MAX_NUM_IRQS_PER_GRP;
+
+  // Store in _int_line_handler_table_x the pointer to the interrupt handler, so
+  // that _get_interrupt_handler can retrieve it when the interrupt is vectored.
+  _int_handler_table[int_grp]._int_line_handler_table[irq % AVR32_INTC_MAX_NUM_IRQS_PER_GRP] = handler;
+
+  // Program the corresponding IPRX register to set the interrupt priority level
+  // and the interrupt vector offset that will be fetched by the core interrupt
+  // system.
+  // NOTE: The _intx functions are intermediate assembly functions between the
+  // core interrupt system and the user interrupt handler.
+  AVR32_INTC.ipr[int_grp] = ipr_val[int_lev & (AVR32_INTC_IPR0_INTLEV_MASK >> AVR32_INTC_IPR0_INTLEV_OFFSET)];
+}