Subversion Repositories openrisc_me

// #========================================================================

// #

// #    i2s_audio_FIQ.S

// #

// #    FIQ handler for EB7209 audio stream

// #

// #========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, 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.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 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.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

// #========================================================================

// ######DESCRIPTIONBEGIN####

// #

// # Author(s):     gthomas

// # Contributors:  gthomas

// # Date:          1999-09-10

// # Purpose:       Support EB7209 audio interrupts

// # Description:   This routine will send data to the audio FIFOs.

// #

// #####DESCRIPTIONEND####

// #

// #========================================================================

#include 

//        .file   "i2s_audio_FIQ.S"

        .extern cur_buf

        .extern next_buf

// These defines must mimic the data structure used by the main program

#define audio_buf_left_ptr   0x0

#define audio_buf_right_ptr  0x4

#define audio_buf_length     0x8

        .code   32

        .text

// Note: when handling an FIQ, registers r8-r14 are free to use

// since they are unique (banked).

        .globl  i2s_FIQ

i2s_FIQ:

        ldr     r11,=FIQ_count

        ldr     r12,[r11]

        add     r12,r12,#1

        str     r12,[r11]

        ldr     r11,=I2S_LEFT_FIFO

        ldr     r12,=I2S_RIGHT_FIFO

// Empty the record FIFOs

// Note: without this, the audio hardware gets stuck

        ldr     r13,[r11]

        ldr     r13,[r12]

        ldr     r13,[r11]

        ldr     r13,[r12]

        ldr     r13,[r11]

        ldr     r13,[r12]

        ldr     r13,[r11]

        ldr     r13,[r12]

// See if there is a buffer to play

        ldr     r8,=cur_buf

        ldr     r9,[r8,#audio_buf_length]

        cmp     r9,#0

        beq     05f

        ldr     r9,[r8,#audio_buf_left_ptr]

        ldr     r10,[r8,#audio_buf_right_ptr]

// Move 4 [16-bit] values to each FIFO

        ldrh    r13,[r9],#2

        str     r13,[r11]

        ldrh    r13,[r10],#2

        str     r13,[r12]

        ldrh    r13,[r9],#2

        str     r13,[r11]

        ldrh    r13,[r10],#2

        str     r13,[r12]

        ldrh    r13,[r9],#2

        str     r13,[r11]

        ldrh    r13,[r10],#2

        str     r13,[r12]

        ldrh    r13,[r9],#2

        str     r13,[r11]

        ldrh    r13,[r10],#2

        str     r13,[r12]

// Update pointers

        str     r9,[r8,#audio_buf_left_ptr]

        str     r10,[r8,#audio_buf_right_ptr]

// Update count

        ldr     r9,[r8,#audio_buf_length]

        sub     r9,r9,#4

        str     r9,[r8,#audio_buf_length]

        cmp     r9,#0

        bgt     10f

// Switch to next buffer

05:     ldr     r9,=next_buf

        ldr     r10,[r9,#audio_buf_left_ptr]

        str     r10,[r8,#audio_buf_left_ptr]

        ldr     r10,[r9,#audio_buf_right_ptr]

        str     r10,[r8,#audio_buf_right_ptr]

        ldr     r10,[r9,#audio_buf_length]

        str     r10,[r8,#audio_buf_length]

        mov     r13,#0

        str     r13,[r9,#audio_buf_length]      // Free buffer

        cmp     r10,#0

        bne     10f

// Disable further interrupts

        ldr     r8,=INTMR3

        ldr     r9,[r8]

        bic     r9,r9,#INTSR3_I2SINT

        str     r9,[r8]

10:

        ldr     r11,=I2S_STAT   // Clear status bits

//        ldr     r10,=(I2S_STAT_RCTSR|I2S_STAT_RCRS|I2S_STAT_LCTSR|I2S_STAT_LCRSR|I2S_STAT_RCTNF|I2S_STAT_RCRNE|I2S_STAT_LCTNF|I2S_STAT_LCRNE)

        ldr     r10,=0xFFF0F

        str     r10,[r11]

        subs    pc,lr,#4        // return from interrupt

        .global hal_disable_interrupts

hal_disable_interrupts:

        mrs     r0,cpsr                 // current state

        orr     r1,r0,#0x80             // mask IRQ

        msr     cpsr,r1

        bx      lr                      // exit, _old_ in r0

        .data

        .global FIQ_count

FIQ_count:

        .long   0