firmware/target/arm/as3525/dbop-as3525.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2009 by Bertrik Sikken
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "config.h"
  23 #include <inttypes.h>
  24 #include "as3525.h"
  25 #include "dbop-as3525.h"
  26
  27 #if defined(SANSA_FUZE) || defined(SANSA_FUZEV2)
  28 #define DBOP_PRECHARGE 0x80FF
  29 #elif defined(SANSA_E200V2) || defined(SANSA_C200V2)
  30 #define DBOP_PRECHARGE 0xF0FF
  31 #endif
  32
  33 #if CONFIG_CPU == AS3525
  34 /* doesn't work with the new ams sansas so far and is not needed */
  35 static short int dbop_input_value = 0;
  36
  37 /* read the DBOP data pins */
  38 unsigned short dbop_read_input(void)
  39 {
  40     unsigned int dbop_ctrl_old = DBOP_CTRL;
  41     unsigned int dbop_timpol23_old = DBOP_TIMPOL_23;
  42
  43     /* make sure that the DBOP FIFO is empty */
  44     while ((DBOP_STAT & (1<<10)) == 0);
  45
  46     int delay = 10;
  47     while (delay--) asm volatile ("nop\n");
  48
  49     /* write DBOP_DOUT to pre-charge DBOP data lines with a defined level */
  50     DBOP_TIMPOL_23 = 0xe007e007;    /* no strobe towards lcd */
  51     DBOP_CTRL = (1 << 19) |         /* tri-state output */
  52                 (1 << 16) |         /* enw=1 (enable write) */
  53                 (1 << 12);          /* ow=1 (16-bit data width) */
  54     DBOP_DOUT = DBOP_PRECHARGE;
  55 #if defined(SANSA_C200V2)
  56     /* two additional writes to precharge longer get rid of the read noise */
  57     DBOP_DOUT = DBOP_PRECHARGE;
  58     DBOP_DOUT = DBOP_PRECHARGE;
  59 #endif
  60     while ((DBOP_STAT & (1<<10)) == 0);
  61
  62 #if defined(SANSA_FUZE) || defined(SANSA_E200V2)
  63     delay = 50;
  64     while (delay--) asm volatile ("nop\n");
  65 #endif
  66
  67     /* perform a DBOP read */
  68     DBOP_CTRL = (1 << 19) |         /* tri-state output */
  69                 (1 << 15) |         /* strd=1 (start read) */
  70                 (1 << 12) |         /* ow=1 (16-bit data width) */
  71                 (31 << 0);          /* rs_t=31 (read DBOP at end of cycle) */
  72     while ((DBOP_STAT & (1<<16)) == 0);
  73     dbop_input_value = DBOP_DIN;
  74
  75     /* restore previous values */
  76     DBOP_TIMPOL_23 = dbop_timpol23_old;
  77     DBOP_CTRL = dbop_ctrl_old;
  78
  79     return dbop_input_value;
  80 }
  81
  82 /* for the debug menu */
  83 unsigned short dbop_debug(void)
  84 {
  85     return dbop_input_value;
  86 }
  87
  88 #endif
  89
  90 static inline void dbop_set_mode(int mode)
  91 {
  92     int delay = 10;
  93     unsigned long ctrl = DBOP_CTRL;
  94     int curr_mode = (DBOP_CTRL >> 13) & 0x3; // bits 14:13
  95 #ifdef SANSA_FUZEV2
  96     if (mode == 32 && curr_mode != 1<<1)
  97         DBOP_CTRL = (ctrl & ~(1<<13)) | (1<<14); // 2 serial half words
  98     else if (mode == 16 && curr_mode != 1<<0)
  99         DBOP_CTRL = (ctrl & ~(1<<14)) | (1<<13); // 2 serial bytes
 100 #else
 101     if (mode == 32 && curr_mode == 0)
 102         DBOP_CTRL = ctrl | (1<<13|1<<14); /* 2 serial half words */
 103     else if (mode == 16 && curr_mode == (1<<1|1<<0))
 104         DBOP_CTRL =  ctrl & ~(1<<14|1<<13); /* 1 serial half word */
 105 #endif
 106     else
 107         return;
 108     while(delay--) asm volatile("nop");
 109 }
 110
 111 void dbop_write_data(const int16_t* p_bytes, int count)
 112 {
 113
 114     const int32_t *data;
 115     if ((intptr_t)p_bytes & 0x3 || count == 1)
 116     {   /* need to do a single 16bit write beforehand if the address is
 117          * not word aligned or count is 1, switch to 16bit mode if needed */
 118         dbop_set_mode(16);
 119         DBOP_DOUT16 = *p_bytes++;
 120         if (!(--count))
 121             return;
 122     }
 123     /* from here, 32bit transfers are save
 124      * set it to transfer 4*(outputwidth) units at a time,
 125      * if bit 12 is set it only does 2 halfwords though (we never set it)
 126      * switch to 32bit output if needed */
 127     dbop_set_mode(32);
 128     data = (int32_t*)p_bytes;
 129     while (count > 1)
 130     {
 131         DBOP_DOUT32 = *data++;
 132         count -= 2;
 133
 134         /* Wait if push fifo is full */
 135         while ((DBOP_STAT & (1<<6)) != 0);
 136     }
 137     /* While push fifo is not empty */
 138     while ((DBOP_STAT & (1<<10)) == 0);
 139
 140     /* due to the 32bit alignment requirement or uneven count,
 141      * we possibly need to do a 16bit transfer at the end also */
 142     if (count > 0)
 143         dbop_write_data((int16_t*)data, 1);
 144 }