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 #if defined(SANSA_C200V2)
  38 /*
  39  * workaround DBOP noise issue cause it's really annoying if your
  40  * buttons don't work in the debug menu...
  41  */
  42 static short int input_value_tmp[2];
  43 int dbop_denoise_reject = 0;
  44 int dbop_denoise_accept = 0;
  45 #endif
  46
  47 /* read the DBOP data pins */
  48 #if defined(SANSA_C200V2)
  49 unsigned short dbop_read_input_once(void);
  50
  51 unsigned short dbop_read_input(void)
  52 {
  53     int i;
  54
  55     while (1) {
  56         for (i=0; i<2; i++) {
  57             input_value_tmp[i] = dbop_read_input_once();
  58         }
  59         /* noise rejection */
  60         if (input_value_tmp[0] == input_value_tmp[1]) {
  61             dbop_denoise_accept++;
  62             break;
  63         } else {
  64             dbop_denoise_reject++;
  65         }
  66     }
  67     if (dbop_denoise_accept + dbop_denoise_reject > 1000) {
  68         dbop_denoise_accept /= 2;
  69         dbop_denoise_reject /= 2;
  70     }
  71
  72     return dbop_input_value;
  73 }
  74
  75 unsigned short dbop_read_input_once(void)
  76 #else
  77 unsigned short dbop_read_input(void)
  78 #endif
  79 {
  80     unsigned int dbop_ctrl_old = DBOP_CTRL;
  81     unsigned int dbop_timpol23_old = DBOP_TIMPOL_23;
  82
  83     /* make sure that the DBOP FIFO is empty */
  84     while ((DBOP_STAT & (1<<10)) == 0);
  85
  86     int delay = 10;
  87     while (delay--) asm volatile ("nop\n");
  88
  89     /* write DBOP_DOUT to pre-charge DBOP data lines with a defined level */
  90     DBOP_TIMPOL_23 = 0xe007e007;    /* no strobe towards lcd */
  91     DBOP_CTRL = (1 << 19) |         /* tri-state output */
  92                 (1 << 16) |         /* enw=1 (enable write) */
  93                 (1 << 12);          /* ow=1 (16-bit data width) */
  94     DBOP_DOUT = DBOP_PRECHARGE;
  95     while ((DBOP_STAT & (1<<10)) == 0);
  96
  97 #if defined(SANSA_FUZE) || defined(SANSA_E200V2)
  98     delay = 50;
  99     while (delay--) asm volatile ("nop\n");
 100 #endif
 101
 102     /* perform a DBOP read */
 103     DBOP_CTRL = (1 << 19) |         /* tri-state output */
 104                 (1 << 15) |         /* strd=1 (start read) */
 105                 (1 << 12) |         /* ow=1 (16-bit data width) */
 106                 (31 << 0);          /* rs_t=31 (read DBOP at end of cycle) */
 107     while ((DBOP_STAT & (1<<16)) == 0);
 108     dbop_input_value = DBOP_DIN;
 109
 110     /* restore previous values */
 111     DBOP_TIMPOL_23 = dbop_timpol23_old;
 112     DBOP_CTRL = dbop_ctrl_old;
 113
 114     return dbop_input_value;
 115 }
 116
 117 /* for the debug menu */
 118 unsigned short dbop_debug(void)
 119 {
 120     return dbop_input_value;
 121 }
 122
 123 #endif
 124
 125 static inline void dbop_set_mode(int mode)
 126 {
 127     int delay = 10;
 128     unsigned long ctrl = DBOP_CTRL;
 129     int curr_mode = (DBOP_CTRL >> 13) & 0x3; // bits 14:13
 130 #ifdef SANSA_FUZEV2
 131     if (mode == 32 && curr_mode != 1<<1)
 132         DBOP_CTRL = (ctrl & ~(1<<13)) | (1<<14); // 2 serial half words
 133     else if (mode == 16 && curr_mode != 1<<0)
 134         DBOP_CTRL = (ctrl & ~(1<<14)) | (1<<13); // 2 serial bytes
 135 #else
 136     if (mode == 32 && curr_mode == 0)
 137         DBOP_CTRL = ctrl | (1<<13|1<<14); /* 2 serial half words */
 138     else if (mode == 16 && curr_mode == (1<<1|1<<0))
 139         DBOP_CTRL =  ctrl & ~(1<<14|1<<13); /* 1 serial half word */
 140 #endif
 141     else
 142         return;
 143     while(delay--) asm volatile("nop");
 144 }
 145
 146 void dbop_write_data(const int16_t* p_bytes, int count)
 147 {
 148
 149     const int32_t *data;
 150     if ((intptr_t)p_bytes & 0x3 || count == 1)
 151     {   /* need to do a single 16bit write beforehand if the address is
 152          * not word aligned or count is 1, switch to 16bit mode if needed */
 153         dbop_set_mode(16);
 154         DBOP_DOUT16 = *p_bytes++;
 155         if (!(--count))
 156             return;
 157     }
 158     /* from here, 32bit transfers are save
 159      * set it to transfer 4*(outputwidth) units at a time,
 160      * if bit 12 is set it only does 2 halfwords though (we never set it)
 161      * switch to 32bit output if needed */
 162     dbop_set_mode(32);
 163     data = (int32_t*)p_bytes;
 164     while (count > 1)
 165     {
 166         DBOP_DOUT32 = *data++;
 167         count -= 2;
 168
 169         /* Wait if push fifo is full */
 170         while ((DBOP_STAT & (1<<6)) != 0);
 171     }
 172     /* While push fifo is not empty */
 173     while ((DBOP_STAT & (1<<10)) == 0);
 174
 175     /* due to the 32bit alignment requirement or uneven count,
 176      * we possibly need to do a 16bit transfer at the end also */
 177     if (count > 0)
 178         dbop_write_data((int16_t*)data, 1);
 179 }