firmware/target/arm/i2c-pp.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * PP502X and PP5002 I2C driver
  11  *
  12  * Based on code from the ipodlinux project - http://ipodlinux.org/
  13  * Adapted for Rockbox in November 2005
  14  *
  15  * Original file: linux/arch/armnommu/mach-ipod/hardware.c
  16  *
  17  * Copyright (c) 2003-2005 Bernard Leach (leachbj@bouncycastle.org)
  18  *
  19  * This program is free software; you can redistribute it and/or
  20  * modify it under the terms of the GNU General Public License
  21  * as published by the Free Software Foundation; either version 2
  22  * of the License, or (at your option) any later version.
  23  *
  24  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  25  * KIND, either express or implied.
  26  *
  27  ****************************************************************************/
  28
  29 #include "cpu.h"
  30 #include "kernel.h"
  31 #include "thread.h"
  32 #include "logf.h"
  33 #include "system.h"
  34 #include "i2c-pp.h"
  35 #include "as3514.h"
  36
  37 /* Local functions definitions */
  38 static struct mutex i2c_mtx SHAREDBSS_ATTR;
  39
  40 #define POLL_TIMEOUT (HZ)
  41
  42 static int pp_i2c_wait_not_busy(void)
  43 {
  44     unsigned long timeout;
  45     timeout = current_tick + POLL_TIMEOUT;
  46     while (TIME_BEFORE(current_tick, timeout)) {
  47          if (!(I2C_STATUS & I2C_BUSY)) {
  48             return 0;
  49          }
  50          yield();
  51     }
  52
  53     return -1;
  54 }
  55
  56 static int pp_i2c_read_byte(unsigned int addr, unsigned int *data)
  57 {
  58     if (pp_i2c_wait_not_busy() < 0)
  59     {
  60         return -1;
  61     }
  62
  63     {
  64         unsigned int byte;
  65         int old_irq_level = disable_irq_save();
  66
  67         /* clear top 15 bits, left shift 1, or in 0x1 for a read */
  68         I2C_ADDR = ((addr << 17) >> 16) | 0x1 ;
  69
  70         I2C_CTRL |= 0x20;
  71
  72         I2C_CTRL |= I2C_SEND;
  73
  74         restore_irq(old_irq_level);
  75         if (pp_i2c_wait_not_busy() < 0)
  76         {
  77             return -1;
  78         }
  79         old_irq_level = disable_irq_save();
  80
  81         byte = I2C_DATA(0);
  82
  83         if (data)
  84             *data = byte;
  85
  86         restore_irq(old_irq_level);
  87     }
  88
  89     return 0;
  90 }
  91
  92 static int pp_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data)
  93 {
  94     unsigned int i;
  95
  96     if (len < 1 || len > 4)
  97     {
  98         return -1;
  99     }
 100
 101     if (pp_i2c_wait_not_busy() < 0)
 102     {
 103         return -2;
 104     }
 105
 106     {
 107         int old_irq_level = disable_irq_save();
 108
 109         /* clear top 15 bits, left shift 1 */
 110         I2C_ADDR = (addr << 17) >> 16;
 111
 112         I2C_CTRL &= ~0x20;
 113
 114         for ( i = 0; i < len; i++ )
 115         {
 116             I2C_DATA(i) = *data++;
 117         }
 118
 119         I2C_CTRL = (I2C_CTRL & ~0x26) | ((len-1) << 1);
 120
 121         I2C_CTRL |= I2C_SEND;
 122
 123         restore_irq(old_irq_level);
 124     }
 125
 126     return 0x0;
 127 }
 128
 129 static int pp_i2c_send_byte(unsigned int addr, int data0)
 130 {
 131     unsigned char data[1];
 132
 133     data[0] = data0;
 134
 135     return pp_i2c_send_bytes(addr, 1, data);
 136 }
 137
 138 /* Public functions */
 139 void i2c_lock(void)
 140 {
 141     mutex_lock(&i2c_mtx);
 142 }
 143
 144 void i2c_unlock(void)
 145 {
 146     mutex_unlock(&i2c_mtx);
 147 }
 148
 149 int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data) {
 150     unsigned int temp;
 151     int i;
 152     mutex_lock(&i2c_mtx);
 153     pp_i2c_send_byte(dev_addr, addr);
 154     for (i = 0; i < len; i++) {
 155         pp_i2c_read_byte(dev_addr, &temp);
 156         data[i] = temp;
 157     }
 158     mutex_unlock(&i2c_mtx);
 159     return i;
 160 }
 161
 162 int i2c_readbyte(unsigned int dev_addr, int addr)
 163 {
 164     int data;
 165
 166     mutex_lock(&i2c_mtx);
 167     pp_i2c_send_byte(dev_addr, addr);
 168     pp_i2c_read_byte(dev_addr, &data);
 169     mutex_unlock(&i2c_mtx);
 170
 171     return data;
 172 }
 173
 174 int pp_i2c_send(unsigned int addr, int data0, int data1)
 175 {
 176     int retval;
 177     unsigned char data[2];
 178
 179     data[0] = data0;
 180     data[1] = data1;
 181
 182     mutex_lock(&i2c_mtx);
 183     retval = pp_i2c_send_bytes(addr, 2, data);
 184     mutex_unlock(&i2c_mtx);
 185
 186     return retval;
 187 }
 188
 189 void i2c_init(void)
 190 {
 191     /* From ipodlinux */
 192     mutex_init(&i2c_mtx);
 193
 194 #ifdef IPOD_MINI
 195     /* GPIO port C disable port 0x10 */
 196     GPIOC_ENABLE &= ~0x10;
 197
 198     /* GPIO port C disable port 0x20 */
 199     GPIOC_ENABLE &= ~0x20;
 200 #endif
 201
 202 #if CONFIG_I2C == I2C_PP5002
 203     DEV_EN |= 0x2;
 204 #else
 205     DEV_EN |= DEV_I2C;  /* Enable I2C */
 206 #endif
 207     DEV_RS |= DEV_I2C;  /* Start I2C Reset */
 208     DEV_RS &=~DEV_I2C;  /* End I2C Reset */
 209
 210 #if CONFIG_I2C == I2C_PP5020
 211     outl(0x0, 0x600060a4);
 212     outl(0x80 | (0 << 8), 0x600060a4);
 213 #elif CONFIG_I2C == I2C_PP5024
 214 #if defined(SANSA_E200) || defined(PHILIPS_SA9200)
 215     /* Sansa OF sets this to 0x20 first, communicates with the AS3514
 216        then sets it to 0x23 - this still works fine though */
 217     outl(0x0, 0x600060a4);
 218     outl(0x23, 0x600060a4);
 219 #elif defined(SANSA_C200)
 220     /* This is the init sequence from the Sansa c200 bootloader.
 221        I'm not sure what's really necessary. */
 222     pp_i2c_wait_not_busy();
 223
 224     outl(0, 0x600060a4);
 225     outl(0x64, 0x600060a4);
 226
 227     outl(0x55, 0x7000c02c);
 228     outl(0x54, 0x7000c030);
 229
 230     outl(0, 0x600060a4);
 231     outl(0x1e, 0x600060a4);
 232
 233     pp_i2c_send(AS3514_I2C_ADDR, AS3514_SUPERVISOR, 5);
 234 #endif
 235 #endif
 236
 237     i2c_readbyte(0x8, 0);
 238 }