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