firmware/drivers/i2c-pp5002.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * PP5002 I2C driver
  11  *
  12  * Based on code from the ipodlinux project - http://ipodlinux.org/
  13  * Adapted for Rockbox in January 2006
  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 "logf.h"
  30 #include "system.h"
  31 #include "i2c-pp5002.h"
  32
  33 /* Local functions definitions */
  34
  35 #define IPOD_I2C_BASE   0xc0008000
  36 #define IPOD_I2C_CTRL   (IPOD_I2C_BASE+0x00)
  37 #define IPOD_I2C_ADDR   (IPOD_I2C_BASE+0x04)
  38 #define IPOD_I2C_DATA0  (IPOD_I2C_BASE+0x0c)
  39 #define IPOD_I2C_DATA1  (IPOD_I2C_BASE+0x10)
  40 #define IPOD_I2C_DATA2  (IPOD_I2C_BASE+0x14)
  41 #define IPOD_I2C_DATA3  (IPOD_I2C_BASE+0x18)
  42 #define IPOD_I2C_STATUS (IPOD_I2C_BASE+0x1c)
  43
  44 /* IPOD_I2C_CTRL bit definitions */
  45 #define IPOD_I2C_SEND   0x80
  46
  47 /* IPOD_I2C_STATUS bit definitions */
  48 #define IPOD_I2C_BUSY   (1<<6)
  49
  50 #define POLL_TIMEOUT (HZ)
  51
  52 static int ipod_i2c_wait_not_busy(void)
  53 {
  54     unsigned long timeout;
  55     timeout = current_tick + POLL_TIMEOUT;
  56     while (TIME_BEFORE(current_tick, timeout)) {
  57          if (!(inb(IPOD_I2C_STATUS) & IPOD_I2C_BUSY)) {
  58             return 0;
  59          }
  60          yield();
  61     }
  62
  63     return -1;
  64 }
  65
  66
  67 /* Public functions */
  68
  69 int ipod_i2c_read_byte(unsigned int addr, unsigned int *data)
  70 {
  71     if (ipod_i2c_wait_not_busy() < 0)
  72     {
  73         return -1;
  74     }
  75
  76     /* clear top 15 bits, left shift 1, or in 0x1 for a read */
  77     outb(((addr << 17) >> 16) | 0x1, IPOD_I2C_ADDR);
  78
  79     outb(inb(IPOD_I2C_CTRL) | 0x20, IPOD_I2C_CTRL);
  80
  81     outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
  82
  83     if (ipod_i2c_wait_not_busy() < 0)
  84     {
  85         return -1;
  86     }
  87
  88     if (data)
  89     {
  90         *data = inb(IPOD_I2C_DATA0);
  91     }
  92
  93     return 0;
  94 }
  95
  96 int ipod_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char *data)
  97 {
  98     int data_addr;
  99     unsigned int i;
 100
 101     if (len < 1 || len > 4)
 102     {
 103         return -1;
 104     }
 105
 106     if (ipod_i2c_wait_not_busy() < 0)
 107     {
 108         return -2;
 109     }
 110
 111     /* clear top 15 bits, left shift 1 */
 112     outb((addr << 17) >> 16, IPOD_I2C_ADDR);
 113
 114     outb(inb(IPOD_I2C_CTRL) & ~0x20, IPOD_I2C_CTRL);
 115
 116     data_addr = IPOD_I2C_DATA0;
 117     for ( i = 0; i < len; i++ )
 118     {
 119         outb(*data++, data_addr);
 120         data_addr += 4;
 121     }
 122
 123     outb((inb(IPOD_I2C_CTRL) & ~0x26) | ((len-1) << 1), IPOD_I2C_CTRL);
 124
 125     outb(inb(IPOD_I2C_CTRL) | IPOD_I2C_SEND, IPOD_I2C_CTRL);
 126
 127     return 0x0;
 128 }
 129
 130 int ipod_i2c_send_byte(unsigned int addr, int data0)
 131 {
 132     unsigned char data[1];
 133
 134     data[0] = data0;
 135
 136     return ipod_i2c_send_bytes(addr, 1, data);
 137 }
 138
 139 int i2c_readbytes(unsigned int dev_addr, int addr, int len, unsigned char *data) {
 140     unsigned int temp;
 141     int i;
 142     ipod_i2c_send_byte(dev_addr, addr);
 143     for (i = 0; i < len; i++) {
 144         ipod_i2c_read_byte(dev_addr, &temp);
 145         data[i] = temp;
 146     }
 147     return i;
 148 }
 149
 150 int i2c_readbyte(unsigned int dev_addr, int addr)
 151 {
 152     int data;
 153
 154     ipod_i2c_send_byte(dev_addr, addr);
 155     ipod_i2c_read_byte(dev_addr, &data);
 156
 157     return data;
 158 }
 159
 160 int ipod_i2c_send(unsigned int addr, int data0, int data1)
 161 {
 162     unsigned char data[2];
 163
 164     data[0] = data0;
 165     data[1] = data1;
 166
 167     return ipod_i2c_send_bytes(addr, 2, data);
 168 }
 169
 170 void i2c_init(void)
 171 {
 172    /* From ipodlinux */
 173
 174    outl(inl(0xcf005000) | 0x2, 0xcf005000);
 175
 176    outl(inl(0xcf005030) | (1<<8), 0xcf005030);
 177    outl(inl(0xcf005030) & ~(1<<8), 0xcf005030);
 178 }