firmware/target/mips/ingenic_jz47xx/i2c-jz4740.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2009 by Maurus Cuelenaere
  11  *
  12  * based on linux/arch/mips/jz4740/i2c.c
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23 #include "config.h"
  24 #include "system.h"
  25 #include "jz4740.h"
  26 #include "logf.h"
  27
  28 /*
  29  * Jz4740 I2C routines.
  30  *
  31  * Copyright (C) 2005,2006 Ingenic Semiconductor Inc.
  32  * Author: <lhhuang@ingenic.cn>
  33  *
  34  *  This program is free software; you can distribute it and/or modify it
  35  *  under the terms of the GNU General Public License (Version 2) as
  36  *  published by the Free Software Foundation.
  37  *
  38  *  This program is distributed in the hope it will be useful, but WITHOUT
  39  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  40  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  41  *  for more details.
  42  *
  43  *  You should have received a copy of the GNU General Public License along
  44  *  with this program; if not, write to the Free Software Foundation, Inc.,
  45  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  46  *
  47  */
  48
  49 /* I2C protocol */
  50 #define I2C_READ    1
  51 #define I2C_WRITE   0
  52
  53 #define TIMEOUT     1000
  54
  55 /*
  56  * I2C bus protocol basic routines
  57  */
  58 static int i2c_put_data(unsigned char data)
  59 {
  60     unsigned int timeout = TIMEOUT*10;
  61
  62     __i2c_write(data);
  63     __i2c_set_drf();
  64     while (__i2c_check_drf() != 0);
  65     while (!__i2c_transmit_ended());
  66     while (!__i2c_received_ack() && timeout)
  67         timeout--;
  68
  69     if (timeout)
  70         return 0;
  71     else
  72         return -1;
  73 }
  74
  75 #if 0
  76 static int i2c_put_data_nack(unsigned char data)
  77 {
  78     unsigned int timeout = TIMEOUT*10;
  79
  80     __i2c_write(data);
  81     __i2c_set_drf();
  82     while (__i2c_check_drf() != 0);
  83     while (!__i2c_transmit_ended());
  84     while (timeout--);
  85
  86     return 0;
  87 }
  88 #endif
  89
  90 static int i2c_get_data(unsigned char *data, int ack)
  91 {
  92     int timeout = TIMEOUT*10;
  93
  94     if (!ack)
  95         __i2c_send_nack();
  96     else
  97         __i2c_send_ack();
  98
  99     while (__i2c_check_drf() == 0 && timeout)
 100         timeout--;
 101
 102     if (timeout)
 103     {
 104         if (!ack)
 105             __i2c_send_stop();
 106         *data = __i2c_read();
 107         __i2c_clear_drf();
 108         return 0;
 109     }
 110     else
 111         return -1;
 112 }
 113
 114 void i2c_setclk(unsigned int i2cclk)
 115 {
 116     __i2c_set_clk(__cpm_get_i2sclk(), i2cclk);
 117 }
 118
 119 /*
 120  * I2C interface
 121  */
 122 static void i2c_open(void)
 123 {
 124     __cpm_start_i2c();
 125     i2c_setclk(10000); /* default 10 KHz */
 126     __i2c_enable();
 127 }
 128
 129 static void i2c_close(void)
 130 {
 131     udelay(300); /* wait for STOP goes over. */
 132     __i2c_disable();
 133     __cpm_stop_i2c();
 134 }
 135
 136 int i2c_read(int device, unsigned char *buf, int count)
 137 {
 138     int cnt = count;
 139     int timeout = 5;
 140
 141     device &= 0xFF;
 142
 143     i2c_open();
 144
 145 L_try_again:
 146     if (timeout < 0)
 147         goto L_timeout;
 148
 149     __i2c_send_nack();    /* Master does not send ACK, slave sends it */
 150
 151     __i2c_send_start();
 152     if (i2c_put_data( (device << 1) | I2C_READ ) < 0)
 153         goto device_err;
 154
 155     __i2c_send_ack();    /* Master sends ACK for continue reading */
 156
 157     while (cnt)
 158     {
 159         if (cnt == 1)
 160         {
 161             if (i2c_get_data(buf, 0) < 0)
 162                 break;
 163         }
 164         else
 165         {
 166             if (i2c_get_data(buf, 1) < 0)
 167                 break;
 168         }
 169         cnt--;
 170         buf++;
 171     }
 172
 173     __i2c_send_stop();
 174     i2c_close();
 175     return count - cnt;
 176
 177 device_err:
 178     timeout--;
 179     __i2c_send_stop();
 180     goto L_try_again;
 181
 182 L_timeout:
 183     __i2c_send_stop();
 184     logf("Read I2C device 0x%2x failed.", device);
 185     i2c_close();
 186     return -1;
 187 }
 188
 189 int i2c_write(int device, unsigned char *buf, int count)
 190 {
 191     int cnt = count;
 192     int timeout = 5;
 193
 194     device &= 0xFF;
 195
 196     i2c_open();
 197
 198     __i2c_send_nack();    /* Master does not send ACK, slave sends it */
 199
 200 W_try_again:
 201     if (timeout < 0)
 202         goto W_timeout;
 203
 204     cnt = count;
 205
 206     __i2c_send_start();
 207     if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
 208         goto device_err;
 209
 210 #if 0 //CONFIG_JZ_TPANEL_ATA2508
 211     if (address == 0xff)
 212     {
 213         while (cnt)
 214         {
 215             if (i2c_put_data_nack(*buf) < 0)
 216                 break;
 217             cnt--;
 218             buf++;
 219         }
 220     }
 221     else
 222 #endif
 223     {
 224         while (cnt)
 225         {
 226             if (i2c_put_data(*buf) < 0)
 227                 break;
 228             cnt--;
 229             buf++;
 230         }
 231     }
 232
 233     __i2c_send_stop();
 234     i2c_close();
 235     return count - cnt;
 236
 237 device_err:
 238     timeout--;
 239     __i2c_send_stop();
 240     goto W_try_again;
 241
 242 W_timeout:
 243     logf("Write I2C device 0x%2x failed.", device);
 244     __i2c_send_stop();
 245     i2c_close();
 246     return -1;
 247 }
 248
 249 void i2c_init(void)
 250 {
 251     __gpio_as_i2c();
 252 }