src/drivers/i2c/at24rf08c/at24rf08c.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2013 Vladimir Serbinenko
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <types.h>
  21 #include <string.h>
  22 #include <arch/io.h>
  23 #include <device/device.h>
  24 #include <device/smbus.h>
  25 #include <smbios.h>
  26 #include <console/console.h>
  27
  28 static void at24rf08c_init(device_t dev)
  29 {
  30         int i, j;
  31
  32         if (!dev->enabled)
  33                 return;
  34
  35         /* Ensure that EEPROM/RFID chip is not accessible through RFID.
  36            Need to do it only on 5c.  */
  37         if (dev->path.type != DEVICE_PATH_I2C || dev->path.i2c.device != 0x5c)
  38                 return;
  39
  40         printk (BIOS_DEBUG, "Locking EEPROM RFID\n");
  41
  42         for (i = 0; i < 8; i++)
  43         {
  44                 /* After a register write AT24RF08C sometimes stops responding.
  45                    Retry several times in case of failure.
  46                  */
  47                 for (j = 0; j < 100; j++)
  48                         if (smbus_write_byte(dev, i, 0x0f) >= 0)
  49                                 break;
  50         }
  51
  52         printk (BIOS_DEBUG, "init EEPROM done\n");
  53 }
  54
  55 static void at24rf08c_noop(device_t dummy)
  56 {
  57 }
  58
  59 static struct device_operations at24rf08c_operations = {
  60         .read_resources = at24rf08c_noop,
  61         .set_resources = at24rf08c_noop,
  62         .enable_resources = at24rf08c_noop,
  63         .init = at24rf08c_init,
  64 };
  65
  66 static void enable_dev(device_t dev)
  67 {
  68         dev->ops = &at24rf08c_operations;
  69 }
  70
  71 struct chip_operations drivers_i2c_at24rf08c_ops = {
  72         CHIP_NAME("AT24RF08C")
  73         .enable_dev = enable_dev,
  74 };