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
  16 #include <types.h>
  17 #include <string.h>
  18 #include <arch/io.h>
  19 #include <device/device.h>
  20 #include <device/smbus.h>
  21 #include <smbios.h>
  22 #include <console/console.h>
  23
  24 static void at24rf08c_init(struct device *dev)
  25 {
  26         int i, j;
  27
  28         if (!dev->enabled)
  29                 return;
  30
  31         /* Ensure that EEPROM/RFID chip is not accessible through RFID.
  32            Need to do it only on 5c.  */
  33         if (dev->path.type != DEVICE_PATH_I2C || dev->path.i2c.device != 0x5c)
  34                 return;
  35
  36         printk (BIOS_DEBUG, "Locking EEPROM RFID\n");
  37
  38         for (i = 0; i < 8; i++)
  39         {
  40                 /* After a register write AT24RF08C sometimes stops responding.
  41                    Retry several times in case of failure.
  42                  */
  43                 for (j = 0; j < 100; j++)
  44                         if (smbus_write_byte(dev, i, 0x0f) >= 0)
  45                                 break;
  46         }
  47
  48         printk (BIOS_DEBUG, "init EEPROM done\n");
  49 }
  50
  51 static struct device_operations at24rf08c_operations = {
  52         .read_resources = DEVICE_NOOP,
  53         .set_resources = DEVICE_NOOP,
  54         .enable_resources = DEVICE_NOOP,
  55         .init = at24rf08c_init,
  56 };
  57
  58 static void enable_dev(struct device *dev)
  59 {
  60         dev->ops = &at24rf08c_operations;
  61 }
  62
  63 struct chip_operations drivers_i2c_at24rf08c_ops = {
  64         CHIP_NAME("AT24RF08C")
  65         .enable_dev = enable_dev,
  66 };