drivers/bootcount/bootcount_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2013
   4  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
   5  */
   6
   7 #include <bootcount.h>
   8 #include <linux/compiler.h>
   9 #include <i2c.h>
  10
  11 #define BC_MAGIC        0xbc
  12
  13 void bootcount_store(ulong a)
  14 {
  15         unsigned char buf[3];
  16         int ret;
  17
  18         buf[0] = BC_MAGIC;
  19         buf[1] = (a & 0xff);
  20         ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, CONFIG_SYS_BOOTCOUNT_ADDR,
  21                   CONFIG_BOOTCOUNT_ALEN, buf, 2);
  22         if (ret != 0)
  23                 puts("Error writing bootcount\n");
  24 }
  25
  26 ulong bootcount_load(void)
  27 {
  28         unsigned char buf[3];
  29         int ret;
  30
  31         ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, CONFIG_SYS_BOOTCOUNT_ADDR,
  32                        CONFIG_BOOTCOUNT_ALEN, buf, 2);
  33         if (ret != 0) {
  34                 puts("Error loading bootcount\n");
  35                 return 0;
  36         }
  37         if (buf[0] == BC_MAGIC)
  38                 return buf[1];
  39
  40         bootcount_store(0);
  41
  42         return 0;
  43 }