LXR uboot/drivers/bootcount/i2c-eeprom.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2019 Collabora
   4 * (C) Copyright 2019 GE
   5 */
   6
   7#include <common.h>
   8#include <bootcount.h>
   9#include <dm.h>
  10#include <i2c_eeprom.h>
  11#include <log.h>
  12
  13static const u8 bootcount_magic = 0xbc;
  14
  15struct bootcount_i2c_eeprom_priv {
  16        struct udevice *i2c_eeprom;
  17        u32 offset;
  18};
  19
  20static int bootcount_i2c_eeprom_set(struct udevice *dev, const u32 a)
  21{
  22        struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
  23        const u16 val = bootcount_magic << 8 | (a & 0xff);
  24
  25        if (i2c_eeprom_write(priv->i2c_eeprom, priv->offset,
  26                             (uint8_t *)&val, 2) < 0) {
  27                debug("%s: write failed\n", __func__);
  28                return -EIO;
  29        }
  30
  31        return 0;
  32}
  33
  34static int bootcount_i2c_eeprom_get(struct udevice *dev, u32 *a)
  35{
  36        struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
  37        u16 val;
  38
  39        if (i2c_eeprom_read(priv->i2c_eeprom, priv->offset,
  40                            (uint8_t *)&val, 2) < 0) {
  41                debug("%s: read failed\n", __func__);
  42                return -EIO;
  43        }
  44
  45        if (val >> 8 == bootcount_magic) {
  46                *a = val & 0xff;
  47                return 0;
  48        }
  49
  50        debug("%s: bootcount magic does not match on %04x\n", __func__, val);
  51        return -EIO;
  52}
  53
  54static int bootcount_i2c_eeprom_probe(struct udevice *dev)
  55{
  56        struct ofnode_phandle_args phandle_args;
  57        struct bootcount_i2c_eeprom_priv *priv = dev_get_priv(dev);
  58        struct udevice *i2c_eeprom;
  59
  60        if (dev_read_phandle_with_args(dev, "i2c-eeprom", NULL, 0, 0,
  61                                       &phandle_args)) {
  62                debug("%s: i2c-eeprom backing device not specified\n",
  63                      dev->name);
  64                return -ENOENT;
  65        }
  66
  67        if (uclass_get_device_by_ofnode(UCLASS_I2C_EEPROM, phandle_args.node,
  68                                        &i2c_eeprom)) {
  69                debug("%s: could not get backing device\n", dev->name);
  70                return -ENODEV;
  71        }
  72
  73        priv->i2c_eeprom = i2c_eeprom;
  74        priv->offset = dev_read_u32_default(dev, "offset", 0);
  75
  76        return 0;
  77}
  78
  79static const struct bootcount_ops bootcount_i2c_eeprom_ops = {
  80        .get = bootcount_i2c_eeprom_get,
  81        .set = bootcount_i2c_eeprom_set,
  82};
  83
  84static const struct udevice_id bootcount_i2c_eeprom_ids[] = {
  85        { .compatible = "u-boot,bootcount-i2c-eeprom" },
  86        { }
  87};
  88
  89U_BOOT_DRIVER(bootcount_spi_flash) = {
  90        .name   = "bootcount-i2c-eeprom",
  91        .id     = UCLASS_BOOTCOUNT,
  92        .priv_auto      = sizeof(struct bootcount_i2c_eeprom_priv),
  93        .probe  = bootcount_i2c_eeprom_probe,
  94        .of_match = bootcount_i2c_eeprom_ids,
  95        .ops    = &bootcount_i2c_eeprom_ops,
  96};
  97