drivers/misc/i2c_eeprom.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2014 Google, Inc
   4  */
   5
   6 #include <common.h>
   7 #include <linux/err.h>
   8 #include <linux/kernel.h>
   9 #include <dm.h>
  10 #include <i2c.h>
  11 #include <i2c_eeprom.h>
  12
  13 int i2c_eeprom_read(struct udevice *dev, int offset, uint8_t *buf, int size)
  14 {
  15         const struct i2c_eeprom_ops *ops = device_get_ops(dev);
  16
  17         if (!ops->read)
  18                 return -ENOSYS;
  19
  20         return ops->read(dev, offset, buf, size);
  21 }
  22
  23 int i2c_eeprom_write(struct udevice *dev, int offset, uint8_t *buf, int size)
  24 {
  25         const struct i2c_eeprom_ops *ops = device_get_ops(dev);
  26
  27         if (!ops->write)
  28                 return -ENOSYS;
  29
  30         return ops->write(dev, offset, buf, size);
  31 }
  32
  33 static int i2c_eeprom_std_read(struct udevice *dev, int offset, uint8_t *buf,
  34                                int size)
  35 {
  36         return dm_i2c_read(dev, offset, buf, size);
  37 }
  38
  39 static int i2c_eeprom_std_write(struct udevice *dev, int offset,
  40                                 const uint8_t *buf, int size)
  41 {
  42         struct i2c_eeprom *priv = dev_get_priv(dev);
  43         int ret;
  44
  45         while (size > 0) {
  46                 int write_size = min_t(int, size, priv->pagesize);
  47
  48                 ret = dm_i2c_write(dev, offset, buf, write_size);
  49                 if (ret)
  50                         return ret;
  51
  52                 offset += write_size;
  53                 buf += write_size;
  54                 size -= write_size;
  55
  56                 udelay(10000);
  57         }
  58
  59         return 0;
  60 }
  61
  62 static const struct i2c_eeprom_ops i2c_eeprom_std_ops = {
  63         .read   = i2c_eeprom_std_read,
  64         .write  = i2c_eeprom_std_write,
  65 };
  66
  67 static int i2c_eeprom_std_ofdata_to_platdata(struct udevice *dev)
  68 {
  69         struct i2c_eeprom *priv = dev_get_priv(dev);
  70         u64 data = dev_get_driver_data(dev);
  71         u32 pagesize;
  72
  73         if (dev_read_u32(dev, "pagesize", &pagesize) == 0) {
  74                 priv->pagesize = pagesize;
  75                 return 0;
  76         }
  77
  78         /* 6 bit -> page size of up to 2^63 (should be sufficient) */
  79         priv->pagewidth = data & 0x3F;
  80         priv->pagesize = (1 << priv->pagewidth);
  81
  82         return 0;
  83 }
  84
  85 static int i2c_eeprom_std_probe(struct udevice *dev)
  86 {
  87         u8 test_byte;
  88         int ret;
  89
  90         /* Verify that the chip is functional */
  91         ret = i2c_eeprom_read(dev, 0, &test_byte, 1);
  92         if (ret)
  93                 return -ENODEV;
  94
  95         return 0;
  96 }
  97
  98 static const struct udevice_id i2c_eeprom_std_ids[] = {
  99         { .compatible = "i2c-eeprom", .data = 0 },
 100         { .compatible = "microchip,24aa02e48", .data = 3 },
 101         { .compatible = "atmel,24c01a", .data = 3 },
 102         { .compatible = "atmel,24c02", .data = 3 },
 103         { .compatible = "atmel,24c04", .data = 4 },
 104         { .compatible = "atmel,24c08", .data = 4 },
 105         { .compatible = "atmel,24c08a", .data = 4 },
 106         { .compatible = "atmel,24c16a", .data = 4 },
 107         { .compatible = "atmel,24mac402", .data = 4 },
 108         { .compatible = "atmel,24c32", .data = 5 },
 109         { .compatible = "atmel,24c64", .data = 5 },
 110         { .compatible = "atmel,24c128", .data = 6 },
 111         { .compatible = "atmel,24c256", .data = 6 },
 112         { .compatible = "atmel,24c512", .data = 6 },
 113         { }
 114 };
 115
 116 U_BOOT_DRIVER(i2c_eeprom_std) = {
 117         .name                   = "i2c_eeprom",
 118         .id                     = UCLASS_I2C_EEPROM,
 119         .of_match               = i2c_eeprom_std_ids,
 120         .probe                  = i2c_eeprom_std_probe,
 121         .ofdata_to_platdata     = i2c_eeprom_std_ofdata_to_platdata,
 122         .priv_auto_alloc_size   = sizeof(struct i2c_eeprom),
 123         .ops                    = &i2c_eeprom_std_ops,
 124 };
 125
 126 UCLASS_DRIVER(i2c_eeprom) = {
 127         .id             = UCLASS_I2C_EEPROM,
 128         .name           = "i2c_eeprom",
 129 };