drivers/w1-eeprom/ds24xxx.c

   1 // SPDX-License-Identifier:     GPL-2.0+
   2 /*
   3  *
   4  * Copyright (c) 2015 Free Electrons
   5  * Copyright (c) 2015 NextThing Co
   6  * Copyright (c) 2018 Microchip Technology, Inc.
   7  *
   8  */
   9
  10 #include <common.h>
  11 #include <linux/err.h>
  12 #include <dm.h>
  13 #include <w1-eeprom.h>
  14 #include <w1.h>
  15
  16 #define W1_F2D_READ_EEPROM      0xf0
  17
  18 static int ds24xxx_read_buf(struct udevice *dev, unsigned int offset,
  19                             u8 *buf, unsigned int count)
  20 {
  21         w1_reset_select(dev);
  22
  23         w1_write_byte(dev, W1_F2D_READ_EEPROM);
  24         w1_write_byte(dev, offset & 0xff);
  25         w1_write_byte(dev, offset >> 8);
  26
  27         return w1_read_buf(dev, buf, count);
  28 }
  29
  30 static int ds24xxx_probe(struct udevice *dev)
  31 {
  32         struct w1_device *w1;
  33
  34         w1 = dev_get_parent_plat(dev);
  35         w1->id = 0;
  36         return 0;
  37 }
  38
  39 static const struct w1_eeprom_ops ds24xxx_ops = {
  40         .read_buf       = ds24xxx_read_buf,
  41 };
  42
  43 static const struct udevice_id ds24xxx_id[] = {
  44         { .compatible = "maxim,ds24b33", .data = W1_FAMILY_DS24B33 },
  45         { .compatible = "maxim,ds2431", .data = W1_FAMILY_DS2431 },
  46         { },
  47 };
  48
  49 U_BOOT_DRIVER(ds24xxx) = {
  50         .name           = "ds24xxx",
  51         .id             = UCLASS_W1_EEPROM,
  52         .of_match       = ds24xxx_id,
  53         .ops            = &ds24xxx_ops,
  54         .probe          = ds24xxx_probe,
  55 };
  56
  57 u8 family_supported[] = {
  58         W1_FAMILY_DS24B33,
  59         W1_FAMILY_DS2431,
  60 };
  61
  62 U_BOOT_W1_DEVICE(ds24xxx, family_supported);