1 /* SPDX-License-Identifier: GPL-2.0+
2 *
3 * Copyright (c) 2018 Microchip Technology, Inc.
4 *
5 */
6
7 #include <common.h>
8 #include <linux/err.h>
9 #include <dm.h>
10 #include <w1-eeprom.h>
11 #include <w1.h>
12
13 #define W1_F2D_READ_EEPROM 0xf0
14
15 #define EEP_SANDBOX_SAMPLE_MEM "this is a sample EEPROM memory string."
16
eep_sandbox_read_buf(struct udevice * dev,unsigned int offset,u8 * buf,unsigned int count)17 static int eep_sandbox_read_buf(struct udevice *dev, unsigned int offset,
18 u8 *buf, unsigned int count)
19 {
20 /* do not allow to copy more than our maximum sample string */
21 if (offset + count < strlen(EEP_SANDBOX_SAMPLE_MEM)) {
22 offset = 0;
23 count = strlen(EEP_SANDBOX_SAMPLE_MEM);
24 }
25 strncpy((char *)buf, EEP_SANDBOX_SAMPLE_MEM, count);
26
27 /*
28 * in case the w1 subsystem uses some different kind of sandbox testing,
29 * like randomized gpio values , we take the buffer from there
30 */
31
32 w1_reset_select(dev);
33
34 w1_write_byte(dev, W1_F2D_READ_EEPROM);
35 w1_write_byte(dev, offset & 0xff);
36 w1_write_byte(dev, offset >> 8);
37
38 w1_read_buf(dev, buf, count);
39
40 /*
41 * even if read buf from w1 fails, return success as we hardcoded
42 * the buffer.
43 */
44 return 0;
45 }
46
47 static const struct w1_eeprom_ops eep_sandbox_ops = {
48 .read_buf = eep_sandbox_read_buf,
49 };
50
51 static const struct udevice_id eep_sandbox_id[] = {
52 { .compatible = "sandbox,w1-eeprom", .data = W1_FAMILY_EEP_SANDBOX },
53 { },
54 };
55
56 U_BOOT_DRIVER(eep_sandbox) = {
57 .name = "eep_sandbox",
58 .id = UCLASS_W1_EEPROM,
59 .of_match = eep_sandbox_id,
60 .ops = &eep_sandbox_ops,
61 };
62