1*84e55bddSEugen Hristev /* SPDX-License-Identifier: GPL-2.0+
2*84e55bddSEugen Hristev *
3*84e55bddSEugen Hristev * Copyright (c) 2018 Microchip Technology, Inc.
4*84e55bddSEugen Hristev *
5*84e55bddSEugen Hristev */
6*84e55bddSEugen Hristev
7*84e55bddSEugen Hristev #include <common.h>
8*84e55bddSEugen Hristev #include <linux/err.h>
9*84e55bddSEugen Hristev #include <dm.h>
10*84e55bddSEugen Hristev #include <w1-eeprom.h>
11*84e55bddSEugen Hristev #include <w1.h>
12*84e55bddSEugen Hristev
13*84e55bddSEugen Hristev #define W1_F2D_READ_EEPROM 0xf0
14*84e55bddSEugen Hristev
15*84e55bddSEugen Hristev #define EEP_SANDBOX_SAMPLE_MEM "this is a sample EEPROM memory string."
16*84e55bddSEugen Hristev
eep_sandbox_read_buf(struct udevice * dev,unsigned int offset,u8 * buf,unsigned int count)17*84e55bddSEugen Hristev static int eep_sandbox_read_buf(struct udevice *dev, unsigned int offset,
18*84e55bddSEugen Hristev u8 *buf, unsigned int count)
19*84e55bddSEugen Hristev {
20*84e55bddSEugen Hristev /* do not allow to copy more than our maximum sample string */
21*84e55bddSEugen Hristev if (offset + count < strlen(EEP_SANDBOX_SAMPLE_MEM)) {
22*84e55bddSEugen Hristev offset = 0;
23*84e55bddSEugen Hristev count = strlen(EEP_SANDBOX_SAMPLE_MEM);
24*84e55bddSEugen Hristev }
25*84e55bddSEugen Hristev strncpy((char *)buf, EEP_SANDBOX_SAMPLE_MEM, count);
26*84e55bddSEugen Hristev
27*84e55bddSEugen Hristev /*
28*84e55bddSEugen Hristev * in case the w1 subsystem uses some different kind of sandbox testing,
29*84e55bddSEugen Hristev * like randomized gpio values , we take the buffer from there
30*84e55bddSEugen Hristev */
31*84e55bddSEugen Hristev
32*84e55bddSEugen Hristev w1_reset_select(dev);
33*84e55bddSEugen Hristev
34*84e55bddSEugen Hristev w1_write_byte(dev, W1_F2D_READ_EEPROM);
35*84e55bddSEugen Hristev w1_write_byte(dev, offset & 0xff);
36*84e55bddSEugen Hristev w1_write_byte(dev, offset >> 8);
37*84e55bddSEugen Hristev
38*84e55bddSEugen Hristev w1_read_buf(dev, buf, count);
39*84e55bddSEugen Hristev
40*84e55bddSEugen Hristev /*
41*84e55bddSEugen Hristev * even if read buf from w1 fails, return success as we hardcoded
42*84e55bddSEugen Hristev * the buffer.
43*84e55bddSEugen Hristev */
44*84e55bddSEugen Hristev return 0;
45*84e55bddSEugen Hristev }
46*84e55bddSEugen Hristev
47*84e55bddSEugen Hristev static const struct w1_eeprom_ops eep_sandbox_ops = {
48*84e55bddSEugen Hristev .read_buf = eep_sandbox_read_buf,
49*84e55bddSEugen Hristev };
50*84e55bddSEugen Hristev
51*84e55bddSEugen Hristev static const struct udevice_id eep_sandbox_id[] = {
52*84e55bddSEugen Hristev { .compatible = "sandbox,w1-eeprom", .data = W1_FAMILY_EEP_SANDBOX },
53*84e55bddSEugen Hristev { },
54*84e55bddSEugen Hristev };
55*84e55bddSEugen Hristev
56*84e55bddSEugen Hristev U_BOOT_DRIVER(eep_sandbox) = {
57*84e55bddSEugen Hristev .name = "eep_sandbox",
58*84e55bddSEugen Hristev .id = UCLASS_W1_EEPROM,
59*84e55bddSEugen Hristev .of_match = eep_sandbox_id,
60*84e55bddSEugen Hristev .ops = &eep_sandbox_ops,
61*84e55bddSEugen Hristev };
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