1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Simulate an I2C port
4 *
5 * Copyright (c) 2014 Google, Inc
6 */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <i2c.h>
12 #include <asm/test.h>
13 #include <dm/lists.h>
14 #include <dm/device-internal.h>
15
16 struct sandbox_i2c_priv {
17 bool test_mode;
18 };
19
get_emul(struct udevice * dev,struct udevice ** devp,struct dm_i2c_ops ** opsp)20 static int get_emul(struct udevice *dev, struct udevice **devp,
21 struct dm_i2c_ops **opsp)
22 {
23 struct dm_i2c_chip *plat;
24 struct udevice *child;
25 int ret;
26
27 *devp = NULL;
28 *opsp = NULL;
29 plat = dev_get_parent_platdata(dev);
30 if (!plat->emul) {
31 ret = dm_scan_fdt_dev(dev);
32 if (ret)
33 return ret;
34
35 for (device_find_first_child(dev, &child); child;
36 device_find_next_child(&child)) {
37 if (device_get_uclass_id(child) != UCLASS_I2C_EMUL)
38 continue;
39
40 ret = device_probe(child);
41 if (ret)
42 return ret;
43
44 break;
45 }
46
47 if (child)
48 plat->emul = child;
49 else
50 return -ENODEV;
51 }
52 *devp = plat->emul;
53 *opsp = i2c_get_ops(plat->emul);
54
55 return 0;
56 }
57
sandbox_i2c_set_test_mode(struct udevice * bus,bool test_mode)58 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
59 {
60 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
61
62 priv->test_mode = test_mode;
63 }
64
sandbox_i2c_xfer(struct udevice * bus,struct i2c_msg * msg,int nmsgs)65 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
66 int nmsgs)
67 {
68 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
69 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
70 struct dm_i2c_ops *ops;
71 struct udevice *emul, *dev;
72 bool is_read;
73 int ret;
74
75 /* Special test code to return success but with no emulation */
76 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
77 return 0;
78
79 ret = i2c_get_chip(bus, msg->addr, 1, &dev);
80 if (ret)
81 return ret;
82
83 ret = get_emul(dev, &emul, &ops);
84 if (ret)
85 return ret;
86
87 if (priv->test_mode) {
88 /*
89 * For testing, don't allow writing above 100KHz for writes and
90 * 400KHz for reads.
91 */
92 is_read = nmsgs > 1;
93 if (i2c->speed_hz > (is_read ? 400000 : 100000)) {
94 debug("%s: Max speed exceeded\n", __func__);
95 return -EINVAL;
96 }
97 }
98
99 return ops->xfer(emul, msg, nmsgs);
100 }
101
102 static const struct dm_i2c_ops sandbox_i2c_ops = {
103 .xfer = sandbox_i2c_xfer,
104 };
105
106 static const struct udevice_id sandbox_i2c_ids[] = {
107 { .compatible = "sandbox,i2c" },
108 { }
109 };
110
111 U_BOOT_DRIVER(i2c_sandbox) = {
112 .name = "i2c_sandbox",
113 .id = UCLASS_I2C,
114 .of_match = sandbox_i2c_ids,
115 .ops = &sandbox_i2c_ops,
116 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
117 };
118