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 int ret;
25
26 *devp = NULL;
27 *opsp = NULL;
28 plat = dev_get_parent_platdata(dev);
29 if (!plat->emul) {
30 ret = i2c_emul_find(dev, &plat->emul);
31 if (ret)
32 return ret;
33 }
34 *devp = plat->emul;
35 *opsp = i2c_get_ops(plat->emul);
36
37 return 0;
38 }
39
sandbox_i2c_set_test_mode(struct udevice * bus,bool test_mode)40 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
41 {
42 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
43
44 priv->test_mode = test_mode;
45 }
46
sandbox_i2c_xfer(struct udevice * bus,struct i2c_msg * msg,int nmsgs)47 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
48 int nmsgs)
49 {
50 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
51 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
52 struct dm_i2c_ops *ops;
53 struct udevice *emul, *dev;
54 bool is_read;
55 int ret;
56
57 /* Special test code to return success but with no emulation */
58 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
59 return 0;
60
61 ret = i2c_get_chip(bus, msg->addr, 1, &dev);
62 if (ret)
63 return ret;
64
65 ret = get_emul(dev, &emul, &ops);
66 if (ret)
67 return ret;
68
69 if (priv->test_mode) {
70 /*
71 * For testing, don't allow writing above 100KHz for writes and
72 * 400KHz for reads.
73 */
74 is_read = nmsgs > 1;
75 if (i2c->speed_hz > (is_read ? 400000 : 100000)) {
76 debug("%s: Max speed exceeded\n", __func__);
77 return -EINVAL;
78 }
79 }
80
81 return ops->xfer(emul, msg, nmsgs);
82 }
83
84 static const struct dm_i2c_ops sandbox_i2c_ops = {
85 .xfer = sandbox_i2c_xfer,
86 };
87
88 static const struct udevice_id sandbox_i2c_ids[] = {
89 { .compatible = "sandbox,i2c" },
90 { }
91 };
92
93 U_BOOT_DRIVER(i2c_sandbox) = {
94 .name = "i2c_sandbox",
95 .id = UCLASS_I2C,
96 .of_match = sandbox_i2c_ids,
97 .ops = &sandbox_i2c_ops,
98 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
99 };
100