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 <log.h>
13 #include <asm/i2c.h>
14 #include <asm/test.h>
15 #include <dm/acpi.h>
16 #include <dm/lists.h>
17 #include <dm/device-internal.h>
18
get_emul(struct udevice * dev,struct udevice ** devp,struct dm_i2c_ops ** opsp)19 static int get_emul(struct udevice *dev, struct udevice **devp,
20 struct dm_i2c_ops **opsp)
21 {
22 struct dm_i2c_chip *plat;
23 int ret;
24
25 *devp = NULL;
26 *opsp = NULL;
27 plat = dev_get_parent_plat(dev);
28 if (!plat->emul) {
29 ret = i2c_emul_find(dev, &plat->emul);
30 if (ret)
31 return ret;
32 }
33 *devp = plat->emul;
34 *opsp = i2c_get_ops(plat->emul);
35
36 return 0;
37 }
38
sandbox_i2c_set_test_mode(struct udevice * bus,bool test_mode)39 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
40 {
41 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
42
43 priv->test_mode = test_mode;
44 }
45
sandbox_i2c_xfer(struct udevice * bus,struct i2c_msg * msg,int nmsgs)46 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
47 int nmsgs)
48 {
49 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
50 struct sandbox_i2c_priv *priv = dev_get_priv(bus);
51 struct dm_i2c_ops *ops;
52 struct udevice *emul, *dev;
53 bool is_read;
54 int ret;
55
56 /* Special test code to return success but with no emulation */
57 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
58 return 0;
59
60 ret = i2c_get_chip(bus, msg->addr, 1, &dev);
61 if (ret)
62 return ret;
63
64 ret = get_emul(dev, &emul, &ops);
65 if (ret)
66 return ret;
67
68 if (priv->test_mode) {
69 /*
70 * For testing, don't allow writing above 100KHz for writes and
71 * 400KHz for reads.
72 */
73 is_read = nmsgs > 1;
74 if (i2c->speed_hz > (is_read ? I2C_SPEED_FAST_RATE :
75 I2C_SPEED_STANDARD_RATE)) {
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(sandbox_i2c) = {
94 .name = "sandbox_i2c",
95 .id = UCLASS_I2C,
96 .of_match = sandbox_i2c_ids,
97 .ops = &sandbox_i2c_ops,
98 .priv_auto = sizeof(struct sandbox_i2c_priv),
99 };
100