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Merge tag 'signed-efi-next' of git://github.com/agraf/u-boot
[u-boot] / drivers / i2c / sandbox_i2c.c
1 /*
2  * Simulate an I2C port
3  *
4  * Copyright (c) 2014 Google, Inc
5  *
6  * SPDX-License-Identifier:     GPL-2.0+
7  */
8
9 #include <common.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <i2c.h>
13 #include <asm/test.h>
14 #include <dm/lists.h>
15 #include <dm/device-internal.h>
16
17 DECLARE_GLOBAL_DATA_PTR;
18
19 struct sandbox_i2c_priv {
20         bool test_mode;
21 };
22
23 static int get_emul(struct udevice *dev, struct udevice **devp,
24                     struct dm_i2c_ops **opsp)
25 {
26         struct dm_i2c_chip *plat;
27         struct udevice *child;
28         int ret;
29
30         *devp = NULL;
31         *opsp = NULL;
32         plat = dev_get_parent_platdata(dev);
33         if (!plat->emul) {
34                 ret = dm_scan_fdt_dev(dev);
35                 if (ret)
36                         return ret;
37
38                 for (device_find_first_child(dev, &child); child;
39                      device_find_next_child(&child)) {
40                         if (device_get_uclass_id(child) != UCLASS_I2C_EMUL)
41                                 continue;
42
43                         ret = device_probe(child);
44                         if (ret)
45                                 return ret;
46
47                         break;
48                 }
49
50                 if (child)
51                         plat->emul = child;
52                 else
53                         return -ENODEV;
54         }
55         *devp = plat->emul;
56         *opsp = i2c_get_ops(plat->emul);
57
58         return 0;
59 }
60
61 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
62 {
63         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
64
65         priv->test_mode = test_mode;
66 }
67
68 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
69                             int nmsgs)
70 {
71         struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
72         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
73         struct dm_i2c_ops *ops;
74         struct udevice *emul, *dev;
75         bool is_read;
76         int ret;
77
78         /* Special test code to return success but with no emulation */
79         if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
80                 return 0;
81
82         ret = i2c_get_chip(bus, msg->addr, 1, &dev);
83         if (ret)
84                 return ret;
85
86         ret = get_emul(dev, &emul, &ops);
87         if (ret)
88                 return ret;
89
90         if (priv->test_mode) {
91                 /*
92                 * For testing, don't allow writing above 100KHz for writes and
93                 * 400KHz for reads.
94                 */
95                 is_read = nmsgs > 1;
96                 if (i2c->speed_hz > (is_read ? 400000 : 100000)) {
97                         debug("%s: Max speed exceeded\n", __func__);
98                         return -EINVAL;
99                 }
100         }
101
102         return ops->xfer(emul, msg, nmsgs);
103 }
104
105 static const struct dm_i2c_ops sandbox_i2c_ops = {
106         .xfer           = sandbox_i2c_xfer,
107 };
108
109 static const struct udevice_id sandbox_i2c_ids[] = {
110         { .compatible = "sandbox,i2c" },
111         { }
112 };
113
114 U_BOOT_DRIVER(i2c_sandbox) = {
115         .name   = "i2c_sandbox",
116         .id     = UCLASS_I2C,
117         .of_match = sandbox_i2c_ids,
118         .ops    = &sandbox_i2c_ops,
119         .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
120 };