blob: 1b70e140545dd938fff9540543a652bbab94ce3d [file] [log] [blame]
Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Simon Glassc70c71d2014-12-10 08:55:49 -07002/*
3 * Copyright (c) 2014 Google, Inc
Simon Glassc70c71d2014-12-10 08:55:49 -07004 */
5
6#include <common.h>
7#include <dm.h>
8#include <i2c.h>
Simon Glassf7ae49f2020-05-10 11:40:05 -06009#include <log.h>
Simon Glassb7c25b12018-11-18 08:14:33 -070010#include <dm/device-internal.h>
11#include <dm/uclass-internal.h>
12
13/*
14 * i2c emulation works using an 'emul' node at the bus level. Each device in
15 * that node is in the UCLASS_I2C_EMUL uclass, and emulates one i2c device. A
16 * pointer to the device it emulates is in the 'dev' property of the emul device
17 * uclass platdata (struct i2c_emul_platdata), put there by i2c_emul_find().
18 * When sandbox wants an emulator for a device, it calls i2c_emul_find() which
19 * searches for the emulator with the correct address. To find the device for an
20 * emulator, call i2c_emul_get_device().
21 *
22 * The 'emul' node is in the UCLASS_I2C_EMUL_PARENT uclass. We use a separate
23 * uclass so avoid having strange devices on the I2C bus.
24 */
25
26/**
27 * struct i2c_emul_uc_platdata - information about the emulator for this device
28 *
29 * This is used by devices in UCLASS_I2C_EMUL to record information about the
30 * device being emulated. It is accessible with dev_get_uclass_platdata()
31 *
32 * @dev: Device being emulated
33 */
34struct i2c_emul_uc_platdata {
35 struct udevice *dev;
36};
37
38struct udevice *i2c_emul_get_device(struct udevice *emul)
39{
40 struct i2c_emul_uc_platdata *uc_plat = dev_get_uclass_platdata(emul);
41
42 return uc_plat->dev;
43}
44
45int i2c_emul_find(struct udevice *dev, struct udevice **emulp)
46{
47 struct i2c_emul_uc_platdata *uc_plat;
48 struct udevice *emul;
49 int ret;
50
51 ret = uclass_find_device_by_phandle(UCLASS_I2C_EMUL, dev,
52 "sandbox,emul", &emul);
53 if (ret) {
54 log_err("No emulators for device '%s'\n", dev->name);
55 return ret;
56 }
57 uc_plat = dev_get_uclass_platdata(emul);
58 uc_plat->dev = dev;
59 *emulp = emul;
60
61 return device_probe(emul);
62}
Simon Glassc70c71d2014-12-10 08:55:49 -070063
64UCLASS_DRIVER(i2c_emul) = {
65 .id = UCLASS_I2C_EMUL,
66 .name = "i2c_emul",
Simon Glassb7c25b12018-11-18 08:14:33 -070067 .per_device_platdata_auto_alloc_size =
68 sizeof(struct i2c_emul_uc_platdata),
69};
70
71/*
72 * This uclass is a child of the i2c bus. Its platdata is not defined here so
73 * is defined by its parent, UCLASS_I2C, which uses struct dm_i2c_chip. See
74 * per_child_platdata_auto_alloc_size in UCLASS_DRIVER(i2c).
75 */
76UCLASS_DRIVER(i2c_emul_parent) = {
77 .id = UCLASS_I2C_EMUL_PARENT,
78 .name = "i2c_emul_parent",
79 .post_bind = dm_scan_fdt_dev,
80};
81
82static const struct udevice_id i2c_emul_parent_ids[] = {
83 { .compatible = "sandbox,i2c-emul-parent" },
84 { }
85};
86
87U_BOOT_DRIVER(i2c_emul_parent_drv) = {
88 .name = "i2c_emul_parent_drv",
89 .id = UCLASS_I2C_EMUL_PARENT,
90 .of_match = i2c_emul_parent_ids,
Simon Glassc70c71d2014-12-10 08:55:49 -070091};