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10#include <linux/i2c.h>
11#include <linux/i2c-mux.h>
12#include <linux/module.h>
13#include <linux/mux/consumer.h>
14#include <linux/of_device.h>
15#include <linux/platform_device.h>
16
17struct mux {
18 struct mux_control *control;
19
20 bool do_not_deselect;
21};
22
23static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
24{
25 struct mux *mux = i2c_mux_priv(muxc);
26 int ret;
27
28 ret = mux_control_select(mux->control, chan);
29 mux->do_not_deselect = ret < 0;
30
31 return ret;
32}
33
34static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
35{
36 struct mux *mux = i2c_mux_priv(muxc);
37
38 if (mux->do_not_deselect)
39 return 0;
40
41 return mux_control_deselect(mux->control);
42}
43
44static struct i2c_adapter *mux_parent_adapter(struct device *dev)
45{
46 struct device_node *np = dev->of_node;
47 struct device_node *parent_np;
48 struct i2c_adapter *parent;
49
50 parent_np = of_parse_phandle(np, "i2c-parent", 0);
51 if (!parent_np) {
52 dev_err(dev, "Cannot parse i2c-parent\n");
53 return ERR_PTR(-ENODEV);
54 }
55 parent = of_find_i2c_adapter_by_node(parent_np);
56 of_node_put(parent_np);
57 if (!parent)
58 return ERR_PTR(-EPROBE_DEFER);
59
60 return parent;
61}
62
63static const struct of_device_id i2c_mux_of_match[] = {
64 { .compatible = "i2c-mux", },
65 {},
66};
67MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
68
69static int i2c_mux_probe(struct platform_device *pdev)
70{
71 struct device *dev = &pdev->dev;
72 struct device_node *np = dev->of_node;
73 struct device_node *child;
74 struct i2c_mux_core *muxc;
75 struct mux *mux;
76 struct i2c_adapter *parent;
77 int children;
78 int ret;
79
80 if (!np)
81 return -ENODEV;
82
83 mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
84 if (!mux)
85 return -ENOMEM;
86
87 mux->control = devm_mux_control_get(dev, NULL);
88 if (IS_ERR(mux->control)) {
89 if (PTR_ERR(mux->control) != -EPROBE_DEFER)
90 dev_err(dev, "failed to get control-mux\n");
91 return PTR_ERR(mux->control);
92 }
93
94 parent = mux_parent_adapter(dev);
95 if (IS_ERR(parent)) {
96 if (PTR_ERR(parent) != -EPROBE_DEFER)
97 dev_err(dev, "failed to get i2c-parent adapter\n");
98 return PTR_ERR(parent);
99 }
100
101 children = of_get_child_count(np);
102
103 muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
104 i2c_mux_select, i2c_mux_deselect);
105 if (!muxc) {
106 ret = -ENOMEM;
107 goto err_parent;
108 }
109 muxc->priv = mux;
110
111 platform_set_drvdata(pdev, muxc);
112
113 muxc->mux_locked = of_property_read_bool(np, "mux-locked");
114
115 for_each_child_of_node(np, child) {
116 u32 chan;
117
118 ret = of_property_read_u32(child, "reg", &chan);
119 if (ret < 0) {
120 dev_err(dev, "no reg property for node '%pOFn'\n",
121 child);
122 goto err_children;
123 }
124
125 if (chan >= mux_control_states(mux->control)) {
126 dev_err(dev, "invalid reg %u\n", chan);
127 ret = -EINVAL;
128 goto err_children;
129 }
130
131 ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
132 if (ret)
133 goto err_children;
134 }
135
136 dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
137
138 return 0;
139
140err_children:
141 i2c_mux_del_adapters(muxc);
142err_parent:
143 i2c_put_adapter(parent);
144
145 return ret;
146}
147
148static int i2c_mux_remove(struct platform_device *pdev)
149{
150 struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
151
152 i2c_mux_del_adapters(muxc);
153 i2c_put_adapter(muxc->parent);
154
155 return 0;
156}
157
158static struct platform_driver i2c_mux_driver = {
159 .probe = i2c_mux_probe,
160 .remove = i2c_mux_remove,
161 .driver = {
162 .name = "i2c-mux-gpmux",
163 .of_match_table = i2c_mux_of_match,
164 },
165};
166module_platform_driver(i2c_mux_driver);
167
168MODULE_DESCRIPTION("General Purpose I2C multiplexer driver");
169MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
170MODULE_LICENSE("GPL v2");
171
