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19#include <linux/i2c.h>
20#include <linux/i2c-mux.h>
21#include <linux/module.h>
22#include <linux/pinctrl/consumer.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25#include <linux/of.h>
26#include "../../pinctrl/core.h"
27
28struct i2c_mux_pinctrl {
29 struct pinctrl *pinctrl;
30 struct pinctrl_state **states;
31};
32
33static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
34{
35 struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
36
37 return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
38}
39
40static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
41{
42 return i2c_mux_pinctrl_select(muxc, muxc->num_adapters);
43}
44
45static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
46 struct pinctrl_state *state)
47{
48 struct i2c_adapter *root = NULL;
49 struct pinctrl_setting *setting;
50 struct i2c_adapter *pin_root;
51
52 list_for_each_entry(setting, &state->settings, node) {
53 pin_root = i2c_root_adapter(setting->pctldev->dev);
54 if (!pin_root)
55 return NULL;
56 if (!root)
57 root = pin_root;
58 else if (root != pin_root)
59 return NULL;
60 }
61
62 return root;
63}
64
65static struct i2c_adapter *i2c_mux_pinctrl_parent_adapter(struct device *dev)
66{
67 struct device_node *np = dev->of_node;
68 struct device_node *parent_np;
69 struct i2c_adapter *parent;
70
71 parent_np = of_parse_phandle(np, "i2c-parent", 0);
72 if (!parent_np) {
73 dev_err(dev, "Cannot parse i2c-parent\n");
74 return ERR_PTR(-ENODEV);
75 }
76 parent = of_find_i2c_adapter_by_node(parent_np);
77 of_node_put(parent_np);
78 if (!parent)
79 return ERR_PTR(-EPROBE_DEFER);
80
81 return parent;
82}
83
84static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
85{
86 struct device *dev = &pdev->dev;
87 struct device_node *np = dev->of_node;
88 struct i2c_mux_core *muxc;
89 struct i2c_mux_pinctrl *mux;
90 struct i2c_adapter *parent;
91 struct i2c_adapter *root;
92 int num_names, i, ret;
93 const char *name;
94
95 num_names = of_property_count_strings(np, "pinctrl-names");
96 if (num_names < 0) {
97 dev_err(dev, "Cannot parse pinctrl-names: %d\n",
98 num_names);
99 return num_names;
100 }
101
102 parent = i2c_mux_pinctrl_parent_adapter(dev);
103 if (IS_ERR(parent))
104 return PTR_ERR(parent);
105
106 muxc = i2c_mux_alloc(parent, dev, num_names,
107 sizeof(*mux) + num_names * sizeof(*mux->states),
108 0, i2c_mux_pinctrl_select, NULL);
109 if (!muxc) {
110 ret = -ENOMEM;
111 goto err_put_parent;
112 }
113 mux = i2c_mux_priv(muxc);
114 mux->states = (struct pinctrl_state **)(mux + 1);
115
116 platform_set_drvdata(pdev, muxc);
117
118 mux->pinctrl = devm_pinctrl_get(dev);
119 if (IS_ERR(mux->pinctrl)) {
120 ret = PTR_ERR(mux->pinctrl);
121 dev_err(dev, "Cannot get pinctrl: %d\n", ret);
122 goto err_put_parent;
123 }
124
125 for (i = 0; i < num_names; i++) {
126 ret = of_property_read_string_index(np, "pinctrl-names", i,
127 &name);
128 if (ret < 0) {
129 dev_err(dev, "Cannot parse pinctrl-names: %d\n", ret);
130 goto err_put_parent;
131 }
132
133 mux->states[i] = pinctrl_lookup_state(mux->pinctrl, name);
134 if (IS_ERR(mux->states[i])) {
135 ret = PTR_ERR(mux->states[i]);
136 dev_err(dev, "Cannot look up pinctrl state %s: %d\n",
137 name, ret);
138 goto err_put_parent;
139 }
140
141 if (strcmp(name, "idle"))
142 continue;
143
144 if (i != num_names - 1) {
145 dev_err(dev, "idle state must be last\n");
146 ret = -EINVAL;
147 goto err_put_parent;
148 }
149 muxc->deselect = i2c_mux_pinctrl_deselect;
150 }
151
152 root = i2c_root_adapter(&muxc->parent->dev);
153
154 muxc->mux_locked = true;
155 for (i = 0; i < num_names; i++) {
156 if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
157 muxc->mux_locked = false;
158 break;
159 }
160 }
161 if (muxc->mux_locked)
162 dev_info(dev, "mux-locked i2c mux\n");
163
164
165 for (i = 0; i < num_names - !!muxc->deselect; i++) {
166 ret = i2c_mux_add_adapter(muxc, 0, i, 0);
167 if (ret)
168 goto err_del_adapter;
169 }
170
171 return 0;
172
173err_del_adapter:
174 i2c_mux_del_adapters(muxc);
175err_put_parent:
176 i2c_put_adapter(parent);
177
178 return ret;
179}
180
181static int i2c_mux_pinctrl_remove(struct platform_device *pdev)
182{
183 struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
184
185 i2c_mux_del_adapters(muxc);
186 i2c_put_adapter(muxc->parent);
187
188 return 0;
189}
190
191static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
192 { .compatible = "i2c-mux-pinctrl", },
193 {},
194};
195MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
196
197static struct platform_driver i2c_mux_pinctrl_driver = {
198 .driver = {
199 .name = "i2c-mux-pinctrl",
200 .of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
201 },
202 .probe = i2c_mux_pinctrl_probe,
203 .remove = i2c_mux_pinctrl_remove,
204};
205module_platform_driver(i2c_mux_pinctrl_driver);
206
207MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
208MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
209MODULE_LICENSE("GPL v2");
210MODULE_ALIAS("platform:i2c-mux-pinctrl");
211
