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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/i2c-mux-pinctrl.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26#include <linux/of.h>
27#include "../../pinctrl/core.h"
28
29struct i2c_mux_pinctrl {
30 struct i2c_mux_pinctrl_platform_data *pdata;
31 struct pinctrl *pinctrl;
32 struct pinctrl_state **states;
33 struct pinctrl_state *state_idle;
34};
35
36static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
37{
38 struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
39
40 return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
41}
42
43static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
44{
45 struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
46
47 return pinctrl_select_state(mux->pinctrl, mux->state_idle);
48}
49
50#ifdef CONFIG_OF
51static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux,
52 struct platform_device *pdev)
53{
54 struct device_node *np = pdev->dev.of_node;
55 int num_names, i, ret;
56 struct device_node *adapter_np;
57 struct i2c_adapter *adapter;
58
59 if (!np)
60 return 0;
61
62 mux->pdata = devm_kzalloc(&pdev->dev, sizeof(*mux->pdata), GFP_KERNEL);
63 if (!mux->pdata)
64 return -ENOMEM;
65
66 num_names = of_property_count_strings(np, "pinctrl-names");
67 if (num_names < 0) {
68 dev_err(&pdev->dev, "Cannot parse pinctrl-names: %d\n",
69 num_names);
70 return num_names;
71 }
72
73 mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev,
74 sizeof(*mux->pdata->pinctrl_states) * num_names,
75 GFP_KERNEL);
76 if (!mux->pdata->pinctrl_states)
77 return -ENOMEM;
78
79 for (i = 0; i < num_names; i++) {
80 ret = of_property_read_string_index(np, "pinctrl-names", i,
81 &mux->pdata->pinctrl_states[mux->pdata->bus_count]);
82 if (ret < 0) {
83 dev_err(&pdev->dev, "Cannot parse pinctrl-names: %d\n",
84 ret);
85 return ret;
86 }
87 if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count],
88 "idle")) {
89 if (i != num_names - 1) {
90 dev_err(&pdev->dev,
91 "idle state must be last\n");
92 return -EINVAL;
93 }
94 mux->pdata->pinctrl_state_idle = "idle";
95 } else {
96 mux->pdata->bus_count++;
97 }
98 }
99
100 adapter_np = of_parse_phandle(np, "i2c-parent", 0);
101 if (!adapter_np) {
102 dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
103 return -ENODEV;
104 }
105 adapter = of_find_i2c_adapter_by_node(adapter_np);
106 of_node_put(adapter_np);
107 if (!adapter) {
108 dev_err(&pdev->dev, "Cannot find parent bus\n");
109 return -EPROBE_DEFER;
110 }
111 mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
112 put_device(&adapter->dev);
113
114 return 0;
115}
116#else
117static inline int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux,
118 struct platform_device *pdev)
119{
120 return 0;
121}
122#endif
123
124static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
125 struct pinctrl_state *state)
126{
127 struct i2c_adapter *root = NULL;
128 struct pinctrl_setting *setting;
129 struct i2c_adapter *pin_root;
130
131 list_for_each_entry(setting, &state->settings, node) {
132 pin_root = i2c_root_adapter(setting->pctldev->dev);
133 if (!pin_root)
134 return NULL;
135 if (!root)
136 root = pin_root;
137 else if (root != pin_root)
138 return NULL;
139 }
140
141 return root;
142}
143
144static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
145{
146 struct i2c_mux_core *muxc;
147 struct i2c_mux_pinctrl *mux;
148 struct i2c_adapter *root;
149 int i, ret;
150
151 mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
152 if (!mux) {
153 ret = -ENOMEM;
154 goto err;
155 }
156
157 mux->pdata = dev_get_platdata(&pdev->dev);
158 if (!mux->pdata) {
159 ret = i2c_mux_pinctrl_parse_dt(mux, pdev);
160 if (ret < 0)
161 goto err;
162 }
163 if (!mux->pdata) {
164 dev_err(&pdev->dev, "Missing platform data\n");
165 ret = -ENODEV;
166 goto err;
167 }
168
169 mux->states = devm_kzalloc(&pdev->dev,
170 sizeof(*mux->states) * mux->pdata->bus_count,
171 GFP_KERNEL);
172 if (!mux->states) {
173 dev_err(&pdev->dev, "Cannot allocate states\n");
174 ret = -ENOMEM;
175 goto err;
176 }
177
178 muxc = i2c_mux_alloc(NULL, &pdev->dev, mux->pdata->bus_count, 0, 0,
179 i2c_mux_pinctrl_select, NULL);
180 if (!muxc) {
181 ret = -ENOMEM;
182 goto err;
183 }
184 muxc->priv = mux;
185
186 platform_set_drvdata(pdev, muxc);
187
188 mux->pinctrl = devm_pinctrl_get(&pdev->dev);
189 if (IS_ERR(mux->pinctrl)) {
190 ret = PTR_ERR(mux->pinctrl);
191 dev_err(&pdev->dev, "Cannot get pinctrl: %d\n", ret);
192 goto err;
193 }
194 for (i = 0; i < mux->pdata->bus_count; i++) {
195 mux->states[i] = pinctrl_lookup_state(mux->pinctrl,
196 mux->pdata->pinctrl_states[i]);
197 if (IS_ERR(mux->states[i])) {
198 ret = PTR_ERR(mux->states[i]);
199 dev_err(&pdev->dev,
200 "Cannot look up pinctrl state %s: %d\n",
201 mux->pdata->pinctrl_states[i], ret);
202 goto err;
203 }
204 }
205 if (mux->pdata->pinctrl_state_idle) {
206 mux->state_idle = pinctrl_lookup_state(mux->pinctrl,
207 mux->pdata->pinctrl_state_idle);
208 if (IS_ERR(mux->state_idle)) {
209 ret = PTR_ERR(mux->state_idle);
210 dev_err(&pdev->dev,
211 "Cannot look up pinctrl state %s: %d\n",
212 mux->pdata->pinctrl_state_idle, ret);
213 goto err;
214 }
215
216 muxc->deselect = i2c_mux_pinctrl_deselect;
217 }
218
219 muxc->parent = i2c_get_adapter(mux->pdata->parent_bus_num);
220 if (!muxc->parent) {
221 dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
222 mux->pdata->parent_bus_num);
223 ret = -EPROBE_DEFER;
224 goto err;
225 }
226
227 root = i2c_root_adapter(&muxc->parent->dev);
228
229 muxc->mux_locked = true;
230 for (i = 0; i < mux->pdata->bus_count; i++) {
231 if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
232 muxc->mux_locked = false;
233 break;
234 }
235 }
236 if (muxc->mux_locked && mux->pdata->pinctrl_state_idle &&
237 root != i2c_mux_pinctrl_root_adapter(mux->state_idle))
238 muxc->mux_locked = false;
239
240 if (muxc->mux_locked)
241 dev_info(&pdev->dev, "mux-locked i2c mux\n");
242
243 for (i = 0; i < mux->pdata->bus_count; i++) {
244 u32 bus = mux->pdata->base_bus_num ?
245 (mux->pdata->base_bus_num + i) : 0;
246
247 ret = i2c_mux_add_adapter(muxc, bus, i, 0);
248 if (ret)
249 goto err_del_adapter;
250 }
251
252 return 0;
253
254err_del_adapter:
255 i2c_mux_del_adapters(muxc);
256 i2c_put_adapter(muxc->parent);
257err:
258 return ret;
259}
260
261static int i2c_mux_pinctrl_remove(struct platform_device *pdev)
262{
263 struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
264
265 i2c_mux_del_adapters(muxc);
266 i2c_put_adapter(muxc->parent);
267 return 0;
268}
269
270#ifdef CONFIG_OF
271static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
272 { .compatible = "i2c-mux-pinctrl", },
273 {},
274};
275MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
276#endif
277
278static struct platform_driver i2c_mux_pinctrl_driver = {
279 .driver = {
280 .name = "i2c-mux-pinctrl",
281 .of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
282 },
283 .probe = i2c_mux_pinctrl_probe,
284 .remove = i2c_mux_pinctrl_remove,
285};
286module_platform_driver(i2c_mux_pinctrl_driver);
287
288MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
289MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
290MODULE_LICENSE("GPL v2");
291MODULE_ALIAS("platform:i2c-mux-pinctrl");
292
