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23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/interrupt.h>
26#include <linux/platform_device.h>
27#include <linux/gpio.h>
28#include <linux/platform_data/mdio-gpio.h>
29
30#include <linux/of_gpio.h>
31#include <linux/of_mdio.h>
32
33struct mdio_gpio_info {
34 struct mdiobb_ctrl ctrl;
35 struct gpio_desc *mdc, *mdio, *mdo;
36};
37
38static void *mdio_gpio_of_get_data(struct platform_device *pdev)
39{
40 struct device_node *np = pdev->dev.of_node;
41 struct mdio_gpio_platform_data *pdata;
42 enum of_gpio_flags flags;
43 int ret;
44
45 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
46 if (!pdata)
47 return NULL;
48
49 ret = of_get_gpio_flags(np, 0, &flags);
50 if (ret < 0)
51 return NULL;
52
53 pdata->mdc = ret;
54 pdata->mdc_active_low = flags & OF_GPIO_ACTIVE_LOW;
55
56 ret = of_get_gpio_flags(np, 1, &flags);
57 if (ret < 0)
58 return NULL;
59 pdata->mdio = ret;
60 pdata->mdio_active_low = flags & OF_GPIO_ACTIVE_LOW;
61
62 ret = of_get_gpio_flags(np, 2, &flags);
63 if (ret > 0) {
64 pdata->mdo = ret;
65 pdata->mdo_active_low = flags & OF_GPIO_ACTIVE_LOW;
66 }
67
68 return pdata;
69}
70
71static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
72{
73 struct mdio_gpio_info *bitbang =
74 container_of(ctrl, struct mdio_gpio_info, ctrl);
75
76 if (bitbang->mdo) {
77
78
79
80
81
82 gpiod_set_value(bitbang->mdo, 1);
83 return;
84 }
85
86 if (dir)
87 gpiod_direction_output(bitbang->mdio, 1);
88 else
89 gpiod_direction_input(bitbang->mdio);
90}
91
92static int mdio_get(struct mdiobb_ctrl *ctrl)
93{
94 struct mdio_gpio_info *bitbang =
95 container_of(ctrl, struct mdio_gpio_info, ctrl);
96
97 return gpiod_get_value(bitbang->mdio);
98}
99
100static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
101{
102 struct mdio_gpio_info *bitbang =
103 container_of(ctrl, struct mdio_gpio_info, ctrl);
104
105 if (bitbang->mdo)
106 gpiod_set_value(bitbang->mdo, what);
107 else
108 gpiod_set_value(bitbang->mdio, what);
109}
110
111static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
112{
113 struct mdio_gpio_info *bitbang =
114 container_of(ctrl, struct mdio_gpio_info, ctrl);
115
116 gpiod_set_value(bitbang->mdc, what);
117}
118
119static const struct mdiobb_ops mdio_gpio_ops = {
120 .owner = THIS_MODULE,
121 .set_mdc = mdc_set,
122 .set_mdio_dir = mdio_dir,
123 .set_mdio_data = mdio_set,
124 .get_mdio_data = mdio_get,
125};
126
127static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
128 struct mdio_gpio_platform_data *pdata,
129 int bus_id)
130{
131 struct mii_bus *new_bus;
132 struct mdio_gpio_info *bitbang;
133 int i;
134 int mdc, mdio, mdo;
135 unsigned long mdc_flags = GPIOF_OUT_INIT_LOW;
136 unsigned long mdio_flags = GPIOF_DIR_IN;
137 unsigned long mdo_flags = GPIOF_OUT_INIT_HIGH;
138
139 bitbang = devm_kzalloc(dev, sizeof(*bitbang), GFP_KERNEL);
140 if (!bitbang)
141 goto out;
142
143 bitbang->ctrl.ops = &mdio_gpio_ops;
144 bitbang->ctrl.reset = pdata->reset;
145 mdc = pdata->mdc;
146 bitbang->mdc = gpio_to_desc(mdc);
147 if (pdata->mdc_active_low)
148 mdc_flags = GPIOF_OUT_INIT_HIGH | GPIOF_ACTIVE_LOW;
149 mdio = pdata->mdio;
150 bitbang->mdio = gpio_to_desc(mdio);
151 if (pdata->mdio_active_low)
152 mdio_flags |= GPIOF_ACTIVE_LOW;
153 mdo = pdata->mdo;
154 if (mdo) {
155 bitbang->mdo = gpio_to_desc(mdo);
156 if (pdata->mdo_active_low)
157 mdo_flags = GPIOF_OUT_INIT_LOW | GPIOF_ACTIVE_LOW;
158 }
159
160 new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
161 if (!new_bus)
162 goto out;
163
164 new_bus->name = "GPIO Bitbanged MDIO",
165
166 new_bus->phy_mask = pdata->phy_mask;
167 new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;
168 memcpy(new_bus->irq, pdata->irqs, sizeof(new_bus->irq));
169 new_bus->parent = dev;
170
171 if (new_bus->phy_mask == ~0)
172 goto out_free_bus;
173
174 for (i = 0; i < PHY_MAX_ADDR; i++)
175 if (!new_bus->irq[i])
176 new_bus->irq[i] = PHY_POLL;
177
178 if (bus_id != -1)
179 snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
180 else
181 strncpy(new_bus->id, "gpio", MII_BUS_ID_SIZE);
182
183 if (devm_gpio_request_one(dev, mdc, mdc_flags, "mdc"))
184 goto out_free_bus;
185
186 if (devm_gpio_request_one(dev, mdio, mdio_flags, "mdio"))
187 goto out_free_bus;
188
189 if (mdo && devm_gpio_request_one(dev, mdo, mdo_flags, "mdo"))
190 goto out_free_bus;
191
192 dev_set_drvdata(dev, new_bus);
193
194 return new_bus;
195
196out_free_bus:
197 free_mdio_bitbang(new_bus);
198out:
199 return NULL;
200}
201
202static void mdio_gpio_bus_deinit(struct device *dev)
203{
204 struct mii_bus *bus = dev_get_drvdata(dev);
205
206 free_mdio_bitbang(bus);
207}
208
209static void mdio_gpio_bus_destroy(struct device *dev)
210{
211 struct mii_bus *bus = dev_get_drvdata(dev);
212
213 mdiobus_unregister(bus);
214 mdio_gpio_bus_deinit(dev);
215}
216
217static int mdio_gpio_probe(struct platform_device *pdev)
218{
219 struct mdio_gpio_platform_data *pdata;
220 struct mii_bus *new_bus;
221 int ret, bus_id;
222
223 if (pdev->dev.of_node) {
224 pdata = mdio_gpio_of_get_data(pdev);
225 bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
226 if (bus_id < 0) {
227 dev_warn(&pdev->dev, "failed to get alias id\n");
228 bus_id = 0;
229 }
230 } else {
231 pdata = dev_get_platdata(&pdev->dev);
232 bus_id = pdev->id;
233 }
234
235 if (!pdata)
236 return -ENODEV;
237
238 new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, bus_id);
239 if (!new_bus)
240 return -ENODEV;
241
242 if (pdev->dev.of_node)
243 ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
244 else
245 ret = mdiobus_register(new_bus);
246
247 if (ret)
248 mdio_gpio_bus_deinit(&pdev->dev);
249
250 return ret;
251}
252
253static int mdio_gpio_remove(struct platform_device *pdev)
254{
255 mdio_gpio_bus_destroy(&pdev->dev);
256
257 return 0;
258}
259
260static const struct of_device_id mdio_gpio_of_match[] = {
261 { .compatible = "virtual,mdio-gpio", },
262 { }
263};
264MODULE_DEVICE_TABLE(of, mdio_gpio_of_match);
265
266static struct platform_driver mdio_gpio_driver = {
267 .probe = mdio_gpio_probe,
268 .remove = mdio_gpio_remove,
269 .driver = {
270 .name = "mdio-gpio",
271 .of_match_table = mdio_gpio_of_match,
272 },
273};
274
275module_platform_driver(mdio_gpio_driver);
276
277MODULE_ALIAS("platform:mdio-gpio");
278MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
279MODULE_LICENSE("GPL");
280MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");
281
