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