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23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/platform_device.h>
28#include <linux/gpio.h>
29#include <linux/mdio-gpio.h>
30
31#include <linux/of_gpio.h>
32#include <linux/of_mdio.h>
33
34struct mdio_gpio_info {
35 struct mdiobb_ctrl ctrl;
36 int mdc, mdio;
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 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(np, 0);
50 if (ret < 0)
51 return NULL;
52
53 pdata->mdc = ret;
54
55 ret = of_get_gpio(np, 1);
56 if (ret < 0)
57 return NULL;
58 pdata->mdio = ret;
59
60 return pdata;
61}
62
63static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
64{
65 struct mdio_gpio_info *bitbang =
66 container_of(ctrl, struct mdio_gpio_info, ctrl);
67
68 if (dir)
69 gpio_direction_output(bitbang->mdio, 1);
70 else
71 gpio_direction_input(bitbang->mdio);
72}
73
74static int mdio_get(struct mdiobb_ctrl *ctrl)
75{
76 struct mdio_gpio_info *bitbang =
77 container_of(ctrl, struct mdio_gpio_info, ctrl);
78
79 return gpio_get_value(bitbang->mdio);
80}
81
82static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
83{
84 struct mdio_gpio_info *bitbang =
85 container_of(ctrl, struct mdio_gpio_info, ctrl);
86
87 gpio_set_value(bitbang->mdio, what);
88}
89
90static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
91{
92 struct mdio_gpio_info *bitbang =
93 container_of(ctrl, struct mdio_gpio_info, ctrl);
94
95 gpio_set_value(bitbang->mdc, what);
96}
97
98static struct mdiobb_ops mdio_gpio_ops = {
99 .owner = THIS_MODULE,
100 .set_mdc = mdc_set,
101 .set_mdio_dir = mdio_dir,
102 .set_mdio_data = mdio_set,
103 .get_mdio_data = mdio_get,
104};
105
106static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
107 struct mdio_gpio_platform_data *pdata,
108 int bus_id)
109{
110 struct mii_bus *new_bus;
111 struct mdio_gpio_info *bitbang;
112 int i;
113
114 bitbang = kzalloc(sizeof(*bitbang), GFP_KERNEL);
115 if (!bitbang)
116 goto out;
117
118 bitbang->ctrl.ops = &mdio_gpio_ops;
119 bitbang->ctrl.reset = pdata->reset;
120 bitbang->mdc = pdata->mdc;
121 bitbang->mdio = pdata->mdio;
122
123 new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
124 if (!new_bus)
125 goto out_free_bitbang;
126
127 new_bus->name = "GPIO Bitbanged MDIO",
128
129 new_bus->phy_mask = pdata->phy_mask;
130 new_bus->irq = pdata->irqs;
131 new_bus->parent = dev;
132
133 if (new_bus->phy_mask == ~0)
134 goto out_free_bus;
135
136 for (i = 0; i < PHY_MAX_ADDR; i++)
137 if (!new_bus->irq[i])
138 new_bus->irq[i] = PHY_POLL;
139
140 snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
141
142 if (gpio_request(bitbang->mdc, "mdc"))
143 goto out_free_bus;
144
145 if (gpio_request(bitbang->mdio, "mdio"))
146 goto out_free_mdc;
147
148 gpio_direction_output(bitbang->mdc, 0);
149
150 dev_set_drvdata(dev, new_bus);
151
152 return new_bus;
153
154out_free_mdc:
155 gpio_free(bitbang->mdc);
156out_free_bus:
157 free_mdio_bitbang(new_bus);
158out_free_bitbang:
159 kfree(bitbang);
160out:
161 return NULL;
162}
163
164static void mdio_gpio_bus_deinit(struct device *dev)
165{
166 struct mii_bus *bus = dev_get_drvdata(dev);
167 struct mdio_gpio_info *bitbang = bus->priv;
168
169 dev_set_drvdata(dev, NULL);
170 gpio_free(bitbang->mdio);
171 gpio_free(bitbang->mdc);
172 free_mdio_bitbang(bus);
173 kfree(bitbang);
174}
175
176static void mdio_gpio_bus_destroy(struct device *dev)
177{
178 struct mii_bus *bus = dev_get_drvdata(dev);
179
180 mdiobus_unregister(bus);
181 mdio_gpio_bus_deinit(dev);
182}
183
184static int mdio_gpio_probe(struct platform_device *pdev)
185{
186 struct mdio_gpio_platform_data *pdata;
187 struct mii_bus *new_bus;
188 int ret, bus_id;
189
190 if (pdev->dev.of_node) {
191 pdata = mdio_gpio_of_get_data(pdev);
192 bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
193 } else {
194 pdata = pdev->dev.platform_data;
195 bus_id = pdev->id;
196 }
197
198 if (!pdata)
199 return -ENODEV;
200
201 new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, bus_id);
202 if (!new_bus)
203 return -ENODEV;
204
205 if (pdev->dev.of_node)
206 ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
207 else
208 ret = mdiobus_register(new_bus);
209
210 if (ret)
211 mdio_gpio_bus_deinit(&pdev->dev);
212
213 return ret;
214}
215
216static int mdio_gpio_remove(struct platform_device *pdev)
217{
218 mdio_gpio_bus_destroy(&pdev->dev);
219
220 return 0;
221}
222
223static struct of_device_id mdio_gpio_of_match[] = {
224 { .compatible = "virtual,mdio-gpio", },
225 { }
226};
227
228static struct platform_driver mdio_gpio_driver = {
229 .probe = mdio_gpio_probe,
230 .remove = mdio_gpio_remove,
231 .driver = {
232 .name = "mdio-gpio",
233 .owner = THIS_MODULE,
234 .of_match_table = mdio_gpio_of_match,
235 },
236};
237
238module_platform_driver(mdio_gpio_driver);
239
240MODULE_ALIAS("platform:mdio-gpio");
241MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
242MODULE_LICENSE("GPL");
243MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");
244
