summaryrefslogtreecommitdiff
path: root/drivers/net/mdio/mdio-gpio.c
blob: 82088741debd9cdcec2ed2a44de874643310ef7d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO based MDIO bitbang driver.
 * Supports OpenFirmware.
 *
 * Copyright (c) 2008 CSE Semaphore Belgium.
 *  by Laurent Pinchart <laurentp@cse-semaphore.com>
 *
 * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 *
 * Based on earlier work by
 *
 * Copyright (c) 2003 Intracom S.A.
 *  by Pantelis Antoniou <panto@intracom.gr>
 *
 * 2005 (c) MontaVista Software, Inc.
 * Vitaly Bordug <vbordug@ru.mvista.com>
 */

#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/mdio-bitbang.h>
#include <linux/mdio-gpio.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/platform_data/mdio-gpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

struct mdio_gpio_info {
	struct mdiobb_ctrl ctrl;
	struct gpio_desc *mdc, *mdio, *mdo;
};

static int mdio_gpio_get_data(struct device *dev,
			      struct mdio_gpio_info *bitbang)
{
	bitbang->mdc = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDC,
					    GPIOD_OUT_LOW);
	if (IS_ERR(bitbang->mdc))
		return PTR_ERR(bitbang->mdc);

	bitbang->mdio = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDIO,
					     GPIOD_IN);
	if (IS_ERR(bitbang->mdio))
		return PTR_ERR(bitbang->mdio);

	bitbang->mdo = devm_gpiod_get_index_optional(dev, NULL, MDIO_GPIO_MDO,
						     GPIOD_OUT_LOW);
	return PTR_ERR_OR_ZERO(bitbang->mdo);
}

static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
{
	struct mdio_gpio_info *bitbang =
		container_of(ctrl, struct mdio_gpio_info, ctrl);

	if (bitbang->mdo) {
		/* Separate output pin. Always set its value to high
		 * when changing direction. If direction is input,
		 * assume the pin serves as pull-up. If direction is
		 * output, the default value is high.
		 */
		gpiod_set_value_cansleep(bitbang->mdo, 1);
		return;
	}

	if (dir)
		gpiod_direction_output(bitbang->mdio, 1);
	else
		gpiod_direction_input(bitbang->mdio);
}

static int mdio_get(struct mdiobb_ctrl *ctrl)
{
	struct mdio_gpio_info *bitbang =
		container_of(ctrl, struct mdio_gpio_info, ctrl);

	return gpiod_get_value_cansleep(bitbang->mdio);
}

static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
{
	struct mdio_gpio_info *bitbang =
		container_of(ctrl, struct mdio_gpio_info, ctrl);

	if (bitbang->mdo)
		gpiod_set_value_cansleep(bitbang->mdo, what);
	else
		gpiod_set_value_cansleep(bitbang->mdio, what);
}

static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
{
	struct mdio_gpio_info *bitbang =
		container_of(ctrl, struct mdio_gpio_info, ctrl);

	gpiod_set_value_cansleep(bitbang->mdc, what);
}

static const struct mdiobb_ops mdio_gpio_ops = {
	.owner = THIS_MODULE,
	.set_mdc = mdc_set,
	.set_mdio_dir = mdio_dir,
	.set_mdio_data = mdio_set,
	.get_mdio_data = mdio_get,
};

static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
					  struct mdio_gpio_info *bitbang,
					  int bus_id)
{
	struct mdio_gpio_platform_data *pdata = dev_get_platdata(dev);
	struct mii_bus *new_bus;

	bitbang->ctrl.ops = &mdio_gpio_ops;

	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
	if (!new_bus)
		return NULL;

	new_bus->name = "GPIO Bitbanged MDIO";
	new_bus->parent = dev;

	if (bus_id != -1)
		snprintf(new_bus->id, sizeof(new_bus->id), "gpio-%x", bus_id);
	else
		strscpy(new_bus->id, "gpio", sizeof(new_bus->id));

	if (pdata) {
		new_bus->phy_mask = pdata->phy_mask;
		new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;
	}

	if (device_is_compatible(dev, "microchip,mdio-smi0")) {
		bitbang->ctrl.op_c22_read = 0;
		bitbang->ctrl.op_c22_write = 0;
		bitbang->ctrl.override_op_c22 = 1;
	}

	dev_set_drvdata(dev, new_bus);

	return new_bus;
}

static void mdio_gpio_bus_deinit(struct device *dev)
{
	struct mii_bus *bus = dev_get_drvdata(dev);

	free_mdio_bitbang(bus);
}

static void mdio_gpio_bus_destroy(struct device *dev)
{
	struct mii_bus *bus = dev_get_drvdata(dev);

	mdiobus_unregister(bus);
	mdio_gpio_bus_deinit(dev);
}

static int mdio_gpio_probe(struct platform_device *pdev)
{
	struct mdio_gpio_info *bitbang;
	struct mii_bus *new_bus;
	int ret, bus_id;

	bitbang = devm_kzalloc(&pdev->dev, sizeof(*bitbang), GFP_KERNEL);
	if (!bitbang)
		return -ENOMEM;

	ret = mdio_gpio_get_data(&pdev->dev, bitbang);
	if (ret)
		return ret;

	if (pdev->dev.of_node) {
		bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
		if (bus_id < 0) {
			dev_warn(&pdev->dev, "failed to get alias id\n");
			bus_id = 0;
		}
	} else {
		bus_id = pdev->id;
	}

	new_bus = mdio_gpio_bus_init(&pdev->dev, bitbang, bus_id);
	if (!new_bus)
		return -ENODEV;

	ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
	if (ret)
		mdio_gpio_bus_deinit(&pdev->dev);

	return ret;
}

static void mdio_gpio_remove(struct platform_device *pdev)
{
	mdio_gpio_bus_destroy(&pdev->dev);
}

static const struct of_device_id mdio_gpio_of_match[] = {
	{ .compatible = "virtual,mdio-gpio", },
	{ .compatible = "microchip,mdio-smi0" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mdio_gpio_of_match);

static struct platform_driver mdio_gpio_driver = {
	.probe = mdio_gpio_probe,
	.remove_new = mdio_gpio_remove,
	.driver		= {
		.name	= "mdio-gpio",
		.of_match_table = mdio_gpio_of_match,
	},
};

module_platform_driver(mdio_gpio_driver);

MODULE_ALIAS("platform:mdio-gpio");
MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");