1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2011, 2012 Cavium, Inc.
7 */
8
9#include <linux/platform_device.h>
10#include <linux/device.h>
11#include <linux/of_mdio.h>
12#include <linux/module.h>
13#include <linux/phy.h>
14#include <linux/mdio-mux.h>
15#include <linux/gpio/consumer.h>
16
17#define DRV_VERSION "1.1"
18#define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
19
20struct mdio_mux_gpio_state {
21	struct gpio_descs *gpios;
22	void *mux_handle;
23};
24
25static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
26				   void *data)
27{
28	struct mdio_mux_gpio_state *s = data;
29	int values[s->gpios->ndescs];
30	unsigned int n;
31
32	if (current_child == desired_child)
33		return 0;
34
35	for (n = 0; n < s->gpios->ndescs; n++)
36		values[n] = (desired_child >> n) & 1;
37
38	gpiod_set_array_cansleep(s->gpios->ndescs, s->gpios->desc, values);
39
40	return 0;
41}
42
43static int mdio_mux_gpio_probe(struct platform_device *pdev)
44{
45	struct mdio_mux_gpio_state *s;
46	int r;
47
48	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
49	if (!s)
50		return -ENOMEM;
51
52	s->gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
53	if (IS_ERR(s->gpios))
54		return PTR_ERR(s->gpios);
55
56	r = mdio_mux_init(&pdev->dev,
57			  mdio_mux_gpio_switch_fn, &s->mux_handle, s);
58
59	if (r != 0) {
60		gpiod_put_array(s->gpios);
61		return r;
62	}
63
64	pdev->dev.platform_data = s;
65	return 0;
66}
67
68static int mdio_mux_gpio_remove(struct platform_device *pdev)
69{
70	struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
71	mdio_mux_uninit(s->mux_handle);
72	gpiod_put_array(s->gpios);
73	return 0;
74}
75
76static const struct of_device_id mdio_mux_gpio_match[] = {
77	{
78		.compatible = "mdio-mux-gpio",
79	},
80	{
81		/* Legacy compatible property. */
82		.compatible = "cavium,mdio-mux-sn74cbtlv3253",
83	},
84	{},
85};
86MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
87
88static struct platform_driver mdio_mux_gpio_driver = {
89	.driver = {
90		.name		= "mdio-mux-gpio",
91		.of_match_table = mdio_mux_gpio_match,
92	},
93	.probe		= mdio_mux_gpio_probe,
94	.remove		= mdio_mux_gpio_remove,
95};
96
97module_platform_driver(mdio_mux_gpio_driver);
98
99MODULE_DESCRIPTION(DRV_DESCRIPTION);
100MODULE_VERSION(DRV_VERSION);
101MODULE_AUTHOR("David Daney");
102MODULE_LICENSE("GPL");
103