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_value_cansleep(s->gpios->ndescs, s->gpios->desc,
39				       values);
40
41	return 0;
42}
43
44static int mdio_mux_gpio_probe(struct platform_device *pdev)
45{
46	struct mdio_mux_gpio_state *s;
47	int r;
48
49	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
50	if (!s)
51		return -ENOMEM;
52
53	s->gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
54	if (IS_ERR(s->gpios))
55		return PTR_ERR(s->gpios);
56
57	r = mdio_mux_init(&pdev->dev,
58			  mdio_mux_gpio_switch_fn, &s->mux_handle, s);
59
60	if (r != 0) {
61		gpiod_put_array(s->gpios);
62		return r;
63	}
64
65	pdev->dev.platform_data = s;
66	return 0;
67}
68
69static int mdio_mux_gpio_remove(struct platform_device *pdev)
70{
71	struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
72	mdio_mux_uninit(s->mux_handle);
73	gpiod_put_array(s->gpios);
74	return 0;
75}
76
77static const struct of_device_id mdio_mux_gpio_match[] = {
78	{
79		.compatible = "mdio-mux-gpio",
80	},
81	{
82		/* Legacy compatible property. */
83		.compatible = "cavium,mdio-mux-sn74cbtlv3253",
84	},
85	{},
86};
87MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
88
89static struct platform_driver mdio_mux_gpio_driver = {
90	.driver = {
91		.name		= "mdio-mux-gpio",
92		.of_match_table = mdio_mux_gpio_match,
93	},
94	.probe		= mdio_mux_gpio_probe,
95	.remove		= mdio_mux_gpio_remove,
96};
97
98module_platform_driver(mdio_mux_gpio_driver);
99
100MODULE_DESCRIPTION(DRV_DESCRIPTION);
101MODULE_VERSION(DRV_VERSION);
102MODULE_AUTHOR("David Daney");
103MODULE_LICENSE("GPL");
104