1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011, 2012 Cavium, Inc.
4 */
5
6#include <linux/device.h>
7#include <linux/gpio/consumer.h>
8#include <linux/mdio-mux.h>
9#include <linux/module.h>
10#include <linux/of_mdio.h>
11#include <linux/phy.h>
12#include <linux/platform_device.h>
13
14#define DRV_VERSION "1.1"
15#define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
16
17struct mdio_mux_gpio_state {
18	struct gpio_descs *gpios;
19	void *mux_handle;
20};
21
22static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
23				   void *data)
24{
25	struct mdio_mux_gpio_state *s = data;
26	DECLARE_BITMAP(values, BITS_PER_TYPE(desired_child));
27
28	if (current_child == desired_child)
29		return 0;
30
31	values[0] = desired_child;
32
33	gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
34				       s->gpios->info, values);
35
36	return 0;
37}
38
39static int mdio_mux_gpio_probe(struct platform_device *pdev)
40{
41	struct mdio_mux_gpio_state *s;
42	struct gpio_descs *gpios;
43	int r;
44
45	gpios = devm_gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
46	if (IS_ERR(gpios))
47		return PTR_ERR(gpios);
48
49	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
50	if (!s)
51		return -ENOMEM;
52
53	s->gpios = gpios;
54
55	r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
56			  mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
57
58	if (r != 0)
59		return r;
60
61	pdev->dev.platform_data = s;
62	return 0;
63}
64
65static void mdio_mux_gpio_remove(struct platform_device *pdev)
66{
67	struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
68	mdio_mux_uninit(s->mux_handle);
69}
70
71static const struct of_device_id mdio_mux_gpio_match[] = {
72	{
73		.compatible = "mdio-mux-gpio",
74	},
75	{
76		/* Legacy compatible property. */
77		.compatible = "cavium,mdio-mux-sn74cbtlv3253",
78	},
79	{},
80};
81MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
82
83static struct platform_driver mdio_mux_gpio_driver = {
84	.driver = {
85		.name		= "mdio-mux-gpio",
86		.of_match_table = mdio_mux_gpio_match,
87	},
88	.probe		= mdio_mux_gpio_probe,
89	.remove_new	= mdio_mux_gpio_remove,
90};
91
92module_platform_driver(mdio_mux_gpio_driver);
93
94MODULE_DESCRIPTION(DRV_DESCRIPTION);
95MODULE_VERSION(DRV_VERSION);
96MODULE_AUTHOR("David Daney");
97MODULE_LICENSE("GPL v2");
98