1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2011, 2012 Cavium, Inc.
  4 */
  5
  6#include <linux/platform_device.h>
  7#include <linux/device.h>
  8#include <linux/of_mdio.h>
  9#include <linux/module.h>
 10#include <linux/phy.h>
 11#include <linux/mdio-mux.h>
 12#include <linux/gpio/consumer.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 = 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		gpiod_put_array(gpios);
 52		return -ENOMEM;
 53	}
 54
 55	s->gpios = gpios;
 56
 57	r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
 58			  mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
 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 v2");