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");