LXR linux/drivers/net/phy/mdio-mux-gpio.c

   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");
 104