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

   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
  20 struct mdio_mux_gpio_state {
  21         struct gpio_descs *gpios;
  22         void *mux_handle;
  23 };
  24
  25 static 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         DECLARE_BITMAP(values, BITS_PER_TYPE(desired_child));
  30
  31         if (current_child == desired_child)
  32                 return 0;
  33
  34         values[0] = desired_child;
  35
  36         gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
  37                                        s->gpios->info, values);
  38
  39         return 0;
  40 }
  41
  42 static int mdio_mux_gpio_probe(struct platform_device *pdev)
  43 {
  44         struct mdio_mux_gpio_state *s;
  45         struct gpio_descs *gpios;
  46         int r;
  47
  48         gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
  49         if (IS_ERR(gpios))
  50                 return PTR_ERR(gpios);
  51
  52         s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
  53         if (!s) {
  54                 gpiod_put_array(gpios);
  55                 return -ENOMEM;
  56         }
  57
  58         s->gpios = gpios;
  59
  60         r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
  61                           mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
  62
  63         if (r != 0) {
  64                 gpiod_put_array(s->gpios);
  65                 return r;
  66         }
  67
  68         pdev->dev.platform_data = s;
  69         return 0;
  70 }
  71
  72 static int mdio_mux_gpio_remove(struct platform_device *pdev)
  73 {
  74         struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
  75         mdio_mux_uninit(s->mux_handle);
  76         gpiod_put_array(s->gpios);
  77         return 0;
  78 }
  79
  80 static const struct of_device_id mdio_mux_gpio_match[] = {
  81         {
  82                 .compatible = "mdio-mux-gpio",
  83         },
  84         {
  85                 /* Legacy compatible property. */
  86                 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
  87         },
  88         {},
  89 };
  90 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
  91
  92 static struct platform_driver mdio_mux_gpio_driver = {
  93         .driver = {
  94                 .name           = "mdio-mux-gpio",
  95                 .of_match_table = mdio_mux_gpio_match,
  96         },
  97         .probe          = mdio_mux_gpio_probe,
  98         .remove         = mdio_mux_gpio_remove,
  99 };
 100
 101 module_platform_driver(mdio_mux_gpio_driver);
 102
 103 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 104 MODULE_VERSION(DRV_VERSION);
 105 MODULE_AUTHOR("David Daney");
 106 MODULE_LICENSE("GPL");