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