drivers/net/phy/mdio-gpio.c

   1 /*
   2  * GPIO based MDIO bitbang driver.
   3  * Supports OpenFirmware.
   4  *
   5  * Copyright (c) 2008 CSE Semaphore Belgium.
   6  *  by Laurent Pinchart <laurentp@cse-semaphore.com>
   7  *
   8  * Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   9  *
  10  * Based on earlier work by
  11  *
  12  * Copyright (c) 2003 Intracom S.A.
  13  *  by Pantelis Antoniou <panto@intracom.gr>
  14  *
  15  * 2005 (c) MontaVista Software, Inc.
  16  * Vitaly Bordug <vbordug@ru.mvista.com>
  17  *
  18  * This file is licensed under the terms of the GNU General Public License
  19  * version 2. This program is licensed "as is" without any warranty of any
  20  * kind, whether express or implied.
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/gpio.h>
  29 #include <linux/mdio-gpio.h>
  30
  31 #include <linux/of_gpio.h>
  32 #include <linux/of_mdio.h>
  33
  34 struct mdio_gpio_info {
  35         struct mdiobb_ctrl ctrl;
  36         int mdc, mdio;
  37 };
  38
  39 static void *mdio_gpio_of_get_data(struct platform_device *pdev)
  40 {
  41         struct device_node *np = pdev->dev.of_node;
  42         struct mdio_gpio_platform_data *pdata;
  43         int ret;
  44
  45         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  46         if (!pdata)
  47                 return NULL;
  48
  49         ret = of_get_gpio(np, 0);
  50         if (ret < 0)
  51                 return NULL;
  52
  53         pdata->mdc = ret;
  54
  55         ret = of_get_gpio(np, 1);
  56         if (ret < 0)
  57                 return NULL;
  58         pdata->mdio = ret;
  59
  60         return pdata;
  61 }
  62
  63 static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
  64 {
  65         struct mdio_gpio_info *bitbang =
  66                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  67
  68         if (dir)
  69                 gpio_direction_output(bitbang->mdio, 1);
  70         else
  71                 gpio_direction_input(bitbang->mdio);
  72 }
  73
  74 static int mdio_get(struct mdiobb_ctrl *ctrl)
  75 {
  76         struct mdio_gpio_info *bitbang =
  77                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  78
  79         return gpio_get_value(bitbang->mdio);
  80 }
  81
  82 static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
  83 {
  84         struct mdio_gpio_info *bitbang =
  85                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  86
  87         gpio_set_value(bitbang->mdio, what);
  88 }
  89
  90 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
  91 {
  92         struct mdio_gpio_info *bitbang =
  93                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  94
  95         gpio_set_value(bitbang->mdc, what);
  96 }
  97
  98 static struct mdiobb_ops mdio_gpio_ops = {
  99         .owner = THIS_MODULE,
 100         .set_mdc = mdc_set,
 101         .set_mdio_dir = mdio_dir,
 102         .set_mdio_data = mdio_set,
 103         .get_mdio_data = mdio_get,
 104 };
 105
 106 static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 107                                           struct mdio_gpio_platform_data *pdata,
 108                                           int bus_id)
 109 {
 110         struct mii_bus *new_bus;
 111         struct mdio_gpio_info *bitbang;
 112         int i;
 113
 114         bitbang = kzalloc(sizeof(*bitbang), GFP_KERNEL);
 115         if (!bitbang)
 116                 goto out;
 117
 118         bitbang->ctrl.ops = &mdio_gpio_ops;
 119         bitbang->ctrl.reset = pdata->reset;
 120         bitbang->mdc = pdata->mdc;
 121         bitbang->mdio = pdata->mdio;
 122
 123         new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
 124         if (!new_bus)
 125                 goto out_free_bitbang;
 126
 127         new_bus->name = "GPIO Bitbanged MDIO",
 128
 129         new_bus->phy_mask = pdata->phy_mask;
 130         new_bus->irq = pdata->irqs;
 131         new_bus->parent = dev;
 132
 133         if (new_bus->phy_mask == ~0)
 134                 goto out_free_bus;
 135
 136         for (i = 0; i < PHY_MAX_ADDR; i++)
 137                 if (!new_bus->irq[i])
 138                         new_bus->irq[i] = PHY_POLL;
 139
 140         snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
 141
 142         if (gpio_request(bitbang->mdc, "mdc"))
 143                 goto out_free_bus;
 144
 145         if (gpio_request(bitbang->mdio, "mdio"))
 146                 goto out_free_mdc;
 147
 148         gpio_direction_output(bitbang->mdc, 0);
 149
 150         dev_set_drvdata(dev, new_bus);
 151
 152         return new_bus;
 153
 154 out_free_mdc:
 155         gpio_free(bitbang->mdc);
 156 out_free_bus:
 157         free_mdio_bitbang(new_bus);
 158 out_free_bitbang:
 159         kfree(bitbang);
 160 out:
 161         return NULL;
 162 }
 163
 164 static void mdio_gpio_bus_deinit(struct device *dev)
 165 {
 166         struct mii_bus *bus = dev_get_drvdata(dev);
 167         struct mdio_gpio_info *bitbang = bus->priv;
 168
 169         dev_set_drvdata(dev, NULL);
 170         gpio_free(bitbang->mdio);
 171         gpio_free(bitbang->mdc);
 172         free_mdio_bitbang(bus);
 173         kfree(bitbang);
 174 }
 175
 176 static void mdio_gpio_bus_destroy(struct device *dev)
 177 {
 178         struct mii_bus *bus = dev_get_drvdata(dev);
 179
 180         mdiobus_unregister(bus);
 181         mdio_gpio_bus_deinit(dev);
 182 }
 183
 184 static int mdio_gpio_probe(struct platform_device *pdev)
 185 {
 186         struct mdio_gpio_platform_data *pdata;
 187         struct mii_bus *new_bus;
 188         int ret, bus_id;
 189
 190         if (pdev->dev.of_node) {
 191                 pdata = mdio_gpio_of_get_data(pdev);
 192                 bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
 193         } else {
 194                 pdata = dev_get_platdata(&pdev->dev);
 195                 bus_id = pdev->id;
 196         }
 197
 198         if (!pdata)
 199                 return -ENODEV;
 200
 201         new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, bus_id);
 202         if (!new_bus)
 203                 return -ENODEV;
 204
 205         if (pdev->dev.of_node)
 206                 ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
 207         else
 208                 ret = mdiobus_register(new_bus);
 209
 210         if (ret)
 211                 mdio_gpio_bus_deinit(&pdev->dev);
 212
 213         return ret;
 214 }
 215
 216 static int mdio_gpio_remove(struct platform_device *pdev)
 217 {
 218         mdio_gpio_bus_destroy(&pdev->dev);
 219
 220         return 0;
 221 }
 222
 223 static struct of_device_id mdio_gpio_of_match[] = {
 224         { .compatible = "virtual,mdio-gpio", },
 225         { /* sentinel */ }
 226 };
 227
 228 static struct platform_driver mdio_gpio_driver = {
 229         .probe = mdio_gpio_probe,
 230         .remove = mdio_gpio_remove,
 231         .driver         = {
 232                 .name   = "mdio-gpio",
 233                 .owner  = THIS_MODULE,
 234                 .of_match_table = mdio_gpio_of_match,
 235         },
 236 };
 237
 238 module_platform_driver(mdio_gpio_driver);
 239
 240 MODULE_ALIAS("platform:mdio-gpio");
 241 MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
 242 MODULE_LICENSE("GPL");
 243 MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");