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/interrupt.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/gpio.h>
  28 #include <linux/mdio-gpio.h>
  29
  30 #include <linux/of_gpio.h>
  31 #include <linux/of_mdio.h>
  32
  33 struct mdio_gpio_info {
  34         struct mdiobb_ctrl ctrl;
  35         int mdc, mdio, mdo;
  36         int mdc_active_low, mdio_active_low, mdo_active_low;
  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         enum of_gpio_flags flags;
  44         int ret;
  45
  46         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  47         if (!pdata)
  48                 return NULL;
  49
  50         ret = of_get_gpio_flags(np, 0, &flags);
  51         if (ret < 0)
  52                 return NULL;
  53
  54         pdata->mdc = ret;
  55         pdata->mdc_active_low = flags & OF_GPIO_ACTIVE_LOW;
  56
  57         ret = of_get_gpio_flags(np, 1, &flags);
  58         if (ret < 0)
  59                 return NULL;
  60         pdata->mdio = ret;
  61         pdata->mdio_active_low = flags & OF_GPIO_ACTIVE_LOW;
  62
  63         ret = of_get_gpio_flags(np, 2, &flags);
  64         if (ret > 0) {
  65                 pdata->mdo = ret;
  66                 pdata->mdo_active_low = flags & OF_GPIO_ACTIVE_LOW;
  67         }
  68
  69         return pdata;
  70 }
  71
  72 static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
  73 {
  74         struct mdio_gpio_info *bitbang =
  75                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  76
  77         if (bitbang->mdo) {
  78                 /* Separate output pin. Always set its value to high
  79                  * when changing direction. If direction is input,
  80                  * assume the pin serves as pull-up. If direction is
  81                  * output, the default value is high.
  82                  */
  83                 gpio_set_value_cansleep(bitbang->mdo,
  84                                         1 ^ bitbang->mdo_active_low);
  85                 return;
  86         }
  87
  88         if (dir)
  89                 gpio_direction_output(bitbang->mdio,
  90                                       1 ^ bitbang->mdio_active_low);
  91         else
  92                 gpio_direction_input(bitbang->mdio);
  93 }
  94
  95 static int mdio_get(struct mdiobb_ctrl *ctrl)
  96 {
  97         struct mdio_gpio_info *bitbang =
  98                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  99
 100         return gpio_get_value_cansleep(bitbang->mdio) ^
 101                 bitbang->mdio_active_low;
 102 }
 103
 104 static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
 105 {
 106         struct mdio_gpio_info *bitbang =
 107                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 108
 109         if (bitbang->mdo)
 110                 gpio_set_value_cansleep(bitbang->mdo,
 111                                         what ^ bitbang->mdo_active_low);
 112         else
 113                 gpio_set_value_cansleep(bitbang->mdio,
 114                                         what ^ bitbang->mdio_active_low);
 115 }
 116
 117 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
 118 {
 119         struct mdio_gpio_info *bitbang =
 120                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 121
 122         gpio_set_value_cansleep(bitbang->mdc, what ^ bitbang->mdc_active_low);
 123 }
 124
 125 static struct mdiobb_ops mdio_gpio_ops = {
 126         .owner = THIS_MODULE,
 127         .set_mdc = mdc_set,
 128         .set_mdio_dir = mdio_dir,
 129         .set_mdio_data = mdio_set,
 130         .get_mdio_data = mdio_get,
 131 };
 132
 133 static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 134                                           struct mdio_gpio_platform_data *pdata,
 135                                           int bus_id)
 136 {
 137         struct mii_bus *new_bus;
 138         struct mdio_gpio_info *bitbang;
 139         int i;
 140
 141         bitbang = devm_kzalloc(dev, sizeof(*bitbang), GFP_KERNEL);
 142         if (!bitbang)
 143                 goto out;
 144
 145         bitbang->ctrl.ops = &mdio_gpio_ops;
 146         bitbang->ctrl.reset = pdata->reset;
 147         bitbang->mdc = pdata->mdc;
 148         bitbang->mdc_active_low = pdata->mdc_active_low;
 149         bitbang->mdio = pdata->mdio;
 150         bitbang->mdio_active_low = pdata->mdio_active_low;
 151         bitbang->mdo = pdata->mdo;
 152         bitbang->mdo_active_low = pdata->mdo_active_low;
 153
 154         new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
 155         if (!new_bus)
 156                 goto out;
 157
 158         new_bus->name = "GPIO Bitbanged MDIO",
 159
 160         new_bus->phy_mask = pdata->phy_mask;
 161         new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;
 162         new_bus->irq = pdata->irqs;
 163         new_bus->parent = dev;
 164
 165         if (new_bus->phy_mask == ~0)
 166                 goto out_free_bus;
 167
 168         for (i = 0; i < PHY_MAX_ADDR; i++)
 169                 if (!new_bus->irq[i])
 170                         new_bus->irq[i] = PHY_POLL;
 171
 172         if (bus_id != -1)
 173                 snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
 174         else
 175                 strncpy(new_bus->id, "gpio", MII_BUS_ID_SIZE);
 176
 177         if (devm_gpio_request(dev, bitbang->mdc, "mdc"))
 178                 goto out_free_bus;
 179
 180         if (devm_gpio_request(dev, bitbang->mdio, "mdio"))
 181                 goto out_free_bus;
 182
 183         if (bitbang->mdo) {
 184                 if (devm_gpio_request(dev, bitbang->mdo, "mdo"))
 185                         goto out_free_bus;
 186                 gpio_direction_output(bitbang->mdo, 1);
 187                 gpio_direction_input(bitbang->mdio);
 188         }
 189
 190         gpio_direction_output(bitbang->mdc, 0);
 191
 192         dev_set_drvdata(dev, new_bus);
 193
 194         return new_bus;
 195
 196 out_free_bus:
 197         free_mdio_bitbang(new_bus);
 198 out:
 199         return NULL;
 200 }
 201
 202 static void mdio_gpio_bus_deinit(struct device *dev)
 203 {
 204         struct mii_bus *bus = dev_get_drvdata(dev);
 205
 206         free_mdio_bitbang(bus);
 207 }
 208
 209 static void mdio_gpio_bus_destroy(struct device *dev)
 210 {
 211         struct mii_bus *bus = dev_get_drvdata(dev);
 212
 213         mdiobus_unregister(bus);
 214         mdio_gpio_bus_deinit(dev);
 215 }
 216
 217 static int mdio_gpio_probe(struct platform_device *pdev)
 218 {
 219         struct mdio_gpio_platform_data *pdata;
 220         struct mii_bus *new_bus;
 221         int ret, bus_id;
 222
 223         if (pdev->dev.of_node) {
 224                 pdata = mdio_gpio_of_get_data(pdev);
 225                 bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
 226                 if (bus_id < 0) {
 227                         dev_warn(&pdev->dev, "failed to get alias id\n");
 228                         bus_id = 0;
 229                 }
 230         } else {
 231                 pdata = dev_get_platdata(&pdev->dev);
 232                 bus_id = pdev->id;
 233         }
 234
 235         if (!pdata)
 236                 return -ENODEV;
 237
 238         new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, bus_id);
 239         if (!new_bus)
 240                 return -ENODEV;
 241
 242         if (pdev->dev.of_node)
 243                 ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
 244         else
 245                 ret = mdiobus_register(new_bus);
 246
 247         if (ret)
 248                 mdio_gpio_bus_deinit(&pdev->dev);
 249
 250         return ret;
 251 }
 252
 253 static int mdio_gpio_remove(struct platform_device *pdev)
 254 {
 255         mdio_gpio_bus_destroy(&pdev->dev);
 256
 257         return 0;
 258 }
 259
 260 static const struct of_device_id mdio_gpio_of_match[] = {
 261         { .compatible = "virtual,mdio-gpio", },
 262         { /* sentinel */ }
 263 };
 264
 265 static struct platform_driver mdio_gpio_driver = {
 266         .probe = mdio_gpio_probe,
 267         .remove = mdio_gpio_remove,
 268         .driver         = {
 269                 .name   = "mdio-gpio",
 270                 .of_match_table = mdio_gpio_of_match,
 271         },
 272 };
 273
 274 module_platform_driver(mdio_gpio_driver);
 275
 276 MODULE_ALIAS("platform:mdio-gpio");
 277 MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
 278 MODULE_LICENSE("GPL");
 279 MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");