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(bitbang->mdo, 1 ^ bitbang->mdo_active_low);
  84                 return;
  85         }
  86
  87         if (dir)
  88                 gpio_direction_output(bitbang->mdio,
  89                                       1 ^ bitbang->mdio_active_low);
  90         else
  91                 gpio_direction_input(bitbang->mdio);
  92 }
  93
  94 static int mdio_get(struct mdiobb_ctrl *ctrl)
  95 {
  96         struct mdio_gpio_info *bitbang =
  97                 container_of(ctrl, struct mdio_gpio_info, ctrl);
  98
  99         return gpio_get_value(bitbang->mdio) ^ bitbang->mdio_active_low;
 100 }
 101
 102 static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
 103 {
 104         struct mdio_gpio_info *bitbang =
 105                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 106
 107         if (bitbang->mdo)
 108                 gpio_set_value(bitbang->mdo, what ^ bitbang->mdo_active_low);
 109         else
 110                 gpio_set_value(bitbang->mdio, what ^ bitbang->mdio_active_low);
 111 }
 112
 113 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
 114 {
 115         struct mdio_gpio_info *bitbang =
 116                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 117
 118         gpio_set_value(bitbang->mdc, what ^ bitbang->mdc_active_low);
 119 }
 120
 121 static struct mdiobb_ops mdio_gpio_ops = {
 122         .owner = THIS_MODULE,
 123         .set_mdc = mdc_set,
 124         .set_mdio_dir = mdio_dir,
 125         .set_mdio_data = mdio_set,
 126         .get_mdio_data = mdio_get,
 127 };
 128
 129 static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 130                                           struct mdio_gpio_platform_data *pdata,
 131                                           int bus_id)
 132 {
 133         struct mii_bus *new_bus;
 134         struct mdio_gpio_info *bitbang;
 135         int i;
 136
 137         bitbang = devm_kzalloc(dev, sizeof(*bitbang), GFP_KERNEL);
 138         if (!bitbang)
 139                 goto out;
 140
 141         bitbang->ctrl.ops = &mdio_gpio_ops;
 142         bitbang->ctrl.reset = pdata->reset;
 143         bitbang->mdc = pdata->mdc;
 144         bitbang->mdc_active_low = pdata->mdc_active_low;
 145         bitbang->mdio = pdata->mdio;
 146         bitbang->mdio_active_low = pdata->mdio_active_low;
 147         bitbang->mdo = pdata->mdo;
 148         bitbang->mdo_active_low = pdata->mdo_active_low;
 149
 150         new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
 151         if (!new_bus)
 152                 goto out;
 153
 154         new_bus->name = "GPIO Bitbanged MDIO",
 155
 156         new_bus->phy_mask = pdata->phy_mask;
 157         new_bus->irq = pdata->irqs;
 158         new_bus->parent = dev;
 159
 160         if (new_bus->phy_mask == ~0)
 161                 goto out_free_bus;
 162
 163         for (i = 0; i < PHY_MAX_ADDR; i++)
 164                 if (!new_bus->irq[i])
 165                         new_bus->irq[i] = PHY_POLL;
 166
 167         snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
 168
 169         if (devm_gpio_request(dev, bitbang->mdc, "mdc"))
 170                 goto out_free_bus;
 171
 172         if (devm_gpio_request(dev, bitbang->mdio, "mdio"))
 173                 goto out_free_bus;
 174
 175         if (bitbang->mdo) {
 176                 if (devm_gpio_request(dev, bitbang->mdo, "mdo"))
 177                         goto out_free_bus;
 178                 gpio_direction_output(bitbang->mdo, 1);
 179                 gpio_direction_input(bitbang->mdio);
 180         }
 181
 182         gpio_direction_output(bitbang->mdc, 0);
 183
 184         dev_set_drvdata(dev, new_bus);
 185
 186         return new_bus;
 187
 188 out_free_bus:
 189         free_mdio_bitbang(new_bus);
 190 out:
 191         return NULL;
 192 }
 193
 194 static void mdio_gpio_bus_deinit(struct device *dev)
 195 {
 196         struct mii_bus *bus = dev_get_drvdata(dev);
 197
 198         free_mdio_bitbang(bus);
 199 }
 200
 201 static void mdio_gpio_bus_destroy(struct device *dev)
 202 {
 203         struct mii_bus *bus = dev_get_drvdata(dev);
 204
 205         mdiobus_unregister(bus);
 206         mdio_gpio_bus_deinit(dev);
 207 }
 208
 209 static int mdio_gpio_probe(struct platform_device *pdev)
 210 {
 211         struct mdio_gpio_platform_data *pdata;
 212         struct mii_bus *new_bus;
 213         int ret, bus_id;
 214
 215         if (pdev->dev.of_node) {
 216                 pdata = mdio_gpio_of_get_data(pdev);
 217                 bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
 218                 if (bus_id < 0) {
 219                         dev_warn(&pdev->dev, "failed to get alias id\n");
 220                         bus_id = 0;
 221                 }
 222         } else {
 223                 pdata = dev_get_platdata(&pdev->dev);
 224                 bus_id = pdev->id;
 225         }
 226
 227         if (!pdata)
 228                 return -ENODEV;
 229
 230         new_bus = mdio_gpio_bus_init(&pdev->dev, pdata, bus_id);
 231         if (!new_bus)
 232                 return -ENODEV;
 233
 234         if (pdev->dev.of_node)
 235                 ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
 236         else
 237                 ret = mdiobus_register(new_bus);
 238
 239         if (ret)
 240                 mdio_gpio_bus_deinit(&pdev->dev);
 241
 242         return ret;
 243 }
 244
 245 static int mdio_gpio_remove(struct platform_device *pdev)
 246 {
 247         mdio_gpio_bus_destroy(&pdev->dev);
 248
 249         return 0;
 250 }
 251
 252 static struct of_device_id mdio_gpio_of_match[] = {
 253         { .compatible = "virtual,mdio-gpio", },
 254         { /* sentinel */ }
 255 };
 256
 257 static struct platform_driver mdio_gpio_driver = {
 258         .probe = mdio_gpio_probe,
 259         .remove = mdio_gpio_remove,
 260         .driver         = {
 261                 .name   = "mdio-gpio",
 262                 .owner  = THIS_MODULE,
 263                 .of_match_table = mdio_gpio_of_match,
 264         },
 265 };
 266
 267 module_platform_driver(mdio_gpio_driver);
 268
 269 MODULE_ALIAS("platform:mdio-gpio");
 270 MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
 271 MODULE_LICENSE("GPL");
 272 MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");