drivers/usb/phy/phy-generic.c

   1 /*
   2  * drivers/usb/otg/nop-usb-xceiv.c
   3  *
   4  * NOP USB transceiver for all USB transceiver which are either built-in
   5  * into USB IP or which are mostly autonomous.
   6  *
   7  * Copyright (C) 2009 Texas Instruments Inc
   8  * Author: Ajay Kumar Gupta <[email protected]>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  *
  24  * Current status:
  25  *      This provides a "nop" transceiver for PHYs which are
  26  *      autonomous such as isp1504, isp1707, etc.
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/dma-mapping.h>
  32 #include <linux/usb/otg.h>
  33 #include <linux/usb/usb_phy_generic.h>
  34 #include <linux/slab.h>
  35 #include <linux/clk.h>
  36 #include <linux/regulator/consumer.h>
  37 #include <linux/of.h>
  38 #include <linux/of_gpio.h>
  39 #include <linux/gpio.h>
  40 #include <linux/delay.h>
  41
  42 #include "phy-generic.h"
  43
  44 struct platform_device *usb_phy_generic_register(void)
  45 {
  46         return platform_device_register_simple("usb_phy_generic",
  47                         PLATFORM_DEVID_AUTO, NULL, 0);
  48 }
  49 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  50
  51 void usb_phy_generic_unregister(struct platform_device *pdev)
  52 {
  53         platform_device_unregister(pdev);
  54 }
  55 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  56
  57 static int nop_set_suspend(struct usb_phy *x, int suspend)
  58 {
  59         return 0;
  60 }
  61
  62 static void nop_reset_set(struct usb_phy_generic *nop, int asserted)
  63 {
  64         int value;
  65
  66         if (!gpio_is_valid(nop->gpio_reset))
  67                 return;
  68
  69         value = asserted;
  70         if (nop->reset_active_low)
  71                 value = !value;
  72
  73         gpio_set_value_cansleep(nop->gpio_reset, value);
  74
  75         if (!asserted)
  76                 usleep_range(10000, 20000);
  77 }
  78
  79 int usb_gen_phy_init(struct usb_phy *phy)
  80 {
  81         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
  82
  83         if (!IS_ERR(nop->vcc)) {
  84                 if (regulator_enable(nop->vcc))
  85                         dev_err(phy->dev, "Failed to enable power\n");
  86         }
  87
  88         if (!IS_ERR(nop->clk))
  89                 clk_prepare_enable(nop->clk);
  90
  91         /* De-assert RESET */
  92         nop_reset_set(nop, 0);
  93
  94         return 0;
  95 }
  96 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
  97
  98 void usb_gen_phy_shutdown(struct usb_phy *phy)
  99 {
 100         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 101
 102         /* Assert RESET */
 103         nop_reset_set(nop, 1);
 104
 105         if (!IS_ERR(nop->clk))
 106                 clk_disable_unprepare(nop->clk);
 107
 108         if (!IS_ERR(nop->vcc)) {
 109                 if (regulator_disable(nop->vcc))
 110                         dev_err(phy->dev, "Failed to disable power\n");
 111         }
 112 }
 113 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 114
 115 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 116 {
 117         if (!otg)
 118                 return -ENODEV;
 119
 120         if (!gadget) {
 121                 otg->gadget = NULL;
 122                 return -ENODEV;
 123         }
 124
 125         otg->gadget = gadget;
 126         otg->phy->state = OTG_STATE_B_IDLE;
 127         return 0;
 128 }
 129
 130 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 131 {
 132         if (!otg)
 133                 return -ENODEV;
 134
 135         if (!host) {
 136                 otg->host = NULL;
 137                 return -ENODEV;
 138         }
 139
 140         otg->host = host;
 141         return 0;
 142 }
 143
 144 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 145                 struct usb_phy_generic_platform_data *pdata)
 146 {
 147         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 148         int err;
 149
 150         u32 clk_rate = 0;
 151         bool needs_vcc = false;
 152
 153         nop->reset_active_low = true;   /* default behaviour */
 154
 155         if (dev->of_node) {
 156                 struct device_node *node = dev->of_node;
 157                 enum of_gpio_flags flags = 0;
 158
 159                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 160                         clk_rate = 0;
 161
 162                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 163                 nop->gpio_reset = of_get_named_gpio_flags(node, "reset-gpios",
 164                                                                 0, &flags);
 165                 if (nop->gpio_reset == -EPROBE_DEFER)
 166                         return -EPROBE_DEFER;
 167
 168                 nop->reset_active_low = flags & OF_GPIO_ACTIVE_LOW;
 169
 170         } else if (pdata) {
 171                 type = pdata->type;
 172                 clk_rate = pdata->clk_rate;
 173                 needs_vcc = pdata->needs_vcc;
 174                 nop->gpio_reset = pdata->gpio_reset;
 175         } else {
 176                 nop->gpio_reset = -1;
 177         }
 178
 179         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 180                         GFP_KERNEL);
 181         if (!nop->phy.otg)
 182                 return -ENOMEM;
 183
 184         nop->clk = devm_clk_get(dev, "main_clk");
 185         if (IS_ERR(nop->clk)) {
 186                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 187                                         PTR_ERR(nop->clk));
 188         }
 189
 190         if (!IS_ERR(nop->clk) && clk_rate) {
 191                 err = clk_set_rate(nop->clk, clk_rate);
 192                 if (err) {
 193                         dev_err(dev, "Error setting clock rate\n");
 194                         return err;
 195                 }
 196         }
 197
 198         nop->vcc = devm_regulator_get(dev, "vcc");
 199         if (IS_ERR(nop->vcc)) {
 200                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 201                                         PTR_ERR(nop->vcc));
 202                 if (needs_vcc)
 203                         return -EPROBE_DEFER;
 204         }
 205
 206         if (gpio_is_valid(nop->gpio_reset)) {
 207                 unsigned long gpio_flags;
 208
 209                 /* Assert RESET */
 210                 if (nop->reset_active_low)
 211                         gpio_flags = GPIOF_OUT_INIT_LOW;
 212                 else
 213                         gpio_flags = GPIOF_OUT_INIT_HIGH;
 214
 215                 err = devm_gpio_request_one(dev, nop->gpio_reset,
 216                                                 gpio_flags, dev_name(dev));
 217                 if (err) {
 218                         dev_err(dev, "Error requesting RESET GPIO %d\n",
 219                                         nop->gpio_reset);
 220                         return err;
 221                 }
 222         }
 223
 224         nop->dev                = dev;
 225         nop->phy.dev            = nop->dev;
 226         nop->phy.label          = "nop-xceiv";
 227         nop->phy.set_suspend    = nop_set_suspend;
 228         nop->phy.state          = OTG_STATE_UNDEFINED;
 229         nop->phy.type           = type;
 230
 231         nop->phy.otg->phy               = &nop->phy;
 232         nop->phy.otg->set_host          = nop_set_host;
 233         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 234
 235         return 0;
 236 }
 237 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 238
 239 static int usb_phy_generic_probe(struct platform_device *pdev)
 240 {
 241         struct device *dev = &pdev->dev;
 242         struct usb_phy_generic  *nop;
 243         int err;
 244
 245         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 246         if (!nop)
 247                 return -ENOMEM;
 248
 249         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 250         if (err)
 251                 return err;
 252
 253         nop->phy.init           = usb_gen_phy_init;
 254         nop->phy.shutdown       = usb_gen_phy_shutdown;
 255
 256         err = usb_add_phy_dev(&nop->phy);
 257         if (err) {
 258                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 259                         err);
 260                 return err;
 261         }
 262
 263         platform_set_drvdata(pdev, nop);
 264
 265         return 0;
 266 }
 267
 268 static int usb_phy_generic_remove(struct platform_device *pdev)
 269 {
 270         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 271
 272         usb_remove_phy(&nop->phy);
 273
 274         return 0;
 275 }
 276
 277 static const struct of_device_id nop_xceiv_dt_ids[] = {
 278         { .compatible = "usb-nop-xceiv" },
 279         { }
 280 };
 281
 282 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 283
 284 static struct platform_driver usb_phy_generic_driver = {
 285         .probe          = usb_phy_generic_probe,
 286         .remove         = usb_phy_generic_remove,
 287         .driver         = {
 288                 .name   = "usb_phy_generic",
 289                 .owner  = THIS_MODULE,
 290                 .of_match_table = nop_xceiv_dt_ids,
 291         },
 292 };
 293
 294 static int __init usb_phy_generic_init(void)
 295 {
 296         return platform_driver_register(&usb_phy_generic_driver);
 297 }
 298 subsys_initcall(usb_phy_generic_init);
 299
 300 static void __exit usb_phy_generic_exit(void)
 301 {
 302         platform_driver_unregister(&usb_phy_generic_driver);
 303 }
 304 module_exit(usb_phy_generic_exit);
 305
 306 MODULE_ALIAS("platform:usb_phy_generic");
 307 MODULE_AUTHOR("Texas Instruments Inc");
 308 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 309 MODULE_LICENSE("GPL");