drivers/usb/phy/phy-generic.c

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