kernel/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/gadget.h>
  31 #include <linux/usb/otg.h>
  32 #include <linux/usb/usb_phy_generic.h>
  33 #include <linux/slab.h>
  34 #include <linux/clk.h>
  35 #include <linux/regulator/consumer.h>
  36 #include <linux/of.h>
  37 #include <linux/of_gpio.h>
  38 #include <linux/gpio.h>
  39 #include <linux/delay.h>
  40
  41 #include "phy-generic.h"
  42
  43 #define VBUS_IRQ_FLAGS \
  44         (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
  45                 IRQF_ONESHOT)
  46
  47 struct platform_device *usb_phy_generic_register(void)
  48 {
  49         return platform_device_register_simple("usb_phy_generic",
  50                         PLATFORM_DEVID_AUTO, NULL, 0);
  51 }
  52 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  53
  54 void usb_phy_generic_unregister(struct platform_device *pdev)
  55 {
  56         platform_device_unregister(pdev);
  57 }
  58 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  59
  60 static int nop_set_suspend(struct usb_phy *x, int suspend)
  61 {
  62         return 0;
  63 }
  64
  65 static void nop_reset(struct usb_phy_generic *nop)
  66 {
  67         if (!nop->gpiod_reset)
  68                 return;
  69
  70         gpiod_set_value(nop->gpiod_reset, 1);
  71         usleep_range(10000, 20000);
  72         gpiod_set_value(nop->gpiod_reset, 0);
  73 }
  74
  75 /* interface to regulator framework */
  76 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
  77 {
  78         struct regulator *vbus_draw = nop->vbus_draw;
  79         int enabled;
  80         int ret;
  81
  82         if (!vbus_draw)
  83                 return;
  84
  85         enabled = nop->vbus_draw_enabled;
  86         if (mA) {
  87                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
  88                 if (!enabled) {
  89                         ret = regulator_enable(vbus_draw);
  90                         if (ret < 0)
  91                                 return;
  92                         nop->vbus_draw_enabled = 1;
  93                 }
  94         } else {
  95                 if (enabled) {
  96                         ret = regulator_disable(vbus_draw);
  97                         if (ret < 0)
  98                                 return;
  99                         nop->vbus_draw_enabled = 0;
 100                 }
 101         }
 102         nop->mA = mA;
 103 }
 104
 105
 106 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 107 {
 108         struct usb_phy_generic *nop = data;
 109         struct usb_otg *otg = nop->phy.otg;
 110         int vbus, status;
 111
 112         vbus = gpiod_get_value(nop->gpiod_vbus);
 113         if ((vbus ^ nop->vbus) == 0)
 114                 return IRQ_HANDLED;
 115         nop->vbus = vbus;
 116
 117         if (vbus) {
 118                 status = USB_EVENT_VBUS;
 119                 otg->state = OTG_STATE_B_PERIPHERAL;
 120                 nop->phy.last_event = status;
 121                 usb_gadget_vbus_connect(otg->gadget);
 122
 123                 /* drawing a "unit load" is *always* OK, except for OTG */
 124                 nop_set_vbus_draw(nop, 100);
 125
 126                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 127                                            otg->gadget);
 128         } else {
 129                 nop_set_vbus_draw(nop, 0);
 130
 131                 usb_gadget_vbus_disconnect(otg->gadget);
 132                 status = USB_EVENT_NONE;
 133                 otg->state = OTG_STATE_B_IDLE;
 134                 nop->phy.last_event = status;
 135
 136                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 137                                            otg->gadget);
 138         }
 139         return IRQ_HANDLED;
 140 }
 141
 142 int usb_gen_phy_init(struct usb_phy *phy)
 143 {
 144         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 145
 146         if (!IS_ERR(nop->vcc)) {
 147                 if (regulator_enable(nop->vcc))
 148                         dev_err(phy->dev, "Failed to enable power\n");
 149         }
 150
 151         if (!IS_ERR(nop->clk))
 152                 clk_prepare_enable(nop->clk);
 153
 154         nop_reset(nop);
 155
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 159
 160 void usb_gen_phy_shutdown(struct usb_phy *phy)
 161 {
 162         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 163
 164         gpiod_set_value(nop->gpiod_reset, 1);
 165
 166         if (!IS_ERR(nop->clk))
 167                 clk_disable_unprepare(nop->clk);
 168
 169         if (!IS_ERR(nop->vcc)) {
 170                 if (regulator_disable(nop->vcc))
 171                         dev_err(phy->dev, "Failed to disable power\n");
 172         }
 173 }
 174 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 175
 176 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 177 {
 178         if (!otg)
 179                 return -ENODEV;
 180
 181         if (!gadget) {
 182                 otg->gadget = NULL;
 183                 return -ENODEV;
 184         }
 185
 186         otg->gadget = gadget;
 187         otg->state = OTG_STATE_B_IDLE;
 188         return 0;
 189 }
 190
 191 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 192 {
 193         if (!otg)
 194                 return -ENODEV;
 195
 196         if (!host) {
 197                 otg->host = NULL;
 198                 return -ENODEV;
 199         }
 200
 201         otg->host = host;
 202         return 0;
 203 }
 204
 205 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 206                 struct usb_phy_generic_platform_data *pdata)
 207 {
 208         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 209         int err = 0;
 210
 211         u32 clk_rate = 0;
 212         bool needs_vcc = false;
 213
 214         if (dev->of_node) {
 215                 struct device_node *node = dev->of_node;
 216
 217                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 218                         clk_rate = 0;
 219
 220                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 221                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset");
 222                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 223                 if (!err) {
 224                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 225                                                          "vbus-detect");
 226                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 227                 }
 228         } else if (pdata) {
 229                 type = pdata->type;
 230                 clk_rate = pdata->clk_rate;
 231                 needs_vcc = pdata->needs_vcc;
 232                 if (gpio_is_valid(pdata->gpio_reset)) {
 233                         err = devm_gpio_request_one(dev, pdata->gpio_reset, 0,
 234                                                     dev_name(dev));
 235                         if (!err)
 236                                 nop->gpiod_reset =
 237                                         gpio_to_desc(pdata->gpio_reset);
 238                 }
 239                 nop->gpiod_vbus = pdata->gpiod_vbus;
 240         }
 241
 242         if (err == -EPROBE_DEFER)
 243                 return -EPROBE_DEFER;
 244         if (err) {
 245                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
 246                 return err;
 247         }
 248         if (nop->gpiod_reset)
 249                 gpiod_direction_output(nop->gpiod_reset, 1);
 250
 251         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 252                         GFP_KERNEL);
 253         if (!nop->phy.otg)
 254                 return -ENOMEM;
 255
 256         nop->clk = devm_clk_get(dev, "main_clk");
 257         if (IS_ERR(nop->clk)) {
 258                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 259                                         PTR_ERR(nop->clk));
 260         }
 261
 262         if (!IS_ERR(nop->clk) && clk_rate) {
 263                 err = clk_set_rate(nop->clk, clk_rate);
 264                 if (err) {
 265                         dev_err(dev, "Error setting clock rate\n");
 266                         return err;
 267                 }
 268         }
 269
 270         nop->vcc = devm_regulator_get(dev, "vcc");
 271         if (IS_ERR(nop->vcc)) {
 272                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 273                                         PTR_ERR(nop->vcc));
 274                 if (needs_vcc)
 275                         return -EPROBE_DEFER;
 276         }
 277
 278         nop->dev                = dev;
 279         nop->phy.dev            = nop->dev;
 280         nop->phy.label          = "nop-xceiv";
 281         nop->phy.set_suspend    = nop_set_suspend;
 282         nop->phy.type           = type;
 283
 284         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 285         nop->phy.otg->usb_phy           = &nop->phy;
 286         nop->phy.otg->set_host          = nop_set_host;
 287         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 288
 289         return 0;
 290 }
 291 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 292
 293 static int usb_phy_generic_probe(struct platform_device *pdev)
 294 {
 295         struct device *dev = &pdev->dev;
 296         struct usb_phy_generic  *nop;
 297         int err;
 298
 299         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 300         if (!nop)
 301                 return -ENOMEM;
 302
 303         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 304         if (err)
 305                 return err;
 306         if (nop->gpiod_vbus) {
 307                 err = devm_request_threaded_irq(&pdev->dev,
 308                                                 gpiod_to_irq(nop->gpiod_vbus),
 309                                                 NULL, nop_gpio_vbus_thread,
 310                                                 VBUS_IRQ_FLAGS, "vbus_detect",
 311                                                 nop);
 312                 if (err) {
 313                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
 314                                 gpiod_to_irq(nop->gpiod_vbus), err);
 315                         return err;
 316                 }
 317         }
 318
 319         nop->phy.init           = usb_gen_phy_init;
 320         nop->phy.shutdown       = usb_gen_phy_shutdown;
 321
 322         err = usb_add_phy_dev(&nop->phy);
 323         if (err) {
 324                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 325                         err);
 326                 return err;
 327         }
 328
 329         platform_set_drvdata(pdev, nop);
 330
 331         return 0;
 332 }
 333
 334 static int usb_phy_generic_remove(struct platform_device *pdev)
 335 {
 336         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 337
 338         usb_remove_phy(&nop->phy);
 339
 340         return 0;
 341 }
 342
 343 static const struct of_device_id nop_xceiv_dt_ids[] = {
 344         { .compatible = "usb-nop-xceiv" },
 345         { }
 346 };
 347
 348 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 349
 350 static struct platform_driver usb_phy_generic_driver = {
 351         .probe          = usb_phy_generic_probe,
 352         .remove         = usb_phy_generic_remove,
 353         .driver         = {
 354                 .name   = "usb_phy_generic",
 355                 .of_match_table = nop_xceiv_dt_ids,
 356         },
 357 };
 358
 359 static int __init usb_phy_generic_init(void)
 360 {
 361         return platform_driver_register(&usb_phy_generic_driver);
 362 }
 363 subsys_initcall(usb_phy_generic_init);
 364
 365 static void __exit usb_phy_generic_exit(void)
 366 {
 367         platform_driver_unregister(&usb_phy_generic_driver);
 368 }
 369 module_exit(usb_phy_generic_exit);
 370
 371 MODULE_ALIAS("platform:usb_phy_generic");
 372 MODULE_AUTHOR("Texas Instruments Inc");
 373 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 374 MODULE_LICENSE("GPL");