drivers/usb/phy/phy-generic.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * NOP USB transceiver for all USB transceiver which are either built-in
   4  * into USB IP or which are mostly autonomous.
   5  *
   6  * Copyright (C) 2009 Texas Instruments Inc
   7  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
   8  *
   9  * Current status:
  10  *      This provides a "nop" transceiver for PHYs which are
  11  *      autonomous such as isp1504, isp1707, etc.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/usb/gadget.h>
  18 #include <linux/usb/otg.h>
  19 #include <linux/usb/usb_phy_generic.h>
  20 #include <linux/slab.h>
  21 #include <linux/clk.h>
  22 #include <linux/regulator/consumer.h>
  23 #include <linux/of.h>
  24 #include <linux/gpio/consumer.h>
  25 #include <linux/delay.h>
  26
  27 #include "phy-generic.h"
  28
  29 #define VBUS_IRQ_FLAGS \
  30         (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
  31                 IRQF_ONESHOT)
  32
  33 struct platform_device *usb_phy_generic_register(void)
  34 {
  35         return platform_device_register_simple("usb_phy_generic",
  36                         PLATFORM_DEVID_AUTO, NULL, 0);
  37 }
  38 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  39
  40 void usb_phy_generic_unregister(struct platform_device *pdev)
  41 {
  42         platform_device_unregister(pdev);
  43 }
  44 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  45
  46 static int nop_set_suspend(struct usb_phy *x, int suspend)
  47 {
  48         struct usb_phy_generic *nop = dev_get_drvdata(x->dev);
  49         int ret = 0;
  50
  51         if (suspend) {
  52                 if (!IS_ERR(nop->clk))
  53                         clk_disable_unprepare(nop->clk);
  54                 if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
  55                         ret = regulator_disable(nop->vcc);
  56         } else {
  57                 if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
  58                         ret = regulator_enable(nop->vcc);
  59                 if (!IS_ERR(nop->clk))
  60                         clk_prepare_enable(nop->clk);
  61         }
  62
  63         return ret;
  64 }
  65
  66 static void nop_reset(struct usb_phy_generic *nop)
  67 {
  68         if (!nop->gpiod_reset)
  69                 return;
  70
  71         gpiod_set_value_cansleep(nop->gpiod_reset, 1);
  72         usleep_range(10000, 20000);
  73         gpiod_set_value_cansleep(nop->gpiod_reset, 0);
  74 }
  75
  76 /* interface to regulator framework */
  77 static int nop_set_vbus(struct usb_otg *otg, bool enable)
  78 {
  79         int ret = 0;
  80         struct usb_phy_generic *nop = dev_get_drvdata(otg->usb_phy->dev);
  81
  82         if (!nop->vbus_draw)
  83                 return 0;
  84
  85         if (enable && !nop->vbus_draw_enabled) {
  86                 ret = regulator_enable(nop->vbus_draw);
  87                 if (ret)
  88                         nop->vbus_draw_enabled = false;
  89                 else
  90                         nop->vbus_draw_enabled = true;
  91
  92         } else if (!enable && nop->vbus_draw_enabled) {
  93                 ret = regulator_disable(nop->vbus_draw);
  94                 nop->vbus_draw_enabled = false;
  95         }
  96         return ret;
  97 }
  98
  99
 100 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 101 {
 102         struct usb_phy_generic *nop = data;
 103         struct usb_otg *otg = nop->phy.otg;
 104         int vbus, status;
 105
 106         vbus = gpiod_get_value(nop->gpiod_vbus);
 107         if ((vbus ^ nop->vbus) == 0)
 108                 return IRQ_HANDLED;
 109         nop->vbus = vbus;
 110
 111         if (vbus) {
 112                 status = USB_EVENT_VBUS;
 113                 otg->state = OTG_STATE_B_PERIPHERAL;
 114                 nop->phy.last_event = status;
 115
 116                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 117                                            otg->gadget);
 118         } else {
 119                 status = USB_EVENT_NONE;
 120                 otg->state = OTG_STATE_B_IDLE;
 121                 nop->phy.last_event = status;
 122
 123                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 124                                            otg->gadget);
 125         }
 126         return IRQ_HANDLED;
 127 }
 128
 129 int usb_gen_phy_init(struct usb_phy *phy)
 130 {
 131         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 132         int ret;
 133
 134         if (!IS_ERR(nop->vcc)) {
 135                 if (regulator_enable(nop->vcc))
 136                         dev_err(phy->dev, "Failed to enable power\n");
 137         }
 138
 139         if (!IS_ERR(nop->clk)) {
 140                 ret = clk_prepare_enable(nop->clk);
 141                 if (ret)
 142                         return ret;
 143         }
 144
 145         nop_reset(nop);
 146
 147         return 0;
 148 }
 149 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 150
 151 void usb_gen_phy_shutdown(struct usb_phy *phy)
 152 {
 153         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 154
 155         gpiod_set_value_cansleep(nop->gpiod_reset, 1);
 156
 157         if (!IS_ERR(nop->clk))
 158                 clk_disable_unprepare(nop->clk);
 159
 160         if (!IS_ERR(nop->vcc)) {
 161                 if (regulator_disable(nop->vcc))
 162                         dev_err(phy->dev, "Failed to disable power\n");
 163         }
 164 }
 165 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 166
 167 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 168 {
 169         if (!otg)
 170                 return -ENODEV;
 171
 172         if (!gadget) {
 173                 otg->gadget = NULL;
 174                 return -ENODEV;
 175         }
 176
 177         otg->gadget = gadget;
 178         if (otg->state == OTG_STATE_B_PERIPHERAL)
 179                 atomic_notifier_call_chain(&otg->usb_phy->notifier,
 180                                            USB_EVENT_VBUS, otg->gadget);
 181         else
 182                 otg->state = OTG_STATE_B_IDLE;
 183         return 0;
 184 }
 185
 186 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 187 {
 188         if (!otg)
 189                 return -ENODEV;
 190
 191         if (!host) {
 192                 otg->host = NULL;
 193                 return -ENODEV;
 194         }
 195
 196         otg->host = host;
 197         return 0;
 198 }
 199
 200 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
 201 {
 202         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 203         int err = 0;
 204
 205         u32 clk_rate = 0;
 206         bool needs_clk = false;
 207
 208         if (dev->of_node) {
 209                 struct device_node *node = dev->of_node;
 210
 211                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 212                         clk_rate = 0;
 213
 214                 needs_clk = of_property_read_bool(node, "clocks");
 215         }
 216         nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
 217                                                    GPIOD_ASIS);
 218         err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 219         if (!err) {
 220                 nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 221                                                  "vbus-detect",
 222                                                  GPIOD_ASIS);
 223                 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 224         }
 225
 226         if (err)
 227                 return dev_err_probe(dev, err,
 228                                      "Error requesting RESET or VBUS GPIO\n");
 229         if (nop->gpiod_reset)
 230                 gpiod_direction_output(nop->gpiod_reset, 1);
 231
 232         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 233                         GFP_KERNEL);
 234         if (!nop->phy.otg)
 235                 return -ENOMEM;
 236
 237         nop->clk = devm_clk_get(dev, "main_clk");
 238         if (IS_ERR(nop->clk)) {
 239                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 240                                         PTR_ERR(nop->clk));
 241                 if (needs_clk)
 242                         return PTR_ERR(nop->clk);
 243         }
 244
 245         if (!IS_ERR(nop->clk) && clk_rate) {
 246                 err = clk_set_rate(nop->clk, clk_rate);
 247                 if (err) {
 248                         dev_err(dev, "Error setting clock rate\n");
 249                         return err;
 250                 }
 251         }
 252
 253         nop->vcc = devm_regulator_get_optional(dev, "vcc");
 254         if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV)
 255                 return dev_err_probe(dev, PTR_ERR(nop->vcc),
 256                                      "could not get vcc regulator\n");
 257
 258         nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
 259         if (PTR_ERR(nop->vbus_draw) == -ENODEV)
 260                 nop->vbus_draw = NULL;
 261         if (IS_ERR(nop->vbus_draw))
 262                 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
 263                                      "could not get vbus regulator\n");
 264
 265         nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
 266         if (PTR_ERR(nop->vbus_draw) == -ENODEV)
 267                 nop->vbus_draw = NULL;
 268         if (IS_ERR(nop->vbus_draw))
 269                 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
 270                                      "could not get vbus regulator\n");
 271
 272         nop->dev                = dev;
 273         nop->phy.dev            = nop->dev;
 274         nop->phy.label          = "nop-xceiv";
 275         nop->phy.set_suspend    = nop_set_suspend;
 276         nop->phy.type           = type;
 277
 278         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 279         nop->phy.otg->usb_phy           = &nop->phy;
 280         nop->phy.otg->set_host          = nop_set_host;
 281         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 282         nop->phy.otg->set_vbus          = nop_set_vbus;
 283
 284         return 0;
 285 }
 286 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 287
 288 static int usb_phy_generic_probe(struct platform_device *pdev)
 289 {
 290         struct device *dev = &pdev->dev;
 291         struct device_node *dn = dev->of_node;
 292         struct usb_phy_generic  *nop;
 293         int err;
 294
 295         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 296         if (!nop)
 297                 return -ENOMEM;
 298
 299         err = usb_phy_gen_create_phy(dev, nop);
 300         if (err)
 301                 return err;
 302         if (nop->gpiod_vbus) {
 303                 err = devm_request_threaded_irq(&pdev->dev,
 304                                                 gpiod_to_irq(nop->gpiod_vbus),
 305                                                 NULL, nop_gpio_vbus_thread,
 306                                                 VBUS_IRQ_FLAGS, "vbus_detect",
 307                                                 nop);
 308                 if (err) {
 309                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
 310                                 gpiod_to_irq(nop->gpiod_vbus), err);
 311                         return err;
 312                 }
 313                 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
 314                         OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
 315         }
 316
 317         nop->phy.init           = usb_gen_phy_init;
 318         nop->phy.shutdown       = usb_gen_phy_shutdown;
 319
 320         err = usb_add_phy_dev(&nop->phy);
 321         if (err) {
 322                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 323                         err);
 324                 return err;
 325         }
 326
 327         platform_set_drvdata(pdev, nop);
 328
 329         device_set_wakeup_capable(&pdev->dev,
 330                                   of_property_read_bool(dn, "wakeup-source"));
 331
 332         return 0;
 333 }
 334
 335 static void usb_phy_generic_remove(struct platform_device *pdev)
 336 {
 337         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 338
 339         usb_remove_phy(&nop->phy);
 340
 341         if (nop->vbus_draw && nop->vbus_draw_enabled)
 342                 regulator_disable(nop->vbus_draw);
 343 }
 344
 345 static const struct of_device_id nop_xceiv_dt_ids[] = {
 346         { .compatible = "usb-nop-xceiv" },
 347         { }
 348 };
 349
 350 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 351
 352 static struct platform_driver usb_phy_generic_driver = {
 353         .probe          = usb_phy_generic_probe,
 354         .remove_new     = usb_phy_generic_remove,
 355         .driver         = {
 356                 .name   = "usb_phy_generic",
 357                 .of_match_table = nop_xceiv_dt_ids,
 358         },
 359 };
 360
 361 static int __init usb_phy_generic_init(void)
 362 {
 363         return platform_driver_register(&usb_phy_generic_driver);
 364 }
 365 subsys_initcall(usb_phy_generic_init);
 366
 367 static void __exit usb_phy_generic_exit(void)
 368 {
 369         platform_driver_unregister(&usb_phy_generic_driver);
 370 }
 371 module_exit(usb_phy_generic_exit);
 372
 373 MODULE_ALIAS("platform:usb_phy_generic");
 374 MODULE_AUTHOR("Texas Instruments Inc");
 375 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 376 MODULE_LICENSE("GPL");