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 void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
  78 {
  79         struct regulator *vbus_draw = nop->vbus_draw;
  80         int enabled;
  81         int ret;
  82
  83         if (!vbus_draw)
  84                 return;
  85
  86         enabled = nop->vbus_draw_enabled;
  87         if (mA) {
  88                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
  89                 if (!enabled) {
  90                         ret = regulator_enable(vbus_draw);
  91                         if (ret < 0)
  92                                 return;
  93                         nop->vbus_draw_enabled = 1;
  94                 }
  95         } else {
  96                 if (enabled) {
  97                         ret = regulator_disable(vbus_draw);
  98                         if (ret < 0)
  99                                 return;
 100                         nop->vbus_draw_enabled = 0;
 101                 }
 102         }
 103         nop->mA = mA;
 104 }
 105
 106
 107 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 108 {
 109         struct usb_phy_generic *nop = data;
 110         struct usb_otg *otg = nop->phy.otg;
 111         int vbus, status;
 112
 113         vbus = gpiod_get_value(nop->gpiod_vbus);
 114         if ((vbus ^ nop->vbus) == 0)
 115                 return IRQ_HANDLED;
 116         nop->vbus = vbus;
 117
 118         if (vbus) {
 119                 status = USB_EVENT_VBUS;
 120                 otg->state = OTG_STATE_B_PERIPHERAL;
 121                 nop->phy.last_event = status;
 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                 status = USB_EVENT_NONE;
 132                 otg->state = OTG_STATE_B_IDLE;
 133                 nop->phy.last_event = status;
 134
 135                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 136                                            otg->gadget);
 137         }
 138         return IRQ_HANDLED;
 139 }
 140
 141 int usb_gen_phy_init(struct usb_phy *phy)
 142 {
 143         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 144         int ret;
 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                 ret = clk_prepare_enable(nop->clk);
 153                 if (ret)
 154                         return ret;
 155         }
 156
 157         nop_reset(nop);
 158
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 162
 163 void usb_gen_phy_shutdown(struct usb_phy *phy)
 164 {
 165         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 166
 167         gpiod_set_value_cansleep(nop->gpiod_reset, 1);
 168
 169         if (!IS_ERR(nop->clk))
 170                 clk_disable_unprepare(nop->clk);
 171
 172         if (!IS_ERR(nop->vcc)) {
 173                 if (regulator_disable(nop->vcc))
 174                         dev_err(phy->dev, "Failed to disable power\n");
 175         }
 176 }
 177 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 178
 179 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 180 {
 181         if (!otg)
 182                 return -ENODEV;
 183
 184         if (!gadget) {
 185                 otg->gadget = NULL;
 186                 return -ENODEV;
 187         }
 188
 189         otg->gadget = gadget;
 190         if (otg->state == OTG_STATE_B_PERIPHERAL)
 191                 atomic_notifier_call_chain(&otg->usb_phy->notifier,
 192                                            USB_EVENT_VBUS, otg->gadget);
 193         else
 194                 otg->state = OTG_STATE_B_IDLE;
 195         return 0;
 196 }
 197
 198 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 199 {
 200         if (!otg)
 201                 return -ENODEV;
 202
 203         if (!host) {
 204                 otg->host = NULL;
 205                 return -ENODEV;
 206         }
 207
 208         otg->host = host;
 209         return 0;
 210 }
 211
 212 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
 213 {
 214         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 215         int err = 0;
 216
 217         u32 clk_rate = 0;
 218         bool needs_clk = false;
 219
 220         if (dev->of_node) {
 221                 struct device_node *node = dev->of_node;
 222
 223                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 224                         clk_rate = 0;
 225
 226                 needs_clk = of_property_read_bool(node, "clocks");
 227         }
 228         nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
 229                                                    GPIOD_ASIS);
 230         err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 231         if (!err) {
 232                 nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 233                                                  "vbus-detect",
 234                                                  GPIOD_ASIS);
 235                 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 236         }
 237
 238         if (err)
 239                 return dev_err_probe(dev, err,
 240                                      "Error requesting RESET or VBUS GPIO\n");
 241         if (nop->gpiod_reset)
 242                 gpiod_direction_output(nop->gpiod_reset, 1);
 243
 244         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 245                         GFP_KERNEL);
 246         if (!nop->phy.otg)
 247                 return -ENOMEM;
 248
 249         nop->clk = devm_clk_get(dev, "main_clk");
 250         if (IS_ERR(nop->clk)) {
 251                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 252                                         PTR_ERR(nop->clk));
 253                 if (needs_clk)
 254                         return PTR_ERR(nop->clk);
 255         }
 256
 257         if (!IS_ERR(nop->clk) && clk_rate) {
 258                 err = clk_set_rate(nop->clk, clk_rate);
 259                 if (err) {
 260                         dev_err(dev, "Error setting clock rate\n");
 261                         return err;
 262                 }
 263         }
 264
 265         nop->vcc = devm_regulator_get_optional(dev, "vcc");
 266         if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV)
 267                 return dev_err_probe(dev, PTR_ERR(nop->vcc),
 268                                      "could not get vcc regulator\n");
 269
 270         nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
 271         if (PTR_ERR(nop->vbus_draw) == -ENODEV)
 272                 nop->vbus_draw = NULL;
 273         if (IS_ERR(nop->vbus_draw))
 274                 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
 275                                      "could not get vbus regulator\n");
 276
 277         nop->dev                = dev;
 278         nop->phy.dev            = nop->dev;
 279         nop->phy.label          = "nop-xceiv";
 280         nop->phy.set_suspend    = nop_set_suspend;
 281         nop->phy.type           = type;
 282
 283         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 284         nop->phy.otg->usb_phy           = &nop->phy;
 285         nop->phy.otg->set_host          = nop_set_host;
 286         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 287
 288         return 0;
 289 }
 290 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 291
 292 static int usb_phy_generic_probe(struct platform_device *pdev)
 293 {
 294         struct device *dev = &pdev->dev;
 295         struct device_node *dn = dev->of_node;
 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);
 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                 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
 318                         OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
 319         }
 320
 321         nop->phy.init           = usb_gen_phy_init;
 322         nop->phy.shutdown       = usb_gen_phy_shutdown;
 323
 324         err = usb_add_phy_dev(&nop->phy);
 325         if (err) {
 326                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 327                         err);
 328                 return err;
 329         }
 330
 331         platform_set_drvdata(pdev, nop);
 332
 333         device_set_wakeup_capable(&pdev->dev,
 334                                   of_property_read_bool(dn, "wakeup-source"));
 335
 336         return 0;
 337 }
 338
 339 static void usb_phy_generic_remove(struct platform_device *pdev)
 340 {
 341         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 342
 343         usb_remove_phy(&nop->phy);
 344 }
 345
 346 static const struct of_device_id nop_xceiv_dt_ids[] = {
 347         { .compatible = "usb-nop-xceiv" },
 348         { }
 349 };
 350
 351 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 352
 353 static struct platform_driver usb_phy_generic_driver = {
 354         .probe          = usb_phy_generic_probe,
 355         .remove_new     = usb_phy_generic_remove,
 356         .driver         = {
 357                 .name   = "usb_phy_generic",
 358                 .of_match_table = nop_xceiv_dt_ids,
 359         },
 360 };
 361
 362 static int __init usb_phy_generic_init(void)
 363 {
 364         return platform_driver_register(&usb_phy_generic_driver);
 365 }
 366 subsys_initcall(usb_phy_generic_init);
 367
 368 static void __exit usb_phy_generic_exit(void)
 369 {
 370         platform_driver_unregister(&usb_phy_generic_driver);
 371 }
 372 module_exit(usb_phy_generic_exit);
 373
 374 MODULE_ALIAS("platform:usb_phy_generic");
 375 MODULE_AUTHOR("Texas Instruments Inc");
 376 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 377 MODULE_LICENSE("GPL");