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/of_gpio.h>
  25 #include <linux/gpio.h>
  26 #include <linux/delay.h>
  27
  28 #include "phy-generic.h"
  29
  30 #define VBUS_IRQ_FLAGS \
  31         (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
  32                 IRQF_ONESHOT)
  33
  34 struct platform_device *usb_phy_generic_register(void)
  35 {
  36         return platform_device_register_simple("usb_phy_generic",
  37                         PLATFORM_DEVID_AUTO, NULL, 0);
  38 }
  39 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
  40
  41 void usb_phy_generic_unregister(struct platform_device *pdev)
  42 {
  43         platform_device_unregister(pdev);
  44 }
  45 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
  46
  47 static int nop_set_suspend(struct usb_phy *x, int suspend)
  48 {
  49         struct usb_phy_generic *nop = dev_get_drvdata(x->dev);
  50
  51         if (!IS_ERR(nop->clk)) {
  52                 if (suspend)
  53                         clk_disable_unprepare(nop->clk);
  54                 else
  55                         clk_prepare_enable(nop->clk);
  56         }
  57
  58         return 0;
  59 }
  60
  61 static void nop_reset(struct usb_phy_generic *nop)
  62 {
  63         if (!nop->gpiod_reset)
  64                 return;
  65
  66         gpiod_set_value(nop->gpiod_reset, 1);
  67         usleep_range(10000, 20000);
  68         gpiod_set_value(nop->gpiod_reset, 0);
  69 }
  70
  71 /* interface to regulator framework */
  72 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
  73 {
  74         struct regulator *vbus_draw = nop->vbus_draw;
  75         int enabled;
  76         int ret;
  77
  78         if (!vbus_draw)
  79                 return;
  80
  81         enabled = nop->vbus_draw_enabled;
  82         if (mA) {
  83                 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
  84                 if (!enabled) {
  85                         ret = regulator_enable(vbus_draw);
  86                         if (ret < 0)
  87                                 return;
  88                         nop->vbus_draw_enabled = 1;
  89                 }
  90         } else {
  91                 if (enabled) {
  92                         ret = regulator_disable(vbus_draw);
  93                         if (ret < 0)
  94                                 return;
  95                         nop->vbus_draw_enabled = 0;
  96                 }
  97         }
  98         nop->mA = mA;
  99 }
 100
 101
 102 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
 103 {
 104         struct usb_phy_generic *nop = data;
 105         struct usb_otg *otg = nop->phy.otg;
 106         int vbus, status;
 107
 108         vbus = gpiod_get_value(nop->gpiod_vbus);
 109         if ((vbus ^ nop->vbus) == 0)
 110                 return IRQ_HANDLED;
 111         nop->vbus = vbus;
 112
 113         if (vbus) {
 114                 status = USB_EVENT_VBUS;
 115                 otg->state = OTG_STATE_B_PERIPHERAL;
 116                 nop->phy.last_event = status;
 117
 118                 /* drawing a "unit load" is *always* OK, except for OTG */
 119                 nop_set_vbus_draw(nop, 100);
 120
 121                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 122                                            otg->gadget);
 123         } else {
 124                 nop_set_vbus_draw(nop, 0);
 125
 126                 status = USB_EVENT_NONE;
 127                 otg->state = OTG_STATE_B_IDLE;
 128                 nop->phy.last_event = status;
 129
 130                 atomic_notifier_call_chain(&nop->phy.notifier, status,
 131                                            otg->gadget);
 132         }
 133         return IRQ_HANDLED;
 134 }
 135
 136 int usb_gen_phy_init(struct usb_phy *phy)
 137 {
 138         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 139         int ret;
 140
 141         if (!IS_ERR(nop->vcc)) {
 142                 if (regulator_enable(nop->vcc))
 143                         dev_err(phy->dev, "Failed to enable power\n");
 144         }
 145
 146         if (!IS_ERR(nop->clk)) {
 147                 ret = clk_prepare_enable(nop->clk);
 148                 if (ret)
 149                         return ret;
 150         }
 151
 152         nop_reset(nop);
 153
 154         return 0;
 155 }
 156 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
 157
 158 void usb_gen_phy_shutdown(struct usb_phy *phy)
 159 {
 160         struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
 161
 162         gpiod_set_value(nop->gpiod_reset, 1);
 163
 164         if (!IS_ERR(nop->clk))
 165                 clk_disable_unprepare(nop->clk);
 166
 167         if (!IS_ERR(nop->vcc)) {
 168                 if (regulator_disable(nop->vcc))
 169                         dev_err(phy->dev, "Failed to disable power\n");
 170         }
 171 }
 172 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
 173
 174 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
 175 {
 176         if (!otg)
 177                 return -ENODEV;
 178
 179         if (!gadget) {
 180                 otg->gadget = NULL;
 181                 return -ENODEV;
 182         }
 183
 184         otg->gadget = gadget;
 185         if (otg->state == OTG_STATE_B_PERIPHERAL)
 186                 atomic_notifier_call_chain(&otg->usb_phy->notifier,
 187                                            USB_EVENT_VBUS, otg->gadget);
 188         else
 189                 otg->state = OTG_STATE_B_IDLE;
 190         return 0;
 191 }
 192
 193 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 194 {
 195         if (!otg)
 196                 return -ENODEV;
 197
 198         if (!host) {
 199                 otg->host = NULL;
 200                 return -ENODEV;
 201         }
 202
 203         otg->host = host;
 204         return 0;
 205 }
 206
 207 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
 208                 struct usb_phy_generic_platform_data *pdata)
 209 {
 210         enum usb_phy_type type = USB_PHY_TYPE_USB2;
 211         int err = 0;
 212
 213         u32 clk_rate = 0;
 214         bool needs_vcc = false, needs_clk = false;
 215
 216         if (dev->of_node) {
 217                 struct device_node *node = dev->of_node;
 218
 219                 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 220                         clk_rate = 0;
 221
 222                 needs_vcc = of_property_read_bool(node, "vcc-supply");
 223                 needs_clk = of_property_read_bool(node, "clocks");
 224                 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
 225                                                            GPIOD_ASIS);
 226                 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
 227                 if (!err) {
 228                         nop->gpiod_vbus = devm_gpiod_get_optional(dev,
 229                                                          "vbus-detect",
 230                                                          GPIOD_ASIS);
 231                         err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
 232                 }
 233         } else if (pdata) {
 234                 type = pdata->type;
 235                 clk_rate = pdata->clk_rate;
 236                 needs_vcc = pdata->needs_vcc;
 237                 if (gpio_is_valid(pdata->gpio_reset)) {
 238                         err = devm_gpio_request_one(dev, pdata->gpio_reset,
 239                                                     GPIOF_ACTIVE_LOW,
 240                                                     dev_name(dev));
 241                         if (!err)
 242                                 nop->gpiod_reset =
 243                                         gpio_to_desc(pdata->gpio_reset);
 244                 }
 245                 nop->gpiod_vbus = pdata->gpiod_vbus;
 246         }
 247
 248         if (err == -EPROBE_DEFER)
 249                 return -EPROBE_DEFER;
 250         if (err) {
 251                 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
 252                 return err;
 253         }
 254         if (nop->gpiod_reset)
 255                 gpiod_direction_output(nop->gpiod_reset, 1);
 256
 257         nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
 258                         GFP_KERNEL);
 259         if (!nop->phy.otg)
 260                 return -ENOMEM;
 261
 262         nop->clk = devm_clk_get(dev, "main_clk");
 263         if (IS_ERR(nop->clk)) {
 264                 dev_dbg(dev, "Can't get phy clock: %ld\n",
 265                                         PTR_ERR(nop->clk));
 266                 if (needs_clk)
 267                         return PTR_ERR(nop->clk);
 268         }
 269
 270         if (!IS_ERR(nop->clk) && clk_rate) {
 271                 err = clk_set_rate(nop->clk, clk_rate);
 272                 if (err) {
 273                         dev_err(dev, "Error setting clock rate\n");
 274                         return err;
 275                 }
 276         }
 277
 278         nop->vcc = devm_regulator_get(dev, "vcc");
 279         if (IS_ERR(nop->vcc)) {
 280                 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
 281                                         PTR_ERR(nop->vcc));
 282                 if (needs_vcc)
 283                         return -EPROBE_DEFER;
 284         }
 285
 286         nop->dev                = dev;
 287         nop->phy.dev            = nop->dev;
 288         nop->phy.label          = "nop-xceiv";
 289         nop->phy.set_suspend    = nop_set_suspend;
 290         nop->phy.type           = type;
 291
 292         nop->phy.otg->state             = OTG_STATE_UNDEFINED;
 293         nop->phy.otg->usb_phy           = &nop->phy;
 294         nop->phy.otg->set_host          = nop_set_host;
 295         nop->phy.otg->set_peripheral    = nop_set_peripheral;
 296
 297         return 0;
 298 }
 299 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
 300
 301 static int usb_phy_generic_probe(struct platform_device *pdev)
 302 {
 303         struct device *dev = &pdev->dev;
 304         struct usb_phy_generic  *nop;
 305         int err;
 306
 307         nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
 308         if (!nop)
 309                 return -ENOMEM;
 310
 311         err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
 312         if (err)
 313                 return err;
 314         if (nop->gpiod_vbus) {
 315                 err = devm_request_threaded_irq(&pdev->dev,
 316                                                 gpiod_to_irq(nop->gpiod_vbus),
 317                                                 NULL, nop_gpio_vbus_thread,
 318                                                 VBUS_IRQ_FLAGS, "vbus_detect",
 319                                                 nop);
 320                 if (err) {
 321                         dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
 322                                 gpiod_to_irq(nop->gpiod_vbus), err);
 323                         return err;
 324                 }
 325                 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
 326                         OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
 327         }
 328
 329         nop->phy.init           = usb_gen_phy_init;
 330         nop->phy.shutdown       = usb_gen_phy_shutdown;
 331
 332         err = usb_add_phy_dev(&nop->phy);
 333         if (err) {
 334                 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
 335                         err);
 336                 return err;
 337         }
 338
 339         platform_set_drvdata(pdev, nop);
 340
 341         return 0;
 342 }
 343
 344 static int usb_phy_generic_remove(struct platform_device *pdev)
 345 {
 346         struct usb_phy_generic *nop = platform_get_drvdata(pdev);
 347
 348         usb_remove_phy(&nop->phy);
 349
 350         return 0;
 351 }
 352
 353 static const struct of_device_id nop_xceiv_dt_ids[] = {
 354         { .compatible = "usb-nop-xceiv" },
 355         { }
 356 };
 357
 358 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
 359
 360 static struct platform_driver usb_phy_generic_driver = {
 361         .probe          = usb_phy_generic_probe,
 362         .remove         = usb_phy_generic_remove,
 363         .driver         = {
 364                 .name   = "usb_phy_generic",
 365                 .of_match_table = nop_xceiv_dt_ids,
 366         },
 367 };
 368
 369 static int __init usb_phy_generic_init(void)
 370 {
 371         return platform_driver_register(&usb_phy_generic_driver);
 372 }
 373 subsys_initcall(usb_phy_generic_init);
 374
 375 static void __exit usb_phy_generic_exit(void)
 376 {
 377         platform_driver_unregister(&usb_phy_generic_driver);
 378 }
 379 module_exit(usb_phy_generic_exit);
 380
 381 MODULE_ALIAS("platform:usb_phy_generic");
 382 MODULE_AUTHOR("Texas Instruments Inc");
 383 MODULE_DESCRIPTION("NOP USB Transceiver driver");
 384 MODULE_LICENSE("GPL");