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