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"); 378