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"); 377