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 usleep_range(10000, 30000); 75 } 76 77 /* interface to regulator framework */ 78 static int nop_set_vbus(struct usb_otg *otg, bool enable) 79 { 80 int ret = 0; 81 struct usb_phy_generic *nop = dev_get_drvdata(otg->usb_phy->dev); 82 83 if (!nop->vbus_draw) 84 return 0; 85 86 if (enable && !nop->vbus_draw_enabled) { 87 ret = regulator_enable(nop->vbus_draw); 88 if (ret) 89 nop->vbus_draw_enabled = false; 90 else 91 nop->vbus_draw_enabled = true; 92 93 } else if (!enable && nop->vbus_draw_enabled) { 94 ret = regulator_disable(nop->vbus_draw); 95 nop->vbus_draw_enabled = false; 96 } 97 return ret; 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 atomic_notifier_call_chain(&nop->phy.notifier, status, 118 otg->gadget); 119 } else { 120 status = USB_EVENT_NONE; 121 otg->state = OTG_STATE_B_IDLE; 122 nop->phy.last_event = status; 123 124 atomic_notifier_call_chain(&nop->phy.notifier, status, 125 otg->gadget); 126 } 127 return IRQ_HANDLED; 128 } 129 130 int usb_gen_phy_init(struct usb_phy *phy) 131 { 132 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 133 int ret; 134 135 if (!IS_ERR(nop->vcc)) { 136 if (regulator_enable(nop->vcc)) 137 dev_err(phy->dev, "Failed to enable power\n"); 138 } 139 140 if (!IS_ERR(nop->clk)) { 141 ret = clk_prepare_enable(nop->clk); 142 if (ret) 143 return ret; 144 } 145 146 nop_reset(nop); 147 148 return 0; 149 } 150 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 151 152 void usb_gen_phy_shutdown(struct usb_phy *phy) 153 { 154 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 155 156 gpiod_set_value_cansleep(nop->gpiod_reset, 1); 157 158 if (!IS_ERR(nop->clk)) 159 clk_disable_unprepare(nop->clk); 160 161 if (!IS_ERR(nop->vcc)) { 162 if (regulator_disable(nop->vcc)) 163 dev_err(phy->dev, "Failed to disable power\n"); 164 } 165 } 166 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 167 168 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 169 { 170 if (!otg) 171 return -ENODEV; 172 173 if (!gadget) { 174 otg->gadget = NULL; 175 return -ENODEV; 176 } 177 178 otg->gadget = gadget; 179 if (otg->state == OTG_STATE_B_PERIPHERAL) 180 atomic_notifier_call_chain(&otg->usb_phy->notifier, 181 USB_EVENT_VBUS, otg->gadget); 182 else 183 otg->state = OTG_STATE_B_IDLE; 184 return 0; 185 } 186 187 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 188 { 189 if (!otg) 190 return -ENODEV; 191 192 if (!host) { 193 otg->host = NULL; 194 return -ENODEV; 195 } 196 197 otg->host = host; 198 return 0; 199 } 200 201 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop) 202 { 203 enum usb_phy_type type = USB_PHY_TYPE_USB2; 204 int err = 0; 205 206 u32 clk_rate = 0; 207 bool needs_clk = false; 208 209 if (dev->of_node) { 210 struct device_node *node = dev->of_node; 211 212 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 213 clk_rate = 0; 214 215 needs_clk = of_property_read_bool(node, "clocks"); 216 } 217 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 218 GPIOD_ASIS); 219 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 220 if (!err) { 221 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 222 "vbus-detect", 223 GPIOD_ASIS); 224 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 225 } 226 227 if (err) 228 return dev_err_probe(dev, err, 229 "Error requesting RESET or VBUS GPIO\n"); 230 if (nop->gpiod_reset) 231 gpiod_direction_output(nop->gpiod_reset, 1); 232 233 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 234 GFP_KERNEL); 235 if (!nop->phy.otg) 236 return -ENOMEM; 237 238 nop->clk = devm_clk_get(dev, "main_clk"); 239 if (IS_ERR(nop->clk)) { 240 dev_dbg(dev, "Can't get phy clock: %ld\n", 241 PTR_ERR(nop->clk)); 242 if (needs_clk) 243 return PTR_ERR(nop->clk); 244 } 245 246 if (!IS_ERR(nop->clk) && clk_rate) { 247 err = clk_set_rate(nop->clk, clk_rate); 248 if (err) { 249 dev_err(dev, "Error setting clock rate\n"); 250 return err; 251 } 252 } 253 254 nop->vcc = devm_regulator_get_optional(dev, "vcc"); 255 if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV) 256 return dev_err_probe(dev, PTR_ERR(nop->vcc), 257 "could not get vcc regulator\n"); 258 259 nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus"); 260 if (PTR_ERR(nop->vbus_draw) == -ENODEV) 261 nop->vbus_draw = NULL; 262 if (IS_ERR(nop->vbus_draw)) 263 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw), 264 "could not get vbus regulator\n"); 265 266 nop->dev = dev; 267 nop->phy.dev = nop->dev; 268 nop->phy.label = "nop-xceiv"; 269 nop->phy.set_suspend = nop_set_suspend; 270 nop->phy.type = type; 271 272 nop->phy.otg->state = OTG_STATE_UNDEFINED; 273 nop->phy.otg->usb_phy = &nop->phy; 274 nop->phy.otg->set_host = nop_set_host; 275 nop->phy.otg->set_peripheral = nop_set_peripheral; 276 nop->phy.otg->set_vbus = nop_set_vbus; 277 278 return 0; 279 } 280 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 281 282 static int usb_phy_generic_probe(struct platform_device *pdev) 283 { 284 struct device *dev = &pdev->dev; 285 struct device_node *dn = dev->of_node; 286 struct usb_phy_generic *nop; 287 int err; 288 289 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 290 if (!nop) 291 return -ENOMEM; 292 293 err = usb_phy_gen_create_phy(dev, nop); 294 if (err) 295 return err; 296 if (nop->gpiod_vbus) { 297 err = devm_request_threaded_irq(&pdev->dev, 298 gpiod_to_irq(nop->gpiod_vbus), 299 NULL, nop_gpio_vbus_thread, 300 VBUS_IRQ_FLAGS, "vbus_detect", 301 nop); 302 if (err) { 303 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 304 gpiod_to_irq(nop->gpiod_vbus), err); 305 return err; 306 } 307 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? 308 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; 309 } 310 311 nop->phy.init = usb_gen_phy_init; 312 nop->phy.shutdown = usb_gen_phy_shutdown; 313 314 err = usb_add_phy_dev(&nop->phy); 315 if (err) { 316 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 317 err); 318 return err; 319 } 320 321 platform_set_drvdata(pdev, nop); 322 323 device_set_wakeup_capable(&pdev->dev, 324 of_property_read_bool(dn, "wakeup-source")); 325 326 return 0; 327 } 328 329 static void 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 if (nop->vbus_draw && nop->vbus_draw_enabled) 336 regulator_disable(nop->vbus_draw); 337 } 338 339 static const struct of_device_id nop_xceiv_dt_ids[] = { 340 { .compatible = "usb-nop-xceiv" }, 341 { } 342 }; 343 344 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 345 346 static struct platform_driver usb_phy_generic_driver = { 347 .probe = usb_phy_generic_probe, 348 .remove_new = usb_phy_generic_remove, 349 .driver = { 350 .name = "usb_phy_generic", 351 .of_match_table = nop_xceiv_dt_ids, 352 }, 353 }; 354 355 static int __init usb_phy_generic_init(void) 356 { 357 return platform_driver_register(&usb_phy_generic_driver); 358 } 359 subsys_initcall(usb_phy_generic_init); 360 361 static void __exit usb_phy_generic_exit(void) 362 { 363 platform_driver_unregister(&usb_phy_generic_driver); 364 } 365 module_exit(usb_phy_generic_exit); 366 367 MODULE_ALIAS("platform:usb_phy_generic"); 368 MODULE_AUTHOR("Texas Instruments Inc"); 369 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 370 MODULE_LICENSE("GPL"); 371