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_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_clk = of_property_read_bool(node, "clocks"); 221 } 222 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 223 GPIOD_ASIS); 224 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 225 if (!err) { 226 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 227 "vbus-detect", 228 GPIOD_ASIS); 229 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 230 } 231 232 if (err) 233 return dev_err_probe(dev, err, 234 "Error requesting RESET or VBUS GPIO\n"); 235 if (nop->gpiod_reset) 236 gpiod_direction_output(nop->gpiod_reset, 1); 237 238 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 239 GFP_KERNEL); 240 if (!nop->phy.otg) 241 return -ENOMEM; 242 243 nop->clk = devm_clk_get(dev, "main_clk"); 244 if (IS_ERR(nop->clk)) { 245 dev_dbg(dev, "Can't get phy clock: %ld\n", 246 PTR_ERR(nop->clk)); 247 if (needs_clk) 248 return PTR_ERR(nop->clk); 249 } 250 251 if (!IS_ERR(nop->clk) && clk_rate) { 252 err = clk_set_rate(nop->clk, clk_rate); 253 if (err) { 254 dev_err(dev, "Error setting clock rate\n"); 255 return err; 256 } 257 } 258 259 nop->vcc = devm_regulator_get_optional(dev, "vcc"); 260 if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV) 261 return dev_err_probe(dev, PTR_ERR(nop->vcc), 262 "could not get vcc regulator\n"); 263 264 nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus"); 265 if (PTR_ERR(nop->vbus_draw) == -ENODEV) 266 nop->vbus_draw = NULL; 267 if (IS_ERR(nop->vbus_draw)) 268 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw), 269 "could not get vbus regulator\n"); 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 device_node *dn = dev->of_node; 290 struct usb_phy_generic *nop; 291 int err; 292 293 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 294 if (!nop) 295 return -ENOMEM; 296 297 err = usb_phy_gen_create_phy(dev, nop); 298 if (err) 299 return err; 300 if (nop->gpiod_vbus) { 301 err = devm_request_threaded_irq(&pdev->dev, 302 gpiod_to_irq(nop->gpiod_vbus), 303 NULL, nop_gpio_vbus_thread, 304 VBUS_IRQ_FLAGS, "vbus_detect", 305 nop); 306 if (err) { 307 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 308 gpiod_to_irq(nop->gpiod_vbus), err); 309 return err; 310 } 311 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? 312 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; 313 } 314 315 nop->phy.init = usb_gen_phy_init; 316 nop->phy.shutdown = usb_gen_phy_shutdown; 317 318 err = usb_add_phy_dev(&nop->phy); 319 if (err) { 320 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 321 err); 322 return err; 323 } 324 325 platform_set_drvdata(pdev, nop); 326 327 device_set_wakeup_capable(&pdev->dev, 328 of_property_read_bool(dn, "wakeup-source")); 329 330 return 0; 331 } 332 333 static void usb_phy_generic_remove(struct platform_device *pdev) 334 { 335 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 336 337 usb_remove_phy(&nop->phy); 338 } 339 340 static const struct of_device_id nop_xceiv_dt_ids[] = { 341 { .compatible = "usb-nop-xceiv" }, 342 { } 343 }; 344 345 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 346 347 static struct platform_driver usb_phy_generic_driver = { 348 .probe = usb_phy_generic_probe, 349 .remove_new = usb_phy_generic_remove, 350 .driver = { 351 .name = "usb_phy_generic", 352 .of_match_table = nop_xceiv_dt_ids, 353 }, 354 }; 355 356 static int __init usb_phy_generic_init(void) 357 { 358 return platform_driver_register(&usb_phy_generic_driver); 359 } 360 subsys_initcall(usb_phy_generic_init); 361 362 static void __exit usb_phy_generic_exit(void) 363 { 364 platform_driver_unregister(&usb_phy_generic_driver); 365 } 366 module_exit(usb_phy_generic_exit); 367 368 MODULE_ALIAS("platform:usb_phy_generic"); 369 MODULE_AUTHOR("Texas Instruments Inc"); 370 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 371 MODULE_LICENSE("GPL"); 372