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/of_gpio.h> 25 #include <linux/gpio.h> 26 #include <linux/delay.h> 27 28 #include "phy-generic.h" 29 30 #define VBUS_IRQ_FLAGS \ 31 (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \ 32 IRQF_ONESHOT) 33 34 struct platform_device *usb_phy_generic_register(void) 35 { 36 return platform_device_register_simple("usb_phy_generic", 37 PLATFORM_DEVID_AUTO, NULL, 0); 38 } 39 EXPORT_SYMBOL_GPL(usb_phy_generic_register); 40 41 void usb_phy_generic_unregister(struct platform_device *pdev) 42 { 43 platform_device_unregister(pdev); 44 } 45 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister); 46 47 static int nop_set_suspend(struct usb_phy *x, int suspend) 48 { 49 struct usb_phy_generic *nop = dev_get_drvdata(x->dev); 50 51 if (!IS_ERR(nop->clk)) { 52 if (suspend) 53 clk_disable_unprepare(nop->clk); 54 else 55 clk_prepare_enable(nop->clk); 56 } 57 58 return 0; 59 } 60 61 static void nop_reset(struct usb_phy_generic *nop) 62 { 63 if (!nop->gpiod_reset) 64 return; 65 66 gpiod_set_value_cansleep(nop->gpiod_reset, 1); 67 usleep_range(10000, 20000); 68 gpiod_set_value_cansleep(nop->gpiod_reset, 0); 69 } 70 71 /* interface to regulator framework */ 72 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA) 73 { 74 struct regulator *vbus_draw = nop->vbus_draw; 75 int enabled; 76 int ret; 77 78 if (!vbus_draw) 79 return; 80 81 enabled = nop->vbus_draw_enabled; 82 if (mA) { 83 regulator_set_current_limit(vbus_draw, 0, 1000 * mA); 84 if (!enabled) { 85 ret = regulator_enable(vbus_draw); 86 if (ret < 0) 87 return; 88 nop->vbus_draw_enabled = 1; 89 } 90 } else { 91 if (enabled) { 92 ret = regulator_disable(vbus_draw); 93 if (ret < 0) 94 return; 95 nop->vbus_draw_enabled = 0; 96 } 97 } 98 nop->mA = mA; 99 } 100 101 102 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data) 103 { 104 struct usb_phy_generic *nop = data; 105 struct usb_otg *otg = nop->phy.otg; 106 int vbus, status; 107 108 vbus = gpiod_get_value(nop->gpiod_vbus); 109 if ((vbus ^ nop->vbus) == 0) 110 return IRQ_HANDLED; 111 nop->vbus = vbus; 112 113 if (vbus) { 114 status = USB_EVENT_VBUS; 115 otg->state = OTG_STATE_B_PERIPHERAL; 116 nop->phy.last_event = status; 117 118 /* drawing a "unit load" is *always* OK, except for OTG */ 119 nop_set_vbus_draw(nop, 100); 120 121 atomic_notifier_call_chain(&nop->phy.notifier, status, 122 otg->gadget); 123 } else { 124 nop_set_vbus_draw(nop, 0); 125 126 status = USB_EVENT_NONE; 127 otg->state = OTG_STATE_B_IDLE; 128 nop->phy.last_event = status; 129 130 atomic_notifier_call_chain(&nop->phy.notifier, status, 131 otg->gadget); 132 } 133 return IRQ_HANDLED; 134 } 135 136 int usb_gen_phy_init(struct usb_phy *phy) 137 { 138 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 139 int ret; 140 141 if (!IS_ERR(nop->vcc)) { 142 if (regulator_enable(nop->vcc)) 143 dev_err(phy->dev, "Failed to enable power\n"); 144 } 145 146 if (!IS_ERR(nop->clk)) { 147 ret = clk_prepare_enable(nop->clk); 148 if (ret) 149 return ret; 150 } 151 152 nop_reset(nop); 153 154 return 0; 155 } 156 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 157 158 void usb_gen_phy_shutdown(struct usb_phy *phy) 159 { 160 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 161 162 gpiod_set_value_cansleep(nop->gpiod_reset, 1); 163 164 if (!IS_ERR(nop->clk)) 165 clk_disable_unprepare(nop->clk); 166 167 if (!IS_ERR(nop->vcc)) { 168 if (regulator_disable(nop->vcc)) 169 dev_err(phy->dev, "Failed to disable power\n"); 170 } 171 } 172 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 173 174 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 175 { 176 if (!otg) 177 return -ENODEV; 178 179 if (!gadget) { 180 otg->gadget = NULL; 181 return -ENODEV; 182 } 183 184 otg->gadget = gadget; 185 if (otg->state == OTG_STATE_B_PERIPHERAL) 186 atomic_notifier_call_chain(&otg->usb_phy->notifier, 187 USB_EVENT_VBUS, otg->gadget); 188 else 189 otg->state = OTG_STATE_B_IDLE; 190 return 0; 191 } 192 193 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 194 { 195 if (!otg) 196 return -ENODEV; 197 198 if (!host) { 199 otg->host = NULL; 200 return -ENODEV; 201 } 202 203 otg->host = host; 204 return 0; 205 } 206 207 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 208 struct usb_phy_generic_platform_data *pdata) 209 { 210 enum usb_phy_type type = USB_PHY_TYPE_USB2; 211 int err = 0; 212 213 u32 clk_rate = 0; 214 bool needs_vcc = false, needs_clk = false; 215 216 if (dev->of_node) { 217 struct device_node *node = dev->of_node; 218 219 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 220 clk_rate = 0; 221 222 needs_vcc = of_property_read_bool(node, "vcc-supply"); 223 needs_clk = of_property_read_bool(node, "clocks"); 224 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 225 GPIOD_ASIS); 226 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 227 if (!err) { 228 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 229 "vbus-detect", 230 GPIOD_ASIS); 231 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 232 } 233 } else if (pdata) { 234 type = pdata->type; 235 clk_rate = pdata->clk_rate; 236 needs_vcc = pdata->needs_vcc; 237 if (gpio_is_valid(pdata->gpio_reset)) { 238 err = devm_gpio_request_one(dev, pdata->gpio_reset, 239 GPIOF_ACTIVE_LOW, 240 dev_name(dev)); 241 if (!err) 242 nop->gpiod_reset = 243 gpio_to_desc(pdata->gpio_reset); 244 } 245 nop->gpiod_vbus = pdata->gpiod_vbus; 246 } 247 248 if (err == -EPROBE_DEFER) 249 return -EPROBE_DEFER; 250 if (err) { 251 dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); 252 return err; 253 } 254 if (nop->gpiod_reset) 255 gpiod_direction_output(nop->gpiod_reset, 1); 256 257 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 258 GFP_KERNEL); 259 if (!nop->phy.otg) 260 return -ENOMEM; 261 262 nop->clk = devm_clk_get(dev, "main_clk"); 263 if (IS_ERR(nop->clk)) { 264 dev_dbg(dev, "Can't get phy clock: %ld\n", 265 PTR_ERR(nop->clk)); 266 if (needs_clk) 267 return PTR_ERR(nop->clk); 268 } 269 270 if (!IS_ERR(nop->clk) && clk_rate) { 271 err = clk_set_rate(nop->clk, clk_rate); 272 if (err) { 273 dev_err(dev, "Error setting clock rate\n"); 274 return err; 275 } 276 } 277 278 nop->vcc = devm_regulator_get(dev, "vcc"); 279 if (IS_ERR(nop->vcc)) { 280 dev_dbg(dev, "Error getting vcc regulator: %ld\n", 281 PTR_ERR(nop->vcc)); 282 if (needs_vcc) 283 return -EPROBE_DEFER; 284 } 285 286 nop->dev = dev; 287 nop->phy.dev = nop->dev; 288 nop->phy.label = "nop-xceiv"; 289 nop->phy.set_suspend = nop_set_suspend; 290 nop->phy.type = type; 291 292 nop->phy.otg->state = OTG_STATE_UNDEFINED; 293 nop->phy.otg->usb_phy = &nop->phy; 294 nop->phy.otg->set_host = nop_set_host; 295 nop->phy.otg->set_peripheral = nop_set_peripheral; 296 297 return 0; 298 } 299 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 300 301 static int usb_phy_generic_probe(struct platform_device *pdev) 302 { 303 struct device *dev = &pdev->dev; 304 struct usb_phy_generic *nop; 305 int err; 306 307 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 308 if (!nop) 309 return -ENOMEM; 310 311 err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev)); 312 if (err) 313 return err; 314 if (nop->gpiod_vbus) { 315 err = devm_request_threaded_irq(&pdev->dev, 316 gpiod_to_irq(nop->gpiod_vbus), 317 NULL, nop_gpio_vbus_thread, 318 VBUS_IRQ_FLAGS, "vbus_detect", 319 nop); 320 if (err) { 321 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 322 gpiod_to_irq(nop->gpiod_vbus), err); 323 return err; 324 } 325 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? 326 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; 327 } 328 329 nop->phy.init = usb_gen_phy_init; 330 nop->phy.shutdown = usb_gen_phy_shutdown; 331 332 err = usb_add_phy_dev(&nop->phy); 333 if (err) { 334 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 335 err); 336 return err; 337 } 338 339 platform_set_drvdata(pdev, nop); 340 341 return 0; 342 } 343 344 static int usb_phy_generic_remove(struct platform_device *pdev) 345 { 346 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 347 348 usb_remove_phy(&nop->phy); 349 350 return 0; 351 } 352 353 static const struct of_device_id nop_xceiv_dt_ids[] = { 354 { .compatible = "usb-nop-xceiv" }, 355 { } 356 }; 357 358 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 359 360 static struct platform_driver usb_phy_generic_driver = { 361 .probe = usb_phy_generic_probe, 362 .remove = usb_phy_generic_remove, 363 .driver = { 364 .name = "usb_phy_generic", 365 .of_match_table = nop_xceiv_dt_ids, 366 }, 367 }; 368 369 static int __init usb_phy_generic_init(void) 370 { 371 return platform_driver_register(&usb_phy_generic_driver); 372 } 373 subsys_initcall(usb_phy_generic_init); 374 375 static void __exit usb_phy_generic_exit(void) 376 { 377 platform_driver_unregister(&usb_phy_generic_driver); 378 } 379 module_exit(usb_phy_generic_exit); 380 381 MODULE_ALIAS("platform:usb_phy_generic"); 382 MODULE_AUTHOR("Texas Instruments Inc"); 383 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 384 MODULE_LICENSE("GPL"); 385