1 /* 2 * NOP USB transceiver for all USB transceiver which are either built-in 3 * into USB IP or which are mostly autonomous. 4 * 5 * Copyright (C) 2009 Texas Instruments Inc 6 * Author: Ajay Kumar Gupta <ajay.gupta@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 * 22 * Current status: 23 * This provides a "nop" transceiver for PHYs which are 24 * autonomous such as isp1504, isp1707, etc. 25 */ 26 27 #include <linux/module.h> 28 #include <linux/platform_device.h> 29 #include <linux/dma-mapping.h> 30 #include <linux/usb/gadget.h> 31 #include <linux/usb/otg.h> 32 #include <linux/usb/usb_phy_generic.h> 33 #include <linux/slab.h> 34 #include <linux/clk.h> 35 #include <linux/regulator/consumer.h> 36 #include <linux/of.h> 37 #include <linux/of_gpio.h> 38 #include <linux/gpio.h> 39 #include <linux/delay.h> 40 41 #include "phy-generic.h" 42 43 #define VBUS_IRQ_FLAGS \ 44 (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \ 45 IRQF_ONESHOT) 46 47 struct platform_device *usb_phy_generic_register(void) 48 { 49 return platform_device_register_simple("usb_phy_generic", 50 PLATFORM_DEVID_AUTO, NULL, 0); 51 } 52 EXPORT_SYMBOL_GPL(usb_phy_generic_register); 53 54 void usb_phy_generic_unregister(struct platform_device *pdev) 55 { 56 platform_device_unregister(pdev); 57 } 58 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister); 59 60 static int nop_set_suspend(struct usb_phy *x, int suspend) 61 { 62 struct usb_phy_generic *nop = dev_get_drvdata(x->dev); 63 64 if (!IS_ERR(nop->clk)) { 65 if (suspend) 66 clk_disable_unprepare(nop->clk); 67 else 68 clk_prepare_enable(nop->clk); 69 } 70 71 return 0; 72 } 73 74 static void nop_reset(struct usb_phy_generic *nop) 75 { 76 if (!nop->gpiod_reset) 77 return; 78 79 gpiod_set_value(nop->gpiod_reset, 1); 80 usleep_range(10000, 20000); 81 gpiod_set_value(nop->gpiod_reset, 0); 82 } 83 84 /* interface to regulator framework */ 85 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA) 86 { 87 struct regulator *vbus_draw = nop->vbus_draw; 88 int enabled; 89 int ret; 90 91 if (!vbus_draw) 92 return; 93 94 enabled = nop->vbus_draw_enabled; 95 if (mA) { 96 regulator_set_current_limit(vbus_draw, 0, 1000 * mA); 97 if (!enabled) { 98 ret = regulator_enable(vbus_draw); 99 if (ret < 0) 100 return; 101 nop->vbus_draw_enabled = 1; 102 } 103 } else { 104 if (enabled) { 105 ret = regulator_disable(vbus_draw); 106 if (ret < 0) 107 return; 108 nop->vbus_draw_enabled = 0; 109 } 110 } 111 nop->mA = mA; 112 } 113 114 115 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data) 116 { 117 struct usb_phy_generic *nop = data; 118 struct usb_otg *otg = nop->phy.otg; 119 int vbus, status; 120 121 vbus = gpiod_get_value(nop->gpiod_vbus); 122 if ((vbus ^ nop->vbus) == 0) 123 return IRQ_HANDLED; 124 nop->vbus = vbus; 125 126 if (vbus) { 127 status = USB_EVENT_VBUS; 128 otg->state = OTG_STATE_B_PERIPHERAL; 129 nop->phy.last_event = status; 130 131 /* drawing a "unit load" is *always* OK, except for OTG */ 132 nop_set_vbus_draw(nop, 100); 133 134 atomic_notifier_call_chain(&nop->phy.notifier, status, 135 otg->gadget); 136 } else { 137 nop_set_vbus_draw(nop, 0); 138 139 status = USB_EVENT_NONE; 140 otg->state = OTG_STATE_B_IDLE; 141 nop->phy.last_event = status; 142 143 atomic_notifier_call_chain(&nop->phy.notifier, status, 144 otg->gadget); 145 } 146 return IRQ_HANDLED; 147 } 148 149 int usb_gen_phy_init(struct usb_phy *phy) 150 { 151 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 152 int ret; 153 154 if (!IS_ERR(nop->vcc)) { 155 if (regulator_enable(nop->vcc)) 156 dev_err(phy->dev, "Failed to enable power\n"); 157 } 158 159 if (!IS_ERR(nop->clk)) { 160 ret = clk_prepare_enable(nop->clk); 161 if (ret) 162 return ret; 163 } 164 165 nop_reset(nop); 166 167 return 0; 168 } 169 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 170 171 void usb_gen_phy_shutdown(struct usb_phy *phy) 172 { 173 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 174 175 gpiod_set_value(nop->gpiod_reset, 1); 176 177 if (!IS_ERR(nop->clk)) 178 clk_disable_unprepare(nop->clk); 179 180 if (!IS_ERR(nop->vcc)) { 181 if (regulator_disable(nop->vcc)) 182 dev_err(phy->dev, "Failed to disable power\n"); 183 } 184 } 185 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 186 187 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 188 { 189 if (!otg) 190 return -ENODEV; 191 192 if (!gadget) { 193 otg->gadget = NULL; 194 return -ENODEV; 195 } 196 197 otg->gadget = gadget; 198 if (otg->state == OTG_STATE_B_PERIPHERAL) 199 atomic_notifier_call_chain(&otg->usb_phy->notifier, 200 USB_EVENT_VBUS, otg->gadget); 201 else 202 otg->state = OTG_STATE_B_IDLE; 203 return 0; 204 } 205 206 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 207 { 208 if (!otg) 209 return -ENODEV; 210 211 if (!host) { 212 otg->host = NULL; 213 return -ENODEV; 214 } 215 216 otg->host = host; 217 return 0; 218 } 219 220 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 221 struct usb_phy_generic_platform_data *pdata) 222 { 223 enum usb_phy_type type = USB_PHY_TYPE_USB2; 224 int err = 0; 225 226 u32 clk_rate = 0; 227 bool needs_vcc = false, needs_clk = false; 228 229 if (dev->of_node) { 230 struct device_node *node = dev->of_node; 231 232 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 233 clk_rate = 0; 234 235 needs_vcc = of_property_read_bool(node, "vcc-supply"); 236 needs_clk = of_property_read_bool(node, "clocks"); 237 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 238 GPIOD_ASIS); 239 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 240 if (!err) { 241 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 242 "vbus-detect", 243 GPIOD_ASIS); 244 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 245 } 246 } else if (pdata) { 247 type = pdata->type; 248 clk_rate = pdata->clk_rate; 249 needs_vcc = pdata->needs_vcc; 250 if (gpio_is_valid(pdata->gpio_reset)) { 251 err = devm_gpio_request_one(dev, pdata->gpio_reset, 252 GPIOF_ACTIVE_LOW, 253 dev_name(dev)); 254 if (!err) 255 nop->gpiod_reset = 256 gpio_to_desc(pdata->gpio_reset); 257 } 258 nop->gpiod_vbus = pdata->gpiod_vbus; 259 } 260 261 if (err == -EPROBE_DEFER) 262 return -EPROBE_DEFER; 263 if (err) { 264 dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); 265 return err; 266 } 267 if (nop->gpiod_reset) 268 gpiod_direction_output(nop->gpiod_reset, 1); 269 270 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 271 GFP_KERNEL); 272 if (!nop->phy.otg) 273 return -ENOMEM; 274 275 nop->clk = devm_clk_get(dev, "main_clk"); 276 if (IS_ERR(nop->clk)) { 277 dev_dbg(dev, "Can't get phy clock: %ld\n", 278 PTR_ERR(nop->clk)); 279 if (needs_clk) 280 return PTR_ERR(nop->clk); 281 } 282 283 if (!IS_ERR(nop->clk) && clk_rate) { 284 err = clk_set_rate(nop->clk, clk_rate); 285 if (err) { 286 dev_err(dev, "Error setting clock rate\n"); 287 return err; 288 } 289 } 290 291 nop->vcc = devm_regulator_get(dev, "vcc"); 292 if (IS_ERR(nop->vcc)) { 293 dev_dbg(dev, "Error getting vcc regulator: %ld\n", 294 PTR_ERR(nop->vcc)); 295 if (needs_vcc) 296 return -EPROBE_DEFER; 297 } 298 299 nop->dev = dev; 300 nop->phy.dev = nop->dev; 301 nop->phy.label = "nop-xceiv"; 302 nop->phy.set_suspend = nop_set_suspend; 303 nop->phy.type = type; 304 305 nop->phy.otg->state = OTG_STATE_UNDEFINED; 306 nop->phy.otg->usb_phy = &nop->phy; 307 nop->phy.otg->set_host = nop_set_host; 308 nop->phy.otg->set_peripheral = nop_set_peripheral; 309 310 return 0; 311 } 312 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 313 314 static int usb_phy_generic_probe(struct platform_device *pdev) 315 { 316 struct device *dev = &pdev->dev; 317 struct usb_phy_generic *nop; 318 int err; 319 320 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 321 if (!nop) 322 return -ENOMEM; 323 324 err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev)); 325 if (err) 326 return err; 327 if (nop->gpiod_vbus) { 328 err = devm_request_threaded_irq(&pdev->dev, 329 gpiod_to_irq(nop->gpiod_vbus), 330 NULL, nop_gpio_vbus_thread, 331 VBUS_IRQ_FLAGS, "vbus_detect", 332 nop); 333 if (err) { 334 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 335 gpiod_to_irq(nop->gpiod_vbus), err); 336 return err; 337 } 338 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? 339 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; 340 } 341 342 nop->phy.init = usb_gen_phy_init; 343 nop->phy.shutdown = usb_gen_phy_shutdown; 344 345 err = usb_add_phy_dev(&nop->phy); 346 if (err) { 347 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 348 err); 349 return err; 350 } 351 352 platform_set_drvdata(pdev, nop); 353 354 return 0; 355 } 356 357 static int usb_phy_generic_remove(struct platform_device *pdev) 358 { 359 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 360 361 usb_remove_phy(&nop->phy); 362 363 return 0; 364 } 365 366 static const struct of_device_id nop_xceiv_dt_ids[] = { 367 { .compatible = "usb-nop-xceiv" }, 368 { } 369 }; 370 371 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 372 373 static struct platform_driver usb_phy_generic_driver = { 374 .probe = usb_phy_generic_probe, 375 .remove = usb_phy_generic_remove, 376 .driver = { 377 .name = "usb_phy_generic", 378 .of_match_table = nop_xceiv_dt_ids, 379 }, 380 }; 381 382 static int __init usb_phy_generic_init(void) 383 { 384 return platform_driver_register(&usb_phy_generic_driver); 385 } 386 subsys_initcall(usb_phy_generic_init); 387 388 static void __exit usb_phy_generic_exit(void) 389 { 390 platform_driver_unregister(&usb_phy_generic_driver); 391 } 392 module_exit(usb_phy_generic_exit); 393 394 MODULE_ALIAS("platform:usb_phy_generic"); 395 MODULE_AUTHOR("Texas Instruments Inc"); 396 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 397 MODULE_LICENSE("GPL"); 398