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 return 0; 63 } 64 65 static void nop_reset(struct usb_phy_generic *nop) 66 { 67 if (!nop->gpiod_reset) 68 return; 69 70 gpiod_set_value(nop->gpiod_reset, 1); 71 usleep_range(10000, 20000); 72 gpiod_set_value(nop->gpiod_reset, 0); 73 } 74 75 /* interface to regulator framework */ 76 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA) 77 { 78 struct regulator *vbus_draw = nop->vbus_draw; 79 int enabled; 80 int ret; 81 82 if (!vbus_draw) 83 return; 84 85 enabled = nop->vbus_draw_enabled; 86 if (mA) { 87 regulator_set_current_limit(vbus_draw, 0, 1000 * mA); 88 if (!enabled) { 89 ret = regulator_enable(vbus_draw); 90 if (ret < 0) 91 return; 92 nop->vbus_draw_enabled = 1; 93 } 94 } else { 95 if (enabled) { 96 ret = regulator_disable(vbus_draw); 97 if (ret < 0) 98 return; 99 nop->vbus_draw_enabled = 0; 100 } 101 } 102 nop->mA = mA; 103 } 104 105 106 static irqreturn_t nop_gpio_vbus_thread(int irq, void *data) 107 { 108 struct usb_phy_generic *nop = data; 109 struct usb_otg *otg = nop->phy.otg; 110 int vbus, status; 111 112 vbus = gpiod_get_value(nop->gpiod_vbus); 113 if ((vbus ^ nop->vbus) == 0) 114 return IRQ_HANDLED; 115 nop->vbus = vbus; 116 117 if (vbus) { 118 status = USB_EVENT_VBUS; 119 otg->state = OTG_STATE_B_PERIPHERAL; 120 nop->phy.last_event = status; 121 if (otg->gadget) 122 usb_gadget_vbus_connect(otg->gadget); 123 124 /* drawing a "unit load" is *always* OK, except for OTG */ 125 nop_set_vbus_draw(nop, 100); 126 127 atomic_notifier_call_chain(&nop->phy.notifier, status, 128 otg->gadget); 129 } else { 130 nop_set_vbus_draw(nop, 0); 131 132 if (otg->gadget) 133 usb_gadget_vbus_disconnect(otg->gadget); 134 status = USB_EVENT_NONE; 135 otg->state = OTG_STATE_B_IDLE; 136 nop->phy.last_event = status; 137 138 atomic_notifier_call_chain(&nop->phy.notifier, status, 139 otg->gadget); 140 } 141 return IRQ_HANDLED; 142 } 143 144 int usb_gen_phy_init(struct usb_phy *phy) 145 { 146 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 147 148 if (!IS_ERR(nop->vcc)) { 149 if (regulator_enable(nop->vcc)) 150 dev_err(phy->dev, "Failed to enable power\n"); 151 } 152 153 if (!IS_ERR(nop->clk)) 154 clk_prepare_enable(nop->clk); 155 156 nop_reset(nop); 157 158 return 0; 159 } 160 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 161 162 void usb_gen_phy_shutdown(struct usb_phy *phy) 163 { 164 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 165 166 gpiod_set_value(nop->gpiod_reset, 1); 167 168 if (!IS_ERR(nop->clk)) 169 clk_disable_unprepare(nop->clk); 170 171 if (!IS_ERR(nop->vcc)) { 172 if (regulator_disable(nop->vcc)) 173 dev_err(phy->dev, "Failed to disable power\n"); 174 } 175 } 176 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 177 178 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 179 { 180 if (!otg) 181 return -ENODEV; 182 183 if (!gadget) { 184 otg->gadget = NULL; 185 return -ENODEV; 186 } 187 188 otg->gadget = gadget; 189 if (otg->state == OTG_STATE_B_PERIPHERAL) 190 usb_gadget_vbus_connect(gadget); 191 else 192 otg->state = OTG_STATE_B_IDLE; 193 return 0; 194 } 195 196 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 197 { 198 if (!otg) 199 return -ENODEV; 200 201 if (!host) { 202 otg->host = NULL; 203 return -ENODEV; 204 } 205 206 otg->host = host; 207 return 0; 208 } 209 210 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 211 struct usb_phy_generic_platform_data *pdata) 212 { 213 enum usb_phy_type type = USB_PHY_TYPE_USB2; 214 int err = 0; 215 216 u32 clk_rate = 0; 217 bool needs_vcc = false; 218 219 if (dev->of_node) { 220 struct device_node *node = dev->of_node; 221 222 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 223 clk_rate = 0; 224 225 needs_vcc = of_property_read_bool(node, "vcc-supply"); 226 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 227 GPIOD_ASIS); 228 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 229 if (!err) { 230 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 231 "vbus-detect", 232 GPIOD_ASIS); 233 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 234 } 235 } else if (pdata) { 236 type = pdata->type; 237 clk_rate = pdata->clk_rate; 238 needs_vcc = pdata->needs_vcc; 239 if (gpio_is_valid(pdata->gpio_reset)) { 240 err = devm_gpio_request_one(dev, pdata->gpio_reset, 241 GPIOF_ACTIVE_LOW, 242 dev_name(dev)); 243 if (!err) 244 nop->gpiod_reset = 245 gpio_to_desc(pdata->gpio_reset); 246 } 247 nop->gpiod_vbus = pdata->gpiod_vbus; 248 } 249 250 if (err == -EPROBE_DEFER) 251 return -EPROBE_DEFER; 252 if (err) { 253 dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); 254 return err; 255 } 256 if (nop->gpiod_reset) 257 gpiod_direction_output(nop->gpiod_reset, 1); 258 259 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 260 GFP_KERNEL); 261 if (!nop->phy.otg) 262 return -ENOMEM; 263 264 nop->clk = devm_clk_get(dev, "main_clk"); 265 if (IS_ERR(nop->clk)) { 266 dev_dbg(dev, "Can't get phy clock: %ld\n", 267 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 } 326 327 nop->phy.init = usb_gen_phy_init; 328 nop->phy.shutdown = usb_gen_phy_shutdown; 329 330 err = usb_add_phy_dev(&nop->phy); 331 if (err) { 332 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 333 err); 334 return err; 335 } 336 337 platform_set_drvdata(pdev, nop); 338 339 return 0; 340 } 341 342 static int usb_phy_generic_remove(struct platform_device *pdev) 343 { 344 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 345 346 usb_remove_phy(&nop->phy); 347 348 return 0; 349 } 350 351 static const struct of_device_id nop_xceiv_dt_ids[] = { 352 { .compatible = "usb-nop-xceiv" }, 353 { } 354 }; 355 356 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 357 358 static struct platform_driver usb_phy_generic_driver = { 359 .probe = usb_phy_generic_probe, 360 .remove = usb_phy_generic_remove, 361 .driver = { 362 .name = "usb_phy_generic", 363 .of_match_table = nop_xceiv_dt_ids, 364 }, 365 }; 366 367 static int __init usb_phy_generic_init(void) 368 { 369 return platform_driver_register(&usb_phy_generic_driver); 370 } 371 subsys_initcall(usb_phy_generic_init); 372 373 static void __exit usb_phy_generic_exit(void) 374 { 375 platform_driver_unregister(&usb_phy_generic_driver); 376 } 377 module_exit(usb_phy_generic_exit); 378 379 MODULE_ALIAS("platform:usb_phy_generic"); 380 MODULE_AUTHOR("Texas Instruments Inc"); 381 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 382 MODULE_LICENSE("GPL"); 383