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; 121 122 /* drawing a "unit load" is *always* OK, except for OTG */ 123 nop_set_vbus_draw(nop, 100); 124 125 atomic_notifier_call_chain(&nop->phy.notifier, status, 126 otg->gadget); 127 } else { 128 nop_set_vbus_draw(nop, 0); 129 130 status = USB_EVENT_NONE; 131 otg->state = OTG_STATE_B_IDLE; 132 nop->phy.last_event = status; 133 134 atomic_notifier_call_chain(&nop->phy.notifier, status, 135 otg->gadget); 136 } 137 return IRQ_HANDLED; 138 } 139 140 int usb_gen_phy_init(struct usb_phy *phy) 141 { 142 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 143 int ret; 144 145 if (!IS_ERR(nop->vcc)) { 146 if (regulator_enable(nop->vcc)) 147 dev_err(phy->dev, "Failed to enable power\n"); 148 } 149 150 if (!IS_ERR(nop->clk)) { 151 ret = clk_prepare_enable(nop->clk); 152 if (ret) 153 return ret; 154 } 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 atomic_notifier_call_chain(&otg->usb_phy->notifier, 191 USB_EVENT_VBUS, otg->gadget); 192 else 193 otg->state = OTG_STATE_B_IDLE; 194 return 0; 195 } 196 197 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 198 { 199 if (!otg) 200 return -ENODEV; 201 202 if (!host) { 203 otg->host = NULL; 204 return -ENODEV; 205 } 206 207 otg->host = host; 208 return 0; 209 } 210 211 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 212 struct usb_phy_generic_platform_data *pdata) 213 { 214 enum usb_phy_type type = USB_PHY_TYPE_USB2; 215 int err = 0; 216 217 u32 clk_rate = 0; 218 bool needs_vcc = false; 219 220 if (dev->of_node) { 221 struct device_node *node = dev->of_node; 222 223 if (of_property_read_u32(node, "clock-frequency", &clk_rate)) 224 clk_rate = 0; 225 226 needs_vcc = of_property_read_bool(node, "vcc-supply"); 227 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset", 228 GPIOD_ASIS); 229 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 230 if (!err) { 231 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 232 "vbus-detect", 233 GPIOD_ASIS); 234 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 235 } 236 } else if (pdata) { 237 type = pdata->type; 238 clk_rate = pdata->clk_rate; 239 needs_vcc = pdata->needs_vcc; 240 if (gpio_is_valid(pdata->gpio_reset)) { 241 err = devm_gpio_request_one(dev, pdata->gpio_reset, 242 GPIOF_ACTIVE_LOW, 243 dev_name(dev)); 244 if (!err) 245 nop->gpiod_reset = 246 gpio_to_desc(pdata->gpio_reset); 247 } 248 nop->gpiod_vbus = pdata->gpiod_vbus; 249 } 250 251 if (err == -EPROBE_DEFER) 252 return -EPROBE_DEFER; 253 if (err) { 254 dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); 255 return err; 256 } 257 if (nop->gpiod_reset) 258 gpiod_direction_output(nop->gpiod_reset, 1); 259 260 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 261 GFP_KERNEL); 262 if (!nop->phy.otg) 263 return -ENOMEM; 264 265 nop->clk = devm_clk_get(dev, "main_clk"); 266 if (IS_ERR(nop->clk)) { 267 dev_dbg(dev, "Can't get phy clock: %ld\n", 268 PTR_ERR(nop->clk)); 269 } 270 271 if (!IS_ERR(nop->clk) && clk_rate) { 272 err = clk_set_rate(nop->clk, clk_rate); 273 if (err) { 274 dev_err(dev, "Error setting clock rate\n"); 275 return err; 276 } 277 } 278 279 nop->vcc = devm_regulator_get(dev, "vcc"); 280 if (IS_ERR(nop->vcc)) { 281 dev_dbg(dev, "Error getting vcc regulator: %ld\n", 282 PTR_ERR(nop->vcc)); 283 if (needs_vcc) 284 return -EPROBE_DEFER; 285 } 286 287 nop->dev = dev; 288 nop->phy.dev = nop->dev; 289 nop->phy.label = "nop-xceiv"; 290 nop->phy.set_suspend = nop_set_suspend; 291 nop->phy.type = type; 292 293 nop->phy.otg->state = OTG_STATE_UNDEFINED; 294 nop->phy.otg->usb_phy = &nop->phy; 295 nop->phy.otg->set_host = nop_set_host; 296 nop->phy.otg->set_peripheral = nop_set_peripheral; 297 298 return 0; 299 } 300 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 301 302 static int usb_phy_generic_probe(struct platform_device *pdev) 303 { 304 struct device *dev = &pdev->dev; 305 struct usb_phy_generic *nop; 306 int err; 307 308 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 309 if (!nop) 310 return -ENOMEM; 311 312 err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev)); 313 if (err) 314 return err; 315 if (nop->gpiod_vbus) { 316 err = devm_request_threaded_irq(&pdev->dev, 317 gpiod_to_irq(nop->gpiod_vbus), 318 NULL, nop_gpio_vbus_thread, 319 VBUS_IRQ_FLAGS, "vbus_detect", 320 nop); 321 if (err) { 322 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 323 gpiod_to_irq(nop->gpiod_vbus), err); 324 return err; 325 } 326 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ? 327 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE; 328 } 329 330 nop->phy.init = usb_gen_phy_init; 331 nop->phy.shutdown = usb_gen_phy_shutdown; 332 333 err = usb_add_phy_dev(&nop->phy); 334 if (err) { 335 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 336 err); 337 return err; 338 } 339 340 platform_set_drvdata(pdev, nop); 341 342 return 0; 343 } 344 345 static int usb_phy_generic_remove(struct platform_device *pdev) 346 { 347 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 348 349 usb_remove_phy(&nop->phy); 350 351 return 0; 352 } 353 354 static const struct of_device_id nop_xceiv_dt_ids[] = { 355 { .compatible = "usb-nop-xceiv" }, 356 { } 357 }; 358 359 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 360 361 static struct platform_driver usb_phy_generic_driver = { 362 .probe = usb_phy_generic_probe, 363 .remove = usb_phy_generic_remove, 364 .driver = { 365 .name = "usb_phy_generic", 366 .of_match_table = nop_xceiv_dt_ids, 367 }, 368 }; 369 370 static int __init usb_phy_generic_init(void) 371 { 372 return platform_driver_register(&usb_phy_generic_driver); 373 } 374 subsys_initcall(usb_phy_generic_init); 375 376 static void __exit usb_phy_generic_exit(void) 377 { 378 platform_driver_unregister(&usb_phy_generic_driver); 379 } 380 module_exit(usb_phy_generic_exit); 381 382 MODULE_ALIAS("platform:usb_phy_generic"); 383 MODULE_AUTHOR("Texas Instruments Inc"); 384 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 385 MODULE_LICENSE("GPL"); 386