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 usb_gadget_vbus_connect(otg->gadget); 122 123 /* drawing a "unit load" is *always* OK, except for OTG */ 124 nop_set_vbus_draw(nop, 100); 125 126 atomic_notifier_call_chain(&nop->phy.notifier, status, 127 otg->gadget); 128 } else { 129 nop_set_vbus_draw(nop, 0); 130 131 usb_gadget_vbus_disconnect(otg->gadget); 132 status = USB_EVENT_NONE; 133 otg->state = OTG_STATE_B_IDLE; 134 nop->phy.last_event = status; 135 136 atomic_notifier_call_chain(&nop->phy.notifier, status, 137 otg->gadget); 138 } 139 return IRQ_HANDLED; 140 } 141 142 int usb_gen_phy_init(struct usb_phy *phy) 143 { 144 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 145 146 if (!IS_ERR(nop->vcc)) { 147 if (regulator_enable(nop->vcc)) 148 dev_err(phy->dev, "Failed to enable power\n"); 149 } 150 151 if (!IS_ERR(nop->clk)) 152 clk_prepare_enable(nop->clk); 153 154 nop_reset(nop); 155 156 return 0; 157 } 158 EXPORT_SYMBOL_GPL(usb_gen_phy_init); 159 160 void usb_gen_phy_shutdown(struct usb_phy *phy) 161 { 162 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev); 163 164 gpiod_set_value(nop->gpiod_reset, 1); 165 166 if (!IS_ERR(nop->clk)) 167 clk_disable_unprepare(nop->clk); 168 169 if (!IS_ERR(nop->vcc)) { 170 if (regulator_disable(nop->vcc)) 171 dev_err(phy->dev, "Failed to disable power\n"); 172 } 173 } 174 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown); 175 176 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget) 177 { 178 if (!otg) 179 return -ENODEV; 180 181 if (!gadget) { 182 otg->gadget = NULL; 183 return -ENODEV; 184 } 185 186 otg->gadget = gadget; 187 otg->state = OTG_STATE_B_IDLE; 188 return 0; 189 } 190 191 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host) 192 { 193 if (!otg) 194 return -ENODEV; 195 196 if (!host) { 197 otg->host = NULL; 198 return -ENODEV; 199 } 200 201 otg->host = host; 202 return 0; 203 } 204 205 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop, 206 struct usb_phy_generic_platform_data *pdata) 207 { 208 enum usb_phy_type type = USB_PHY_TYPE_USB2; 209 int err = 0; 210 211 u32 clk_rate = 0; 212 bool needs_vcc = 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_vcc = of_property_read_bool(node, "vcc-supply"); 221 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset"); 222 err = PTR_ERR_OR_ZERO(nop->gpiod_reset); 223 if (!err) { 224 nop->gpiod_vbus = devm_gpiod_get_optional(dev, 225 "vbus-detect"); 226 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus); 227 } 228 } else if (pdata) { 229 type = pdata->type; 230 clk_rate = pdata->clk_rate; 231 needs_vcc = pdata->needs_vcc; 232 if (gpio_is_valid(pdata->gpio_reset)) { 233 err = devm_gpio_request_one(dev, pdata->gpio_reset, 0, 234 dev_name(dev)); 235 if (!err) 236 nop->gpiod_reset = 237 gpio_to_desc(pdata->gpio_reset); 238 } 239 nop->gpiod_vbus = pdata->gpiod_vbus; 240 } 241 242 if (err == -EPROBE_DEFER) 243 return -EPROBE_DEFER; 244 if (err) { 245 dev_err(dev, "Error requesting RESET or VBUS GPIO\n"); 246 return err; 247 } 248 if (nop->gpiod_reset) 249 gpiod_direction_output(nop->gpiod_reset, 1); 250 251 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg), 252 GFP_KERNEL); 253 if (!nop->phy.otg) 254 return -ENOMEM; 255 256 nop->clk = devm_clk_get(dev, "main_clk"); 257 if (IS_ERR(nop->clk)) { 258 dev_dbg(dev, "Can't get phy clock: %ld\n", 259 PTR_ERR(nop->clk)); 260 } 261 262 if (!IS_ERR(nop->clk) && clk_rate) { 263 err = clk_set_rate(nop->clk, clk_rate); 264 if (err) { 265 dev_err(dev, "Error setting clock rate\n"); 266 return err; 267 } 268 } 269 270 nop->vcc = devm_regulator_get(dev, "vcc"); 271 if (IS_ERR(nop->vcc)) { 272 dev_dbg(dev, "Error getting vcc regulator: %ld\n", 273 PTR_ERR(nop->vcc)); 274 if (needs_vcc) 275 return -EPROBE_DEFER; 276 } 277 278 nop->dev = dev; 279 nop->phy.dev = nop->dev; 280 nop->phy.label = "nop-xceiv"; 281 nop->phy.set_suspend = nop_set_suspend; 282 nop->phy.type = type; 283 284 nop->phy.otg->state = OTG_STATE_UNDEFINED; 285 nop->phy.otg->usb_phy = &nop->phy; 286 nop->phy.otg->set_host = nop_set_host; 287 nop->phy.otg->set_peripheral = nop_set_peripheral; 288 289 return 0; 290 } 291 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy); 292 293 static int usb_phy_generic_probe(struct platform_device *pdev) 294 { 295 struct device *dev = &pdev->dev; 296 struct usb_phy_generic *nop; 297 int err; 298 299 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL); 300 if (!nop) 301 return -ENOMEM; 302 303 err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev)); 304 if (err) 305 return err; 306 if (nop->gpiod_vbus) { 307 err = devm_request_threaded_irq(&pdev->dev, 308 gpiod_to_irq(nop->gpiod_vbus), 309 NULL, nop_gpio_vbus_thread, 310 VBUS_IRQ_FLAGS, "vbus_detect", 311 nop); 312 if (err) { 313 dev_err(&pdev->dev, "can't request irq %i, err: %d\n", 314 gpiod_to_irq(nop->gpiod_vbus), err); 315 return err; 316 } 317 } 318 319 nop->phy.init = usb_gen_phy_init; 320 nop->phy.shutdown = usb_gen_phy_shutdown; 321 322 err = usb_add_phy_dev(&nop->phy); 323 if (err) { 324 dev_err(&pdev->dev, "can't register transceiver, err: %d\n", 325 err); 326 return err; 327 } 328 329 platform_set_drvdata(pdev, nop); 330 331 return 0; 332 } 333 334 static int usb_phy_generic_remove(struct platform_device *pdev) 335 { 336 struct usb_phy_generic *nop = platform_get_drvdata(pdev); 337 338 usb_remove_phy(&nop->phy); 339 340 return 0; 341 } 342 343 static const struct of_device_id nop_xceiv_dt_ids[] = { 344 { .compatible = "usb-nop-xceiv" }, 345 { } 346 }; 347 348 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids); 349 350 static struct platform_driver usb_phy_generic_driver = { 351 .probe = usb_phy_generic_probe, 352 .remove = usb_phy_generic_remove, 353 .driver = { 354 .name = "usb_phy_generic", 355 .of_match_table = nop_xceiv_dt_ids, 356 }, 357 }; 358 359 static int __init usb_phy_generic_init(void) 360 { 361 return platform_driver_register(&usb_phy_generic_driver); 362 } 363 subsys_initcall(usb_phy_generic_init); 364 365 static void __exit usb_phy_generic_exit(void) 366 { 367 platform_driver_unregister(&usb_phy_generic_driver); 368 } 369 module_exit(usb_phy_generic_exit); 370 371 MODULE_ALIAS("platform:usb_phy_generic"); 372 MODULE_AUTHOR("Texas Instruments Inc"); 373 MODULE_DESCRIPTION("NOP USB Transceiver driver"); 374 MODULE_LICENSE("GPL"); 375