1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Cadence USBSS and USBSSP DRD Driver. 4 * 5 * Copyright (C) 2018-2020 Cadence. 6 * Copyright (C) 2019 Texas Instruments 7 * 8 * Author: Pawel Laszczak <pawell@cadence.com> 9 * Roger Quadros <rogerq@ti.com> 10 * 11 */ 12 #include <linux/kernel.h> 13 #include <linux/interrupt.h> 14 #include <linux/delay.h> 15 #include <linux/iopoll.h> 16 #include <linux/usb/otg.h> 17 18 #include "drd.h" 19 #include "core.h" 20 21 /** 22 * cdns_set_mode - change mode of OTG Core 23 * @cdns: pointer to context structure 24 * @mode: selected mode from cdns_role 25 * 26 * Returns 0 on success otherwise negative errno 27 */ 28 static int cdns_set_mode(struct cdns *cdns, enum usb_dr_mode mode) 29 { 30 void __iomem *override_reg; 31 u32 reg; 32 33 switch (mode) { 34 case USB_DR_MODE_PERIPHERAL: 35 break; 36 case USB_DR_MODE_HOST: 37 break; 38 case USB_DR_MODE_OTG: 39 dev_dbg(cdns->dev, "Set controller to OTG mode\n"); 40 41 if (cdns->version == CDNSP_CONTROLLER_V2) 42 override_reg = &cdns->otg_cdnsp_regs->override; 43 else if (cdns->version == CDNS3_CONTROLLER_V1) 44 override_reg = &cdns->otg_v1_regs->override; 45 else 46 override_reg = &cdns->otg_v0_regs->ctrl1; 47 48 reg = readl(override_reg); 49 50 if (cdns->version != CDNS3_CONTROLLER_V0) 51 reg |= OVERRIDE_IDPULLUP; 52 else 53 reg |= OVERRIDE_IDPULLUP_V0; 54 55 writel(reg, override_reg); 56 57 if (cdns->version == CDNS3_CONTROLLER_V1) { 58 /* 59 * Enable work around feature built into the 60 * controller to address issue with RX Sensitivity 61 * est (EL_17) for USB2 PHY. The issue only occures 62 * for 0x0002450D controller version. 63 */ 64 if (cdns->phyrst_a_enable) { 65 reg = readl(&cdns->otg_v1_regs->phyrst_cfg); 66 reg |= PHYRST_CFG_PHYRST_A_ENABLE; 67 writel(reg, &cdns->otg_v1_regs->phyrst_cfg); 68 } 69 } 70 71 /* 72 * Hardware specification says: "ID_VALUE must be valid within 73 * 50ms after idpullup is set to '1" so driver must wait 74 * 50ms before reading this pin. 75 */ 76 usleep_range(50000, 60000); 77 break; 78 default: 79 dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode); 80 return -EINVAL; 81 } 82 83 return 0; 84 } 85 86 int cdns_get_id(struct cdns *cdns) 87 { 88 int id; 89 90 id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE; 91 dev_dbg(cdns->dev, "OTG ID: %d", id); 92 93 return id; 94 } 95 96 int cdns_get_vbus(struct cdns *cdns) 97 { 98 int vbus; 99 100 vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID); 101 dev_dbg(cdns->dev, "OTG VBUS: %d", vbus); 102 103 return vbus; 104 } 105 106 void cdns_clear_vbus(struct cdns *cdns) 107 { 108 u32 reg; 109 110 if (cdns->version != CDNSP_CONTROLLER_V2) 111 return; 112 113 reg = readl(&cdns->otg_cdnsp_regs->override); 114 reg |= OVERRIDE_SESS_VLD_SEL; 115 writel(reg, &cdns->otg_cdnsp_regs->override); 116 } 117 EXPORT_SYMBOL_GPL(cdns_clear_vbus); 118 119 void cdns_set_vbus(struct cdns *cdns) 120 { 121 u32 reg; 122 123 if (cdns->version != CDNSP_CONTROLLER_V2) 124 return; 125 126 reg = readl(&cdns->otg_cdnsp_regs->override); 127 reg &= ~OVERRIDE_SESS_VLD_SEL; 128 writel(reg, &cdns->otg_cdnsp_regs->override); 129 } 130 EXPORT_SYMBOL_GPL(cdns_set_vbus); 131 132 bool cdns_is_host(struct cdns *cdns) 133 { 134 if (cdns->dr_mode == USB_DR_MODE_HOST) 135 return true; 136 else if (cdns_get_id(cdns) == CDNS3_ID_HOST) 137 return true; 138 139 return false; 140 } 141 142 bool cdns_is_device(struct cdns *cdns) 143 { 144 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) 145 return true; 146 else if (cdns->dr_mode == USB_DR_MODE_OTG) 147 if (cdns_get_id(cdns) == CDNS3_ID_PERIPHERAL) 148 return true; 149 150 return false; 151 } 152 153 /** 154 * cdns_otg_disable_irq - Disable all OTG interrupts 155 * @cdns: Pointer to controller context structure 156 */ 157 static void cdns_otg_disable_irq(struct cdns *cdns) 158 { 159 writel(0, &cdns->otg_irq_regs->ien); 160 } 161 162 /** 163 * cdns_otg_enable_irq - enable id and sess_valid interrupts 164 * @cdns: Pointer to controller context structure 165 */ 166 static void cdns_otg_enable_irq(struct cdns *cdns) 167 { 168 writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT | 169 OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_irq_regs->ien); 170 } 171 172 /** 173 * cdns_drd_host_on - start host. 174 * @cdns: Pointer to controller context structure. 175 * 176 * Returns 0 on success otherwise negative errno. 177 */ 178 int cdns_drd_host_on(struct cdns *cdns) 179 { 180 u32 val, ready_bit; 181 int ret; 182 183 /* Enable host mode. */ 184 writel(OTGCMD_HOST_BUS_REQ | OTGCMD_OTG_DIS, 185 &cdns->otg_regs->cmd); 186 187 if (cdns->version == CDNSP_CONTROLLER_V2) 188 ready_bit = OTGSTS_CDNSP_XHCI_READY; 189 else 190 ready_bit = OTGSTS_CDNS3_XHCI_READY; 191 192 dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n"); 193 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val, 194 val & ready_bit, 1, 100000); 195 196 if (ret) 197 dev_err(cdns->dev, "timeout waiting for xhci_ready\n"); 198 199 phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_HOST); 200 return ret; 201 } 202 203 /** 204 * cdns_drd_host_off - stop host. 205 * @cdns: Pointer to controller context structure. 206 */ 207 void cdns_drd_host_off(struct cdns *cdns) 208 { 209 u32 val; 210 211 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP | 212 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF, 213 &cdns->otg_regs->cmd); 214 215 /* Waiting till H_IDLE state.*/ 216 readl_poll_timeout_atomic(&cdns->otg_regs->state, val, 217 !(val & OTGSTATE_HOST_STATE_MASK), 218 1, 2000000); 219 phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID); 220 } 221 222 /** 223 * cdns_drd_gadget_on - start gadget. 224 * @cdns: Pointer to controller context structure. 225 * 226 * Returns 0 on success otherwise negative errno 227 */ 228 int cdns_drd_gadget_on(struct cdns *cdns) 229 { 230 u32 reg = OTGCMD_OTG_DIS; 231 u32 ready_bit; 232 int ret, val; 233 234 /* switch OTG core */ 235 writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd); 236 237 dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n"); 238 239 if (cdns->version == CDNSP_CONTROLLER_V2) 240 ready_bit = OTGSTS_CDNSP_DEV_READY; 241 else 242 ready_bit = OTGSTS_CDNS3_DEV_READY; 243 244 ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val, 245 val & ready_bit, 1, 100000); 246 if (ret) { 247 dev_err(cdns->dev, "timeout waiting for dev_ready\n"); 248 return ret; 249 } 250 251 phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_DEVICE); 252 return 0; 253 } 254 EXPORT_SYMBOL_GPL(cdns_drd_gadget_on); 255 256 /** 257 * cdns_drd_gadget_off - stop gadget. 258 * @cdns: Pointer to controller context structure. 259 */ 260 void cdns_drd_gadget_off(struct cdns *cdns) 261 { 262 u32 val; 263 264 /* 265 * Driver should wait at least 10us after disabling Device 266 * before turning-off Device (DEV_BUS_DROP). 267 */ 268 usleep_range(20, 30); 269 writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP | 270 OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF, 271 &cdns->otg_regs->cmd); 272 /* Waiting till DEV_IDLE state.*/ 273 readl_poll_timeout_atomic(&cdns->otg_regs->state, val, 274 !(val & OTGSTATE_DEV_STATE_MASK), 275 1, 2000000); 276 phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID); 277 } 278 EXPORT_SYMBOL_GPL(cdns_drd_gadget_off); 279 280 /** 281 * cdns_init_otg_mode - initialize drd controller 282 * @cdns: Pointer to controller context structure 283 * 284 * Returns 0 on success otherwise negative errno 285 */ 286 static int cdns_init_otg_mode(struct cdns *cdns) 287 { 288 int ret; 289 290 cdns_otg_disable_irq(cdns); 291 /* clear all interrupts */ 292 writel(~0, &cdns->otg_irq_regs->ivect); 293 294 ret = cdns_set_mode(cdns, USB_DR_MODE_OTG); 295 if (ret) 296 return ret; 297 298 cdns_otg_enable_irq(cdns); 299 300 return 0; 301 } 302 303 /** 304 * cdns_drd_update_mode - initialize mode of operation 305 * @cdns: Pointer to controller context structure 306 * 307 * Returns 0 on success otherwise negative errno 308 */ 309 int cdns_drd_update_mode(struct cdns *cdns) 310 { 311 int ret; 312 313 switch (cdns->dr_mode) { 314 case USB_DR_MODE_PERIPHERAL: 315 ret = cdns_set_mode(cdns, USB_DR_MODE_PERIPHERAL); 316 break; 317 case USB_DR_MODE_HOST: 318 ret = cdns_set_mode(cdns, USB_DR_MODE_HOST); 319 break; 320 case USB_DR_MODE_OTG: 321 ret = cdns_init_otg_mode(cdns); 322 break; 323 default: 324 dev_err(cdns->dev, "Unsupported mode of operation %d\n", 325 cdns->dr_mode); 326 return -EINVAL; 327 } 328 329 return ret; 330 } 331 332 static irqreturn_t cdns_drd_thread_irq(int irq, void *data) 333 { 334 struct cdns *cdns = data; 335 336 cdns_hw_role_switch(cdns); 337 338 return IRQ_HANDLED; 339 } 340 341 /** 342 * cdns_drd_irq - interrupt handler for OTG events 343 * 344 * @irq: irq number for cdns core device 345 * @data: structure of cdns 346 * 347 * Returns IRQ_HANDLED or IRQ_NONE 348 */ 349 static irqreturn_t cdns_drd_irq(int irq, void *data) 350 { 351 irqreturn_t ret = IRQ_NONE; 352 struct cdns *cdns = data; 353 u32 reg; 354 355 if (cdns->dr_mode != USB_DR_MODE_OTG) 356 return IRQ_NONE; 357 358 if (cdns->in_lpm) 359 return ret; 360 361 reg = readl(&cdns->otg_irq_regs->ivect); 362 363 if (!reg) 364 return IRQ_NONE; 365 366 if (reg & OTGIEN_ID_CHANGE_INT) { 367 dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n", 368 cdns_get_id(cdns)); 369 370 ret = IRQ_WAKE_THREAD; 371 } 372 373 if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) { 374 dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n", 375 cdns_get_vbus(cdns)); 376 377 ret = IRQ_WAKE_THREAD; 378 } 379 380 writel(~0, &cdns->otg_irq_regs->ivect); 381 return ret; 382 } 383 384 int cdns_drd_init(struct cdns *cdns) 385 { 386 void __iomem *regs; 387 u32 state; 388 int ret; 389 390 regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res); 391 if (IS_ERR(regs)) 392 return PTR_ERR(regs); 393 394 /* Detection of DRD version. Controller has been released 395 * in three versions. All are very similar and are software compatible, 396 * but they have same changes in register maps. 397 * The first register in oldest version is command register and it's 398 * read only. Driver should read 0 from it. On the other hand, in v1 399 * and v2 the first register contains device ID number which is not 400 * set to 0. Driver uses this fact to detect the proper version of 401 * controller. 402 */ 403 cdns->otg_v0_regs = regs; 404 if (!readl(&cdns->otg_v0_regs->cmd)) { 405 cdns->version = CDNS3_CONTROLLER_V0; 406 cdns->otg_v1_regs = NULL; 407 cdns->otg_cdnsp_regs = NULL; 408 cdns->otg_regs = regs; 409 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *) 410 &cdns->otg_v0_regs->ien; 411 writel(1, &cdns->otg_v0_regs->simulate); 412 dev_dbg(cdns->dev, "DRD version v0 (%08x)\n", 413 readl(&cdns->otg_v0_regs->version)); 414 } else { 415 cdns->otg_v0_regs = NULL; 416 cdns->otg_v1_regs = regs; 417 cdns->otg_cdnsp_regs = regs; 418 419 cdns->otg_regs = (void __iomem *)&cdns->otg_v1_regs->cmd; 420 421 if (readl(&cdns->otg_cdnsp_regs->did) == OTG_CDNSP_DID) { 422 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *) 423 &cdns->otg_cdnsp_regs->ien; 424 cdns->version = CDNSP_CONTROLLER_V2; 425 } else { 426 cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *) 427 &cdns->otg_v1_regs->ien; 428 writel(1, &cdns->otg_v1_regs->simulate); 429 cdns->version = CDNS3_CONTROLLER_V1; 430 } 431 432 dev_dbg(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n", 433 readl(&cdns->otg_v1_regs->did), 434 readl(&cdns->otg_v1_regs->rid)); 435 } 436 437 state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts)); 438 439 /* Update dr_mode according to STRAP configuration. */ 440 cdns->dr_mode = USB_DR_MODE_OTG; 441 442 if ((cdns->version == CDNSP_CONTROLLER_V2 && 443 state == OTGSTS_CDNSP_STRAP_HOST) || 444 (cdns->version != CDNSP_CONTROLLER_V2 && 445 state == OTGSTS_STRAP_HOST)) { 446 dev_dbg(cdns->dev, "Controller strapped to HOST\n"); 447 cdns->dr_mode = USB_DR_MODE_HOST; 448 } else if ((cdns->version == CDNSP_CONTROLLER_V2 && 449 state == OTGSTS_CDNSP_STRAP_GADGET) || 450 (cdns->version != CDNSP_CONTROLLER_V2 && 451 state == OTGSTS_STRAP_GADGET)) { 452 dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n"); 453 cdns->dr_mode = USB_DR_MODE_PERIPHERAL; 454 } 455 456 ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq, 457 cdns_drd_irq, 458 cdns_drd_thread_irq, 459 IRQF_SHARED, 460 dev_name(cdns->dev), cdns); 461 if (ret) { 462 dev_err(cdns->dev, "couldn't get otg_irq\n"); 463 return ret; 464 } 465 466 state = readl(&cdns->otg_regs->sts); 467 if (OTGSTS_OTG_NRDY(state)) { 468 dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n"); 469 return -ENODEV; 470 } 471 472 return 0; 473 } 474 475 int cdns_drd_exit(struct cdns *cdns) 476 { 477 cdns_otg_disable_irq(cdns); 478 479 return 0; 480 } 481 482 483 /* Indicate the cdns3 core was power lost before */ 484 bool cdns_power_is_lost(struct cdns *cdns) 485 { 486 if (cdns->version == CDNS3_CONTROLLER_V1) { 487 if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0))) 488 return true; 489 } else { 490 if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0))) 491 return true; 492 } 493 return false; 494 } 495 EXPORT_SYMBOL_GPL(cdns_power_is_lost); 496