1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * MAX3420 Device Controller driver for USB. 4 * 5 * Author: Jaswinder Singh Brar <jaswinder.singh@linaro.org> 6 * (C) Copyright 2019-2020 Linaro Ltd 7 * 8 * Based on: 9 * o MAX3420E datasheet 10 * https://datasheets.maximintegrated.com/en/ds/MAX3420E.pdf 11 * o MAX342{0,1}E Programming Guides 12 * https://pdfserv.maximintegrated.com/en/an/AN3598.pdf 13 * https://pdfserv.maximintegrated.com/en/an/AN3785.pdf 14 */ 15 16#include <linux/delay.h> 17#include <linux/device.h> 18#include <linux/interrupt.h> 19#include <linux/io.h> 20#include <linux/module.h> 21#include <linux/bitfield.h> 22#include <linux/of.h> 23#include <linux/of_irq.h> 24#include <linux/prefetch.h> 25#include <linux/usb/ch9.h> 26#include <linux/usb/gadget.h> 27#include <linux/spi/spi.h> 28#include <linux/gpio/consumer.h> 29 30#define MAX3420_MAX_EPS 4 31#define MAX3420_EP_MAX_PACKET 64 /* Same for all Endpoints */ 32#define MAX3420_EPNAME_SIZE 16 /* Buffer size for endpoint name */ 33 34#define MAX3420_ACKSTAT BIT(0) 35 36#define MAX3420_SPI_DIR_RD 0 /* read register from MAX3420 */ 37#define MAX3420_SPI_DIR_WR 1 /* write register to MAX3420 */ 38 39/* SPI commands: */ 40#define MAX3420_SPI_DIR_SHIFT 1 41#define MAX3420_SPI_REG_SHIFT 3 42 43#define MAX3420_REG_EP0FIFO 0 44#define MAX3420_REG_EP1FIFO 1 45#define MAX3420_REG_EP2FIFO 2 46#define MAX3420_REG_EP3FIFO 3 47#define MAX3420_REG_SUDFIFO 4 48#define MAX3420_REG_EP0BC 5 49#define MAX3420_REG_EP1BC 6 50#define MAX3420_REG_EP2BC 7 51#define MAX3420_REG_EP3BC 8 52 53#define MAX3420_REG_EPSTALLS 9 54 #define ACKSTAT BIT(6) 55 #define STLSTAT BIT(5) 56 #define STLEP3IN BIT(4) 57 #define STLEP2IN BIT(3) 58 #define STLEP1OUT BIT(2) 59 #define STLEP0OUT BIT(1) 60 #define STLEP0IN BIT(0) 61 62#define MAX3420_REG_CLRTOGS 10 63 #define EP3DISAB BIT(7) 64 #define EP2DISAB BIT(6) 65 #define EP1DISAB BIT(5) 66 #define CTGEP3IN BIT(4) 67 #define CTGEP2IN BIT(3) 68 #define CTGEP1OUT BIT(2) 69 70#define MAX3420_REG_EPIRQ 11 71#define MAX3420_REG_EPIEN 12 72 #define SUDAVIRQ BIT(5) 73 #define IN3BAVIRQ BIT(4) 74 #define IN2BAVIRQ BIT(3) 75 #define OUT1DAVIRQ BIT(2) 76 #define OUT0DAVIRQ BIT(1) 77 #define IN0BAVIRQ BIT(0) 78 79#define MAX3420_REG_USBIRQ 13 80#define MAX3420_REG_USBIEN 14 81 #define OSCOKIRQ BIT(0) 82 #define RWUDNIRQ BIT(1) 83 #define BUSACTIRQ BIT(2) 84 #define URESIRQ BIT(3) 85 #define SUSPIRQ BIT(4) 86 #define NOVBUSIRQ BIT(5) 87 #define VBUSIRQ BIT(6) 88 #define URESDNIRQ BIT(7) 89 90#define MAX3420_REG_USBCTL 15 91 #define HOSCSTEN BIT(7) 92 #define VBGATE BIT(6) 93 #define CHIPRES BIT(5) 94 #define PWRDOWN BIT(4) 95 #define CONNECT BIT(3) 96 #define SIGRWU BIT(2) 97 98#define MAX3420_REG_CPUCTL 16 99 #define IE BIT(0) 100 101#define MAX3420_REG_PINCTL 17 102 #define EP3INAK BIT(7) 103 #define EP2INAK BIT(6) 104 #define EP0INAK BIT(5) 105 #define FDUPSPI BIT(4) 106 #define INTLEVEL BIT(3) 107 #define POSINT BIT(2) 108 #define GPXB BIT(1) 109 #define GPXA BIT(0) 110 111#define MAX3420_REG_REVISION 18 112 113#define MAX3420_REG_FNADDR 19 114 #define FNADDR_MASK 0x7f 115 116#define MAX3420_REG_IOPINS 20 117#define MAX3420_REG_IOPINS2 21 118#define MAX3420_REG_GPINIRQ 22 119#define MAX3420_REG_GPINIEN 23 120#define MAX3420_REG_GPINPOL 24 121#define MAX3420_REG_HIRQ 25 122#define MAX3420_REG_HIEN 26 123#define MAX3420_REG_MODE 27 124#define MAX3420_REG_PERADDR 28 125#define MAX3420_REG_HCTL 29 126#define MAX3420_REG_HXFR 30 127#define MAX3420_REG_HRSL 31 128 129#define ENABLE_IRQ BIT(0) 130#define IOPIN_UPDATE BIT(1) 131#define REMOTE_WAKEUP BIT(2) 132#define CONNECT_HOST GENMASK(4, 3) 133#define HCONNECT (1 << 3) 134#define HDISCONNECT (3 << 3) 135#define UDC_START GENMASK(6, 5) 136#define START (1 << 5) 137#define STOP (3 << 5) 138#define ENABLE_EP GENMASK(8, 7) 139#define ENABLE (1 << 7) 140#define DISABLE (3 << 7) 141#define STALL_EP GENMASK(10, 9) 142#define STALL (1 << 9) 143#define UNSTALL (3 << 9) 144 145#define MAX3420_CMD(c) FIELD_PREP(GENMASK(7, 3), c) 146#define MAX3420_SPI_CMD_RD(c) (MAX3420_CMD(c) | (0 << 1)) 147#define MAX3420_SPI_CMD_WR(c) (MAX3420_CMD(c) | (1 << 1)) 148 149struct max3420_req { 150 struct usb_request usb_req; 151 struct list_head queue; 152 struct max3420_ep *ep; 153}; 154 155struct max3420_ep { 156 struct usb_ep ep_usb; 157 struct max3420_udc *udc; 158 struct list_head queue; 159 char name[MAX3420_EPNAME_SIZE]; 160 unsigned int maxpacket; 161 spinlock_t lock; 162 int halted; 163 u32 todo; 164 int id; 165}; 166 167struct max3420_udc { 168 struct usb_gadget gadget; 169 struct max3420_ep ep[MAX3420_MAX_EPS]; 170 struct usb_gadget_driver *driver; 171 struct task_struct *thread_task; 172 int remote_wkp, is_selfpowered; 173 bool vbus_active, softconnect; 174 struct usb_ctrlrequest setup; 175 struct mutex spi_bus_mutex; 176 struct max3420_req ep0req; 177 struct spi_device *spi; 178 struct device *dev; 179 spinlock_t lock; 180 bool suspended; 181 u8 ep0buf[64]; 182 u32 todo; 183}; 184 185#define to_max3420_req(r) container_of((r), struct max3420_req, usb_req) 186#define to_max3420_ep(e) container_of((e), struct max3420_ep, ep_usb) 187#define to_udc(g) container_of((g), struct max3420_udc, gadget) 188 189#define DRIVER_DESC "MAX3420 USB Device-Mode Driver" 190static const char driver_name[] = "max3420-udc"; 191 192/* Control endpoint configuration.*/ 193static const struct usb_endpoint_descriptor ep0_desc = { 194 .bEndpointAddress = USB_DIR_OUT, 195 .bmAttributes = USB_ENDPOINT_XFER_CONTROL, 196 .wMaxPacketSize = cpu_to_le16(MAX3420_EP_MAX_PACKET), 197}; 198 199static void spi_ack_ctrl(struct max3420_udc *udc) 200{ 201 struct spi_device *spi = udc->spi; 202 struct spi_transfer transfer; 203 struct spi_message msg; 204 u8 txdata[1]; 205 206 memset(&transfer, 0, sizeof(transfer)); 207 208 spi_message_init(&msg); 209 210 txdata[0] = MAX3420_ACKSTAT; 211 transfer.tx_buf = txdata; 212 transfer.len = 1; 213 214 spi_message_add_tail(&transfer, &msg); 215 spi_sync(spi, &msg); 216} 217 218static u8 spi_rd8_ack(struct max3420_udc *udc, u8 reg, int actstat) 219{ 220 struct spi_device *spi = udc->spi; 221 struct spi_transfer transfer; 222 struct spi_message msg; 223 u8 txdata[2], rxdata[2]; 224 225 memset(&transfer, 0, sizeof(transfer)); 226 227 spi_message_init(&msg); 228 229 txdata[0] = MAX3420_SPI_CMD_RD(reg) | (actstat ? MAX3420_ACKSTAT : 0); 230 transfer.tx_buf = txdata; 231 transfer.rx_buf = rxdata; 232 transfer.len = 2; 233 234 spi_message_add_tail(&transfer, &msg); 235 spi_sync(spi, &msg); 236 237 return rxdata[1]; 238} 239 240static u8 spi_rd8(struct max3420_udc *udc, u8 reg) 241{ 242 return spi_rd8_ack(udc, reg, 0); 243} 244 245static void spi_wr8_ack(struct max3420_udc *udc, u8 reg, u8 val, int actstat) 246{ 247 struct spi_device *spi = udc->spi; 248 struct spi_transfer transfer; 249 struct spi_message msg; 250 u8 txdata[2]; 251 252 memset(&transfer, 0, sizeof(transfer)); 253 254 spi_message_init(&msg); 255 256 txdata[0] = MAX3420_SPI_CMD_WR(reg) | (actstat ? MAX3420_ACKSTAT : 0); 257 txdata[1] = val; 258 259 transfer.tx_buf = txdata; 260 transfer.len = 2; 261 262 spi_message_add_tail(&transfer, &msg); 263 spi_sync(spi, &msg); 264} 265 266static void spi_wr8(struct max3420_udc *udc, u8 reg, u8 val) 267{ 268 spi_wr8_ack(udc, reg, val, 0); 269} 270 271static void spi_rd_buf(struct max3420_udc *udc, u8 reg, void *buf, u8 len) 272{ 273 struct spi_device *spi = udc->spi; 274 struct spi_transfer transfer; 275 struct spi_message msg; 276 u8 local_buf[MAX3420_EP_MAX_PACKET + 1] = {}; 277 278 memset(&transfer, 0, sizeof(transfer)); 279 280 spi_message_init(&msg); 281 282 local_buf[0] = MAX3420_SPI_CMD_RD(reg); 283 transfer.tx_buf = &local_buf[0]; 284 transfer.rx_buf = &local_buf[0]; 285 transfer.len = len + 1; 286 287 spi_message_add_tail(&transfer, &msg); 288 spi_sync(spi, &msg); 289 290 memcpy(buf, &local_buf[1], len); 291} 292 293static void spi_wr_buf(struct max3420_udc *udc, u8 reg, void *buf, u8 len) 294{ 295 struct spi_device *spi = udc->spi; 296 struct spi_transfer transfer; 297 struct spi_message msg; 298 u8 local_buf[MAX3420_EP_MAX_PACKET + 1] = {}; 299 300 memset(&transfer, 0, sizeof(transfer)); 301 302 spi_message_init(&msg); 303 304 local_buf[0] = MAX3420_SPI_CMD_WR(reg); 305 memcpy(&local_buf[1], buf, len); 306 307 transfer.tx_buf = local_buf; 308 transfer.len = len + 1; 309 310 spi_message_add_tail(&transfer, &msg); 311 spi_sync(spi, &msg); 312} 313 314static int spi_max3420_enable(struct max3420_ep *ep) 315{ 316 struct max3420_udc *udc = ep->udc; 317 unsigned long flags; 318 u8 epdis, epien; 319 int todo; 320 321 spin_lock_irqsave(&ep->lock, flags); 322 todo = ep->todo & ENABLE_EP; 323 ep->todo &= ~ENABLE_EP; 324 spin_unlock_irqrestore(&ep->lock, flags); 325 326 if (!todo || ep->id == 0) 327 return false; 328 329 epien = spi_rd8(udc, MAX3420_REG_EPIEN); 330 epdis = spi_rd8(udc, MAX3420_REG_CLRTOGS); 331 332 if (todo == ENABLE) { 333 epdis &= ~BIT(ep->id + 4); 334 epien |= BIT(ep->id + 1); 335 } else { 336 epdis |= BIT(ep->id + 4); 337 epien &= ~BIT(ep->id + 1); 338 } 339 340 spi_wr8(udc, MAX3420_REG_CLRTOGS, epdis); 341 spi_wr8(udc, MAX3420_REG_EPIEN, epien); 342 343 return true; 344} 345 346static int spi_max3420_stall(struct max3420_ep *ep) 347{ 348 struct max3420_udc *udc = ep->udc; 349 unsigned long flags; 350 u8 epstalls; 351 int todo; 352 353 spin_lock_irqsave(&ep->lock, flags); 354 todo = ep->todo & STALL_EP; 355 ep->todo &= ~STALL_EP; 356 spin_unlock_irqrestore(&ep->lock, flags); 357 358 if (!todo || ep->id == 0) 359 return false; 360 361 epstalls = spi_rd8(udc, MAX3420_REG_EPSTALLS); 362 if (todo == STALL) { 363 ep->halted = 1; 364 epstalls |= BIT(ep->id + 1); 365 } else { 366 u8 clrtogs; 367 368 ep->halted = 0; 369 epstalls &= ~BIT(ep->id + 1); 370 clrtogs = spi_rd8(udc, MAX3420_REG_CLRTOGS); 371 clrtogs |= BIT(ep->id + 1); 372 spi_wr8(udc, MAX3420_REG_CLRTOGS, clrtogs); 373 } 374 spi_wr8(udc, MAX3420_REG_EPSTALLS, epstalls | ACKSTAT); 375 376 return true; 377} 378 379static int spi_max3420_rwkup(struct max3420_udc *udc) 380{ 381 unsigned long flags; 382 int wake_remote; 383 u8 usbctl; 384 385 spin_lock_irqsave(&udc->lock, flags); 386 wake_remote = udc->todo & REMOTE_WAKEUP; 387 udc->todo &= ~REMOTE_WAKEUP; 388 spin_unlock_irqrestore(&udc->lock, flags); 389 390 if (!wake_remote || !udc->suspended) 391 return false; 392 393 /* Set Remote-WkUp Signal*/ 394 usbctl = spi_rd8(udc, MAX3420_REG_USBCTL); 395 usbctl |= SIGRWU; 396 spi_wr8(udc, MAX3420_REG_USBCTL, usbctl); 397 398 msleep_interruptible(5); 399 400 /* Clear Remote-WkUp Signal*/ 401 usbctl = spi_rd8(udc, MAX3420_REG_USBCTL); 402 usbctl &= ~SIGRWU; 403 spi_wr8(udc, MAX3420_REG_USBCTL, usbctl); 404 405 udc->suspended = false; 406 407 return true; 408} 409 410static void max3420_nuke(struct max3420_ep *ep, int status); 411static void __max3420_stop(struct max3420_udc *udc) 412{ 413 u8 val; 414 int i; 415 416 /* clear all pending requests */ 417 for (i = 1; i < MAX3420_MAX_EPS; i++) 418 max3420_nuke(&udc->ep[i], -ECONNRESET); 419 420 /* Disable IRQ to CPU */ 421 spi_wr8(udc, MAX3420_REG_CPUCTL, 0); 422 423 val = spi_rd8(udc, MAX3420_REG_USBCTL); 424 val |= PWRDOWN; 425 if (udc->is_selfpowered) 426 val &= ~HOSCSTEN; 427 else 428 val |= HOSCSTEN; 429 spi_wr8(udc, MAX3420_REG_USBCTL, val); 430} 431 432static void __max3420_start(struct max3420_udc *udc) 433{ 434 u8 val; 435 436 /* Need this delay if bus-powered, 437 * but even for self-powered it helps stability 438 */ 439 msleep_interruptible(250); 440 441 /* configure SPI */ 442 spi_wr8(udc, MAX3420_REG_PINCTL, FDUPSPI); 443 444 /* Chip Reset */ 445 spi_wr8(udc, MAX3420_REG_USBCTL, CHIPRES); 446 msleep_interruptible(5); 447 spi_wr8(udc, MAX3420_REG_USBCTL, 0); 448 449 /* Poll for OSC to stabilize */ 450 while (1) { 451 val = spi_rd8(udc, MAX3420_REG_USBIRQ); 452 if (val & OSCOKIRQ) 453 break; 454 cond_resched(); 455 } 456 457 /* Enable PULL-UP only when Vbus detected */ 458 val = spi_rd8(udc, MAX3420_REG_USBCTL); 459 val |= VBGATE | CONNECT; 460 spi_wr8(udc, MAX3420_REG_USBCTL, val); 461 462 val = URESDNIRQ | URESIRQ; 463 if (udc->is_selfpowered) 464 val |= NOVBUSIRQ; 465 spi_wr8(udc, MAX3420_REG_USBIEN, val); 466 467 /* Enable only EP0 interrupts */ 468 val = IN0BAVIRQ | OUT0DAVIRQ | SUDAVIRQ; 469 spi_wr8(udc, MAX3420_REG_EPIEN, val); 470 471 /* Enable IRQ to CPU */ 472 spi_wr8(udc, MAX3420_REG_CPUCTL, IE); 473} 474 475static int max3420_start(struct max3420_udc *udc) 476{ 477 unsigned long flags; 478 int todo; 479 480 spin_lock_irqsave(&udc->lock, flags); 481 todo = udc->todo & UDC_START; 482 udc->todo &= ~UDC_START; 483 spin_unlock_irqrestore(&udc->lock, flags); 484 485 if (!todo) 486 return false; 487 488 if (udc->vbus_active && udc->softconnect) 489 __max3420_start(udc); 490 else 491 __max3420_stop(udc); 492 493 return true; 494} 495 496static irqreturn_t max3420_vbus_handler(int irq, void *dev_id) 497{ 498 struct max3420_udc *udc = dev_id; 499 unsigned long flags; 500 501 spin_lock_irqsave(&udc->lock, flags); 502 /* its a vbus change interrupt */ 503 udc->vbus_active = !udc->vbus_active; 504 udc->todo |= UDC_START; 505 usb_udc_vbus_handler(&udc->gadget, udc->vbus_active); 506 usb_gadget_set_state(&udc->gadget, udc->vbus_active 507 ? USB_STATE_POWERED : USB_STATE_NOTATTACHED); 508 spin_unlock_irqrestore(&udc->lock, flags); 509 510 if (udc->thread_task) 511 wake_up_process(udc->thread_task); 512 513 return IRQ_HANDLED; 514} 515 516static irqreturn_t max3420_irq_handler(int irq, void *dev_id) 517{ 518 struct max3420_udc *udc = dev_id; 519 struct spi_device *spi = udc->spi; 520 unsigned long flags; 521 522 spin_lock_irqsave(&udc->lock, flags); 523 if ((udc->todo & ENABLE_IRQ) == 0) { 524 disable_irq_nosync(spi->irq); 525 udc->todo |= ENABLE_IRQ; 526 } 527 spin_unlock_irqrestore(&udc->lock, flags); 528 529 if (udc->thread_task) 530 wake_up_process(udc->thread_task); 531 532 return IRQ_HANDLED; 533} 534 535static void max3420_getstatus(struct max3420_udc *udc) 536{ 537 struct max3420_ep *ep; 538 u16 status = 0; 539 540 switch (udc->setup.bRequestType & USB_RECIP_MASK) { 541 case USB_RECIP_DEVICE: 542 /* Get device status */ 543 status = udc->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED; 544 status |= (udc->remote_wkp << USB_DEVICE_REMOTE_WAKEUP); 545 break; 546 case USB_RECIP_INTERFACE: 547 if (udc->driver->setup(&udc->gadget, &udc->setup) < 0) 548 goto stall; 549 break; 550 case USB_RECIP_ENDPOINT: 551 ep = &udc->ep[udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK]; 552 if (udc->setup.wIndex & USB_DIR_IN) { 553 if (!ep->ep_usb.caps.dir_in) 554 goto stall; 555 } else { 556 if (!ep->ep_usb.caps.dir_out) 557 goto stall; 558 } 559 if (ep->halted) 560 status = 1 << USB_ENDPOINT_HALT; 561 break; 562 default: 563 goto stall; 564 } 565 566 status = cpu_to_le16(status); 567 spi_wr_buf(udc, MAX3420_REG_EP0FIFO, &status, 2); 568 spi_wr8_ack(udc, MAX3420_REG_EP0BC, 2, 1); 569 return; 570stall: 571 dev_err(udc->dev, "Can't respond to getstatus request\n"); 572 spi_wr8(udc, MAX3420_REG_EPSTALLS, STLEP0IN | STLEP0OUT | STLSTAT); 573} 574 575static void max3420_set_clear_feature(struct max3420_udc *udc) 576{ 577 struct max3420_ep *ep; 578 int set = udc->setup.bRequest == USB_REQ_SET_FEATURE; 579 unsigned long flags; 580 int id; 581 582 switch (udc->setup.bRequestType) { 583 case USB_RECIP_DEVICE: 584 if (udc->setup.wValue != USB_DEVICE_REMOTE_WAKEUP) 585 break; 586 587 if (udc->setup.bRequest == USB_REQ_SET_FEATURE) 588 udc->remote_wkp = 1; 589 else 590 udc->remote_wkp = 0; 591 592 return spi_ack_ctrl(udc); 593 594 case USB_RECIP_ENDPOINT: 595 if (udc->setup.wValue != USB_ENDPOINT_HALT) 596 break; 597 598 id = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK; 599 ep = &udc->ep[id]; 600 601 spin_lock_irqsave(&ep->lock, flags); 602 ep->todo &= ~STALL_EP; 603 if (set) 604 ep->todo |= STALL; 605 else 606 ep->todo |= UNSTALL; 607 spin_unlock_irqrestore(&ep->lock, flags); 608 609 spi_max3420_stall(ep); 610 return; 611 default: 612 break; 613 } 614 615 dev_err(udc->dev, "Can't respond to SET/CLEAR FEATURE\n"); 616 spi_wr8(udc, MAX3420_REG_EPSTALLS, STLEP0IN | STLEP0OUT | STLSTAT); 617} 618 619static void max3420_handle_setup(struct max3420_udc *udc) 620{ 621 struct usb_ctrlrequest setup; 622 623 spi_rd_buf(udc, MAX3420_REG_SUDFIFO, (void *)&setup, 8); 624 625 udc->setup = setup; 626 udc->setup.wValue = cpu_to_le16(setup.wValue); 627 udc->setup.wIndex = cpu_to_le16(setup.wIndex); 628 udc->setup.wLength = cpu_to_le16(setup.wLength); 629 630 switch (udc->setup.bRequest) { 631 case USB_REQ_GET_STATUS: 632 /* Data+Status phase form udc */ 633 if ((udc->setup.bRequestType & 634 (USB_DIR_IN | USB_TYPE_MASK)) != 635 (USB_DIR_IN | USB_TYPE_STANDARD)) { 636 break; 637 } 638 return max3420_getstatus(udc); 639 case USB_REQ_SET_ADDRESS: 640 /* Status phase from udc */ 641 if (udc->setup.bRequestType != (USB_DIR_OUT | 642 USB_TYPE_STANDARD | USB_RECIP_DEVICE)) { 643 break; 644 } 645 spi_rd8_ack(udc, MAX3420_REG_FNADDR, 1); 646 dev_dbg(udc->dev, "Assigned Address=%d\n", udc->setup.wValue); 647 return; 648 case USB_REQ_CLEAR_FEATURE: 649 case USB_REQ_SET_FEATURE: 650 /* Requests with no data phase, status phase from udc */ 651 if ((udc->setup.bRequestType & USB_TYPE_MASK) 652 != USB_TYPE_STANDARD) 653 break; 654 return max3420_set_clear_feature(udc); 655 default: 656 break; 657 } 658 659 if (udc->driver->setup(&udc->gadget, &setup) < 0) { 660 /* Stall EP0 */ 661 spi_wr8(udc, MAX3420_REG_EPSTALLS, 662 STLEP0IN | STLEP0OUT | STLSTAT); 663 } 664} 665 666static void max3420_req_done(struct max3420_req *req, int status) 667{ 668 struct max3420_ep *ep = req->ep; 669 struct max3420_udc *udc = ep->udc; 670 671 if (req->usb_req.status == -EINPROGRESS) 672 req->usb_req.status = status; 673 else 674 status = req->usb_req.status; 675 676 if (status && status != -ESHUTDOWN) 677 dev_err(udc->dev, "%s done %p, status %d\n", 678 ep->ep_usb.name, req, status); 679 680 if (req->usb_req.complete) 681 req->usb_req.complete(&ep->ep_usb, &req->usb_req); 682} 683 684static int max3420_do_data(struct max3420_udc *udc, int ep_id, int in) 685{ 686 struct max3420_ep *ep = &udc->ep[ep_id]; 687 struct max3420_req *req; 688 int done, length, psz; 689 void *buf; 690 691 if (list_empty(&ep->queue)) 692 return false; 693 694 req = list_first_entry(&ep->queue, struct max3420_req, queue); 695 buf = req->usb_req.buf + req->usb_req.actual; 696 697 psz = ep->ep_usb.maxpacket; 698 length = req->usb_req.length - req->usb_req.actual; 699 length = min(length, psz); 700 701 if (length == 0) { 702 done = 1; 703 goto xfer_done; 704 } 705 706 done = 0; 707 if (in) { 708 prefetch(buf); 709 spi_wr_buf(udc, MAX3420_REG_EP0FIFO + ep_id, buf, length); 710 spi_wr8(udc, MAX3420_REG_EP0BC + ep_id, length); 711 if (length < psz) 712 done = 1; 713 } else { 714 psz = spi_rd8(udc, MAX3420_REG_EP0BC + ep_id); 715 length = min(length, psz); 716 prefetchw(buf); 717 spi_rd_buf(udc, MAX3420_REG_EP0FIFO + ep_id, buf, length); 718 if (length < ep->ep_usb.maxpacket) 719 done = 1; 720 } 721 722 req->usb_req.actual += length; 723 724 if (req->usb_req.actual == req->usb_req.length) 725 done = 1; 726 727xfer_done: 728 if (done) { 729 unsigned long flags; 730 731 spin_lock_irqsave(&ep->lock, flags); 732 list_del_init(&req->queue); 733 spin_unlock_irqrestore(&ep->lock, flags); 734 735 if (ep_id == 0) 736 spi_ack_ctrl(udc); 737 738 max3420_req_done(req, 0); 739 } 740 741 return true; 742} 743 744static int max3420_handle_irqs(struct max3420_udc *udc) 745{ 746 u8 epien, epirq, usbirq, usbien, reg[4]; 747 bool ret = false; 748 749 spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 4); 750 epirq = reg[0]; 751 epien = reg[1]; 752 usbirq = reg[2]; 753 usbien = reg[3]; 754 755 usbirq &= usbien; 756 epirq &= epien; 757 758 if (epirq & SUDAVIRQ) { 759 spi_wr8(udc, MAX3420_REG_EPIRQ, SUDAVIRQ); 760 max3420_handle_setup(udc); 761 return true; 762 } 763 764 if (usbirq & VBUSIRQ) { 765 spi_wr8(udc, MAX3420_REG_USBIRQ, VBUSIRQ); 766 dev_dbg(udc->dev, "Cable plugged in\n"); 767 return true; 768 } 769 770 if (usbirq & NOVBUSIRQ) { 771 spi_wr8(udc, MAX3420_REG_USBIRQ, NOVBUSIRQ); 772 dev_dbg(udc->dev, "Cable pulled out\n"); 773 return true; 774 } 775 776 if (usbirq & URESIRQ) { 777 spi_wr8(udc, MAX3420_REG_USBIRQ, URESIRQ); 778 dev_dbg(udc->dev, "USB Reset - Start\n"); 779 return true; 780 } 781 782 if (usbirq & URESDNIRQ) { 783 spi_wr8(udc, MAX3420_REG_USBIRQ, URESDNIRQ); 784 dev_dbg(udc->dev, "USB Reset - END\n"); 785 spi_wr8(udc, MAX3420_REG_USBIEN, URESDNIRQ | URESIRQ); 786 spi_wr8(udc, MAX3420_REG_EPIEN, SUDAVIRQ | IN0BAVIRQ 787 | OUT0DAVIRQ); 788 return true; 789 } 790 791 if (usbirq & SUSPIRQ) { 792 spi_wr8(udc, MAX3420_REG_USBIRQ, SUSPIRQ); 793 dev_dbg(udc->dev, "USB Suspend - Enter\n"); 794 udc->suspended = true; 795 return true; 796 } 797 798 if (usbirq & BUSACTIRQ) { 799 spi_wr8(udc, MAX3420_REG_USBIRQ, BUSACTIRQ); 800 dev_dbg(udc->dev, "USB Suspend - Exit\n"); 801 udc->suspended = false; 802 return true; 803 } 804 805 if (usbirq & RWUDNIRQ) { 806 spi_wr8(udc, MAX3420_REG_USBIRQ, RWUDNIRQ); 807 dev_dbg(udc->dev, "Asked Host to wakeup\n"); 808 return true; 809 } 810 811 if (usbirq & OSCOKIRQ) { 812 spi_wr8(udc, MAX3420_REG_USBIRQ, OSCOKIRQ); 813 dev_dbg(udc->dev, "Osc stabilized, start work\n"); 814 return true; 815 } 816 817 if (epirq & OUT0DAVIRQ && max3420_do_data(udc, 0, 0)) { 818 spi_wr8_ack(udc, MAX3420_REG_EPIRQ, OUT0DAVIRQ, 1); 819 ret = true; 820 } 821 822 if (epirq & IN0BAVIRQ && max3420_do_data(udc, 0, 1)) 823 ret = true; 824 825 if (epirq & OUT1DAVIRQ && max3420_do_data(udc, 1, 0)) { 826 spi_wr8_ack(udc, MAX3420_REG_EPIRQ, OUT1DAVIRQ, 1); 827 ret = true; 828 } 829 830 if (epirq & IN2BAVIRQ && max3420_do_data(udc, 2, 1)) 831 ret = true; 832 833 if (epirq & IN3BAVIRQ && max3420_do_data(udc, 3, 1)) 834 ret = true; 835 836 return ret; 837} 838 839static int max3420_thread(void *dev_id) 840{ 841 struct max3420_udc *udc = dev_id; 842 struct spi_device *spi = udc->spi; 843 int i, loop_again = 1; 844 unsigned long flags; 845 846 while (!kthread_should_stop()) { 847 if (!loop_again) { 848 ktime_t kt = ns_to_ktime(1000 * 1000 * 250); /* 250ms */ 849 850 set_current_state(TASK_INTERRUPTIBLE); 851 852 spin_lock_irqsave(&udc->lock, flags); 853 if (udc->todo & ENABLE_IRQ) { 854 enable_irq(spi->irq); 855 udc->todo &= ~ENABLE_IRQ; 856 } 857 spin_unlock_irqrestore(&udc->lock, flags); 858 859 schedule_hrtimeout(&kt, HRTIMER_MODE_REL); 860 } 861 loop_again = 0; 862 863 mutex_lock(&udc->spi_bus_mutex); 864 865 /* If bus-vbus_active and disconnected */ 866 if (!udc->vbus_active || !udc->softconnect) 867 goto loop; 868 869 if (max3420_start(udc)) { 870 loop_again = 1; 871 goto loop; 872 } 873 874 if (max3420_handle_irqs(udc)) { 875 loop_again = 1; 876 goto loop; 877 } 878 879 if (spi_max3420_rwkup(udc)) { 880 loop_again = 1; 881 goto loop; 882 } 883 884 max3420_do_data(udc, 0, 1); /* get done with the EP0 ZLP */ 885 886 for (i = 1; i < MAX3420_MAX_EPS; i++) { 887 struct max3420_ep *ep = &udc->ep[i]; 888 889 if (spi_max3420_enable(ep)) 890 loop_again = 1; 891 if (spi_max3420_stall(ep)) 892 loop_again = 1; 893 } 894loop: 895 mutex_unlock(&udc->spi_bus_mutex); 896 } 897 898 set_current_state(TASK_RUNNING); 899 dev_info(udc->dev, "SPI thread exiting\n"); 900 return 0; 901} 902 903static int max3420_ep_set_halt(struct usb_ep *_ep, int stall) 904{ 905 struct max3420_ep *ep = to_max3420_ep(_ep); 906 struct max3420_udc *udc = ep->udc; 907 unsigned long flags; 908 909 spin_lock_irqsave(&ep->lock, flags); 910 911 ep->todo &= ~STALL_EP; 912 if (stall) 913 ep->todo |= STALL; 914 else 915 ep->todo |= UNSTALL; 916 917 spin_unlock_irqrestore(&ep->lock, flags); 918 919 wake_up_process(udc->thread_task); 920 921 dev_dbg(udc->dev, "%sStall %s\n", stall ? "" : "Un", ep->name); 922 return 0; 923} 924 925static int __max3420_ep_enable(struct max3420_ep *ep, 926 const struct usb_endpoint_descriptor *desc) 927{ 928 unsigned int maxp = usb_endpoint_maxp(desc); 929 unsigned long flags; 930 931 spin_lock_irqsave(&ep->lock, flags); 932 ep->ep_usb.desc = desc; 933 ep->ep_usb.maxpacket = maxp; 934 935 ep->todo &= ~ENABLE_EP; 936 ep->todo |= ENABLE; 937 spin_unlock_irqrestore(&ep->lock, flags); 938 939 return 0; 940} 941 942static int max3420_ep_enable(struct usb_ep *_ep, 943 const struct usb_endpoint_descriptor *desc) 944{ 945 struct max3420_ep *ep = to_max3420_ep(_ep); 946 struct max3420_udc *udc = ep->udc; 947 948 __max3420_ep_enable(ep, desc); 949 950 wake_up_process(udc->thread_task); 951 952 return 0; 953} 954 955static void max3420_nuke(struct max3420_ep *ep, int status) 956{ 957 struct max3420_req *req, *r; 958 unsigned long flags; 959 960 spin_lock_irqsave(&ep->lock, flags); 961 962 list_for_each_entry_safe(req, r, &ep->queue, queue) { 963 list_del_init(&req->queue); 964 965 spin_unlock_irqrestore(&ep->lock, flags); 966 max3420_req_done(req, status); 967 spin_lock_irqsave(&ep->lock, flags); 968 } 969 970 spin_unlock_irqrestore(&ep->lock, flags); 971} 972 973static void __max3420_ep_disable(struct max3420_ep *ep) 974{ 975 struct max3420_udc *udc = ep->udc; 976 unsigned long flags; 977 978 spin_lock_irqsave(&ep->lock, flags); 979 980 ep->ep_usb.desc = NULL; 981 982 ep->todo &= ~ENABLE_EP; 983 ep->todo |= DISABLE; 984 985 spin_unlock_irqrestore(&ep->lock, flags); 986 987 dev_dbg(udc->dev, "Disabled %s\n", ep->name); 988} 989 990static int max3420_ep_disable(struct usb_ep *_ep) 991{ 992 struct max3420_ep *ep = to_max3420_ep(_ep); 993 struct max3420_udc *udc = ep->udc; 994 995 max3420_nuke(ep, -ESHUTDOWN); 996 997 __max3420_ep_disable(ep); 998 999 wake_up_process(udc->thread_task); 1000 1001 return 0; 1002} 1003 1004static struct usb_request *max3420_alloc_request(struct usb_ep *_ep, 1005 gfp_t gfp_flags) 1006{ 1007 struct max3420_ep *ep = to_max3420_ep(_ep); 1008 struct max3420_req *req; 1009 1010 req = kzalloc(sizeof(*req), gfp_flags); 1011 if (!req) 1012 return NULL; 1013 1014 req->ep = ep; 1015 1016 return &req->usb_req; 1017} 1018 1019static void max3420_free_request(struct usb_ep *_ep, struct usb_request *_req) 1020{ 1021 kfree(to_max3420_req(_req)); 1022} 1023 1024static int max3420_ep_queue(struct usb_ep *_ep, struct usb_request *_req, 1025 gfp_t ignored) 1026{ 1027 struct max3420_req *req = to_max3420_req(_req); 1028 struct max3420_ep *ep = to_max3420_ep(_ep); 1029 struct max3420_udc *udc = ep->udc; 1030 unsigned long flags; 1031 1032 _req->status = -EINPROGRESS; 1033 _req->actual = 0; 1034 1035 spin_lock_irqsave(&ep->lock, flags); 1036 list_add_tail(&req->queue, &ep->queue); 1037 spin_unlock_irqrestore(&ep->lock, flags); 1038 1039 wake_up_process(udc->thread_task); 1040 return 0; 1041} 1042 1043static int max3420_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) 1044{ 1045 struct max3420_req *t = NULL; 1046 struct max3420_req *req = to_max3420_req(_req); 1047 struct max3420_req *iter; 1048 struct max3420_ep *ep = to_max3420_ep(_ep); 1049 unsigned long flags; 1050 1051 spin_lock_irqsave(&ep->lock, flags); 1052 1053 /* Pluck the descriptor from queue */ 1054 list_for_each_entry(iter, &ep->queue, queue) { 1055 if (iter != req) 1056 continue; 1057 list_del_init(&req->queue); 1058 t = iter; 1059 break; 1060 } 1061 1062 spin_unlock_irqrestore(&ep->lock, flags); 1063 1064 if (t) 1065 max3420_req_done(req, -ECONNRESET); 1066 1067 return 0; 1068} 1069 1070static const struct usb_ep_ops max3420_ep_ops = { 1071 .enable = max3420_ep_enable, 1072 .disable = max3420_ep_disable, 1073 .alloc_request = max3420_alloc_request, 1074 .free_request = max3420_free_request, 1075 .queue = max3420_ep_queue, 1076 .dequeue = max3420_ep_dequeue, 1077 .set_halt = max3420_ep_set_halt, 1078}; 1079 1080static int max3420_wakeup(struct usb_gadget *gadget) 1081{ 1082 struct max3420_udc *udc = to_udc(gadget); 1083 unsigned long flags; 1084 int ret = -EINVAL; 1085 1086 spin_lock_irqsave(&udc->lock, flags); 1087 1088 /* Only if wakeup allowed by host */ 1089 if (udc->remote_wkp) { 1090 udc->todo |= REMOTE_WAKEUP; 1091 ret = 0; 1092 } 1093 1094 spin_unlock_irqrestore(&udc->lock, flags); 1095 1096 if (udc->thread_task) 1097 wake_up_process(udc->thread_task); 1098 return ret; 1099} 1100 1101static int max3420_udc_start(struct usb_gadget *gadget, 1102 struct usb_gadget_driver *driver) 1103{ 1104 struct max3420_udc *udc = to_udc(gadget); 1105 unsigned long flags; 1106 1107 spin_lock_irqsave(&udc->lock, flags); 1108 /* hook up the driver */ 1109 udc->driver = driver; 1110 udc->gadget.speed = USB_SPEED_FULL; 1111 1112 udc->gadget.is_selfpowered = udc->is_selfpowered; 1113 udc->remote_wkp = 0; 1114 udc->softconnect = true; 1115 udc->todo |= UDC_START; 1116 spin_unlock_irqrestore(&udc->lock, flags); 1117 1118 if (udc->thread_task) 1119 wake_up_process(udc->thread_task); 1120 1121 return 0; 1122} 1123 1124static int max3420_udc_stop(struct usb_gadget *gadget) 1125{ 1126 struct max3420_udc *udc = to_udc(gadget); 1127 unsigned long flags; 1128 1129 spin_lock_irqsave(&udc->lock, flags); 1130 udc->is_selfpowered = udc->gadget.is_selfpowered; 1131 udc->gadget.speed = USB_SPEED_UNKNOWN; 1132 udc->driver = NULL; 1133 udc->softconnect = false; 1134 udc->todo |= UDC_START; 1135 spin_unlock_irqrestore(&udc->lock, flags); 1136 1137 if (udc->thread_task) 1138 wake_up_process(udc->thread_task); 1139 1140 return 0; 1141} 1142 1143static const struct usb_gadget_ops max3420_udc_ops = { 1144 .udc_start = max3420_udc_start, 1145 .udc_stop = max3420_udc_stop, 1146 .wakeup = max3420_wakeup, 1147}; 1148 1149static void max3420_eps_init(struct max3420_udc *udc) 1150{ 1151 int idx; 1152 1153 INIT_LIST_HEAD(&udc->gadget.ep_list); 1154 1155 for (idx = 0; idx < MAX3420_MAX_EPS; idx++) { 1156 struct max3420_ep *ep = &udc->ep[idx]; 1157 1158 spin_lock_init(&ep->lock); 1159 INIT_LIST_HEAD(&ep->queue); 1160 1161 ep->udc = udc; 1162 ep->id = idx; 1163 ep->halted = 0; 1164 ep->maxpacket = 0; 1165 ep->ep_usb.name = ep->name; 1166 ep->ep_usb.ops = &max3420_ep_ops; 1167 usb_ep_set_maxpacket_limit(&ep->ep_usb, MAX3420_EP_MAX_PACKET); 1168 1169 if (idx == 0) { /* For EP0 */ 1170 ep->ep_usb.desc = &ep0_desc; 1171 ep->ep_usb.maxpacket = usb_endpoint_maxp(&ep0_desc); 1172 ep->ep_usb.caps.type_control = true; 1173 ep->ep_usb.caps.dir_in = true; 1174 ep->ep_usb.caps.dir_out = true; 1175 snprintf(ep->name, MAX3420_EPNAME_SIZE, "ep0"); 1176 continue; 1177 } 1178 1179 if (idx == 1) { /* EP1 is OUT */ 1180 ep->ep_usb.caps.dir_in = false; 1181 ep->ep_usb.caps.dir_out = true; 1182 snprintf(ep->name, MAX3420_EPNAME_SIZE, "ep1-bulk-out"); 1183 } else { /* EP2 & EP3 are IN */ 1184 ep->ep_usb.caps.dir_in = true; 1185 ep->ep_usb.caps.dir_out = false; 1186 snprintf(ep->name, MAX3420_EPNAME_SIZE, 1187 "ep%d-bulk-in", idx); 1188 } 1189 ep->ep_usb.caps.type_iso = false; 1190 ep->ep_usb.caps.type_int = false; 1191 ep->ep_usb.caps.type_bulk = true; 1192 1193 list_add_tail(&ep->ep_usb.ep_list, 1194 &udc->gadget.ep_list); 1195 } 1196} 1197 1198static int max3420_probe(struct spi_device *spi) 1199{ 1200 struct max3420_udc *udc; 1201 int err, irq; 1202 u8 reg[8]; 1203 1204 if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) { 1205 dev_err(&spi->dev, "UDC needs full duplex to work\n"); 1206 return -EINVAL; 1207 } 1208 1209 spi->mode = SPI_MODE_3; 1210 spi->bits_per_word = 8; 1211 1212 err = spi_setup(spi); 1213 if (err) { 1214 dev_err(&spi->dev, "Unable to setup SPI bus\n"); 1215 return -EFAULT; 1216 } 1217 1218 udc = devm_kzalloc(&spi->dev, sizeof(*udc), GFP_KERNEL); 1219 if (!udc) 1220 return -ENOMEM; 1221 1222 udc->spi = spi; 1223 1224 udc->remote_wkp = 0; 1225 1226 /* Setup gadget structure */ 1227 udc->gadget.ops = &max3420_udc_ops; 1228 udc->gadget.max_speed = USB_SPEED_FULL; 1229 udc->gadget.speed = USB_SPEED_UNKNOWN; 1230 udc->gadget.ep0 = &udc->ep[0].ep_usb; 1231 udc->gadget.name = driver_name; 1232 1233 spin_lock_init(&udc->lock); 1234 mutex_init(&udc->spi_bus_mutex); 1235 1236 udc->ep0req.ep = &udc->ep[0]; 1237 udc->ep0req.usb_req.buf = udc->ep0buf; 1238 INIT_LIST_HEAD(&udc->ep0req.queue); 1239 1240 /* setup Endpoints */ 1241 max3420_eps_init(udc); 1242 1243 /* configure SPI */ 1244 spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 8); 1245 spi_wr8(udc, MAX3420_REG_PINCTL, FDUPSPI); 1246 1247 err = usb_add_gadget_udc(&spi->dev, &udc->gadget); 1248 if (err) 1249 return err; 1250 1251 udc->dev = &udc->gadget.dev; 1252 1253 spi_set_drvdata(spi, udc); 1254 1255 irq = of_irq_get_byname(spi->dev.of_node, "udc"); 1256 err = devm_request_irq(&spi->dev, irq, max3420_irq_handler, 0, 1257 "max3420", udc); 1258 if (err < 0) 1259 goto del_gadget; 1260 1261 udc->thread_task = kthread_create(max3420_thread, udc, 1262 "max3420-thread"); 1263 if (IS_ERR(udc->thread_task)) { 1264 err = PTR_ERR(udc->thread_task); 1265 goto del_gadget; 1266 } 1267 1268 irq = of_irq_get_byname(spi->dev.of_node, "vbus"); 1269 if (irq <= 0) { /* no vbus irq implies self-powered design */ 1270 udc->is_selfpowered = 1; 1271 udc->vbus_active = true; 1272 udc->todo |= UDC_START; 1273 usb_udc_vbus_handler(&udc->gadget, udc->vbus_active); 1274 usb_gadget_set_state(&udc->gadget, USB_STATE_POWERED); 1275 max3420_start(udc); 1276 } else { 1277 udc->is_selfpowered = 0; 1278 /* Detect current vbus status */ 1279 spi_rd_buf(udc, MAX3420_REG_EPIRQ, reg, 8); 1280 if (reg[7] != 0xff) 1281 udc->vbus_active = true; 1282 1283 err = devm_request_irq(&spi->dev, irq, 1284 max3420_vbus_handler, 0, "vbus", udc); 1285 if (err < 0) 1286 goto del_gadget; 1287 } 1288 1289 return 0; 1290 1291del_gadget: 1292 usb_del_gadget_udc(&udc->gadget); 1293 return err; 1294} 1295 1296static void max3420_remove(struct spi_device *spi) 1297{ 1298 struct max3420_udc *udc = spi_get_drvdata(spi); 1299 unsigned long flags; 1300 1301 usb_del_gadget_udc(&udc->gadget); 1302 1303 spin_lock_irqsave(&udc->lock, flags); 1304 1305 kthread_stop(udc->thread_task); 1306 1307 spin_unlock_irqrestore(&udc->lock, flags); 1308} 1309 1310static const struct of_device_id max3420_udc_of_match[] = { 1311 { .compatible = "maxim,max3420-udc"}, 1312 { .compatible = "maxim,max3421-udc"}, 1313 {}, 1314}; 1315MODULE_DEVICE_TABLE(of, max3420_udc_of_match); 1316 1317static struct spi_driver max3420_driver = { 1318 .driver = { 1319 .name = "max3420-udc", 1320 .of_match_table = max3420_udc_of_match, 1321 }, 1322 .probe = max3420_probe, 1323 .remove = max3420_remove, 1324}; 1325 1326module_spi_driver(max3420_driver); 1327 1328MODULE_DESCRIPTION(DRIVER_DESC); 1329MODULE_AUTHOR("Jassi Brar <jaswinder.singh@linaro.org>"); 1330MODULE_LICENSE("GPL"); 1331