xref: /openbmc/linux/drivers/usb/host/max3421-hcd.c (revision 94cdda6b)
1 /*
2  * MAX3421 Host Controller driver for USB.
3  *
4  * Author: David Mosberger-Tang <davidm@egauge.net>
5  *
6  * (C) Copyright 2014 David Mosberger-Tang <davidm@egauge.net>
7  *
8  * MAX3421 is a chip implementing a USB 2.0 Full-/Low-Speed host
9  * controller on a SPI bus.
10  *
11  * Based on:
12  *	o MAX3421E datasheet
13  *		http://datasheets.maximintegrated.com/en/ds/MAX3421E.pdf
14  *	o MAX3421E Programming Guide
15  *		http://www.hdl.co.jp/ftpdata/utl-001/AN3785.pdf
16  *	o gadget/dummy_hcd.c
17  *		For USB HCD implementation.
18  *	o Arduino MAX3421 driver
19  *	     https://github.com/felis/USB_Host_Shield_2.0/blob/master/Usb.cpp
20  *
21  * This file is licenced under the GPL v2.
22  *
23  * Important note on worst-case (full-speed) packet size constraints
24  * (See USB 2.0 Section 5.6.3 and following):
25  *
26  *	- control:	  64 bytes
27  *	- isochronous:	1023 bytes
28  *	- interrupt:	  64 bytes
29  *	- bulk:		  64 bytes
30  *
31  * Since the MAX3421 FIFO size is 64 bytes, we do not have to work about
32  * multi-FIFO writes/reads for a single USB packet *except* for isochronous
33  * transfers.  We don't support isochronous transfers at this time, so we
34  * just assume that a USB packet always fits into a single FIFO buffer.
35  *
36  * NOTE: The June 2006 version of "MAX3421E Programming Guide"
37  * (AN3785) has conflicting info for the RCVDAVIRQ bit:
38  *
39  *	The description of RCVDAVIRQ says "The CPU *must* clear
40  *	this IRQ bit (by writing a 1 to it) before reading the
41  *	RCVFIFO data.
42  *
43  * However, the earlier section on "Programming BULK-IN
44  * Transfers" says * that:
45  *
46  *	After the CPU retrieves the data, it clears the
47  *	RCVDAVIRQ bit.
48  *
49  * The December 2006 version has been corrected and it consistently
50  * states the second behavior is the correct one.
51  *
52  * Synchronous SPI transactions sleep so we can't perform any such
53  * transactions while holding a spin-lock (and/or while interrupts are
54  * masked).  To achieve this, all SPI transactions are issued from a
55  * single thread (max3421_spi_thread).
56  */
57 
58 #include <linux/jiffies.h>
59 #include <linux/module.h>
60 #include <linux/spi/spi.h>
61 #include <linux/usb.h>
62 #include <linux/usb/hcd.h>
63 
64 #include <linux/platform_data/max3421-hcd.h>
65 
66 #define DRIVER_DESC	"MAX3421 USB Host-Controller Driver"
67 #define DRIVER_VERSION	"1.0"
68 
69 /* 11-bit counter that wraps around (USB 2.0 Section 8.3.3): */
70 #define USB_MAX_FRAME_NUMBER	0x7ff
71 #define USB_MAX_RETRIES		3 /* # of retries before error is reported */
72 
73 /*
74  * Max. # of times we're willing to retransmit a request immediately in
75  * resposne to a NAK.  Afterwards, we fall back on trying once a frame.
76  */
77 #define NAK_MAX_FAST_RETRANSMITS	2
78 
79 #define POWER_BUDGET	500	/* in mA; use 8 for low-power port testing */
80 
81 /* Port-change mask: */
82 #define PORT_C_MASK	((USB_PORT_STAT_C_CONNECTION |	\
83 			  USB_PORT_STAT_C_ENABLE |	\
84 			  USB_PORT_STAT_C_SUSPEND |	\
85 			  USB_PORT_STAT_C_OVERCURRENT | \
86 			  USB_PORT_STAT_C_RESET) << 16)
87 
88 enum max3421_rh_state {
89 	MAX3421_RH_RESET,
90 	MAX3421_RH_SUSPENDED,
91 	MAX3421_RH_RUNNING
92 };
93 
94 enum pkt_state {
95 	PKT_STATE_SETUP,	/* waiting to send setup packet to ctrl pipe */
96 	PKT_STATE_TRANSFER,	/* waiting to xfer transfer_buffer */
97 	PKT_STATE_TERMINATE	/* waiting to terminate control transfer */
98 };
99 
100 enum scheduling_pass {
101 	SCHED_PASS_PERIODIC,
102 	SCHED_PASS_NON_PERIODIC,
103 	SCHED_PASS_DONE
104 };
105 
106 /* Bit numbers for max3421_hcd->todo: */
107 enum {
108 	ENABLE_IRQ = 0,
109 	RESET_HCD,
110 	RESET_PORT,
111 	CHECK_UNLINK,
112 	IOPIN_UPDATE
113 };
114 
115 struct max3421_dma_buf {
116 	u8 data[2];
117 };
118 
119 struct max3421_hcd {
120 	spinlock_t lock;
121 
122 	struct task_struct *spi_thread;
123 
124 	struct max3421_hcd *next;
125 
126 	enum max3421_rh_state rh_state;
127 	/* lower 16 bits contain port status, upper 16 bits the change mask: */
128 	u32 port_status;
129 
130 	unsigned active:1;
131 
132 	struct list_head ep_list;	/* list of EP's with work */
133 
134 	/*
135 	 * The following are owned by spi_thread (may be accessed by
136 	 * SPI-thread without acquiring the HCD lock:
137 	 */
138 	u8 rev;				/* chip revision */
139 	u16 frame_number;
140 	/*
141 	 * kmalloc'd buffers guaranteed to be in separate (DMA)
142 	 * cache-lines:
143 	 */
144 	struct max3421_dma_buf *tx;
145 	struct max3421_dma_buf *rx;
146 	/*
147 	 * URB we're currently processing.  Must not be reset to NULL
148 	 * unless MAX3421E chip is idle:
149 	 */
150 	struct urb *curr_urb;
151 	enum scheduling_pass sched_pass;
152 	struct usb_device *loaded_dev;	/* dev that's loaded into the chip */
153 	int loaded_epnum;		/* epnum whose toggles are loaded */
154 	int urb_done;			/* > 0 -> no errors, < 0: errno */
155 	size_t curr_len;
156 	u8 hien;
157 	u8 mode;
158 	u8 iopins[2];
159 	unsigned long todo;
160 #ifdef DEBUG
161 	unsigned long err_stat[16];
162 #endif
163 };
164 
165 struct max3421_ep {
166 	struct usb_host_endpoint *ep;
167 	struct list_head ep_list;
168 	u32 naks;
169 	u16 last_active;		/* frame # this ep was last active */
170 	enum pkt_state pkt_state;
171 	u8 retries;
172 	u8 retransmit;			/* packet needs retransmission */
173 };
174 
175 static struct max3421_hcd *max3421_hcd_list;
176 
177 #define MAX3421_FIFO_SIZE	64
178 
179 #define MAX3421_SPI_DIR_RD	0	/* read register from MAX3421 */
180 #define MAX3421_SPI_DIR_WR	1	/* write register to MAX3421 */
181 
182 /* SPI commands: */
183 #define MAX3421_SPI_DIR_SHIFT	1
184 #define MAX3421_SPI_REG_SHIFT	3
185 
186 #define MAX3421_REG_RCVFIFO	1
187 #define MAX3421_REG_SNDFIFO	2
188 #define MAX3421_REG_SUDFIFO	4
189 #define MAX3421_REG_RCVBC	6
190 #define MAX3421_REG_SNDBC	7
191 #define MAX3421_REG_USBIRQ	13
192 #define MAX3421_REG_USBIEN	14
193 #define MAX3421_REG_USBCTL	15
194 #define MAX3421_REG_CPUCTL	16
195 #define MAX3421_REG_PINCTL	17
196 #define MAX3421_REG_REVISION	18
197 #define MAX3421_REG_IOPINS1	20
198 #define MAX3421_REG_IOPINS2	21
199 #define MAX3421_REG_GPINIRQ	22
200 #define MAX3421_REG_GPINIEN	23
201 #define MAX3421_REG_GPINPOL	24
202 #define MAX3421_REG_HIRQ	25
203 #define MAX3421_REG_HIEN	26
204 #define MAX3421_REG_MODE	27
205 #define MAX3421_REG_PERADDR	28
206 #define MAX3421_REG_HCTL	29
207 #define MAX3421_REG_HXFR	30
208 #define MAX3421_REG_HRSL	31
209 
210 enum {
211 	MAX3421_USBIRQ_OSCOKIRQ_BIT = 0,
212 	MAX3421_USBIRQ_NOVBUSIRQ_BIT = 5,
213 	MAX3421_USBIRQ_VBUSIRQ_BIT
214 };
215 
216 enum {
217 	MAX3421_CPUCTL_IE_BIT = 0,
218 	MAX3421_CPUCTL_PULSEWID0_BIT = 6,
219 	MAX3421_CPUCTL_PULSEWID1_BIT
220 };
221 
222 enum {
223 	MAX3421_USBCTL_PWRDOWN_BIT = 4,
224 	MAX3421_USBCTL_CHIPRES_BIT
225 };
226 
227 enum {
228 	MAX3421_PINCTL_GPXA_BIT	= 0,
229 	MAX3421_PINCTL_GPXB_BIT,
230 	MAX3421_PINCTL_POSINT_BIT,
231 	MAX3421_PINCTL_INTLEVEL_BIT,
232 	MAX3421_PINCTL_FDUPSPI_BIT,
233 	MAX3421_PINCTL_EP0INAK_BIT,
234 	MAX3421_PINCTL_EP2INAK_BIT,
235 	MAX3421_PINCTL_EP3INAK_BIT,
236 };
237 
238 enum {
239 	MAX3421_HI_BUSEVENT_BIT = 0,	/* bus-reset/-resume */
240 	MAX3421_HI_RWU_BIT,		/* remote wakeup */
241 	MAX3421_HI_RCVDAV_BIT,		/* receive FIFO data available */
242 	MAX3421_HI_SNDBAV_BIT,		/* send buffer available */
243 	MAX3421_HI_SUSDN_BIT,		/* suspend operation done */
244 	MAX3421_HI_CONDET_BIT,		/* peripheral connect/disconnect */
245 	MAX3421_HI_FRAME_BIT,		/* frame generator */
246 	MAX3421_HI_HXFRDN_BIT,		/* host transfer done */
247 };
248 
249 enum {
250 	MAX3421_HCTL_BUSRST_BIT = 0,
251 	MAX3421_HCTL_FRMRST_BIT,
252 	MAX3421_HCTL_SAMPLEBUS_BIT,
253 	MAX3421_HCTL_SIGRSM_BIT,
254 	MAX3421_HCTL_RCVTOG0_BIT,
255 	MAX3421_HCTL_RCVTOG1_BIT,
256 	MAX3421_HCTL_SNDTOG0_BIT,
257 	MAX3421_HCTL_SNDTOG1_BIT
258 };
259 
260 enum {
261 	MAX3421_MODE_HOST_BIT = 0,
262 	MAX3421_MODE_LOWSPEED_BIT,
263 	MAX3421_MODE_HUBPRE_BIT,
264 	MAX3421_MODE_SOFKAENAB_BIT,
265 	MAX3421_MODE_SEPIRQ_BIT,
266 	MAX3421_MODE_DELAYISO_BIT,
267 	MAX3421_MODE_DMPULLDN_BIT,
268 	MAX3421_MODE_DPPULLDN_BIT
269 };
270 
271 enum {
272 	MAX3421_HRSL_OK = 0,
273 	MAX3421_HRSL_BUSY,
274 	MAX3421_HRSL_BADREQ,
275 	MAX3421_HRSL_UNDEF,
276 	MAX3421_HRSL_NAK,
277 	MAX3421_HRSL_STALL,
278 	MAX3421_HRSL_TOGERR,
279 	MAX3421_HRSL_WRONGPID,
280 	MAX3421_HRSL_BADBC,
281 	MAX3421_HRSL_PIDERR,
282 	MAX3421_HRSL_PKTERR,
283 	MAX3421_HRSL_CRCERR,
284 	MAX3421_HRSL_KERR,
285 	MAX3421_HRSL_JERR,
286 	MAX3421_HRSL_TIMEOUT,
287 	MAX3421_HRSL_BABBLE,
288 	MAX3421_HRSL_RESULT_MASK = 0xf,
289 	MAX3421_HRSL_RCVTOGRD_BIT = 4,
290 	MAX3421_HRSL_SNDTOGRD_BIT,
291 	MAX3421_HRSL_KSTATUS_BIT,
292 	MAX3421_HRSL_JSTATUS_BIT
293 };
294 
295 /* Return same error-codes as ohci.h:cc_to_error: */
296 static const int hrsl_to_error[] = {
297 	[MAX3421_HRSL_OK] =		0,
298 	[MAX3421_HRSL_BUSY] =		-EINVAL,
299 	[MAX3421_HRSL_BADREQ] =		-EINVAL,
300 	[MAX3421_HRSL_UNDEF] =		-EINVAL,
301 	[MAX3421_HRSL_NAK] =		-EAGAIN,
302 	[MAX3421_HRSL_STALL] =		-EPIPE,
303 	[MAX3421_HRSL_TOGERR] =		-EILSEQ,
304 	[MAX3421_HRSL_WRONGPID] =	-EPROTO,
305 	[MAX3421_HRSL_BADBC] =		-EREMOTEIO,
306 	[MAX3421_HRSL_PIDERR] =		-EPROTO,
307 	[MAX3421_HRSL_PKTERR] =		-EPROTO,
308 	[MAX3421_HRSL_CRCERR] =		-EILSEQ,
309 	[MAX3421_HRSL_KERR] =		-EIO,
310 	[MAX3421_HRSL_JERR] =		-EIO,
311 	[MAX3421_HRSL_TIMEOUT] =	-ETIME,
312 	[MAX3421_HRSL_BABBLE] =		-EOVERFLOW
313 };
314 
315 /*
316  * See http://www.beyondlogic.org/usbnutshell/usb4.shtml#Control for a
317  * reasonable overview of how control transfers use the the IN/OUT
318  * tokens.
319  */
320 #define MAX3421_HXFR_BULK_IN(ep)	(0x00 | (ep))	/* bulk or interrupt */
321 #define MAX3421_HXFR_SETUP		 0x10
322 #define MAX3421_HXFR_BULK_OUT(ep)	(0x20 | (ep))	/* bulk or interrupt */
323 #define MAX3421_HXFR_ISO_IN(ep)		(0x40 | (ep))
324 #define MAX3421_HXFR_ISO_OUT(ep)	(0x60 | (ep))
325 #define MAX3421_HXFR_HS_IN		 0x80		/* handshake in */
326 #define MAX3421_HXFR_HS_OUT		 0xa0		/* handshake out */
327 
328 #define field(val, bit)	((val) << (bit))
329 
330 static inline s16
331 frame_diff(u16 left, u16 right)
332 {
333 	return ((unsigned) (left - right)) % (USB_MAX_FRAME_NUMBER + 1);
334 }
335 
336 static inline struct max3421_hcd *
337 hcd_to_max3421(struct usb_hcd *hcd)
338 {
339 	return (struct max3421_hcd *) hcd->hcd_priv;
340 }
341 
342 static inline struct usb_hcd *
343 max3421_to_hcd(struct max3421_hcd *max3421_hcd)
344 {
345 	return container_of((void *) max3421_hcd, struct usb_hcd, hcd_priv);
346 }
347 
348 static u8
349 spi_rd8(struct usb_hcd *hcd, unsigned int reg)
350 {
351 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
352 	struct spi_device *spi = to_spi_device(hcd->self.controller);
353 	struct spi_transfer transfer;
354 	struct spi_message msg;
355 
356 	memset(&transfer, 0, sizeof(transfer));
357 
358 	spi_message_init(&msg);
359 
360 	max3421_hcd->tx->data[0] =
361 		(field(reg, MAX3421_SPI_REG_SHIFT) |
362 		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
363 
364 	transfer.tx_buf = max3421_hcd->tx->data;
365 	transfer.rx_buf = max3421_hcd->rx->data;
366 	transfer.len = 2;
367 
368 	spi_message_add_tail(&transfer, &msg);
369 	spi_sync(spi, &msg);
370 
371 	return max3421_hcd->rx->data[1];
372 }
373 
374 static void
375 spi_wr8(struct usb_hcd *hcd, unsigned int reg, u8 val)
376 {
377 	struct spi_device *spi = to_spi_device(hcd->self.controller);
378 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
379 	struct spi_transfer transfer;
380 	struct spi_message msg;
381 
382 	memset(&transfer, 0, sizeof(transfer));
383 
384 	spi_message_init(&msg);
385 
386 	max3421_hcd->tx->data[0] =
387 		(field(reg, MAX3421_SPI_REG_SHIFT) |
388 		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
389 	max3421_hcd->tx->data[1] = val;
390 
391 	transfer.tx_buf = max3421_hcd->tx->data;
392 	transfer.len = 2;
393 
394 	spi_message_add_tail(&transfer, &msg);
395 	spi_sync(spi, &msg);
396 }
397 
398 static void
399 spi_rd_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
400 {
401 	struct spi_device *spi = to_spi_device(hcd->self.controller);
402 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
403 	struct spi_transfer transfer[2];
404 	struct spi_message msg;
405 
406 	memset(transfer, 0, sizeof(transfer));
407 
408 	spi_message_init(&msg);
409 
410 	max3421_hcd->tx->data[0] =
411 		(field(reg, MAX3421_SPI_REG_SHIFT) |
412 		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
413 	transfer[0].tx_buf = max3421_hcd->tx->data;
414 	transfer[0].len = 1;
415 
416 	transfer[1].rx_buf = buf;
417 	transfer[1].len = len;
418 
419 	spi_message_add_tail(&transfer[0], &msg);
420 	spi_message_add_tail(&transfer[1], &msg);
421 	spi_sync(spi, &msg);
422 }
423 
424 static void
425 spi_wr_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
426 {
427 	struct spi_device *spi = to_spi_device(hcd->self.controller);
428 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
429 	struct spi_transfer transfer[2];
430 	struct spi_message msg;
431 
432 	memset(transfer, 0, sizeof(transfer));
433 
434 	spi_message_init(&msg);
435 
436 	max3421_hcd->tx->data[0] =
437 		(field(reg, MAX3421_SPI_REG_SHIFT) |
438 		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
439 
440 	transfer[0].tx_buf = max3421_hcd->tx->data;
441 	transfer[0].len = 1;
442 
443 	transfer[1].tx_buf = buf;
444 	transfer[1].len = len;
445 
446 	spi_message_add_tail(&transfer[0], &msg);
447 	spi_message_add_tail(&transfer[1], &msg);
448 	spi_sync(spi, &msg);
449 }
450 
451 /*
452  * Figure out the correct setting for the LOWSPEED and HUBPRE mode
453  * bits.  The HUBPRE bit needs to be set when MAX3421E operates at
454  * full speed, but it's talking to a low-speed device (i.e., through a
455  * hub).  Setting that bit ensures that every low-speed packet is
456  * preceded by a full-speed PRE PID.  Possible configurations:
457  *
458  * Hub speed:	Device speed:	=>	LOWSPEED bit:	HUBPRE bit:
459  *	FULL	FULL		=>	0		0
460  *	FULL	LOW		=>	1		1
461  *	LOW	LOW		=>	1		0
462  *	LOW	FULL		=>	1		0
463  */
464 static void
465 max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev)
466 {
467 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
468 	u8 mode_lowspeed, mode_hubpre, mode = max3421_hcd->mode;
469 
470 	mode_lowspeed = BIT(MAX3421_MODE_LOWSPEED_BIT);
471 	mode_hubpre   = BIT(MAX3421_MODE_HUBPRE_BIT);
472 	if (max3421_hcd->port_status & USB_PORT_STAT_LOW_SPEED) {
473 		mode |=  mode_lowspeed;
474 		mode &= ~mode_hubpre;
475 	} else if (dev->speed == USB_SPEED_LOW) {
476 		mode |= mode_lowspeed | mode_hubpre;
477 	} else {
478 		mode &= ~(mode_lowspeed | mode_hubpre);
479 	}
480 	if (mode != max3421_hcd->mode) {
481 		max3421_hcd->mode = mode;
482 		spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
483 	}
484 
485 }
486 
487 /*
488  * Caller must NOT hold HCD spinlock.
489  */
490 static void
491 max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum,
492 		    int force_toggles)
493 {
494 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
495 	int old_epnum, same_ep, rcvtog, sndtog;
496 	struct usb_device *old_dev;
497 	u8 hctl;
498 
499 	old_dev = max3421_hcd->loaded_dev;
500 	old_epnum = max3421_hcd->loaded_epnum;
501 
502 	same_ep = (dev == old_dev && epnum == old_epnum);
503 	if (same_ep && !force_toggles)
504 		return;
505 
506 	if (old_dev && !same_ep) {
507 		/* save the old end-points toggles: */
508 		u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
509 
510 		rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1;
511 		sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
512 
513 		/* no locking: HCD (i.e., we) own toggles, don't we? */
514 		usb_settoggle(old_dev, old_epnum, 0, rcvtog);
515 		usb_settoggle(old_dev, old_epnum, 1, sndtog);
516 	}
517 	/* setup new endpoint's toggle bits: */
518 	rcvtog = usb_gettoggle(dev, epnum, 0);
519 	sndtog = usb_gettoggle(dev, epnum, 1);
520 	hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) |
521 		BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
522 
523 	max3421_hcd->loaded_epnum = epnum;
524 	spi_wr8(hcd, MAX3421_REG_HCTL, hctl);
525 
526 	/*
527 	 * Note: devnum for one and the same device can change during
528 	 * address-assignment so it's best to just always load the
529 	 * address whenever the end-point changed/was forced.
530 	 */
531 	max3421_hcd->loaded_dev = dev;
532 	spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum);
533 }
534 
535 static int
536 max3421_ctrl_setup(struct usb_hcd *hcd, struct urb *urb)
537 {
538 	spi_wr_buf(hcd, MAX3421_REG_SUDFIFO, urb->setup_packet, 8);
539 	return MAX3421_HXFR_SETUP;
540 }
541 
542 static int
543 max3421_transfer_in(struct usb_hcd *hcd, struct urb *urb)
544 {
545 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
546 	int epnum = usb_pipeendpoint(urb->pipe);
547 
548 	max3421_hcd->curr_len = 0;
549 	max3421_hcd->hien |= BIT(MAX3421_HI_RCVDAV_BIT);
550 	return MAX3421_HXFR_BULK_IN(epnum);
551 }
552 
553 static int
554 max3421_transfer_out(struct usb_hcd *hcd, struct urb *urb, int fast_retransmit)
555 {
556 	struct spi_device *spi = to_spi_device(hcd->self.controller);
557 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
558 	int epnum = usb_pipeendpoint(urb->pipe);
559 	u32 max_packet;
560 	void *src;
561 
562 	src = urb->transfer_buffer + urb->actual_length;
563 
564 	if (fast_retransmit) {
565 		if (max3421_hcd->rev == 0x12) {
566 			/* work around rev 0x12 bug: */
567 			spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
568 			spi_wr8(hcd, MAX3421_REG_SNDFIFO, ((u8 *) src)[0]);
569 			spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
570 		}
571 		return MAX3421_HXFR_BULK_OUT(epnum);
572 	}
573 
574 	max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
575 
576 	if (max_packet > MAX3421_FIFO_SIZE) {
577 		/*
578 		 * We do not support isochronous transfers at this
579 		 * time.
580 		 */
581 		dev_err(&spi->dev,
582 			"%s: packet-size of %u too big (limit is %u bytes)",
583 			__func__, max_packet, MAX3421_FIFO_SIZE);
584 		max3421_hcd->urb_done = -EMSGSIZE;
585 		return -EMSGSIZE;
586 	}
587 	max3421_hcd->curr_len = min((urb->transfer_buffer_length -
588 				     urb->actual_length), max_packet);
589 
590 	spi_wr_buf(hcd, MAX3421_REG_SNDFIFO, src, max3421_hcd->curr_len);
591 	spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
592 	return MAX3421_HXFR_BULK_OUT(epnum);
593 }
594 
595 /*
596  * Issue the next host-transfer command.
597  * Caller must NOT hold HCD spinlock.
598  */
599 static void
600 max3421_next_transfer(struct usb_hcd *hcd, int fast_retransmit)
601 {
602 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
603 	struct urb *urb = max3421_hcd->curr_urb;
604 	struct max3421_ep *max3421_ep;
605 	int cmd = -EINVAL;
606 
607 	if (!urb)
608 		return;	/* nothing to do */
609 
610 	max3421_ep = urb->ep->hcpriv;
611 
612 	switch (max3421_ep->pkt_state) {
613 	case PKT_STATE_SETUP:
614 		cmd = max3421_ctrl_setup(hcd, urb);
615 		break;
616 
617 	case PKT_STATE_TRANSFER:
618 		if (usb_urb_dir_in(urb))
619 			cmd = max3421_transfer_in(hcd, urb);
620 		else
621 			cmd = max3421_transfer_out(hcd, urb, fast_retransmit);
622 		break;
623 
624 	case PKT_STATE_TERMINATE:
625 		/*
626 		 * IN transfers are terminated with HS_OUT token,
627 		 * OUT transfers with HS_IN:
628 		 */
629 		if (usb_urb_dir_in(urb))
630 			cmd = MAX3421_HXFR_HS_OUT;
631 		else
632 			cmd = MAX3421_HXFR_HS_IN;
633 		break;
634 	}
635 
636 	if (cmd < 0)
637 		return;
638 
639 	/* issue the command and wait for host-xfer-done interrupt: */
640 
641 	spi_wr8(hcd, MAX3421_REG_HXFR, cmd);
642 	max3421_hcd->hien |= BIT(MAX3421_HI_HXFRDN_BIT);
643 }
644 
645 /*
646  * Find the next URB to process and start its execution.
647  *
648  * At this time, we do not anticipate ever connecting a USB hub to the
649  * MAX3421 chip, so at most USB device can be connected and we can use
650  * a simplistic scheduler: at the start of a frame, schedule all
651  * periodic transfers.  Once that is done, use the remainder of the
652  * frame to process non-periodic (bulk & control) transfers.
653  *
654  * Preconditions:
655  * o Caller must NOT hold HCD spinlock.
656  * o max3421_hcd->curr_urb MUST BE NULL.
657  * o MAX3421E chip must be idle.
658  */
659 static int
660 max3421_select_and_start_urb(struct usb_hcd *hcd)
661 {
662 	struct spi_device *spi = to_spi_device(hcd->self.controller);
663 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
664 	struct urb *urb, *curr_urb = NULL;
665 	struct max3421_ep *max3421_ep;
666 	int epnum, force_toggles = 0;
667 	struct usb_host_endpoint *ep;
668 	struct list_head *pos;
669 	unsigned long flags;
670 
671 	spin_lock_irqsave(&max3421_hcd->lock, flags);
672 
673 	for (;
674 	     max3421_hcd->sched_pass < SCHED_PASS_DONE;
675 	     ++max3421_hcd->sched_pass)
676 		list_for_each(pos, &max3421_hcd->ep_list) {
677 			urb = NULL;
678 			max3421_ep = container_of(pos, struct max3421_ep,
679 						  ep_list);
680 			ep = max3421_ep->ep;
681 
682 			switch (usb_endpoint_type(&ep->desc)) {
683 			case USB_ENDPOINT_XFER_ISOC:
684 			case USB_ENDPOINT_XFER_INT:
685 				if (max3421_hcd->sched_pass !=
686 				    SCHED_PASS_PERIODIC)
687 					continue;
688 				break;
689 
690 			case USB_ENDPOINT_XFER_CONTROL:
691 			case USB_ENDPOINT_XFER_BULK:
692 				if (max3421_hcd->sched_pass !=
693 				    SCHED_PASS_NON_PERIODIC)
694 					continue;
695 				break;
696 			}
697 
698 			if (list_empty(&ep->urb_list))
699 				continue;	/* nothing to do */
700 			urb = list_first_entry(&ep->urb_list, struct urb,
701 					       urb_list);
702 			if (urb->unlinked) {
703 				dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
704 					__func__, urb, urb->unlinked);
705 				max3421_hcd->curr_urb = urb;
706 				max3421_hcd->urb_done = 1;
707 				spin_unlock_irqrestore(&max3421_hcd->lock,
708 						       flags);
709 				return 1;
710 			}
711 
712 			switch (usb_endpoint_type(&ep->desc)) {
713 			case USB_ENDPOINT_XFER_CONTROL:
714 				/*
715 				 * Allow one control transaction per
716 				 * frame per endpoint:
717 				 */
718 				if (frame_diff(max3421_ep->last_active,
719 					       max3421_hcd->frame_number) == 0)
720 					continue;
721 				break;
722 
723 			case USB_ENDPOINT_XFER_BULK:
724 				if (max3421_ep->retransmit
725 				    && (frame_diff(max3421_ep->last_active,
726 						   max3421_hcd->frame_number)
727 					== 0))
728 					/*
729 					 * We already tried this EP
730 					 * during this frame and got a
731 					 * NAK or error; wait for next frame
732 					 */
733 					continue;
734 				break;
735 
736 			case USB_ENDPOINT_XFER_ISOC:
737 			case USB_ENDPOINT_XFER_INT:
738 				if (frame_diff(max3421_hcd->frame_number,
739 					       max3421_ep->last_active)
740 				    < urb->interval)
741 					/*
742 					 * We already processed this
743 					 * end-point in the current
744 					 * frame
745 					 */
746 					continue;
747 				break;
748 			}
749 
750 			/* move current ep to tail: */
751 			list_move_tail(pos, &max3421_hcd->ep_list);
752 			curr_urb = urb;
753 			goto done;
754 		}
755 done:
756 	if (!curr_urb) {
757 		spin_unlock_irqrestore(&max3421_hcd->lock, flags);
758 		return 0;
759 	}
760 
761 	urb = max3421_hcd->curr_urb = curr_urb;
762 	epnum = usb_endpoint_num(&urb->ep->desc);
763 	if (max3421_ep->retransmit)
764 		/* restart (part of) a USB transaction: */
765 		max3421_ep->retransmit = 0;
766 	else {
767 		/* start USB transaction: */
768 		if (usb_endpoint_xfer_control(&ep->desc)) {
769 			/*
770 			 * See USB 2.0 spec section 8.6.1
771 			 * Initialization via SETUP Token:
772 			 */
773 			usb_settoggle(urb->dev, epnum, 0, 1);
774 			usb_settoggle(urb->dev, epnum, 1, 1);
775 			max3421_ep->pkt_state = PKT_STATE_SETUP;
776 			force_toggles = 1;
777 		} else
778 			max3421_ep->pkt_state = PKT_STATE_TRANSFER;
779 	}
780 
781 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
782 
783 	max3421_ep->last_active = max3421_hcd->frame_number;
784 	max3421_set_address(hcd, urb->dev, epnum, force_toggles);
785 	max3421_set_speed(hcd, urb->dev);
786 	max3421_next_transfer(hcd, 0);
787 	return 1;
788 }
789 
790 /*
791  * Check all endpoints for URBs that got unlinked.
792  *
793  * Caller must NOT hold HCD spinlock.
794  */
795 static int
796 max3421_check_unlink(struct usb_hcd *hcd)
797 {
798 	struct spi_device *spi = to_spi_device(hcd->self.controller);
799 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
800 	struct list_head *pos, *upos, *next_upos;
801 	struct max3421_ep *max3421_ep;
802 	struct usb_host_endpoint *ep;
803 	struct urb *urb;
804 	unsigned long flags;
805 	int retval = 0;
806 
807 	spin_lock_irqsave(&max3421_hcd->lock, flags);
808 	list_for_each(pos, &max3421_hcd->ep_list) {
809 		max3421_ep = container_of(pos, struct max3421_ep, ep_list);
810 		ep = max3421_ep->ep;
811 		list_for_each_safe(upos, next_upos, &ep->urb_list) {
812 			urb = container_of(upos, struct urb, urb_list);
813 			if (urb->unlinked) {
814 				retval = 1;
815 				dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
816 					__func__, urb, urb->unlinked);
817 				usb_hcd_unlink_urb_from_ep(hcd, urb);
818 				spin_unlock_irqrestore(&max3421_hcd->lock,
819 						       flags);
820 				usb_hcd_giveback_urb(hcd, urb, 0);
821 				spin_lock_irqsave(&max3421_hcd->lock, flags);
822 			}
823 		}
824 	}
825 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
826 	return retval;
827 }
828 
829 /*
830  * Caller must NOT hold HCD spinlock.
831  */
832 static void
833 max3421_slow_retransmit(struct usb_hcd *hcd)
834 {
835 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
836 	struct urb *urb = max3421_hcd->curr_urb;
837 	struct max3421_ep *max3421_ep;
838 
839 	max3421_ep = urb->ep->hcpriv;
840 	max3421_ep->retransmit = 1;
841 	max3421_hcd->curr_urb = NULL;
842 }
843 
844 /*
845  * Caller must NOT hold HCD spinlock.
846  */
847 static void
848 max3421_recv_data_available(struct usb_hcd *hcd)
849 {
850 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
851 	struct urb *urb = max3421_hcd->curr_urb;
852 	size_t remaining, transfer_size;
853 	u8 rcvbc;
854 
855 	rcvbc = spi_rd8(hcd, MAX3421_REG_RCVBC);
856 
857 	if (rcvbc > MAX3421_FIFO_SIZE)
858 		rcvbc = MAX3421_FIFO_SIZE;
859 	if (urb->actual_length >= urb->transfer_buffer_length)
860 		remaining = 0;
861 	else
862 		remaining = urb->transfer_buffer_length - urb->actual_length;
863 	transfer_size = rcvbc;
864 	if (transfer_size > remaining)
865 		transfer_size = remaining;
866 	if (transfer_size > 0) {
867 		void *dst = urb->transfer_buffer + urb->actual_length;
868 
869 		spi_rd_buf(hcd, MAX3421_REG_RCVFIFO, dst, transfer_size);
870 		urb->actual_length += transfer_size;
871 		max3421_hcd->curr_len = transfer_size;
872 	}
873 
874 	/* ack the RCVDAV irq now that the FIFO has been read: */
875 	spi_wr8(hcd, MAX3421_REG_HIRQ, BIT(MAX3421_HI_RCVDAV_BIT));
876 }
877 
878 static void
879 max3421_handle_error(struct usb_hcd *hcd, u8 hrsl)
880 {
881 	struct spi_device *spi = to_spi_device(hcd->self.controller);
882 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
883 	u8 result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
884 	struct urb *urb = max3421_hcd->curr_urb;
885 	struct max3421_ep *max3421_ep = urb->ep->hcpriv;
886 	int switch_sndfifo;
887 
888 	/*
889 	 * If an OUT command results in any response other than OK
890 	 * (i.e., error or NAK), we have to perform a dummy-write to
891 	 * SNDBC so the FIFO gets switched back to us.  Otherwise, we
892 	 * get out of sync with the SNDFIFO double buffer.
893 	 */
894 	switch_sndfifo = (max3421_ep->pkt_state == PKT_STATE_TRANSFER &&
895 			  usb_urb_dir_out(urb));
896 
897 	switch (result_code) {
898 	case MAX3421_HRSL_OK:
899 		return;			/* this shouldn't happen */
900 
901 	case MAX3421_HRSL_WRONGPID:	/* received wrong PID */
902 	case MAX3421_HRSL_BUSY:		/* SIE busy */
903 	case MAX3421_HRSL_BADREQ:	/* bad val in HXFR */
904 	case MAX3421_HRSL_UNDEF:	/* reserved */
905 	case MAX3421_HRSL_KERR:		/* K-state instead of response */
906 	case MAX3421_HRSL_JERR:		/* J-state instead of response */
907 		/*
908 		 * packet experienced an error that we cannot recover
909 		 * from; report error
910 		 */
911 		max3421_hcd->urb_done = hrsl_to_error[result_code];
912 		dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
913 			__func__, hrsl);
914 		break;
915 
916 	case MAX3421_HRSL_TOGERR:
917 		if (usb_urb_dir_in(urb))
918 			; /* don't do anything (device will switch toggle) */
919 		else {
920 			/* flip the send toggle bit: */
921 			int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
922 
923 			sndtog ^= 1;
924 			spi_wr8(hcd, MAX3421_REG_HCTL,
925 				BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
926 		}
927 		/* FALL THROUGH */
928 	case MAX3421_HRSL_BADBC:	/* bad byte count */
929 	case MAX3421_HRSL_PIDERR:	/* received PID is corrupted */
930 	case MAX3421_HRSL_PKTERR:	/* packet error (stuff, EOP) */
931 	case MAX3421_HRSL_CRCERR:	/* CRC error */
932 	case MAX3421_HRSL_BABBLE:	/* device talked too long */
933 	case MAX3421_HRSL_TIMEOUT:
934 		if (max3421_ep->retries++ < USB_MAX_RETRIES)
935 			/* retry the packet again in the next frame */
936 			max3421_slow_retransmit(hcd);
937 		else {
938 			/* Based on ohci.h cc_to_err[]: */
939 			max3421_hcd->urb_done = hrsl_to_error[result_code];
940 			dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
941 				__func__, hrsl);
942 		}
943 		break;
944 
945 	case MAX3421_HRSL_STALL:
946 		dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
947 			__func__, hrsl);
948 		max3421_hcd->urb_done = hrsl_to_error[result_code];
949 		break;
950 
951 	case MAX3421_HRSL_NAK:
952 		/*
953 		 * Device wasn't ready for data or has no data
954 		 * available: retry the packet again.
955 		 */
956 		if (max3421_ep->naks++ < NAK_MAX_FAST_RETRANSMITS) {
957 			max3421_next_transfer(hcd, 1);
958 			switch_sndfifo = 0;
959 		} else
960 			max3421_slow_retransmit(hcd);
961 		break;
962 	}
963 	if (switch_sndfifo)
964 		spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
965 }
966 
967 /*
968  * Caller must NOT hold HCD spinlock.
969  */
970 static int
971 max3421_transfer_in_done(struct usb_hcd *hcd, struct urb *urb)
972 {
973 	struct spi_device *spi = to_spi_device(hcd->self.controller);
974 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
975 	u32 max_packet;
976 
977 	if (urb->actual_length >= urb->transfer_buffer_length)
978 		return 1;	/* read is complete, so we're done */
979 
980 	/*
981 	 * USB 2.0 Section 5.3.2 Pipes: packets must be full size
982 	 * except for last one.
983 	 */
984 	max_packet = usb_maxpacket(urb->dev, urb->pipe, 0);
985 	if (max_packet > MAX3421_FIFO_SIZE) {
986 		/*
987 		 * We do not support isochronous transfers at this
988 		 * time...
989 		 */
990 		dev_err(&spi->dev,
991 			"%s: packet-size of %u too big (limit is %u bytes)",
992 			__func__, max_packet, MAX3421_FIFO_SIZE);
993 		return -EINVAL;
994 	}
995 
996 	if (max3421_hcd->curr_len < max_packet) {
997 		if (urb->transfer_flags & URB_SHORT_NOT_OK) {
998 			/*
999 			 * remaining > 0 and received an
1000 			 * unexpected partial packet ->
1001 			 * error
1002 			 */
1003 			return -EREMOTEIO;
1004 		} else
1005 			/* short read, but it's OK */
1006 			return 1;
1007 	}
1008 	return 0;	/* not done */
1009 }
1010 
1011 /*
1012  * Caller must NOT hold HCD spinlock.
1013  */
1014 static int
1015 max3421_transfer_out_done(struct usb_hcd *hcd, struct urb *urb)
1016 {
1017 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1018 
1019 	urb->actual_length += max3421_hcd->curr_len;
1020 	if (urb->actual_length < urb->transfer_buffer_length)
1021 		return 0;
1022 	if (urb->transfer_flags & URB_ZERO_PACKET) {
1023 		/*
1024 		 * Some hardware needs a zero-size packet at the end
1025 		 * of a bulk-out transfer if the last transfer was a
1026 		 * full-sized packet (i.e., such hardware use <
1027 		 * max_packet as an indicator that the end of the
1028 		 * packet has been reached).
1029 		 */
1030 		u32 max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
1031 
1032 		if (max3421_hcd->curr_len == max_packet)
1033 			return 0;
1034 	}
1035 	return 1;
1036 }
1037 
1038 /*
1039  * Caller must NOT hold HCD spinlock.
1040  */
1041 static void
1042 max3421_host_transfer_done(struct usb_hcd *hcd)
1043 {
1044 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1045 	struct urb *urb = max3421_hcd->curr_urb;
1046 	struct max3421_ep *max3421_ep;
1047 	u8 result_code, hrsl;
1048 	int urb_done = 0;
1049 
1050 	max3421_hcd->hien &= ~(BIT(MAX3421_HI_HXFRDN_BIT) |
1051 			       BIT(MAX3421_HI_RCVDAV_BIT));
1052 
1053 	hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1054 	result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
1055 
1056 #ifdef DEBUG
1057 	++max3421_hcd->err_stat[result_code];
1058 #endif
1059 
1060 	max3421_ep = urb->ep->hcpriv;
1061 
1062 	if (unlikely(result_code != MAX3421_HRSL_OK)) {
1063 		max3421_handle_error(hcd, hrsl);
1064 		return;
1065 	}
1066 
1067 	max3421_ep->naks = 0;
1068 	max3421_ep->retries = 0;
1069 	switch (max3421_ep->pkt_state) {
1070 
1071 	case PKT_STATE_SETUP:
1072 		if (urb->transfer_buffer_length > 0)
1073 			max3421_ep->pkt_state = PKT_STATE_TRANSFER;
1074 		else
1075 			max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1076 		break;
1077 
1078 	case PKT_STATE_TRANSFER:
1079 		if (usb_urb_dir_in(urb))
1080 			urb_done = max3421_transfer_in_done(hcd, urb);
1081 		else
1082 			urb_done = max3421_transfer_out_done(hcd, urb);
1083 		if (urb_done > 0 && usb_pipetype(urb->pipe) == PIPE_CONTROL) {
1084 			/*
1085 			 * We aren't really done - we still need to
1086 			 * terminate the control transfer:
1087 			 */
1088 			max3421_hcd->urb_done = urb_done = 0;
1089 			max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1090 		}
1091 		break;
1092 
1093 	case PKT_STATE_TERMINATE:
1094 		urb_done = 1;
1095 		break;
1096 	}
1097 
1098 	if (urb_done)
1099 		max3421_hcd->urb_done = urb_done;
1100 	else
1101 		max3421_next_transfer(hcd, 0);
1102 }
1103 
1104 /*
1105  * Caller must NOT hold HCD spinlock.
1106  */
1107 static void
1108 max3421_detect_conn(struct usb_hcd *hcd)
1109 {
1110 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1111 	unsigned int jk, have_conn = 0;
1112 	u32 old_port_status, chg;
1113 	unsigned long flags;
1114 	u8 hrsl, mode;
1115 
1116 	hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1117 
1118 	jk = ((((hrsl >> MAX3421_HRSL_JSTATUS_BIT) & 1) << 0) |
1119 	      (((hrsl >> MAX3421_HRSL_KSTATUS_BIT) & 1) << 1));
1120 
1121 	mode = max3421_hcd->mode;
1122 
1123 	switch (jk) {
1124 	case 0x0: /* SE0: disconnect */
1125 		/*
1126 		 * Turn off SOFKAENAB bit to avoid getting interrupt
1127 		 * every milli-second:
1128 		 */
1129 		mode &= ~BIT(MAX3421_MODE_SOFKAENAB_BIT);
1130 		break;
1131 
1132 	case 0x1: /* J=0,K=1: low-speed (in full-speed or vice versa) */
1133 	case 0x2: /* J=1,K=0: full-speed (in full-speed or vice versa) */
1134 		if (jk == 0x2)
1135 			/* need to switch to the other speed: */
1136 			mode ^= BIT(MAX3421_MODE_LOWSPEED_BIT);
1137 		/* turn on SOFKAENAB bit: */
1138 		mode |= BIT(MAX3421_MODE_SOFKAENAB_BIT);
1139 		have_conn = 1;
1140 		break;
1141 
1142 	case 0x3: /* illegal */
1143 		break;
1144 	}
1145 
1146 	max3421_hcd->mode = mode;
1147 	spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1148 
1149 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1150 	old_port_status = max3421_hcd->port_status;
1151 	if (have_conn)
1152 		max3421_hcd->port_status |=  USB_PORT_STAT_CONNECTION;
1153 	else
1154 		max3421_hcd->port_status &= ~USB_PORT_STAT_CONNECTION;
1155 	if (mode & BIT(MAX3421_MODE_LOWSPEED_BIT))
1156 		max3421_hcd->port_status |=  USB_PORT_STAT_LOW_SPEED;
1157 	else
1158 		max3421_hcd->port_status &= ~USB_PORT_STAT_LOW_SPEED;
1159 	chg = (old_port_status ^ max3421_hcd->port_status);
1160 	max3421_hcd->port_status |= chg << 16;
1161 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1162 }
1163 
1164 static irqreturn_t
1165 max3421_irq_handler(int irq, void *dev_id)
1166 {
1167 	struct usb_hcd *hcd = dev_id;
1168 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1169 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1170 
1171 	if (max3421_hcd->spi_thread &&
1172 	    max3421_hcd->spi_thread->state != TASK_RUNNING)
1173 		wake_up_process(max3421_hcd->spi_thread);
1174 	if (!test_and_set_bit(ENABLE_IRQ, &max3421_hcd->todo))
1175 		disable_irq_nosync(spi->irq);
1176 	return IRQ_HANDLED;
1177 }
1178 
1179 #ifdef DEBUG
1180 
1181 static void
1182 dump_eps(struct usb_hcd *hcd)
1183 {
1184 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1185 	struct max3421_ep *max3421_ep;
1186 	struct usb_host_endpoint *ep;
1187 	struct list_head *pos, *upos;
1188 	char ubuf[512], *dp, *end;
1189 	unsigned long flags;
1190 	struct urb *urb;
1191 	int epnum, ret;
1192 
1193 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1194 	list_for_each(pos, &max3421_hcd->ep_list) {
1195 		max3421_ep = container_of(pos, struct max3421_ep, ep_list);
1196 		ep = max3421_ep->ep;
1197 
1198 		dp = ubuf;
1199 		end = dp + sizeof(ubuf);
1200 		*dp = '\0';
1201 		list_for_each(upos, &ep->urb_list) {
1202 			urb = container_of(upos, struct urb, urb_list);
1203 			ret = snprintf(dp, end - dp, " %p(%d.%s %d/%d)", urb,
1204 				       usb_pipetype(urb->pipe),
1205 				       usb_urb_dir_in(urb) ? "IN" : "OUT",
1206 				       urb->actual_length,
1207 				       urb->transfer_buffer_length);
1208 			if (ret < 0 || ret >= end - dp)
1209 				break;	/* error or buffer full */
1210 			dp += ret;
1211 		}
1212 
1213 		epnum = usb_endpoint_num(&ep->desc);
1214 		pr_info("EP%0u %u lst %04u rtr %u nak %6u rxmt %u: %s\n",
1215 			epnum, max3421_ep->pkt_state, max3421_ep->last_active,
1216 			max3421_ep->retries, max3421_ep->naks,
1217 			max3421_ep->retransmit, ubuf);
1218 	}
1219 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1220 }
1221 
1222 #endif /* DEBUG */
1223 
1224 /* Return zero if no work was performed, 1 otherwise.  */
1225 static int
1226 max3421_handle_irqs(struct usb_hcd *hcd)
1227 {
1228 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1229 	u32 chg, old_port_status;
1230 	unsigned long flags;
1231 	u8 hirq;
1232 
1233 	/*
1234 	 * Read and ack pending interrupts (CPU must never
1235 	 * clear SNDBAV directly and RCVDAV must be cleared by
1236 	 * max3421_recv_data_available()!):
1237 	 */
1238 	hirq = spi_rd8(hcd, MAX3421_REG_HIRQ);
1239 	hirq &= max3421_hcd->hien;
1240 	if (!hirq)
1241 		return 0;
1242 
1243 	spi_wr8(hcd, MAX3421_REG_HIRQ,
1244 		hirq & ~(BIT(MAX3421_HI_SNDBAV_BIT) |
1245 			 BIT(MAX3421_HI_RCVDAV_BIT)));
1246 
1247 	if (hirq & BIT(MAX3421_HI_FRAME_BIT)) {
1248 		max3421_hcd->frame_number = ((max3421_hcd->frame_number + 1)
1249 					     & USB_MAX_FRAME_NUMBER);
1250 		max3421_hcd->sched_pass = SCHED_PASS_PERIODIC;
1251 	}
1252 
1253 	if (hirq & BIT(MAX3421_HI_RCVDAV_BIT))
1254 		max3421_recv_data_available(hcd);
1255 
1256 	if (hirq & BIT(MAX3421_HI_HXFRDN_BIT))
1257 		max3421_host_transfer_done(hcd);
1258 
1259 	if (hirq & BIT(MAX3421_HI_CONDET_BIT))
1260 		max3421_detect_conn(hcd);
1261 
1262 	/*
1263 	 * Now process interrupts that may affect HCD state
1264 	 * other than the end-points:
1265 	 */
1266 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1267 
1268 	old_port_status = max3421_hcd->port_status;
1269 	if (hirq & BIT(MAX3421_HI_BUSEVENT_BIT)) {
1270 		if (max3421_hcd->port_status & USB_PORT_STAT_RESET) {
1271 			/* BUSEVENT due to completion of Bus Reset */
1272 			max3421_hcd->port_status &= ~USB_PORT_STAT_RESET;
1273 			max3421_hcd->port_status |=  USB_PORT_STAT_ENABLE;
1274 		} else {
1275 			/* BUSEVENT due to completion of Bus Resume */
1276 			pr_info("%s: BUSEVENT Bus Resume Done\n", __func__);
1277 		}
1278 	}
1279 	if (hirq & BIT(MAX3421_HI_RWU_BIT))
1280 		pr_info("%s: RWU\n", __func__);
1281 	if (hirq & BIT(MAX3421_HI_SUSDN_BIT))
1282 		pr_info("%s: SUSDN\n", __func__);
1283 
1284 	chg = (old_port_status ^ max3421_hcd->port_status);
1285 	max3421_hcd->port_status |= chg << 16;
1286 
1287 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1288 
1289 #ifdef DEBUG
1290 	{
1291 		static unsigned long last_time;
1292 		char sbuf[16 * 16], *dp, *end;
1293 		int i;
1294 
1295 		if (time_after(jiffies, last_time + 5*HZ)) {
1296 			dp = sbuf;
1297 			end = sbuf + sizeof(sbuf);
1298 			*dp = '\0';
1299 			for (i = 0; i < 16; ++i) {
1300 				int ret = snprintf(dp, end - dp, " %lu",
1301 						   max3421_hcd->err_stat[i]);
1302 				if (ret < 0 || ret >= end - dp)
1303 					break;	/* error or buffer full */
1304 				dp += ret;
1305 			}
1306 			pr_info("%s: hrsl_stats %s\n", __func__, sbuf);
1307 			memset(max3421_hcd->err_stat, 0,
1308 			       sizeof(max3421_hcd->err_stat));
1309 			last_time = jiffies;
1310 
1311 			dump_eps(hcd);
1312 		}
1313 	}
1314 #endif
1315 	return 1;
1316 }
1317 
1318 static int
1319 max3421_reset_hcd(struct usb_hcd *hcd)
1320 {
1321 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1322 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1323 	int timeout;
1324 
1325 	/* perform a chip reset and wait for OSCIRQ signal to appear: */
1326 	spi_wr8(hcd, MAX3421_REG_USBCTL, BIT(MAX3421_USBCTL_CHIPRES_BIT));
1327 	/* clear reset: */
1328 	spi_wr8(hcd, MAX3421_REG_USBCTL, 0);
1329 	timeout = 1000;
1330 	while (1) {
1331 		if (spi_rd8(hcd, MAX3421_REG_USBIRQ)
1332 		    & BIT(MAX3421_USBIRQ_OSCOKIRQ_BIT))
1333 			break;
1334 		if (--timeout < 0) {
1335 			dev_err(&spi->dev,
1336 				"timed out waiting for oscillator OK signal");
1337 			return 1;
1338 		}
1339 		cond_resched();
1340 	}
1341 
1342 	/*
1343 	 * Turn on host mode, automatic generation of SOF packets, and
1344 	 * enable pull-down registers on DM/DP:
1345 	 */
1346 	max3421_hcd->mode = (BIT(MAX3421_MODE_HOST_BIT) |
1347 			     BIT(MAX3421_MODE_SOFKAENAB_BIT) |
1348 			     BIT(MAX3421_MODE_DMPULLDN_BIT) |
1349 			     BIT(MAX3421_MODE_DPPULLDN_BIT));
1350 	spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1351 
1352 	/* reset frame-number: */
1353 	max3421_hcd->frame_number = USB_MAX_FRAME_NUMBER;
1354 	spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_FRMRST_BIT));
1355 
1356 	/* sample the state of the D+ and D- lines */
1357 	spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_SAMPLEBUS_BIT));
1358 	max3421_detect_conn(hcd);
1359 
1360 	/* enable frame, connection-detected, and bus-event interrupts: */
1361 	max3421_hcd->hien = (BIT(MAX3421_HI_FRAME_BIT) |
1362 			     BIT(MAX3421_HI_CONDET_BIT) |
1363 			     BIT(MAX3421_HI_BUSEVENT_BIT));
1364 	spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1365 
1366 	/* enable interrupts: */
1367 	spi_wr8(hcd, MAX3421_REG_CPUCTL, BIT(MAX3421_CPUCTL_IE_BIT));
1368 	return 1;
1369 }
1370 
1371 static int
1372 max3421_urb_done(struct usb_hcd *hcd)
1373 {
1374 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1375 	unsigned long flags;
1376 	struct urb *urb;
1377 	int status;
1378 
1379 	status = max3421_hcd->urb_done;
1380 	max3421_hcd->urb_done = 0;
1381 	if (status > 0)
1382 		status = 0;
1383 	urb = max3421_hcd->curr_urb;
1384 	if (urb) {
1385 		max3421_hcd->curr_urb = NULL;
1386 		spin_lock_irqsave(&max3421_hcd->lock, flags);
1387 		usb_hcd_unlink_urb_from_ep(hcd, urb);
1388 		spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1389 
1390 		/* must be called without the HCD spinlock: */
1391 		usb_hcd_giveback_urb(hcd, urb, status);
1392 	}
1393 	return 1;
1394 }
1395 
1396 static int
1397 max3421_spi_thread(void *dev_id)
1398 {
1399 	struct usb_hcd *hcd = dev_id;
1400 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1401 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1402 	int i, i_worked = 1;
1403 
1404 	/* set full-duplex SPI mode, low-active interrupt pin: */
1405 	spi_wr8(hcd, MAX3421_REG_PINCTL,
1406 		(BIT(MAX3421_PINCTL_FDUPSPI_BIT) |	/* full-duplex */
1407 		 BIT(MAX3421_PINCTL_INTLEVEL_BIT)));	/* low-active irq */
1408 
1409 	while (!kthread_should_stop()) {
1410 		max3421_hcd->rev = spi_rd8(hcd, MAX3421_REG_REVISION);
1411 		if (max3421_hcd->rev == 0x12 || max3421_hcd->rev == 0x13)
1412 			break;
1413 		dev_err(&spi->dev, "bad rev 0x%02x", max3421_hcd->rev);
1414 		msleep(10000);
1415 	}
1416 	dev_info(&spi->dev, "rev 0x%x, SPI clk %dHz, bpw %u, irq %d\n",
1417 		 max3421_hcd->rev, spi->max_speed_hz, spi->bits_per_word,
1418 		 spi->irq);
1419 
1420 	while (!kthread_should_stop()) {
1421 		if (!i_worked) {
1422 			/*
1423 			 * We'll be waiting for wakeups from the hard
1424 			 * interrupt handler, so now is a good time to
1425 			 * sync our hien with the chip:
1426 			 */
1427 			spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1428 
1429 			set_current_state(TASK_INTERRUPTIBLE);
1430 			if (test_and_clear_bit(ENABLE_IRQ, &max3421_hcd->todo))
1431 				enable_irq(spi->irq);
1432 			schedule();
1433 			__set_current_state(TASK_RUNNING);
1434 		}
1435 
1436 		i_worked = 0;
1437 
1438 		if (max3421_hcd->urb_done)
1439 			i_worked |= max3421_urb_done(hcd);
1440 		else if (max3421_handle_irqs(hcd))
1441 			i_worked = 1;
1442 		else if (!max3421_hcd->curr_urb)
1443 			i_worked |= max3421_select_and_start_urb(hcd);
1444 
1445 		if (test_and_clear_bit(RESET_HCD, &max3421_hcd->todo))
1446 			/* reset the HCD: */
1447 			i_worked |= max3421_reset_hcd(hcd);
1448 		if (test_and_clear_bit(RESET_PORT, &max3421_hcd->todo)) {
1449 			/* perform a USB bus reset: */
1450 			spi_wr8(hcd, MAX3421_REG_HCTL,
1451 				BIT(MAX3421_HCTL_BUSRST_BIT));
1452 			i_worked = 1;
1453 		}
1454 		if (test_and_clear_bit(CHECK_UNLINK, &max3421_hcd->todo))
1455 			i_worked |= max3421_check_unlink(hcd);
1456 		if (test_and_clear_bit(IOPIN_UPDATE, &max3421_hcd->todo)) {
1457 			/*
1458 			 * IOPINS1/IOPINS2 do not auto-increment, so we can't
1459 			 * use spi_wr_buf().
1460 			 */
1461 			for (i = 0; i < ARRAY_SIZE(max3421_hcd->iopins); ++i) {
1462 				u8 val = spi_rd8(hcd, MAX3421_REG_IOPINS1);
1463 
1464 				val = ((val & 0xf0) |
1465 				       (max3421_hcd->iopins[i] & 0x0f));
1466 				spi_wr8(hcd, MAX3421_REG_IOPINS1 + i, val);
1467 				max3421_hcd->iopins[i] = val;
1468 			}
1469 			i_worked = 1;
1470 		}
1471 	}
1472 	set_current_state(TASK_RUNNING);
1473 	dev_info(&spi->dev, "SPI thread exiting");
1474 	return 0;
1475 }
1476 
1477 static int
1478 max3421_reset_port(struct usb_hcd *hcd)
1479 {
1480 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1481 
1482 	max3421_hcd->port_status &= ~(USB_PORT_STAT_ENABLE |
1483 				      USB_PORT_STAT_LOW_SPEED);
1484 	max3421_hcd->port_status |= USB_PORT_STAT_RESET;
1485 	set_bit(RESET_PORT, &max3421_hcd->todo);
1486 	wake_up_process(max3421_hcd->spi_thread);
1487 	return 0;
1488 }
1489 
1490 static int
1491 max3421_reset(struct usb_hcd *hcd)
1492 {
1493 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1494 
1495 	hcd->self.sg_tablesize = 0;
1496 	hcd->speed = HCD_USB2;
1497 	hcd->self.root_hub->speed = USB_SPEED_FULL;
1498 	set_bit(RESET_HCD, &max3421_hcd->todo);
1499 	wake_up_process(max3421_hcd->spi_thread);
1500 	return 0;
1501 }
1502 
1503 static int
1504 max3421_start(struct usb_hcd *hcd)
1505 {
1506 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1507 
1508 	spin_lock_init(&max3421_hcd->lock);
1509 	max3421_hcd->rh_state = MAX3421_RH_RUNNING;
1510 
1511 	INIT_LIST_HEAD(&max3421_hcd->ep_list);
1512 
1513 	hcd->power_budget = POWER_BUDGET;
1514 	hcd->state = HC_STATE_RUNNING;
1515 	hcd->uses_new_polling = 1;
1516 	return 0;
1517 }
1518 
1519 static void
1520 max3421_stop(struct usb_hcd *hcd)
1521 {
1522 }
1523 
1524 static int
1525 max3421_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1526 {
1527 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1528 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1529 	struct max3421_ep *max3421_ep;
1530 	unsigned long flags;
1531 	int retval;
1532 
1533 	switch (usb_pipetype(urb->pipe)) {
1534 	case PIPE_INTERRUPT:
1535 	case PIPE_ISOCHRONOUS:
1536 		if (urb->interval < 0) {
1537 			dev_err(&spi->dev,
1538 			  "%s: interval=%d for intr-/iso-pipe; expected > 0\n",
1539 				__func__, urb->interval);
1540 			return -EINVAL;
1541 		}
1542 	default:
1543 		break;
1544 	}
1545 
1546 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1547 
1548 	max3421_ep = urb->ep->hcpriv;
1549 	if (!max3421_ep) {
1550 		/* gets freed in max3421_endpoint_disable: */
1551 		max3421_ep = kzalloc(sizeof(struct max3421_ep), GFP_ATOMIC);
1552 		if (!max3421_ep) {
1553 			retval = -ENOMEM;
1554 			goto out;
1555 		}
1556 		max3421_ep->ep = urb->ep;
1557 		max3421_ep->last_active = max3421_hcd->frame_number;
1558 		urb->ep->hcpriv = max3421_ep;
1559 
1560 		list_add_tail(&max3421_ep->ep_list, &max3421_hcd->ep_list);
1561 	}
1562 
1563 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
1564 	if (retval == 0) {
1565 		/* Since we added to the queue, restart scheduling: */
1566 		max3421_hcd->sched_pass = SCHED_PASS_PERIODIC;
1567 		wake_up_process(max3421_hcd->spi_thread);
1568 	}
1569 
1570 out:
1571 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1572 	return retval;
1573 }
1574 
1575 static int
1576 max3421_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
1577 {
1578 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1579 	unsigned long flags;
1580 	int retval;
1581 
1582 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1583 
1584 	/*
1585 	 * This will set urb->unlinked which in turn causes the entry
1586 	 * to be dropped at the next opportunity.
1587 	 */
1588 	retval = usb_hcd_check_unlink_urb(hcd, urb, status);
1589 	if (retval == 0) {
1590 		set_bit(CHECK_UNLINK, &max3421_hcd->todo);
1591 		wake_up_process(max3421_hcd->spi_thread);
1592 	}
1593 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1594 	return retval;
1595 }
1596 
1597 static void
1598 max3421_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
1599 {
1600 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1601 	unsigned long flags;
1602 
1603 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1604 
1605 	if (ep->hcpriv) {
1606 		struct max3421_ep *max3421_ep = ep->hcpriv;
1607 
1608 		/* remove myself from the ep_list: */
1609 		if (!list_empty(&max3421_ep->ep_list))
1610 			list_del(&max3421_ep->ep_list);
1611 		kfree(max3421_ep);
1612 		ep->hcpriv = NULL;
1613 	}
1614 
1615 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1616 }
1617 
1618 static int
1619 max3421_get_frame_number(struct usb_hcd *hcd)
1620 {
1621 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1622 	return max3421_hcd->frame_number;
1623 }
1624 
1625 /*
1626  * Should return a non-zero value when any port is undergoing a resume
1627  * transition while the root hub is suspended.
1628  */
1629 static int
1630 max3421_hub_status_data(struct usb_hcd *hcd, char *buf)
1631 {
1632 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1633 	unsigned long flags;
1634 	int retval = 0;
1635 
1636 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1637 	if (!HCD_HW_ACCESSIBLE(hcd))
1638 		goto done;
1639 
1640 	*buf = 0;
1641 	if ((max3421_hcd->port_status & PORT_C_MASK) != 0) {
1642 		*buf = (1 << 1); /* a hub over-current condition exists */
1643 		dev_dbg(hcd->self.controller,
1644 			"port status 0x%08x has changes\n",
1645 			max3421_hcd->port_status);
1646 		retval = 1;
1647 		if (max3421_hcd->rh_state == MAX3421_RH_SUSPENDED)
1648 			usb_hcd_resume_root_hub(hcd);
1649 	}
1650 done:
1651 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1652 	return retval;
1653 }
1654 
1655 static inline void
1656 hub_descriptor(struct usb_hub_descriptor *desc)
1657 {
1658 	memset(desc, 0, sizeof(*desc));
1659 	/*
1660 	 * See Table 11-13: Hub Descriptor in USB 2.0 spec.
1661 	 */
1662 	desc->bDescriptorType = USB_DT_HUB; /* hub descriptor */
1663 	desc->bDescLength = 9;
1664 	desc->wHubCharacteristics = cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM |
1665 						HUB_CHAR_COMMON_OCPM);
1666 	desc->bNbrPorts = 1;
1667 }
1668 
1669 /*
1670  * Set the MAX3421E general-purpose output with number PIN_NUMBER to
1671  * VALUE (0 or 1).  PIN_NUMBER may be in the range from 1-8.  For
1672  * any other value, this function acts as a no-op.
1673  */
1674 static void
1675 max3421_gpout_set_value(struct usb_hcd *hcd, u8 pin_number, u8 value)
1676 {
1677 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1678 	u8 mask, idx;
1679 
1680 	--pin_number;
1681 	if (pin_number > 7)
1682 		return;
1683 
1684 	mask = 1u << pin_number;
1685 	idx = pin_number / 4;
1686 
1687 	if (value)
1688 		max3421_hcd->iopins[idx] |=  mask;
1689 	else
1690 		max3421_hcd->iopins[idx] &= ~mask;
1691 	set_bit(IOPIN_UPDATE, &max3421_hcd->todo);
1692 	wake_up_process(max3421_hcd->spi_thread);
1693 }
1694 
1695 static int
1696 max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
1697 		    char *buf, u16 length)
1698 {
1699 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1700 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1701 	struct max3421_hcd_platform_data *pdata;
1702 	unsigned long flags;
1703 	int retval = 0;
1704 
1705 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1706 
1707 	pdata = spi->dev.platform_data;
1708 
1709 	switch (type_req) {
1710 	case ClearHubFeature:
1711 		break;
1712 	case ClearPortFeature:
1713 		switch (value) {
1714 		case USB_PORT_FEAT_SUSPEND:
1715 			break;
1716 		case USB_PORT_FEAT_POWER:
1717 			dev_dbg(hcd->self.controller, "power-off\n");
1718 			max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1719 						!pdata->vbus_active_level);
1720 			/* FALLS THROUGH */
1721 		default:
1722 			max3421_hcd->port_status &= ~(1 << value);
1723 		}
1724 		break;
1725 	case GetHubDescriptor:
1726 		hub_descriptor((struct usb_hub_descriptor *) buf);
1727 		break;
1728 
1729 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
1730 	case GetPortErrorCount:
1731 	case SetHubDepth:
1732 		/* USB3 only */
1733 		goto error;
1734 
1735 	case GetHubStatus:
1736 		*(__le32 *) buf = cpu_to_le32(0);
1737 		break;
1738 
1739 	case GetPortStatus:
1740 		if (index != 1) {
1741 			retval = -EPIPE;
1742 			goto error;
1743 		}
1744 		((__le16 *) buf)[0] = cpu_to_le16(max3421_hcd->port_status);
1745 		((__le16 *) buf)[1] =
1746 			cpu_to_le16(max3421_hcd->port_status >> 16);
1747 		break;
1748 
1749 	case SetHubFeature:
1750 		retval = -EPIPE;
1751 		break;
1752 
1753 	case SetPortFeature:
1754 		switch (value) {
1755 		case USB_PORT_FEAT_LINK_STATE:
1756 		case USB_PORT_FEAT_U1_TIMEOUT:
1757 		case USB_PORT_FEAT_U2_TIMEOUT:
1758 		case USB_PORT_FEAT_BH_PORT_RESET:
1759 			goto error;
1760 		case USB_PORT_FEAT_SUSPEND:
1761 			if (max3421_hcd->active)
1762 				max3421_hcd->port_status |=
1763 					USB_PORT_STAT_SUSPEND;
1764 			break;
1765 		case USB_PORT_FEAT_POWER:
1766 			dev_dbg(hcd->self.controller, "power-on\n");
1767 			max3421_hcd->port_status |= USB_PORT_STAT_POWER;
1768 			max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1769 						pdata->vbus_active_level);
1770 			break;
1771 		case USB_PORT_FEAT_RESET:
1772 			max3421_reset_port(hcd);
1773 			/* FALLS THROUGH */
1774 		default:
1775 			if ((max3421_hcd->port_status & USB_PORT_STAT_POWER)
1776 			    != 0)
1777 				max3421_hcd->port_status |= (1 << value);
1778 		}
1779 		break;
1780 
1781 	default:
1782 		dev_dbg(hcd->self.controller,
1783 			"hub control req%04x v%04x i%04x l%d\n",
1784 			type_req, value, index, length);
1785 error:		/* "protocol stall" on error */
1786 		retval = -EPIPE;
1787 	}
1788 
1789 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1790 	return retval;
1791 }
1792 
1793 static int
1794 max3421_bus_suspend(struct usb_hcd *hcd)
1795 {
1796 	return -1;
1797 }
1798 
1799 static int
1800 max3421_bus_resume(struct usb_hcd *hcd)
1801 {
1802 	return -1;
1803 }
1804 
1805 /*
1806  * The SPI driver already takes care of DMA-mapping/unmapping, so no
1807  * reason to do it twice.
1808  */
1809 static int
1810 max3421_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1811 {
1812 	return 0;
1813 }
1814 
1815 static void
1816 max3421_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1817 {
1818 }
1819 
1820 static struct hc_driver max3421_hcd_desc = {
1821 	.description =		"max3421",
1822 	.product_desc =		DRIVER_DESC,
1823 	.hcd_priv_size =	sizeof(struct max3421_hcd),
1824 	.flags =		HCD_USB11,
1825 	.reset =		max3421_reset,
1826 	.start =		max3421_start,
1827 	.stop =			max3421_stop,
1828 	.get_frame_number =	max3421_get_frame_number,
1829 	.urb_enqueue =		max3421_urb_enqueue,
1830 	.urb_dequeue =		max3421_urb_dequeue,
1831 	.map_urb_for_dma =	max3421_map_urb_for_dma,
1832 	.unmap_urb_for_dma =	max3421_unmap_urb_for_dma,
1833 	.endpoint_disable =	max3421_endpoint_disable,
1834 	.hub_status_data =	max3421_hub_status_data,
1835 	.hub_control =		max3421_hub_control,
1836 	.bus_suspend =		max3421_bus_suspend,
1837 	.bus_resume =		max3421_bus_resume,
1838 };
1839 
1840 static int
1841 max3421_probe(struct spi_device *spi)
1842 {
1843 	struct max3421_hcd *max3421_hcd;
1844 	struct usb_hcd *hcd = NULL;
1845 	int retval = -ENOMEM;
1846 
1847 	if (spi_setup(spi) < 0) {
1848 		dev_err(&spi->dev, "Unable to setup SPI bus");
1849 		return -EFAULT;
1850 	}
1851 
1852 	hcd = usb_create_hcd(&max3421_hcd_desc, &spi->dev,
1853 			     dev_name(&spi->dev));
1854 	if (!hcd) {
1855 		dev_err(&spi->dev, "failed to create HCD structure\n");
1856 		goto error;
1857 	}
1858 	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
1859 	max3421_hcd = hcd_to_max3421(hcd);
1860 	max3421_hcd->next = max3421_hcd_list;
1861 	max3421_hcd_list = max3421_hcd;
1862 	INIT_LIST_HEAD(&max3421_hcd->ep_list);
1863 
1864 	max3421_hcd->tx = kmalloc(sizeof(*max3421_hcd->tx), GFP_KERNEL);
1865 	if (!max3421_hcd->tx) {
1866 		dev_err(&spi->dev, "failed to kmalloc tx buffer\n");
1867 		goto error;
1868 	}
1869 	max3421_hcd->rx = kmalloc(sizeof(*max3421_hcd->rx), GFP_KERNEL);
1870 	if (!max3421_hcd->rx) {
1871 		dev_err(&spi->dev, "failed to kmalloc rx buffer\n");
1872 		goto error;
1873 	}
1874 
1875 	max3421_hcd->spi_thread = kthread_run(max3421_spi_thread, hcd,
1876 					      "max3421_spi_thread");
1877 	if (max3421_hcd->spi_thread == ERR_PTR(-ENOMEM)) {
1878 		dev_err(&spi->dev,
1879 			"failed to create SPI thread (out of memory)\n");
1880 		goto error;
1881 	}
1882 
1883 	retval = usb_add_hcd(hcd, 0, 0);
1884 	if (retval) {
1885 		dev_err(&spi->dev, "failed to add HCD\n");
1886 		goto error;
1887 	}
1888 
1889 	retval = request_irq(spi->irq, max3421_irq_handler,
1890 			     IRQF_TRIGGER_LOW, "max3421", hcd);
1891 	if (retval < 0) {
1892 		dev_err(&spi->dev, "failed to request irq %d\n", spi->irq);
1893 		goto error;
1894 	}
1895 	return 0;
1896 
1897 error:
1898 	if (hcd) {
1899 		kfree(max3421_hcd->tx);
1900 		kfree(max3421_hcd->rx);
1901 		if (max3421_hcd->spi_thread)
1902 			kthread_stop(max3421_hcd->spi_thread);
1903 		usb_put_hcd(hcd);
1904 	}
1905 	return retval;
1906 }
1907 
1908 static int
1909 max3421_remove(struct spi_device *spi)
1910 {
1911 	struct max3421_hcd *max3421_hcd = NULL, **prev;
1912 	struct usb_hcd *hcd = NULL;
1913 	unsigned long flags;
1914 
1915 	for (prev = &max3421_hcd_list; *prev; prev = &(*prev)->next) {
1916 		max3421_hcd = *prev;
1917 		hcd = max3421_to_hcd(max3421_hcd);
1918 		if (hcd->self.controller == &spi->dev)
1919 			break;
1920 	}
1921 	if (!max3421_hcd) {
1922 		dev_err(&spi->dev, "no MAX3421 HCD found for SPI device %p\n",
1923 			spi);
1924 		return -ENODEV;
1925 	}
1926 
1927 	usb_remove_hcd(hcd);
1928 
1929 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1930 
1931 	kthread_stop(max3421_hcd->spi_thread);
1932 	*prev = max3421_hcd->next;
1933 
1934 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1935 
1936 	free_irq(spi->irq, hcd);
1937 
1938 	usb_put_hcd(hcd);
1939 	return 0;
1940 }
1941 
1942 static struct spi_driver max3421_driver = {
1943 	.probe		= max3421_probe,
1944 	.remove		= max3421_remove,
1945 	.driver		= {
1946 		.name	= "max3421-hcd",
1947 		.owner	= THIS_MODULE,
1948 	},
1949 };
1950 
1951 module_spi_driver(max3421_driver);
1952 
1953 MODULE_DESCRIPTION(DRIVER_DESC);
1954 MODULE_AUTHOR("David Mosberger <davidm@egauge.net>");
1955 MODULE_LICENSE("GPL");
1956