xref: /linux/drivers/usb/host/max3421-hcd.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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/module.h>
59 #include <linux/spi/spi.h>
60 #include <linux/usb.h>
61 #include <linux/usb/hcd.h>
62 
63 #include <linux/platform_data/max3421-hcd.h>
64 
65 #define DRIVER_DESC	"MAX3421 USB Host-Controller Driver"
66 #define DRIVER_VERSION	"1.0"
67 
68 /* 11-bit counter that wraps around (USB 2.0 Section 8.3.3): */
69 #define USB_MAX_FRAME_NUMBER	0x7ff
70 #define USB_MAX_RETRIES		3 /* # of retries before error is reported */
71 
72 /*
73  * Max. # of times we're willing to retransmit a request immediately in
74  * resposne to a NAK.  Afterwards, we fall back on trying once a frame.
75  */
76 #define NAK_MAX_FAST_RETRANSMITS	2
77 
78 #define POWER_BUDGET	500	/* in mA; use 8 for low-power port testing */
79 
80 /* Port-change mask: */
81 #define PORT_C_MASK	((USB_PORT_STAT_C_CONNECTION |	\
82 			  USB_PORT_STAT_C_ENABLE |	\
83 			  USB_PORT_STAT_C_SUSPEND |	\
84 			  USB_PORT_STAT_C_OVERCURRENT | \
85 			  USB_PORT_STAT_C_RESET) << 16)
86 
87 enum max3421_rh_state {
88 	MAX3421_RH_RESET,
89 	MAX3421_RH_SUSPENDED,
90 	MAX3421_RH_RUNNING
91 };
92 
93 enum pkt_state {
94 	PKT_STATE_SETUP,	/* waiting to send setup packet to ctrl pipe */
95 	PKT_STATE_TRANSFER,	/* waiting to xfer transfer_buffer */
96 	PKT_STATE_TERMINATE	/* waiting to terminate control transfer */
97 };
98 
99 enum scheduling_pass {
100 	SCHED_PASS_PERIODIC,
101 	SCHED_PASS_NON_PERIODIC,
102 	SCHED_PASS_DONE
103 };
104 
105 /* Bit numbers for max3421_hcd->todo: */
106 enum {
107 	ENABLE_IRQ = 0,
108 	RESET_HCD,
109 	RESET_PORT,
110 	CHECK_UNLINK,
111 	IOPIN_UPDATE
112 };
113 
114 struct max3421_dma_buf {
115 	u8 data[2];
116 };
117 
118 struct max3421_hcd {
119 	spinlock_t lock;
120 
121 	struct task_struct *spi_thread;
122 
123 	struct max3421_hcd *next;
124 
125 	enum max3421_rh_state rh_state;
126 	/* lower 16 bits contain port status, upper 16 bits the change mask: */
127 	u32 port_status;
128 
129 	unsigned active:1;
130 
131 	struct list_head ep_list;	/* list of EP's with work */
132 
133 	/*
134 	 * The following are owned by spi_thread (may be accessed by
135 	 * SPI-thread without acquiring the HCD lock:
136 	 */
137 	u8 rev;				/* chip revision */
138 	u16 frame_number;
139 	/*
140 	 * kmalloc'd buffers guaranteed to be in separate (DMA)
141 	 * cache-lines:
142 	 */
143 	struct max3421_dma_buf *tx;
144 	struct max3421_dma_buf *rx;
145 	/*
146 	 * URB we're currently processing.  Must not be reset to NULL
147 	 * unless MAX3421E chip is idle:
148 	 */
149 	struct urb *curr_urb;
150 	enum scheduling_pass sched_pass;
151 	struct usb_device *loaded_dev;	/* dev that's loaded into the chip */
152 	int loaded_epnum;		/* epnum whose toggles are loaded */
153 	int urb_done;			/* > 0 -> no errors, < 0: errno */
154 	size_t curr_len;
155 	u8 hien;
156 	u8 mode;
157 	u8 iopins[2];
158 	unsigned long todo;
159 #ifdef DEBUG
160 	unsigned long err_stat[16];
161 #endif
162 };
163 
164 struct max3421_ep {
165 	struct usb_host_endpoint *ep;
166 	struct list_head ep_list;
167 	u32 naks;
168 	u16 last_active;		/* frame # this ep was last active */
169 	enum pkt_state pkt_state;
170 	u8 retries;
171 	u8 retransmit;			/* packet needs retransmission */
172 };
173 
174 static struct max3421_hcd *max3421_hcd_list;
175 
176 #define MAX3421_FIFO_SIZE	64
177 
178 #define MAX3421_SPI_DIR_RD	0	/* read register from MAX3421 */
179 #define MAX3421_SPI_DIR_WR	1	/* write register to MAX3421 */
180 
181 /* SPI commands: */
182 #define MAX3421_SPI_DIR_SHIFT	1
183 #define MAX3421_SPI_REG_SHIFT	3
184 
185 #define MAX3421_REG_RCVFIFO	1
186 #define MAX3421_REG_SNDFIFO	2
187 #define MAX3421_REG_SUDFIFO	4
188 #define MAX3421_REG_RCVBC	6
189 #define MAX3421_REG_SNDBC	7
190 #define MAX3421_REG_USBIRQ	13
191 #define MAX3421_REG_USBIEN	14
192 #define MAX3421_REG_USBCTL	15
193 #define MAX3421_REG_CPUCTL	16
194 #define MAX3421_REG_PINCTL	17
195 #define MAX3421_REG_REVISION	18
196 #define MAX3421_REG_IOPINS1	20
197 #define MAX3421_REG_IOPINS2	21
198 #define MAX3421_REG_GPINIRQ	22
199 #define MAX3421_REG_GPINIEN	23
200 #define MAX3421_REG_GPINPOL	24
201 #define MAX3421_REG_HIRQ	25
202 #define MAX3421_REG_HIEN	26
203 #define MAX3421_REG_MODE	27
204 #define MAX3421_REG_PERADDR	28
205 #define MAX3421_REG_HCTL	29
206 #define MAX3421_REG_HXFR	30
207 #define MAX3421_REG_HRSL	31
208 
209 enum {
210 	MAX3421_USBIRQ_OSCOKIRQ_BIT = 0,
211 	MAX3421_USBIRQ_NOVBUSIRQ_BIT = 5,
212 	MAX3421_USBIRQ_VBUSIRQ_BIT
213 };
214 
215 enum {
216 	MAX3421_CPUCTL_IE_BIT = 0,
217 	MAX3421_CPUCTL_PULSEWID0_BIT = 6,
218 	MAX3421_CPUCTL_PULSEWID1_BIT
219 };
220 
221 enum {
222 	MAX3421_USBCTL_PWRDOWN_BIT = 4,
223 	MAX3421_USBCTL_CHIPRES_BIT
224 };
225 
226 enum {
227 	MAX3421_PINCTL_GPXA_BIT	= 0,
228 	MAX3421_PINCTL_GPXB_BIT,
229 	MAX3421_PINCTL_POSINT_BIT,
230 	MAX3421_PINCTL_INTLEVEL_BIT,
231 	MAX3421_PINCTL_FDUPSPI_BIT,
232 	MAX3421_PINCTL_EP0INAK_BIT,
233 	MAX3421_PINCTL_EP2INAK_BIT,
234 	MAX3421_PINCTL_EP3INAK_BIT,
235 };
236 
237 enum {
238 	MAX3421_HI_BUSEVENT_BIT = 0,	/* bus-reset/-resume */
239 	MAX3421_HI_RWU_BIT,		/* remote wakeup */
240 	MAX3421_HI_RCVDAV_BIT,		/* receive FIFO data available */
241 	MAX3421_HI_SNDBAV_BIT,		/* send buffer available */
242 	MAX3421_HI_SUSDN_BIT,		/* suspend operation done */
243 	MAX3421_HI_CONDET_BIT,		/* peripheral connect/disconnect */
244 	MAX3421_HI_FRAME_BIT,		/* frame generator */
245 	MAX3421_HI_HXFRDN_BIT,		/* host transfer done */
246 };
247 
248 enum {
249 	MAX3421_HCTL_BUSRST_BIT = 0,
250 	MAX3421_HCTL_FRMRST_BIT,
251 	MAX3421_HCTL_SAMPLEBUS_BIT,
252 	MAX3421_HCTL_SIGRSM_BIT,
253 	MAX3421_HCTL_RCVTOG0_BIT,
254 	MAX3421_HCTL_RCVTOG1_BIT,
255 	MAX3421_HCTL_SNDTOG0_BIT,
256 	MAX3421_HCTL_SNDTOG1_BIT
257 };
258 
259 enum {
260 	MAX3421_MODE_HOST_BIT = 0,
261 	MAX3421_MODE_LOWSPEED_BIT,
262 	MAX3421_MODE_HUBPRE_BIT,
263 	MAX3421_MODE_SOFKAENAB_BIT,
264 	MAX3421_MODE_SEPIRQ_BIT,
265 	MAX3421_MODE_DELAYISO_BIT,
266 	MAX3421_MODE_DMPULLDN_BIT,
267 	MAX3421_MODE_DPPULLDN_BIT
268 };
269 
270 enum {
271 	MAX3421_HRSL_OK = 0,
272 	MAX3421_HRSL_BUSY,
273 	MAX3421_HRSL_BADREQ,
274 	MAX3421_HRSL_UNDEF,
275 	MAX3421_HRSL_NAK,
276 	MAX3421_HRSL_STALL,
277 	MAX3421_HRSL_TOGERR,
278 	MAX3421_HRSL_WRONGPID,
279 	MAX3421_HRSL_BADBC,
280 	MAX3421_HRSL_PIDERR,
281 	MAX3421_HRSL_PKTERR,
282 	MAX3421_HRSL_CRCERR,
283 	MAX3421_HRSL_KERR,
284 	MAX3421_HRSL_JERR,
285 	MAX3421_HRSL_TIMEOUT,
286 	MAX3421_HRSL_BABBLE,
287 	MAX3421_HRSL_RESULT_MASK = 0xf,
288 	MAX3421_HRSL_RCVTOGRD_BIT = 4,
289 	MAX3421_HRSL_SNDTOGRD_BIT,
290 	MAX3421_HRSL_KSTATUS_BIT,
291 	MAX3421_HRSL_JSTATUS_BIT
292 };
293 
294 /* Return same error-codes as ohci.h:cc_to_error: */
295 static const int hrsl_to_error[] = {
296 	[MAX3421_HRSL_OK] =		0,
297 	[MAX3421_HRSL_BUSY] =		-EINVAL,
298 	[MAX3421_HRSL_BADREQ] =		-EINVAL,
299 	[MAX3421_HRSL_UNDEF] =		-EINVAL,
300 	[MAX3421_HRSL_NAK] =		-EAGAIN,
301 	[MAX3421_HRSL_STALL] =		-EPIPE,
302 	[MAX3421_HRSL_TOGERR] =		-EILSEQ,
303 	[MAX3421_HRSL_WRONGPID] =	-EPROTO,
304 	[MAX3421_HRSL_BADBC] =		-EREMOTEIO,
305 	[MAX3421_HRSL_PIDERR] =		-EPROTO,
306 	[MAX3421_HRSL_PKTERR] =		-EPROTO,
307 	[MAX3421_HRSL_CRCERR] =		-EILSEQ,
308 	[MAX3421_HRSL_KERR] =		-EIO,
309 	[MAX3421_HRSL_JERR] =		-EIO,
310 	[MAX3421_HRSL_TIMEOUT] =	-ETIME,
311 	[MAX3421_HRSL_BABBLE] =		-EOVERFLOW
312 };
313 
314 /*
315  * See http://www.beyondlogic.org/usbnutshell/usb4.shtml#Control for a
316  * reasonable overview of how control transfers use the the IN/OUT
317  * tokens.
318  */
319 #define MAX3421_HXFR_BULK_IN(ep)	(0x00 | (ep))	/* bulk or interrupt */
320 #define MAX3421_HXFR_SETUP		 0x10
321 #define MAX3421_HXFR_BULK_OUT(ep)	(0x20 | (ep))	/* bulk or interrupt */
322 #define MAX3421_HXFR_ISO_IN(ep)		(0x40 | (ep))
323 #define MAX3421_HXFR_ISO_OUT(ep)	(0x60 | (ep))
324 #define MAX3421_HXFR_HS_IN		 0x80		/* handshake in */
325 #define MAX3421_HXFR_HS_OUT		 0xa0		/* handshake out */
326 
327 #define field(val, bit)	((val) << (bit))
328 
329 static inline s16
330 frame_diff(u16 left, u16 right)
331 {
332 	return ((unsigned) (left - right)) % (USB_MAX_FRAME_NUMBER + 1);
333 }
334 
335 static inline struct max3421_hcd *
336 hcd_to_max3421(struct usb_hcd *hcd)
337 {
338 	return (struct max3421_hcd *) hcd->hcd_priv;
339 }
340 
341 static inline struct usb_hcd *
342 max3421_to_hcd(struct max3421_hcd *max3421_hcd)
343 {
344 	return container_of((void *) max3421_hcd, struct usb_hcd, hcd_priv);
345 }
346 
347 static u8
348 spi_rd8(struct usb_hcd *hcd, unsigned int reg)
349 {
350 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
351 	struct spi_device *spi = to_spi_device(hcd->self.controller);
352 	struct spi_transfer transfer;
353 	struct spi_message msg;
354 
355 	memset(&transfer, 0, sizeof(transfer));
356 
357 	spi_message_init(&msg);
358 
359 	max3421_hcd->tx->data[0] =
360 		(field(reg, MAX3421_SPI_REG_SHIFT) |
361 		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
362 
363 	transfer.tx_buf = max3421_hcd->tx->data;
364 	transfer.rx_buf = max3421_hcd->rx->data;
365 	transfer.len = 2;
366 
367 	spi_message_add_tail(&transfer, &msg);
368 	spi_sync(spi, &msg);
369 
370 	return max3421_hcd->rx->data[1];
371 }
372 
373 static void
374 spi_wr8(struct usb_hcd *hcd, unsigned int reg, u8 val)
375 {
376 	struct spi_device *spi = to_spi_device(hcd->self.controller);
377 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
378 	struct spi_transfer transfer;
379 	struct spi_message msg;
380 
381 	memset(&transfer, 0, sizeof(transfer));
382 
383 	spi_message_init(&msg);
384 
385 	max3421_hcd->tx->data[0] =
386 		(field(reg, MAX3421_SPI_REG_SHIFT) |
387 		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
388 	max3421_hcd->tx->data[1] = val;
389 
390 	transfer.tx_buf = max3421_hcd->tx->data;
391 	transfer.len = 2;
392 
393 	spi_message_add_tail(&transfer, &msg);
394 	spi_sync(spi, &msg);
395 }
396 
397 static void
398 spi_rd_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
399 {
400 	struct spi_device *spi = to_spi_device(hcd->self.controller);
401 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
402 	struct spi_transfer transfer[2];
403 	struct spi_message msg;
404 
405 	memset(transfer, 0, sizeof(transfer));
406 
407 	spi_message_init(&msg);
408 
409 	max3421_hcd->tx->data[0] =
410 		(field(reg, MAX3421_SPI_REG_SHIFT) |
411 		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
412 	transfer[0].tx_buf = max3421_hcd->tx->data;
413 	transfer[0].len = 1;
414 
415 	transfer[1].rx_buf = buf;
416 	transfer[1].len = len;
417 
418 	spi_message_add_tail(&transfer[0], &msg);
419 	spi_message_add_tail(&transfer[1], &msg);
420 	spi_sync(spi, &msg);
421 }
422 
423 static void
424 spi_wr_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
425 {
426 	struct spi_device *spi = to_spi_device(hcd->self.controller);
427 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
428 	struct spi_transfer transfer[2];
429 	struct spi_message msg;
430 
431 	memset(transfer, 0, sizeof(transfer));
432 
433 	spi_message_init(&msg);
434 
435 	max3421_hcd->tx->data[0] =
436 		(field(reg, MAX3421_SPI_REG_SHIFT) |
437 		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
438 
439 	transfer[0].tx_buf = max3421_hcd->tx->data;
440 	transfer[0].len = 1;
441 
442 	transfer[1].tx_buf = buf;
443 	transfer[1].len = len;
444 
445 	spi_message_add_tail(&transfer[0], &msg);
446 	spi_message_add_tail(&transfer[1], &msg);
447 	spi_sync(spi, &msg);
448 }
449 
450 /*
451  * Figure out the correct setting for the LOWSPEED and HUBPRE mode
452  * bits.  The HUBPRE bit needs to be set when MAX3421E operates at
453  * full speed, but it's talking to a low-speed device (i.e., through a
454  * hub).  Setting that bit ensures that every low-speed packet is
455  * preceded by a full-speed PRE PID.  Possible configurations:
456  *
457  * Hub speed:	Device speed:	=>	LOWSPEED bit:	HUBPRE bit:
458  *	FULL	FULL		=>	0		0
459  *	FULL	LOW		=>	1		1
460  *	LOW	LOW		=>	1		0
461  *	LOW	FULL		=>	1		0
462  */
463 static void
464 max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev)
465 {
466 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
467 	u8 mode_lowspeed, mode_hubpre, mode = max3421_hcd->mode;
468 
469 	mode_lowspeed = BIT(MAX3421_MODE_LOWSPEED_BIT);
470 	mode_hubpre   = BIT(MAX3421_MODE_HUBPRE_BIT);
471 	if (max3421_hcd->port_status & USB_PORT_STAT_LOW_SPEED) {
472 		mode |=  mode_lowspeed;
473 		mode &= ~mode_hubpre;
474 	} else if (dev->speed == USB_SPEED_LOW) {
475 		mode |= mode_lowspeed | mode_hubpre;
476 	} else {
477 		mode &= ~(mode_lowspeed | mode_hubpre);
478 	}
479 	if (mode != max3421_hcd->mode) {
480 		max3421_hcd->mode = mode;
481 		spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
482 	}
483 
484 }
485 
486 /*
487  * Caller must NOT hold HCD spinlock.
488  */
489 static void
490 max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum,
491 		    int force_toggles)
492 {
493 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
494 	int old_epnum, same_ep, rcvtog, sndtog;
495 	struct usb_device *old_dev;
496 	u8 hctl;
497 
498 	old_dev = max3421_hcd->loaded_dev;
499 	old_epnum = max3421_hcd->loaded_epnum;
500 
501 	same_ep = (dev == old_dev && epnum == old_epnum);
502 	if (same_ep && !force_toggles)
503 		return;
504 
505 	if (old_dev && !same_ep) {
506 		/* save the old end-points toggles: */
507 		u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
508 
509 		rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1;
510 		sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
511 
512 		/* no locking: HCD (i.e., we) own toggles, don't we? */
513 		usb_settoggle(old_dev, old_epnum, 0, rcvtog);
514 		usb_settoggle(old_dev, old_epnum, 1, sndtog);
515 	}
516 	/* setup new endpoint's toggle bits: */
517 	rcvtog = usb_gettoggle(dev, epnum, 0);
518 	sndtog = usb_gettoggle(dev, epnum, 1);
519 	hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) |
520 		BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
521 
522 	max3421_hcd->loaded_epnum = epnum;
523 	spi_wr8(hcd, MAX3421_REG_HCTL, hctl);
524 
525 	/*
526 	 * Note: devnum for one and the same device can change during
527 	 * address-assignment so it's best to just always load the
528 	 * address whenever the end-point changed/was forced.
529 	 */
530 	max3421_hcd->loaded_dev = dev;
531 	spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum);
532 }
533 
534 static int
535 max3421_ctrl_setup(struct usb_hcd *hcd, struct urb *urb)
536 {
537 	spi_wr_buf(hcd, MAX3421_REG_SUDFIFO, urb->setup_packet, 8);
538 	return MAX3421_HXFR_SETUP;
539 }
540 
541 static int
542 max3421_transfer_in(struct usb_hcd *hcd, struct urb *urb)
543 {
544 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
545 	int epnum = usb_pipeendpoint(urb->pipe);
546 
547 	max3421_hcd->curr_len = 0;
548 	max3421_hcd->hien |= BIT(MAX3421_HI_RCVDAV_BIT);
549 	return MAX3421_HXFR_BULK_IN(epnum);
550 }
551 
552 static int
553 max3421_transfer_out(struct usb_hcd *hcd, struct urb *urb, int fast_retransmit)
554 {
555 	struct spi_device *spi = to_spi_device(hcd->self.controller);
556 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
557 	int epnum = usb_pipeendpoint(urb->pipe);
558 	u32 max_packet;
559 	void *src;
560 
561 	src = urb->transfer_buffer + urb->actual_length;
562 
563 	if (fast_retransmit) {
564 		if (max3421_hcd->rev == 0x12) {
565 			/* work around rev 0x12 bug: */
566 			spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
567 			spi_wr8(hcd, MAX3421_REG_SNDFIFO, ((u8 *) src)[0]);
568 			spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
569 		}
570 		return MAX3421_HXFR_BULK_OUT(epnum);
571 	}
572 
573 	max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
574 
575 	if (max_packet > MAX3421_FIFO_SIZE) {
576 		/*
577 		 * We do not support isochronous transfers at this
578 		 * time.
579 		 */
580 		dev_err(&spi->dev,
581 			"%s: packet-size of %u too big (limit is %u bytes)",
582 			__func__, max_packet, MAX3421_FIFO_SIZE);
583 		max3421_hcd->urb_done = -EMSGSIZE;
584 		return -EMSGSIZE;
585 	}
586 	max3421_hcd->curr_len = min((urb->transfer_buffer_length -
587 				     urb->actual_length), max_packet);
588 
589 	spi_wr_buf(hcd, MAX3421_REG_SNDFIFO, src, max3421_hcd->curr_len);
590 	spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
591 	return MAX3421_HXFR_BULK_OUT(epnum);
592 }
593 
594 /*
595  * Issue the next host-transfer command.
596  * Caller must NOT hold HCD spinlock.
597  */
598 static void
599 max3421_next_transfer(struct usb_hcd *hcd, int fast_retransmit)
600 {
601 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
602 	struct urb *urb = max3421_hcd->curr_urb;
603 	struct max3421_ep *max3421_ep;
604 	int cmd = -EINVAL;
605 
606 	if (!urb)
607 		return;	/* nothing to do */
608 
609 	max3421_ep = urb->ep->hcpriv;
610 
611 	switch (max3421_ep->pkt_state) {
612 	case PKT_STATE_SETUP:
613 		cmd = max3421_ctrl_setup(hcd, urb);
614 		break;
615 
616 	case PKT_STATE_TRANSFER:
617 		if (usb_urb_dir_in(urb))
618 			cmd = max3421_transfer_in(hcd, urb);
619 		else
620 			cmd = max3421_transfer_out(hcd, urb, fast_retransmit);
621 		break;
622 
623 	case PKT_STATE_TERMINATE:
624 		/*
625 		 * IN transfers are terminated with HS_OUT token,
626 		 * OUT transfers with HS_IN:
627 		 */
628 		if (usb_urb_dir_in(urb))
629 			cmd = MAX3421_HXFR_HS_OUT;
630 		else
631 			cmd = MAX3421_HXFR_HS_IN;
632 		break;
633 	}
634 
635 	if (cmd < 0)
636 		return;
637 
638 	/* issue the command and wait for host-xfer-done interrupt: */
639 
640 	spi_wr8(hcd, MAX3421_REG_HXFR, cmd);
641 	max3421_hcd->hien |= BIT(MAX3421_HI_HXFRDN_BIT);
642 }
643 
644 /*
645  * Find the next URB to process and start its execution.
646  *
647  * At this time, we do not anticipate ever connecting a USB hub to the
648  * MAX3421 chip, so at most USB device can be connected and we can use
649  * a simplistic scheduler: at the start of a frame, schedule all
650  * periodic transfers.  Once that is done, use the remainder of the
651  * frame to process non-periodic (bulk & control) transfers.
652  *
653  * Preconditions:
654  * o Caller must NOT hold HCD spinlock.
655  * o max3421_hcd->curr_urb MUST BE NULL.
656  * o MAX3421E chip must be idle.
657  */
658 static int
659 max3421_select_and_start_urb(struct usb_hcd *hcd)
660 {
661 	struct spi_device *spi = to_spi_device(hcd->self.controller);
662 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
663 	struct urb *urb, *curr_urb = NULL;
664 	struct max3421_ep *max3421_ep;
665 	int epnum, force_toggles = 0;
666 	struct usb_host_endpoint *ep;
667 	struct list_head *pos;
668 	unsigned long flags;
669 
670 	spin_lock_irqsave(&max3421_hcd->lock, flags);
671 
672 	for (;
673 	     max3421_hcd->sched_pass < SCHED_PASS_DONE;
674 	     ++max3421_hcd->sched_pass)
675 		list_for_each(pos, &max3421_hcd->ep_list) {
676 			urb = NULL;
677 			max3421_ep = container_of(pos, struct max3421_ep,
678 						  ep_list);
679 			ep = max3421_ep->ep;
680 
681 			switch (usb_endpoint_type(&ep->desc)) {
682 			case USB_ENDPOINT_XFER_ISOC:
683 			case USB_ENDPOINT_XFER_INT:
684 				if (max3421_hcd->sched_pass !=
685 				    SCHED_PASS_PERIODIC)
686 					continue;
687 				break;
688 
689 			case USB_ENDPOINT_XFER_CONTROL:
690 			case USB_ENDPOINT_XFER_BULK:
691 				if (max3421_hcd->sched_pass !=
692 				    SCHED_PASS_NON_PERIODIC)
693 					continue;
694 				break;
695 			}
696 
697 			if (list_empty(&ep->urb_list))
698 				continue;	/* nothing to do */
699 			urb = list_first_entry(&ep->urb_list, struct urb,
700 					       urb_list);
701 			if (urb->unlinked) {
702 				dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
703 					__func__, urb, urb->unlinked);
704 				max3421_hcd->curr_urb = urb;
705 				max3421_hcd->urb_done = 1;
706 				spin_unlock_irqrestore(&max3421_hcd->lock,
707 						       flags);
708 				return 1;
709 			}
710 
711 			switch (usb_endpoint_type(&ep->desc)) {
712 			case USB_ENDPOINT_XFER_CONTROL:
713 				/*
714 				 * Allow one control transaction per
715 				 * frame per endpoint:
716 				 */
717 				if (frame_diff(max3421_ep->last_active,
718 					       max3421_hcd->frame_number) == 0)
719 					continue;
720 				break;
721 
722 			case USB_ENDPOINT_XFER_BULK:
723 				if (max3421_ep->retransmit
724 				    && (frame_diff(max3421_ep->last_active,
725 						   max3421_hcd->frame_number)
726 					== 0))
727 					/*
728 					 * We already tried this EP
729 					 * during this frame and got a
730 					 * NAK or error; wait for next frame
731 					 */
732 					continue;
733 				break;
734 
735 			case USB_ENDPOINT_XFER_ISOC:
736 			case USB_ENDPOINT_XFER_INT:
737 				if (frame_diff(max3421_hcd->frame_number,
738 					       max3421_ep->last_active)
739 				    < urb->interval)
740 					/*
741 					 * We already processed this
742 					 * end-point in the current
743 					 * frame
744 					 */
745 					continue;
746 				break;
747 			}
748 
749 			/* move current ep to tail: */
750 			list_move_tail(pos, &max3421_hcd->ep_list);
751 			curr_urb = urb;
752 			goto done;
753 		}
754 done:
755 	if (!curr_urb) {
756 		spin_unlock_irqrestore(&max3421_hcd->lock, flags);
757 		return 0;
758 	}
759 
760 	urb = max3421_hcd->curr_urb = curr_urb;
761 	epnum = usb_endpoint_num(&urb->ep->desc);
762 	if (max3421_ep->retransmit)
763 		/* restart (part of) a USB transaction: */
764 		max3421_ep->retransmit = 0;
765 	else {
766 		/* start USB transaction: */
767 		if (usb_endpoint_xfer_control(&ep->desc)) {
768 			/*
769 			 * See USB 2.0 spec section 8.6.1
770 			 * Initialization via SETUP Token:
771 			 */
772 			usb_settoggle(urb->dev, epnum, 0, 1);
773 			usb_settoggle(urb->dev, epnum, 1, 1);
774 			max3421_ep->pkt_state = PKT_STATE_SETUP;
775 			force_toggles = 1;
776 		} else
777 			max3421_ep->pkt_state = PKT_STATE_TRANSFER;
778 	}
779 
780 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
781 
782 	max3421_ep->last_active = max3421_hcd->frame_number;
783 	max3421_set_address(hcd, urb->dev, epnum, force_toggles);
784 	max3421_set_speed(hcd, urb->dev);
785 	max3421_next_transfer(hcd, 0);
786 	return 1;
787 }
788 
789 /*
790  * Check all endpoints for URBs that got unlinked.
791  *
792  * Caller must NOT hold HCD spinlock.
793  */
794 static int
795 max3421_check_unlink(struct usb_hcd *hcd)
796 {
797 	struct spi_device *spi = to_spi_device(hcd->self.controller);
798 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
799 	struct list_head *pos, *upos, *next_upos;
800 	struct max3421_ep *max3421_ep;
801 	struct usb_host_endpoint *ep;
802 	struct urb *urb;
803 	unsigned long flags;
804 	int retval = 0;
805 
806 	spin_lock_irqsave(&max3421_hcd->lock, flags);
807 	list_for_each(pos, &max3421_hcd->ep_list) {
808 		max3421_ep = container_of(pos, struct max3421_ep, ep_list);
809 		ep = max3421_ep->ep;
810 		list_for_each_safe(upos, next_upos, &ep->urb_list) {
811 			urb = container_of(upos, struct urb, urb_list);
812 			if (urb->unlinked) {
813 				retval = 1;
814 				dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
815 					__func__, urb, urb->unlinked);
816 				usb_hcd_unlink_urb_from_ep(hcd, urb);
817 				spin_unlock_irqrestore(&max3421_hcd->lock,
818 						       flags);
819 				usb_hcd_giveback_urb(hcd, urb, 0);
820 				spin_lock_irqsave(&max3421_hcd->lock, flags);
821 			}
822 		}
823 	}
824 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
825 	return retval;
826 }
827 
828 /*
829  * Caller must NOT hold HCD spinlock.
830  */
831 static void
832 max3421_slow_retransmit(struct usb_hcd *hcd)
833 {
834 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
835 	struct urb *urb = max3421_hcd->curr_urb;
836 	struct max3421_ep *max3421_ep;
837 
838 	max3421_ep = urb->ep->hcpriv;
839 	max3421_ep->retransmit = 1;
840 	max3421_hcd->curr_urb = NULL;
841 }
842 
843 /*
844  * Caller must NOT hold HCD spinlock.
845  */
846 static void
847 max3421_recv_data_available(struct usb_hcd *hcd)
848 {
849 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
850 	struct urb *urb = max3421_hcd->curr_urb;
851 	size_t remaining, transfer_size;
852 	u8 rcvbc;
853 
854 	rcvbc = spi_rd8(hcd, MAX3421_REG_RCVBC);
855 
856 	if (rcvbc > MAX3421_FIFO_SIZE)
857 		rcvbc = MAX3421_FIFO_SIZE;
858 	if (urb->actual_length >= urb->transfer_buffer_length)
859 		remaining = 0;
860 	else
861 		remaining = urb->transfer_buffer_length - urb->actual_length;
862 	transfer_size = rcvbc;
863 	if (transfer_size > remaining)
864 		transfer_size = remaining;
865 	if (transfer_size > 0) {
866 		void *dst = urb->transfer_buffer + urb->actual_length;
867 
868 		spi_rd_buf(hcd, MAX3421_REG_RCVFIFO, dst, transfer_size);
869 		urb->actual_length += transfer_size;
870 		max3421_hcd->curr_len = transfer_size;
871 	}
872 
873 	/* ack the RCVDAV irq now that the FIFO has been read: */
874 	spi_wr8(hcd, MAX3421_REG_HIRQ, BIT(MAX3421_HI_RCVDAV_BIT));
875 }
876 
877 static void
878 max3421_handle_error(struct usb_hcd *hcd, u8 hrsl)
879 {
880 	struct spi_device *spi = to_spi_device(hcd->self.controller);
881 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
882 	u8 result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
883 	struct urb *urb = max3421_hcd->curr_urb;
884 	struct max3421_ep *max3421_ep = urb->ep->hcpriv;
885 	int switch_sndfifo;
886 
887 	/*
888 	 * If an OUT command results in any response other than OK
889 	 * (i.e., error or NAK), we have to perform a dummy-write to
890 	 * SNDBC so the FIFO gets switched back to us.  Otherwise, we
891 	 * get out of sync with the SNDFIFO double buffer.
892 	 */
893 	switch_sndfifo = (max3421_ep->pkt_state == PKT_STATE_TRANSFER &&
894 			  usb_urb_dir_out(urb));
895 
896 	switch (result_code) {
897 	case MAX3421_HRSL_OK:
898 		return;			/* this shouldn't happen */
899 
900 	case MAX3421_HRSL_WRONGPID:	/* received wrong PID */
901 	case MAX3421_HRSL_BUSY:		/* SIE busy */
902 	case MAX3421_HRSL_BADREQ:	/* bad val in HXFR */
903 	case MAX3421_HRSL_UNDEF:	/* reserved */
904 	case MAX3421_HRSL_KERR:		/* K-state instead of response */
905 	case MAX3421_HRSL_JERR:		/* J-state instead of response */
906 		/*
907 		 * packet experienced an error that we cannot recover
908 		 * from; report error
909 		 */
910 		max3421_hcd->urb_done = hrsl_to_error[result_code];
911 		dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
912 			__func__, hrsl);
913 		break;
914 
915 	case MAX3421_HRSL_TOGERR:
916 		if (usb_urb_dir_in(urb))
917 			; /* don't do anything (device will switch toggle) */
918 		else {
919 			/* flip the send toggle bit: */
920 			int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
921 
922 			sndtog ^= 1;
923 			spi_wr8(hcd, MAX3421_REG_HCTL,
924 				BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
925 		}
926 		/* FALL THROUGH */
927 	case MAX3421_HRSL_BADBC:	/* bad byte count */
928 	case MAX3421_HRSL_PIDERR:	/* received PID is corrupted */
929 	case MAX3421_HRSL_PKTERR:	/* packet error (stuff, EOP) */
930 	case MAX3421_HRSL_CRCERR:	/* CRC error */
931 	case MAX3421_HRSL_BABBLE:	/* device talked too long */
932 	case MAX3421_HRSL_TIMEOUT:
933 		if (max3421_ep->retries++ < USB_MAX_RETRIES)
934 			/* retry the packet again in the next frame */
935 			max3421_slow_retransmit(hcd);
936 		else {
937 			/* Based on ohci.h cc_to_err[]: */
938 			max3421_hcd->urb_done = hrsl_to_error[result_code];
939 			dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
940 				__func__, hrsl);
941 		}
942 		break;
943 
944 	case MAX3421_HRSL_STALL:
945 		dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
946 			__func__, hrsl);
947 		max3421_hcd->urb_done = hrsl_to_error[result_code];
948 		break;
949 
950 	case MAX3421_HRSL_NAK:
951 		/*
952 		 * Device wasn't ready for data or has no data
953 		 * available: retry the packet again.
954 		 */
955 		if (max3421_ep->naks++ < NAK_MAX_FAST_RETRANSMITS) {
956 			max3421_next_transfer(hcd, 1);
957 			switch_sndfifo = 0;
958 		} else
959 			max3421_slow_retransmit(hcd);
960 		break;
961 	}
962 	if (switch_sndfifo)
963 		spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
964 }
965 
966 /*
967  * Caller must NOT hold HCD spinlock.
968  */
969 static int
970 max3421_transfer_in_done(struct usb_hcd *hcd, struct urb *urb)
971 {
972 	struct spi_device *spi = to_spi_device(hcd->self.controller);
973 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
974 	u32 max_packet;
975 
976 	if (urb->actual_length >= urb->transfer_buffer_length)
977 		return 1;	/* read is complete, so we're done */
978 
979 	/*
980 	 * USB 2.0 Section 5.3.2 Pipes: packets must be full size
981 	 * except for last one.
982 	 */
983 	max_packet = usb_maxpacket(urb->dev, urb->pipe, 0);
984 	if (max_packet > MAX3421_FIFO_SIZE) {
985 		/*
986 		 * We do not support isochronous transfers at this
987 		 * time...
988 		 */
989 		dev_err(&spi->dev,
990 			"%s: packet-size of %u too big (limit is %u bytes)",
991 			__func__, max_packet, MAX3421_FIFO_SIZE);
992 		return -EINVAL;
993 	}
994 
995 	if (max3421_hcd->curr_len < max_packet) {
996 		if (urb->transfer_flags & URB_SHORT_NOT_OK) {
997 			/*
998 			 * remaining > 0 and received an
999 			 * unexpected partial packet ->
1000 			 * error
1001 			 */
1002 			return -EREMOTEIO;
1003 		} else
1004 			/* short read, but it's OK */
1005 			return 1;
1006 	}
1007 	return 0;	/* not done */
1008 }
1009 
1010 /*
1011  * Caller must NOT hold HCD spinlock.
1012  */
1013 static int
1014 max3421_transfer_out_done(struct usb_hcd *hcd, struct urb *urb)
1015 {
1016 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1017 
1018 	urb->actual_length += max3421_hcd->curr_len;
1019 	if (urb->actual_length < urb->transfer_buffer_length)
1020 		return 0;
1021 	if (urb->transfer_flags & URB_ZERO_PACKET) {
1022 		/*
1023 		 * Some hardware needs a zero-size packet at the end
1024 		 * of a bulk-out transfer if the last transfer was a
1025 		 * full-sized packet (i.e., such hardware use <
1026 		 * max_packet as an indicator that the end of the
1027 		 * packet has been reached).
1028 		 */
1029 		u32 max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
1030 
1031 		if (max3421_hcd->curr_len == max_packet)
1032 			return 0;
1033 	}
1034 	return 1;
1035 }
1036 
1037 /*
1038  * Caller must NOT hold HCD spinlock.
1039  */
1040 static void
1041 max3421_host_transfer_done(struct usb_hcd *hcd)
1042 {
1043 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1044 	struct urb *urb = max3421_hcd->curr_urb;
1045 	struct max3421_ep *max3421_ep;
1046 	u8 result_code, hrsl;
1047 	int urb_done = 0;
1048 
1049 	max3421_hcd->hien &= ~(BIT(MAX3421_HI_HXFRDN_BIT) |
1050 			       BIT(MAX3421_HI_RCVDAV_BIT));
1051 
1052 	hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1053 	result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
1054 
1055 #ifdef DEBUG
1056 	++max3421_hcd->err_stat[result_code];
1057 #endif
1058 
1059 	max3421_ep = urb->ep->hcpriv;
1060 
1061 	if (unlikely(result_code != MAX3421_HRSL_OK)) {
1062 		max3421_handle_error(hcd, hrsl);
1063 		return;
1064 	}
1065 
1066 	max3421_ep->naks = 0;
1067 	max3421_ep->retries = 0;
1068 	switch (max3421_ep->pkt_state) {
1069 
1070 	case PKT_STATE_SETUP:
1071 		if (urb->transfer_buffer_length > 0)
1072 			max3421_ep->pkt_state = PKT_STATE_TRANSFER;
1073 		else
1074 			max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1075 		break;
1076 
1077 	case PKT_STATE_TRANSFER:
1078 		if (usb_urb_dir_in(urb))
1079 			urb_done = max3421_transfer_in_done(hcd, urb);
1080 		else
1081 			urb_done = max3421_transfer_out_done(hcd, urb);
1082 		if (urb_done > 0 && usb_pipetype(urb->pipe) == PIPE_CONTROL) {
1083 			/*
1084 			 * We aren't really done - we still need to
1085 			 * terminate the control transfer:
1086 			 */
1087 			max3421_hcd->urb_done = urb_done = 0;
1088 			max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1089 		}
1090 		break;
1091 
1092 	case PKT_STATE_TERMINATE:
1093 		urb_done = 1;
1094 		break;
1095 	}
1096 
1097 	if (urb_done)
1098 		max3421_hcd->urb_done = urb_done;
1099 	else
1100 		max3421_next_transfer(hcd, 0);
1101 }
1102 
1103 /*
1104  * Caller must NOT hold HCD spinlock.
1105  */
1106 static void
1107 max3421_detect_conn(struct usb_hcd *hcd)
1108 {
1109 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1110 	unsigned int jk, have_conn = 0;
1111 	u32 old_port_status, chg;
1112 	unsigned long flags;
1113 	u8 hrsl, mode;
1114 
1115 	hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1116 
1117 	jk = ((((hrsl >> MAX3421_HRSL_JSTATUS_BIT) & 1) << 0) |
1118 	      (((hrsl >> MAX3421_HRSL_KSTATUS_BIT) & 1) << 1));
1119 
1120 	mode = max3421_hcd->mode;
1121 
1122 	switch (jk) {
1123 	case 0x0: /* SE0: disconnect */
1124 		/*
1125 		 * Turn off SOFKAENAB bit to avoid getting interrupt
1126 		 * every milli-second:
1127 		 */
1128 		mode &= ~BIT(MAX3421_MODE_SOFKAENAB_BIT);
1129 		break;
1130 
1131 	case 0x1: /* J=0,K=1: low-speed (in full-speed or vice versa) */
1132 	case 0x2: /* J=1,K=0: full-speed (in full-speed or vice versa) */
1133 		if (jk == 0x2)
1134 			/* need to switch to the other speed: */
1135 			mode ^= BIT(MAX3421_MODE_LOWSPEED_BIT);
1136 		/* turn on SOFKAENAB bit: */
1137 		mode |= BIT(MAX3421_MODE_SOFKAENAB_BIT);
1138 		have_conn = 1;
1139 		break;
1140 
1141 	case 0x3: /* illegal */
1142 		break;
1143 	}
1144 
1145 	max3421_hcd->mode = mode;
1146 	spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1147 
1148 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1149 	old_port_status = max3421_hcd->port_status;
1150 	if (have_conn)
1151 		max3421_hcd->port_status |=  USB_PORT_STAT_CONNECTION;
1152 	else
1153 		max3421_hcd->port_status &= ~USB_PORT_STAT_CONNECTION;
1154 	if (mode & BIT(MAX3421_MODE_LOWSPEED_BIT))
1155 		max3421_hcd->port_status |=  USB_PORT_STAT_LOW_SPEED;
1156 	else
1157 		max3421_hcd->port_status &= ~USB_PORT_STAT_LOW_SPEED;
1158 	chg = (old_port_status ^ max3421_hcd->port_status);
1159 	max3421_hcd->port_status |= chg << 16;
1160 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1161 }
1162 
1163 static irqreturn_t
1164 max3421_irq_handler(int irq, void *dev_id)
1165 {
1166 	struct usb_hcd *hcd = dev_id;
1167 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1168 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1169 
1170 	if (max3421_hcd->spi_thread &&
1171 	    max3421_hcd->spi_thread->state != TASK_RUNNING)
1172 		wake_up_process(max3421_hcd->spi_thread);
1173 	if (!test_and_set_bit(ENABLE_IRQ, &max3421_hcd->todo))
1174 		disable_irq_nosync(spi->irq);
1175 	return IRQ_HANDLED;
1176 }
1177 
1178 #ifdef DEBUG
1179 
1180 static void
1181 dump_eps(struct usb_hcd *hcd)
1182 {
1183 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1184 	struct max3421_ep *max3421_ep;
1185 	struct usb_host_endpoint *ep;
1186 	struct list_head *pos, *upos;
1187 	char ubuf[512], *dp, *end;
1188 	unsigned long flags;
1189 	struct urb *urb;
1190 	int epnum, ret;
1191 
1192 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1193 	list_for_each(pos, &max3421_hcd->ep_list) {
1194 		max3421_ep = container_of(pos, struct max3421_ep, ep_list);
1195 		ep = max3421_ep->ep;
1196 
1197 		dp = ubuf;
1198 		end = dp + sizeof(ubuf);
1199 		*dp = '\0';
1200 		list_for_each(upos, &ep->urb_list) {
1201 			urb = container_of(upos, struct urb, urb_list);
1202 			ret = snprintf(dp, end - dp, " %p(%d.%s %d/%d)", urb,
1203 				       usb_pipetype(urb->pipe),
1204 				       usb_urb_dir_in(urb) ? "IN" : "OUT",
1205 				       urb->actual_length,
1206 				       urb->transfer_buffer_length);
1207 			if (ret < 0 || ret >= end - dp)
1208 				break;	/* error or buffer full */
1209 			dp += ret;
1210 		}
1211 
1212 		epnum = usb_endpoint_num(&ep->desc);
1213 		pr_info("EP%0u %u lst %04u rtr %u nak %6u rxmt %u: %s\n",
1214 			epnum, max3421_ep->pkt_state, max3421_ep->last_active,
1215 			max3421_ep->retries, max3421_ep->naks,
1216 			max3421_ep->retransmit, ubuf);
1217 	}
1218 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1219 }
1220 
1221 #endif /* DEBUG */
1222 
1223 /* Return zero if no work was performed, 1 otherwise.  */
1224 static int
1225 max3421_handle_irqs(struct usb_hcd *hcd)
1226 {
1227 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1228 	u32 chg, old_port_status;
1229 	unsigned long flags;
1230 	u8 hirq;
1231 
1232 	/*
1233 	 * Read and ack pending interrupts (CPU must never
1234 	 * clear SNDBAV directly and RCVDAV must be cleared by
1235 	 * max3421_recv_data_available()!):
1236 	 */
1237 	hirq = spi_rd8(hcd, MAX3421_REG_HIRQ);
1238 	hirq &= max3421_hcd->hien;
1239 	if (!hirq)
1240 		return 0;
1241 
1242 	spi_wr8(hcd, MAX3421_REG_HIRQ,
1243 		hirq & ~(BIT(MAX3421_HI_SNDBAV_BIT) |
1244 			 BIT(MAX3421_HI_RCVDAV_BIT)));
1245 
1246 	if (hirq & BIT(MAX3421_HI_FRAME_BIT)) {
1247 		max3421_hcd->frame_number = ((max3421_hcd->frame_number + 1)
1248 					     & USB_MAX_FRAME_NUMBER);
1249 		max3421_hcd->sched_pass = SCHED_PASS_PERIODIC;
1250 	}
1251 
1252 	if (hirq & BIT(MAX3421_HI_RCVDAV_BIT))
1253 		max3421_recv_data_available(hcd);
1254 
1255 	if (hirq & BIT(MAX3421_HI_HXFRDN_BIT))
1256 		max3421_host_transfer_done(hcd);
1257 
1258 	if (hirq & BIT(MAX3421_HI_CONDET_BIT))
1259 		max3421_detect_conn(hcd);
1260 
1261 	/*
1262 	 * Now process interrupts that may affect HCD state
1263 	 * other than the end-points:
1264 	 */
1265 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1266 
1267 	old_port_status = max3421_hcd->port_status;
1268 	if (hirq & BIT(MAX3421_HI_BUSEVENT_BIT)) {
1269 		if (max3421_hcd->port_status & USB_PORT_STAT_RESET) {
1270 			/* BUSEVENT due to completion of Bus Reset */
1271 			max3421_hcd->port_status &= ~USB_PORT_STAT_RESET;
1272 			max3421_hcd->port_status |=  USB_PORT_STAT_ENABLE;
1273 		} else {
1274 			/* BUSEVENT due to completion of Bus Resume */
1275 			pr_info("%s: BUSEVENT Bus Resume Done\n", __func__);
1276 		}
1277 	}
1278 	if (hirq & BIT(MAX3421_HI_RWU_BIT))
1279 		pr_info("%s: RWU\n", __func__);
1280 	if (hirq & BIT(MAX3421_HI_SUSDN_BIT))
1281 		pr_info("%s: SUSDN\n", __func__);
1282 
1283 	chg = (old_port_status ^ max3421_hcd->port_status);
1284 	max3421_hcd->port_status |= chg << 16;
1285 
1286 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1287 
1288 #ifdef DEBUG
1289 	{
1290 		static unsigned long last_time;
1291 		char sbuf[16 * 16], *dp, *end;
1292 		int i;
1293 
1294 		if (jiffies - last_time > 5*HZ) {
1295 			dp = sbuf;
1296 			end = sbuf + sizeof(sbuf);
1297 			*dp = '\0';
1298 			for (i = 0; i < 16; ++i) {
1299 				int ret = snprintf(dp, end - dp, " %lu",
1300 						   max3421_hcd->err_stat[i]);
1301 				if (ret < 0 || ret >= end - dp)
1302 					break;	/* error or buffer full */
1303 				dp += ret;
1304 			}
1305 			pr_info("%s: hrsl_stats %s\n", __func__, sbuf);
1306 			memset(max3421_hcd->err_stat, 0,
1307 			       sizeof(max3421_hcd->err_stat));
1308 			last_time = jiffies;
1309 
1310 			dump_eps(hcd);
1311 		}
1312 	}
1313 #endif
1314 	return 1;
1315 }
1316 
1317 static int
1318 max3421_reset_hcd(struct usb_hcd *hcd)
1319 {
1320 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1321 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1322 	int timeout;
1323 
1324 	/* perform a chip reset and wait for OSCIRQ signal to appear: */
1325 	spi_wr8(hcd, MAX3421_REG_USBCTL, BIT(MAX3421_USBCTL_CHIPRES_BIT));
1326 	/* clear reset: */
1327 	spi_wr8(hcd, MAX3421_REG_USBCTL, 0);
1328 	timeout = 1000;
1329 	while (1) {
1330 		if (spi_rd8(hcd, MAX3421_REG_USBIRQ)
1331 		    & BIT(MAX3421_USBIRQ_OSCOKIRQ_BIT))
1332 			break;
1333 		if (--timeout < 0) {
1334 			dev_err(&spi->dev,
1335 				"timed out waiting for oscillator OK signal");
1336 			return 1;
1337 		}
1338 		cond_resched();
1339 	}
1340 
1341 	/*
1342 	 * Turn on host mode, automatic generation of SOF packets, and
1343 	 * enable pull-down registers on DM/DP:
1344 	 */
1345 	max3421_hcd->mode = (BIT(MAX3421_MODE_HOST_BIT) |
1346 			     BIT(MAX3421_MODE_SOFKAENAB_BIT) |
1347 			     BIT(MAX3421_MODE_DMPULLDN_BIT) |
1348 			     BIT(MAX3421_MODE_DPPULLDN_BIT));
1349 	spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1350 
1351 	/* reset frame-number: */
1352 	max3421_hcd->frame_number = USB_MAX_FRAME_NUMBER;
1353 	spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_FRMRST_BIT));
1354 
1355 	/* sample the state of the D+ and D- lines */
1356 	spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_SAMPLEBUS_BIT));
1357 	max3421_detect_conn(hcd);
1358 
1359 	/* enable frame, connection-detected, and bus-event interrupts: */
1360 	max3421_hcd->hien = (BIT(MAX3421_HI_FRAME_BIT) |
1361 			     BIT(MAX3421_HI_CONDET_BIT) |
1362 			     BIT(MAX3421_HI_BUSEVENT_BIT));
1363 	spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1364 
1365 	/* enable interrupts: */
1366 	spi_wr8(hcd, MAX3421_REG_CPUCTL, BIT(MAX3421_CPUCTL_IE_BIT));
1367 	return 1;
1368 }
1369 
1370 static int
1371 max3421_urb_done(struct usb_hcd *hcd)
1372 {
1373 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1374 	unsigned long flags;
1375 	struct urb *urb;
1376 	int status;
1377 
1378 	status = max3421_hcd->urb_done;
1379 	max3421_hcd->urb_done = 0;
1380 	if (status > 0)
1381 		status = 0;
1382 	urb = max3421_hcd->curr_urb;
1383 	if (urb) {
1384 		max3421_hcd->curr_urb = NULL;
1385 		spin_lock_irqsave(&max3421_hcd->lock, flags);
1386 		usb_hcd_unlink_urb_from_ep(hcd, urb);
1387 		spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1388 
1389 		/* must be called without the HCD spinlock: */
1390 		usb_hcd_giveback_urb(hcd, urb, status);
1391 	}
1392 	return 1;
1393 }
1394 
1395 static int
1396 max3421_spi_thread(void *dev_id)
1397 {
1398 	struct usb_hcd *hcd = dev_id;
1399 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1400 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1401 	int i, i_worked = 1;
1402 
1403 	/* set full-duplex SPI mode, low-active interrupt pin: */
1404 	spi_wr8(hcd, MAX3421_REG_PINCTL,
1405 		(BIT(MAX3421_PINCTL_FDUPSPI_BIT) |	/* full-duplex */
1406 		 BIT(MAX3421_PINCTL_INTLEVEL_BIT)));	/* low-active irq */
1407 
1408 	while (!kthread_should_stop()) {
1409 		max3421_hcd->rev = spi_rd8(hcd, MAX3421_REG_REVISION);
1410 		if (max3421_hcd->rev == 0x12 || max3421_hcd->rev == 0x13)
1411 			break;
1412 		dev_err(&spi->dev, "bad rev 0x%02x", max3421_hcd->rev);
1413 		msleep(10000);
1414 	}
1415 	dev_info(&spi->dev, "rev 0x%x, SPI clk %dHz, bpw %u, irq %d\n",
1416 		 max3421_hcd->rev, spi->max_speed_hz, spi->bits_per_word,
1417 		 spi->irq);
1418 
1419 	while (!kthread_should_stop()) {
1420 		if (!i_worked) {
1421 			/*
1422 			 * We'll be waiting for wakeups from the hard
1423 			 * interrupt handler, so now is a good time to
1424 			 * sync our hien with the chip:
1425 			 */
1426 			spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1427 
1428 			set_current_state(TASK_INTERRUPTIBLE);
1429 			if (test_and_clear_bit(ENABLE_IRQ, &max3421_hcd->todo))
1430 				enable_irq(spi->irq);
1431 			schedule();
1432 			__set_current_state(TASK_RUNNING);
1433 		}
1434 
1435 		i_worked = 0;
1436 
1437 		if (max3421_hcd->urb_done)
1438 			i_worked |= max3421_urb_done(hcd);
1439 		else if (max3421_handle_irqs(hcd))
1440 			i_worked = 1;
1441 		else if (!max3421_hcd->curr_urb)
1442 			i_worked |= max3421_select_and_start_urb(hcd);
1443 
1444 		if (test_and_clear_bit(RESET_HCD, &max3421_hcd->todo))
1445 			/* reset the HCD: */
1446 			i_worked |= max3421_reset_hcd(hcd);
1447 		if (test_and_clear_bit(RESET_PORT, &max3421_hcd->todo)) {
1448 			/* perform a USB bus reset: */
1449 			spi_wr8(hcd, MAX3421_REG_HCTL,
1450 				BIT(MAX3421_HCTL_BUSRST_BIT));
1451 			i_worked = 1;
1452 		}
1453 		if (test_and_clear_bit(CHECK_UNLINK, &max3421_hcd->todo))
1454 			i_worked |= max3421_check_unlink(hcd);
1455 		if (test_and_clear_bit(IOPIN_UPDATE, &max3421_hcd->todo)) {
1456 			/*
1457 			 * IOPINS1/IOPINS2 do not auto-increment, so we can't
1458 			 * use spi_wr_buf().
1459 			 */
1460 			for (i = 0; i < ARRAY_SIZE(max3421_hcd->iopins); ++i) {
1461 				u8 val = spi_rd8(hcd, MAX3421_REG_IOPINS1);
1462 
1463 				val = ((val & 0xf0) |
1464 				       (max3421_hcd->iopins[i] & 0x0f));
1465 				spi_wr8(hcd, MAX3421_REG_IOPINS1 + i, val);
1466 				max3421_hcd->iopins[i] = val;
1467 			}
1468 			i_worked = 1;
1469 		}
1470 	}
1471 	set_current_state(TASK_RUNNING);
1472 	dev_info(&spi->dev, "SPI thread exiting");
1473 	return 0;
1474 }
1475 
1476 static int
1477 max3421_reset_port(struct usb_hcd *hcd)
1478 {
1479 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1480 
1481 	max3421_hcd->port_status &= ~(USB_PORT_STAT_ENABLE |
1482 				      USB_PORT_STAT_LOW_SPEED);
1483 	max3421_hcd->port_status |= USB_PORT_STAT_RESET;
1484 	set_bit(RESET_PORT, &max3421_hcd->todo);
1485 	wake_up_process(max3421_hcd->spi_thread);
1486 	return 0;
1487 }
1488 
1489 static int
1490 max3421_reset(struct usb_hcd *hcd)
1491 {
1492 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1493 
1494 	hcd->self.sg_tablesize = 0;
1495 	hcd->speed = HCD_USB2;
1496 	hcd->self.root_hub->speed = USB_SPEED_FULL;
1497 	set_bit(RESET_HCD, &max3421_hcd->todo);
1498 	wake_up_process(max3421_hcd->spi_thread);
1499 	return 0;
1500 }
1501 
1502 static int
1503 max3421_start(struct usb_hcd *hcd)
1504 {
1505 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1506 
1507 	spin_lock_init(&max3421_hcd->lock);
1508 	max3421_hcd->rh_state = MAX3421_RH_RUNNING;
1509 
1510 	INIT_LIST_HEAD(&max3421_hcd->ep_list);
1511 
1512 	hcd->power_budget = POWER_BUDGET;
1513 	hcd->state = HC_STATE_RUNNING;
1514 	hcd->uses_new_polling = 1;
1515 	return 0;
1516 }
1517 
1518 static void
1519 max3421_stop(struct usb_hcd *hcd)
1520 {
1521 }
1522 
1523 static int
1524 max3421_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1525 {
1526 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1527 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1528 	struct max3421_ep *max3421_ep;
1529 	unsigned long flags;
1530 	int retval;
1531 
1532 	switch (usb_pipetype(urb->pipe)) {
1533 	case PIPE_INTERRUPT:
1534 	case PIPE_ISOCHRONOUS:
1535 		if (urb->interval < 0) {
1536 			dev_err(&spi->dev,
1537 			  "%s: interval=%d for intr-/iso-pipe; expected > 0\n",
1538 				__func__, urb->interval);
1539 			return -EINVAL;
1540 		}
1541 	default:
1542 		break;
1543 	}
1544 
1545 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1546 
1547 	max3421_ep = urb->ep->hcpriv;
1548 	if (!max3421_ep) {
1549 		/* gets freed in max3421_endpoint_disable: */
1550 		max3421_ep = kzalloc(sizeof(struct max3421_ep), GFP_ATOMIC);
1551 		if (!max3421_ep) {
1552 			retval = -ENOMEM;
1553 			goto out;
1554 		}
1555 		max3421_ep->ep = urb->ep;
1556 		max3421_ep->last_active = max3421_hcd->frame_number;
1557 		urb->ep->hcpriv = max3421_ep;
1558 
1559 		list_add_tail(&max3421_ep->ep_list, &max3421_hcd->ep_list);
1560 	}
1561 
1562 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
1563 	if (retval == 0) {
1564 		/* Since we added to the queue, restart scheduling: */
1565 		max3421_hcd->sched_pass = SCHED_PASS_PERIODIC;
1566 		wake_up_process(max3421_hcd->spi_thread);
1567 	}
1568 
1569 out:
1570 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1571 	return retval;
1572 }
1573 
1574 static int
1575 max3421_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
1576 {
1577 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1578 	unsigned long flags;
1579 	int retval;
1580 
1581 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1582 
1583 	/*
1584 	 * This will set urb->unlinked which in turn causes the entry
1585 	 * to be dropped at the next opportunity.
1586 	 */
1587 	retval = usb_hcd_check_unlink_urb(hcd, urb, status);
1588 	if (retval == 0) {
1589 		set_bit(CHECK_UNLINK, &max3421_hcd->todo);
1590 		wake_up_process(max3421_hcd->spi_thread);
1591 	}
1592 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1593 	return retval;
1594 }
1595 
1596 static void
1597 max3421_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
1598 {
1599 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1600 	unsigned long flags;
1601 
1602 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1603 
1604 	if (ep->hcpriv) {
1605 		struct max3421_ep *max3421_ep = ep->hcpriv;
1606 
1607 		/* remove myself from the ep_list: */
1608 		if (!list_empty(&max3421_ep->ep_list))
1609 			list_del(&max3421_ep->ep_list);
1610 		kfree(max3421_ep);
1611 		ep->hcpriv = NULL;
1612 	}
1613 
1614 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1615 }
1616 
1617 static int
1618 max3421_get_frame_number(struct usb_hcd *hcd)
1619 {
1620 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1621 	return max3421_hcd->frame_number;
1622 }
1623 
1624 /*
1625  * Should return a non-zero value when any port is undergoing a resume
1626  * transition while the root hub is suspended.
1627  */
1628 static int
1629 max3421_hub_status_data(struct usb_hcd *hcd, char *buf)
1630 {
1631 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1632 	unsigned long flags;
1633 	int retval = 0;
1634 
1635 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1636 	if (!HCD_HW_ACCESSIBLE(hcd))
1637 		goto done;
1638 
1639 	*buf = 0;
1640 	if ((max3421_hcd->port_status & PORT_C_MASK) != 0) {
1641 		*buf = (1 << 1); /* a hub over-current condition exists */
1642 		dev_dbg(hcd->self.controller,
1643 			"port status 0x%08x has changes\n",
1644 			max3421_hcd->port_status);
1645 		retval = 1;
1646 		if (max3421_hcd->rh_state == MAX3421_RH_SUSPENDED)
1647 			usb_hcd_resume_root_hub(hcd);
1648 	}
1649 done:
1650 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1651 	return retval;
1652 }
1653 
1654 static inline void
1655 hub_descriptor(struct usb_hub_descriptor *desc)
1656 {
1657 	memset(desc, 0, sizeof(*desc));
1658 	/*
1659 	 * See Table 11-13: Hub Descriptor in USB 2.0 spec.
1660 	 */
1661 	desc->bDescriptorType = 0x29;	/* hub descriptor */
1662 	desc->bDescLength = 9;
1663 	desc->wHubCharacteristics = cpu_to_le16(0x0001);
1664 	desc->bNbrPorts = 1;
1665 }
1666 
1667 /*
1668  * Set the MAX3421E general-purpose output with number PIN_NUMBER to
1669  * VALUE (0 or 1).  PIN_NUMBER may be in the range from 1-8.  For
1670  * any other value, this function acts as a no-op.
1671  */
1672 static void
1673 max3421_gpout_set_value(struct usb_hcd *hcd, u8 pin_number, u8 value)
1674 {
1675 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1676 	u8 mask, idx;
1677 
1678 	--pin_number;
1679 	if (pin_number > 7)
1680 		return;
1681 
1682 	mask = 1u << pin_number;
1683 	idx = pin_number / 4;
1684 
1685 	if (value)
1686 		max3421_hcd->iopins[idx] |=  mask;
1687 	else
1688 		max3421_hcd->iopins[idx] &= ~mask;
1689 	set_bit(IOPIN_UPDATE, &max3421_hcd->todo);
1690 	wake_up_process(max3421_hcd->spi_thread);
1691 }
1692 
1693 static int
1694 max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
1695 		    char *buf, u16 length)
1696 {
1697 	struct spi_device *spi = to_spi_device(hcd->self.controller);
1698 	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1699 	struct max3421_hcd_platform_data *pdata;
1700 	unsigned long flags;
1701 	int retval = 0;
1702 
1703 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1704 
1705 	pdata = spi->dev.platform_data;
1706 
1707 	switch (type_req) {
1708 	case ClearHubFeature:
1709 		break;
1710 	case ClearPortFeature:
1711 		switch (value) {
1712 		case USB_PORT_FEAT_SUSPEND:
1713 			break;
1714 		case USB_PORT_FEAT_POWER:
1715 			dev_dbg(hcd->self.controller, "power-off\n");
1716 			max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1717 						!pdata->vbus_active_level);
1718 			/* FALLS THROUGH */
1719 		default:
1720 			max3421_hcd->port_status &= ~(1 << value);
1721 		}
1722 		break;
1723 	case GetHubDescriptor:
1724 		hub_descriptor((struct usb_hub_descriptor *) buf);
1725 		break;
1726 
1727 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
1728 	case GetPortErrorCount:
1729 	case SetHubDepth:
1730 		/* USB3 only */
1731 		goto error;
1732 
1733 	case GetHubStatus:
1734 		*(__le32 *) buf = cpu_to_le32(0);
1735 		break;
1736 
1737 	case GetPortStatus:
1738 		if (index != 1) {
1739 			retval = -EPIPE;
1740 			goto error;
1741 		}
1742 		((__le16 *) buf)[0] = cpu_to_le16(max3421_hcd->port_status);
1743 		((__le16 *) buf)[1] =
1744 			cpu_to_le16(max3421_hcd->port_status >> 16);
1745 		break;
1746 
1747 	case SetHubFeature:
1748 		retval = -EPIPE;
1749 		break;
1750 
1751 	case SetPortFeature:
1752 		switch (value) {
1753 		case USB_PORT_FEAT_LINK_STATE:
1754 		case USB_PORT_FEAT_U1_TIMEOUT:
1755 		case USB_PORT_FEAT_U2_TIMEOUT:
1756 		case USB_PORT_FEAT_BH_PORT_RESET:
1757 			goto error;
1758 		case USB_PORT_FEAT_SUSPEND:
1759 			if (max3421_hcd->active)
1760 				max3421_hcd->port_status |=
1761 					USB_PORT_STAT_SUSPEND;
1762 			break;
1763 		case USB_PORT_FEAT_POWER:
1764 			dev_dbg(hcd->self.controller, "power-on\n");
1765 			max3421_hcd->port_status |= USB_PORT_STAT_POWER;
1766 			max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1767 						pdata->vbus_active_level);
1768 			break;
1769 		case USB_PORT_FEAT_RESET:
1770 			max3421_reset_port(hcd);
1771 			/* FALLS THROUGH */
1772 		default:
1773 			if ((max3421_hcd->port_status & USB_PORT_STAT_POWER)
1774 			    != 0)
1775 				max3421_hcd->port_status |= (1 << value);
1776 		}
1777 		break;
1778 
1779 	default:
1780 		dev_dbg(hcd->self.controller,
1781 			"hub control req%04x v%04x i%04x l%d\n",
1782 			type_req, value, index, length);
1783 error:		/* "protocol stall" on error */
1784 		retval = -EPIPE;
1785 	}
1786 
1787 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1788 	return retval;
1789 }
1790 
1791 static int
1792 max3421_bus_suspend(struct usb_hcd *hcd)
1793 {
1794 	return -1;
1795 }
1796 
1797 static int
1798 max3421_bus_resume(struct usb_hcd *hcd)
1799 {
1800 	return -1;
1801 }
1802 
1803 /*
1804  * The SPI driver already takes care of DMA-mapping/unmapping, so no
1805  * reason to do it twice.
1806  */
1807 static int
1808 max3421_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1809 {
1810 	return 0;
1811 }
1812 
1813 static void
1814 max3421_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1815 {
1816 }
1817 
1818 static struct hc_driver max3421_hcd_desc = {
1819 	.description =		"max3421",
1820 	.product_desc =		DRIVER_DESC,
1821 	.hcd_priv_size =	sizeof(struct max3421_hcd),
1822 	.flags =		HCD_USB11,
1823 	.reset =		max3421_reset,
1824 	.start =		max3421_start,
1825 	.stop =			max3421_stop,
1826 	.get_frame_number =	max3421_get_frame_number,
1827 	.urb_enqueue =		max3421_urb_enqueue,
1828 	.urb_dequeue =		max3421_urb_dequeue,
1829 	.map_urb_for_dma =	max3421_map_urb_for_dma,
1830 	.unmap_urb_for_dma =	max3421_unmap_urb_for_dma,
1831 	.endpoint_disable =	max3421_endpoint_disable,
1832 	.hub_status_data =	max3421_hub_status_data,
1833 	.hub_control =		max3421_hub_control,
1834 	.bus_suspend =		max3421_bus_suspend,
1835 	.bus_resume =		max3421_bus_resume,
1836 };
1837 
1838 static int
1839 max3421_probe(struct spi_device *spi)
1840 {
1841 	struct max3421_hcd *max3421_hcd;
1842 	struct usb_hcd *hcd = NULL;
1843 	int retval = -ENOMEM;
1844 
1845 	if (spi_setup(spi) < 0) {
1846 		dev_err(&spi->dev, "Unable to setup SPI bus");
1847 		return -EFAULT;
1848 	}
1849 
1850 	hcd = usb_create_hcd(&max3421_hcd_desc, &spi->dev,
1851 			     dev_name(&spi->dev));
1852 	if (!hcd) {
1853 		dev_err(&spi->dev, "failed to create HCD structure\n");
1854 		goto error;
1855 	}
1856 	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
1857 	max3421_hcd = hcd_to_max3421(hcd);
1858 	max3421_hcd->next = max3421_hcd_list;
1859 	max3421_hcd_list = max3421_hcd;
1860 	INIT_LIST_HEAD(&max3421_hcd->ep_list);
1861 
1862 	max3421_hcd->tx = kmalloc(sizeof(*max3421_hcd->tx), GFP_KERNEL);
1863 	if (!max3421_hcd->tx) {
1864 		dev_err(&spi->dev, "failed to kmalloc tx buffer\n");
1865 		goto error;
1866 	}
1867 	max3421_hcd->rx = kmalloc(sizeof(*max3421_hcd->rx), GFP_KERNEL);
1868 	if (!max3421_hcd->rx) {
1869 		dev_err(&spi->dev, "failed to kmalloc rx buffer\n");
1870 		goto error;
1871 	}
1872 
1873 	max3421_hcd->spi_thread = kthread_run(max3421_spi_thread, hcd,
1874 					      "max3421_spi_thread");
1875 	if (max3421_hcd->spi_thread == ERR_PTR(-ENOMEM)) {
1876 		dev_err(&spi->dev,
1877 			"failed to create SPI thread (out of memory)\n");
1878 		goto error;
1879 	}
1880 
1881 	retval = usb_add_hcd(hcd, 0, 0);
1882 	if (retval) {
1883 		dev_err(&spi->dev, "failed to add HCD\n");
1884 		goto error;
1885 	}
1886 
1887 	retval = request_irq(spi->irq, max3421_irq_handler,
1888 			     IRQF_TRIGGER_LOW, "max3421", hcd);
1889 	if (retval < 0) {
1890 		dev_err(&spi->dev, "failed to request irq %d\n", spi->irq);
1891 		goto error;
1892 	}
1893 	return 0;
1894 
1895 error:
1896 	if (hcd) {
1897 		kfree(max3421_hcd->tx);
1898 		kfree(max3421_hcd->rx);
1899 		if (max3421_hcd->spi_thread)
1900 			kthread_stop(max3421_hcd->spi_thread);
1901 		usb_put_hcd(hcd);
1902 	}
1903 	return retval;
1904 }
1905 
1906 static int
1907 max3421_remove(struct spi_device *spi)
1908 {
1909 	struct max3421_hcd *max3421_hcd = NULL, **prev;
1910 	struct usb_hcd *hcd = NULL;
1911 	unsigned long flags;
1912 
1913 	for (prev = &max3421_hcd_list; *prev; prev = &(*prev)->next) {
1914 		max3421_hcd = *prev;
1915 		hcd = max3421_to_hcd(max3421_hcd);
1916 		if (hcd->self.controller == &spi->dev)
1917 			break;
1918 	}
1919 	if (!max3421_hcd) {
1920 		dev_err(&spi->dev, "no MAX3421 HCD found for SPI device %p\n",
1921 			spi);
1922 		return -ENODEV;
1923 	}
1924 
1925 	usb_remove_hcd(hcd);
1926 
1927 	spin_lock_irqsave(&max3421_hcd->lock, flags);
1928 
1929 	kthread_stop(max3421_hcd->spi_thread);
1930 	*prev = max3421_hcd->next;
1931 
1932 	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1933 
1934 	free_irq(spi->irq, hcd);
1935 
1936 	usb_put_hcd(hcd);
1937 	return 0;
1938 }
1939 
1940 static struct spi_driver max3421_driver = {
1941 	.probe		= max3421_probe,
1942 	.remove		= max3421_remove,
1943 	.driver		= {
1944 		.name	= "max3421-hcd",
1945 		.owner	= THIS_MODULE,
1946 	},
1947 };
1948 
1949 module_spi_driver(max3421_driver);
1950 
1951 MODULE_DESCRIPTION(DRIVER_DESC);
1952 MODULE_AUTHOR("David Mosberger <davidm@egauge.net>");
1953 MODULE_LICENSE("GPL");
1954