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
88enum max3421_rh_state {
89	MAX3421_RH_RESET,
90	MAX3421_RH_SUSPENDED,
91	MAX3421_RH_RUNNING
92};
93
94enum 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
100enum scheduling_pass {
101	SCHED_PASS_PERIODIC,
102	SCHED_PASS_NON_PERIODIC,
103	SCHED_PASS_DONE
104};
105
106/* Bit numbers for max3421_hcd->todo: */
107enum {
108	ENABLE_IRQ = 0,
109	RESET_HCD,
110	RESET_PORT,
111	CHECK_UNLINK,
112	IOPIN_UPDATE
113};
114
115struct max3421_dma_buf {
116	u8 data[2];
117};
118
119struct 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
165struct 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
175static 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
210enum {
211	MAX3421_USBIRQ_OSCOKIRQ_BIT = 0,
212	MAX3421_USBIRQ_NOVBUSIRQ_BIT = 5,
213	MAX3421_USBIRQ_VBUSIRQ_BIT
214};
215
216enum {
217	MAX3421_CPUCTL_IE_BIT = 0,
218	MAX3421_CPUCTL_PULSEWID0_BIT = 6,
219	MAX3421_CPUCTL_PULSEWID1_BIT
220};
221
222enum {
223	MAX3421_USBCTL_PWRDOWN_BIT = 4,
224	MAX3421_USBCTL_CHIPRES_BIT
225};
226
227enum {
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
238enum {
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
249enum {
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
260enum {
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
271enum {
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: */
296static 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
330static inline s16
331frame_diff(u16 left, u16 right)
332{
333	return ((unsigned) (left - right)) % (USB_MAX_FRAME_NUMBER + 1);
334}
335
336static inline struct max3421_hcd *
337hcd_to_max3421(struct usb_hcd *hcd)
338{
339	return (struct max3421_hcd *) hcd->hcd_priv;
340}
341
342static inline struct usb_hcd *
343max3421_to_hcd(struct max3421_hcd *max3421_hcd)
344{
345	return container_of((void *) max3421_hcd, struct usb_hcd, hcd_priv);
346}
347
348static u8
349spi_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
374static void
375spi_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
398static void
399spi_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
424static void
425spi_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 */
464static void
465max3421_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 */
490static void
491max3421_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
535static int
536max3421_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
542static int
543max3421_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
553static int
554max3421_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 */
599static void
600max3421_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 */
659static int
660max3421_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		}
755done:
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 */
795static int
796max3421_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 */
832static void
833max3421_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 */
847static void
848max3421_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
878static void
879max3421_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 */
970static int
971max3421_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 */
1014static int
1015max3421_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 */
1041static void
1042max3421_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 */
1107static void
1108max3421_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
1164static irqreturn_t
1165max3421_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
1181static void
1182dump_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.  */
1225static int
1226max3421_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
1318static int
1319max3421_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
1371static int
1372max3421_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
1396static int
1397max3421_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
1477static int
1478max3421_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
1490static int
1491max3421_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
1503static int
1504max3421_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
1519static void
1520max3421_stop(struct usb_hcd *hcd)
1521{
1522}
1523
1524static int
1525max3421_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
1570out:
1571	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1572	return retval;
1573}
1574
1575static int
1576max3421_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
1597static void
1598max3421_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
1618static int
1619max3421_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 */
1629static int
1630max3421_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	}
1650done:
1651	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1652	return retval;
1653}
1654
1655static inline void
1656hub_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 */
1674static void
1675max3421_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
1695static int
1696max3421_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);
1785error:		/* "protocol stall" on error */
1786		retval = -EPIPE;
1787	}
1788
1789	spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1790	return retval;
1791}
1792
1793static int
1794max3421_bus_suspend(struct usb_hcd *hcd)
1795{
1796	return -1;
1797}
1798
1799static int
1800max3421_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 */
1809static int
1810max3421_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1811{
1812	return 0;
1813}
1814
1815static void
1816max3421_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1817{
1818}
1819
1820static 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
1840static int
1841max3421_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
1897error:
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
1908static int
1909max3421_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
1942static 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
1951module_spi_driver(max3421_driver);
1952
1953MODULE_DESCRIPTION(DRIVER_DESC);
1954MODULE_AUTHOR("David Mosberger <davidm@egauge.net>");
1955MODULE_LICENSE("GPL");
1956