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[linux/fpc-iii.git] / drivers / usb / host / max3421-hcd.c
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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MAX3421 Host Controller driver for USB.
5 * Author: David Mosberger-Tang <davidm@egauge.net>
7 * (C) Copyright 2014 David Mosberger-Tang <davidm@egauge.net>
9 * MAX3421 is a chip implementing a USB 2.0 Full-/Low-Speed host
10 * controller on a SPI bus.
12 * Based on:
13 * o MAX3421E datasheet
14 * https://datasheets.maximintegrated.com/en/ds/MAX3421E.pdf
15 * o MAX3421E Programming Guide
16 * https://www.hdl.co.jp/ftpdata/utl-001/AN3785.pdf
17 * o gadget/dummy_hcd.c
18 * For USB HCD implementation.
19 * o Arduino MAX3421 driver
20 * https://github.com/felis/USB_Host_Shield_2.0/blob/master/Usb.cpp
22 * This file is licenced under the GPL v2.
24 * Important note on worst-case (full-speed) packet size constraints
25 * (See USB 2.0 Section 5.6.3 and following):
27 * - control: 64 bytes
28 * - isochronous: 1023 bytes
29 * - interrupt: 64 bytes
30 * - bulk: 64 bytes
32 * Since the MAX3421 FIFO size is 64 bytes, we do not have to work about
33 * multi-FIFO writes/reads for a single USB packet *except* for isochronous
34 * transfers. We don't support isochronous transfers at this time, so we
35 * just assume that a USB packet always fits into a single FIFO buffer.
37 * NOTE: The June 2006 version of "MAX3421E Programming Guide"
38 * (AN3785) has conflicting info for the RCVDAVIRQ bit:
40 * The description of RCVDAVIRQ says "The CPU *must* clear
41 * this IRQ bit (by writing a 1 to it) before reading the
42 * RCVFIFO data.
44 * However, the earlier section on "Programming BULK-IN
45 * Transfers" says * that:
47 * After the CPU retrieves the data, it clears the
48 * RCVDAVIRQ bit.
50 * The December 2006 version has been corrected and it consistently
51 * states the second behavior is the correct one.
53 * Synchronous SPI transactions sleep so we can't perform any such
54 * transactions while holding a spin-lock (and/or while interrupts are
55 * masked). To achieve this, all SPI transactions are issued from a
56 * single thread (max3421_spi_thread).
59 #include <linux/jiffies.h>
60 #include <linux/module.h>
61 #include <linux/spi/spi.h>
62 #include <linux/usb.h>
63 #include <linux/usb/hcd.h>
64 #include <linux/of.h>
66 #include <linux/platform_data/max3421-hcd.h>
68 #define DRIVER_DESC "MAX3421 USB Host-Controller Driver"
69 #define DRIVER_VERSION "1.0"
71 /* 11-bit counter that wraps around (USB 2.0 Section 8.3.3): */
72 #define USB_MAX_FRAME_NUMBER 0x7ff
73 #define USB_MAX_RETRIES 3 /* # of retries before error is reported */
76 * Max. # of times we're willing to retransmit a request immediately in
77 * resposne to a NAK. Afterwards, we fall back on trying once a frame.
79 #define NAK_MAX_FAST_RETRANSMITS 2
81 #define POWER_BUDGET 500 /* in mA; use 8 for low-power port testing */
83 /* Port-change mask: */
84 #define PORT_C_MASK ((USB_PORT_STAT_C_CONNECTION | \
85 USB_PORT_STAT_C_ENABLE | \
86 USB_PORT_STAT_C_SUSPEND | \
87 USB_PORT_STAT_C_OVERCURRENT | \
88 USB_PORT_STAT_C_RESET) << 16)
90 #define MAX3421_GPOUT_COUNT 8
92 enum max3421_rh_state {
93 MAX3421_RH_RESET,
94 MAX3421_RH_SUSPENDED,
95 MAX3421_RH_RUNNING
98 enum pkt_state {
99 PKT_STATE_SETUP, /* waiting to send setup packet to ctrl pipe */
100 PKT_STATE_TRANSFER, /* waiting to xfer transfer_buffer */
101 PKT_STATE_TERMINATE /* waiting to terminate control transfer */
104 enum scheduling_pass {
105 SCHED_PASS_PERIODIC,
106 SCHED_PASS_NON_PERIODIC,
107 SCHED_PASS_DONE
110 /* Bit numbers for max3421_hcd->todo: */
111 enum {
112 ENABLE_IRQ = 0,
113 RESET_HCD,
114 RESET_PORT,
115 CHECK_UNLINK,
116 IOPIN_UPDATE
119 struct max3421_dma_buf {
120 u8 data[2];
123 struct max3421_hcd {
124 spinlock_t lock;
126 struct task_struct *spi_thread;
128 struct max3421_hcd *next;
130 enum max3421_rh_state rh_state;
131 /* lower 16 bits contain port status, upper 16 bits the change mask: */
132 u32 port_status;
134 unsigned active:1;
136 struct list_head ep_list; /* list of EP's with work */
139 * The following are owned by spi_thread (may be accessed by
140 * SPI-thread without acquiring the HCD lock:
142 u8 rev; /* chip revision */
143 u16 frame_number;
145 * kmalloc'd buffers guaranteed to be in separate (DMA)
146 * cache-lines:
148 struct max3421_dma_buf *tx;
149 struct max3421_dma_buf *rx;
151 * URB we're currently processing. Must not be reset to NULL
152 * unless MAX3421E chip is idle:
154 struct urb *curr_urb;
155 enum scheduling_pass sched_pass;
156 struct usb_device *loaded_dev; /* dev that's loaded into the chip */
157 int loaded_epnum; /* epnum whose toggles are loaded */
158 int urb_done; /* > 0 -> no errors, < 0: errno */
159 size_t curr_len;
160 u8 hien;
161 u8 mode;
162 u8 iopins[2];
163 unsigned long todo;
164 #ifdef DEBUG
165 unsigned long err_stat[16];
166 #endif
169 struct max3421_ep {
170 struct usb_host_endpoint *ep;
171 struct list_head ep_list;
172 u32 naks;
173 u16 last_active; /* frame # this ep was last active */
174 enum pkt_state pkt_state;
175 u8 retries;
176 u8 retransmit; /* packet needs retransmission */
179 static struct max3421_hcd *max3421_hcd_list;
181 #define MAX3421_FIFO_SIZE 64
183 #define MAX3421_SPI_DIR_RD 0 /* read register from MAX3421 */
184 #define MAX3421_SPI_DIR_WR 1 /* write register to MAX3421 */
186 /* SPI commands: */
187 #define MAX3421_SPI_DIR_SHIFT 1
188 #define MAX3421_SPI_REG_SHIFT 3
190 #define MAX3421_REG_RCVFIFO 1
191 #define MAX3421_REG_SNDFIFO 2
192 #define MAX3421_REG_SUDFIFO 4
193 #define MAX3421_REG_RCVBC 6
194 #define MAX3421_REG_SNDBC 7
195 #define MAX3421_REG_USBIRQ 13
196 #define MAX3421_REG_USBIEN 14
197 #define MAX3421_REG_USBCTL 15
198 #define MAX3421_REG_CPUCTL 16
199 #define MAX3421_REG_PINCTL 17
200 #define MAX3421_REG_REVISION 18
201 #define MAX3421_REG_IOPINS1 20
202 #define MAX3421_REG_IOPINS2 21
203 #define MAX3421_REG_GPINIRQ 22
204 #define MAX3421_REG_GPINIEN 23
205 #define MAX3421_REG_GPINPOL 24
206 #define MAX3421_REG_HIRQ 25
207 #define MAX3421_REG_HIEN 26
208 #define MAX3421_REG_MODE 27
209 #define MAX3421_REG_PERADDR 28
210 #define MAX3421_REG_HCTL 29
211 #define MAX3421_REG_HXFR 30
212 #define MAX3421_REG_HRSL 31
214 enum {
215 MAX3421_USBIRQ_OSCOKIRQ_BIT = 0,
216 MAX3421_USBIRQ_NOVBUSIRQ_BIT = 5,
217 MAX3421_USBIRQ_VBUSIRQ_BIT
220 enum {
221 MAX3421_CPUCTL_IE_BIT = 0,
222 MAX3421_CPUCTL_PULSEWID0_BIT = 6,
223 MAX3421_CPUCTL_PULSEWID1_BIT
226 enum {
227 MAX3421_USBCTL_PWRDOWN_BIT = 4,
228 MAX3421_USBCTL_CHIPRES_BIT
231 enum {
232 MAX3421_PINCTL_GPXA_BIT = 0,
233 MAX3421_PINCTL_GPXB_BIT,
234 MAX3421_PINCTL_POSINT_BIT,
235 MAX3421_PINCTL_INTLEVEL_BIT,
236 MAX3421_PINCTL_FDUPSPI_BIT,
237 MAX3421_PINCTL_EP0INAK_BIT,
238 MAX3421_PINCTL_EP2INAK_BIT,
239 MAX3421_PINCTL_EP3INAK_BIT,
242 enum {
243 MAX3421_HI_BUSEVENT_BIT = 0, /* bus-reset/-resume */
244 MAX3421_HI_RWU_BIT, /* remote wakeup */
245 MAX3421_HI_RCVDAV_BIT, /* receive FIFO data available */
246 MAX3421_HI_SNDBAV_BIT, /* send buffer available */
247 MAX3421_HI_SUSDN_BIT, /* suspend operation done */
248 MAX3421_HI_CONDET_BIT, /* peripheral connect/disconnect */
249 MAX3421_HI_FRAME_BIT, /* frame generator */
250 MAX3421_HI_HXFRDN_BIT, /* host transfer done */
253 enum {
254 MAX3421_HCTL_BUSRST_BIT = 0,
255 MAX3421_HCTL_FRMRST_BIT,
256 MAX3421_HCTL_SAMPLEBUS_BIT,
257 MAX3421_HCTL_SIGRSM_BIT,
258 MAX3421_HCTL_RCVTOG0_BIT,
259 MAX3421_HCTL_RCVTOG1_BIT,
260 MAX3421_HCTL_SNDTOG0_BIT,
261 MAX3421_HCTL_SNDTOG1_BIT
264 enum {
265 MAX3421_MODE_HOST_BIT = 0,
266 MAX3421_MODE_LOWSPEED_BIT,
267 MAX3421_MODE_HUBPRE_BIT,
268 MAX3421_MODE_SOFKAENAB_BIT,
269 MAX3421_MODE_SEPIRQ_BIT,
270 MAX3421_MODE_DELAYISO_BIT,
271 MAX3421_MODE_DMPULLDN_BIT,
272 MAX3421_MODE_DPPULLDN_BIT
275 enum {
276 MAX3421_HRSL_OK = 0,
277 MAX3421_HRSL_BUSY,
278 MAX3421_HRSL_BADREQ,
279 MAX3421_HRSL_UNDEF,
280 MAX3421_HRSL_NAK,
281 MAX3421_HRSL_STALL,
282 MAX3421_HRSL_TOGERR,
283 MAX3421_HRSL_WRONGPID,
284 MAX3421_HRSL_BADBC,
285 MAX3421_HRSL_PIDERR,
286 MAX3421_HRSL_PKTERR,
287 MAX3421_HRSL_CRCERR,
288 MAX3421_HRSL_KERR,
289 MAX3421_HRSL_JERR,
290 MAX3421_HRSL_TIMEOUT,
291 MAX3421_HRSL_BABBLE,
292 MAX3421_HRSL_RESULT_MASK = 0xf,
293 MAX3421_HRSL_RCVTOGRD_BIT = 4,
294 MAX3421_HRSL_SNDTOGRD_BIT,
295 MAX3421_HRSL_KSTATUS_BIT,
296 MAX3421_HRSL_JSTATUS_BIT
299 /* Return same error-codes as ohci.h:cc_to_error: */
300 static const int hrsl_to_error[] = {
301 [MAX3421_HRSL_OK] = 0,
302 [MAX3421_HRSL_BUSY] = -EINVAL,
303 [MAX3421_HRSL_BADREQ] = -EINVAL,
304 [MAX3421_HRSL_UNDEF] = -EINVAL,
305 [MAX3421_HRSL_NAK] = -EAGAIN,
306 [MAX3421_HRSL_STALL] = -EPIPE,
307 [MAX3421_HRSL_TOGERR] = -EILSEQ,
308 [MAX3421_HRSL_WRONGPID] = -EPROTO,
309 [MAX3421_HRSL_BADBC] = -EREMOTEIO,
310 [MAX3421_HRSL_PIDERR] = -EPROTO,
311 [MAX3421_HRSL_PKTERR] = -EPROTO,
312 [MAX3421_HRSL_CRCERR] = -EILSEQ,
313 [MAX3421_HRSL_KERR] = -EIO,
314 [MAX3421_HRSL_JERR] = -EIO,
315 [MAX3421_HRSL_TIMEOUT] = -ETIME,
316 [MAX3421_HRSL_BABBLE] = -EOVERFLOW
320 * See https://www.beyondlogic.org/usbnutshell/usb4.shtml#Control for a
321 * reasonable overview of how control transfers use the the IN/OUT
322 * tokens.
324 #define MAX3421_HXFR_BULK_IN(ep) (0x00 | (ep)) /* bulk or interrupt */
325 #define MAX3421_HXFR_SETUP 0x10
326 #define MAX3421_HXFR_BULK_OUT(ep) (0x20 | (ep)) /* bulk or interrupt */
327 #define MAX3421_HXFR_ISO_IN(ep) (0x40 | (ep))
328 #define MAX3421_HXFR_ISO_OUT(ep) (0x60 | (ep))
329 #define MAX3421_HXFR_HS_IN 0x80 /* handshake in */
330 #define MAX3421_HXFR_HS_OUT 0xa0 /* handshake out */
332 #define field(val, bit) ((val) << (bit))
334 static inline s16
335 frame_diff(u16 left, u16 right)
337 return ((unsigned) (left - right)) % (USB_MAX_FRAME_NUMBER + 1);
340 static inline struct max3421_hcd *
341 hcd_to_max3421(struct usb_hcd *hcd)
343 return (struct max3421_hcd *) hcd->hcd_priv;
346 static inline struct usb_hcd *
347 max3421_to_hcd(struct max3421_hcd *max3421_hcd)
349 return container_of((void *) max3421_hcd, struct usb_hcd, hcd_priv);
352 static u8
353 spi_rd8(struct usb_hcd *hcd, unsigned int reg)
355 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
356 struct spi_device *spi = to_spi_device(hcd->self.controller);
357 struct spi_transfer transfer;
358 struct spi_message msg;
360 memset(&transfer, 0, sizeof(transfer));
362 spi_message_init(&msg);
364 max3421_hcd->tx->data[0] =
365 (field(reg, MAX3421_SPI_REG_SHIFT) |
366 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
368 transfer.tx_buf = max3421_hcd->tx->data;
369 transfer.rx_buf = max3421_hcd->rx->data;
370 transfer.len = 2;
372 spi_message_add_tail(&transfer, &msg);
373 spi_sync(spi, &msg);
375 return max3421_hcd->rx->data[1];
378 static void
379 spi_wr8(struct usb_hcd *hcd, unsigned int reg, u8 val)
381 struct spi_device *spi = to_spi_device(hcd->self.controller);
382 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
383 struct spi_transfer transfer;
384 struct spi_message msg;
386 memset(&transfer, 0, sizeof(transfer));
388 spi_message_init(&msg);
390 max3421_hcd->tx->data[0] =
391 (field(reg, MAX3421_SPI_REG_SHIFT) |
392 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
393 max3421_hcd->tx->data[1] = val;
395 transfer.tx_buf = max3421_hcd->tx->data;
396 transfer.len = 2;
398 spi_message_add_tail(&transfer, &msg);
399 spi_sync(spi, &msg);
402 static void
403 spi_rd_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
405 struct spi_device *spi = to_spi_device(hcd->self.controller);
406 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
407 struct spi_transfer transfer[2];
408 struct spi_message msg;
410 memset(transfer, 0, sizeof(transfer));
412 spi_message_init(&msg);
414 max3421_hcd->tx->data[0] =
415 (field(reg, MAX3421_SPI_REG_SHIFT) |
416 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));
417 transfer[0].tx_buf = max3421_hcd->tx->data;
418 transfer[0].len = 1;
420 transfer[1].rx_buf = buf;
421 transfer[1].len = len;
423 spi_message_add_tail(&transfer[0], &msg);
424 spi_message_add_tail(&transfer[1], &msg);
425 spi_sync(spi, &msg);
428 static void
429 spi_wr_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)
431 struct spi_device *spi = to_spi_device(hcd->self.controller);
432 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
433 struct spi_transfer transfer[2];
434 struct spi_message msg;
436 memset(transfer, 0, sizeof(transfer));
438 spi_message_init(&msg);
440 max3421_hcd->tx->data[0] =
441 (field(reg, MAX3421_SPI_REG_SHIFT) |
442 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));
444 transfer[0].tx_buf = max3421_hcd->tx->data;
445 transfer[0].len = 1;
447 transfer[1].tx_buf = buf;
448 transfer[1].len = len;
450 spi_message_add_tail(&transfer[0], &msg);
451 spi_message_add_tail(&transfer[1], &msg);
452 spi_sync(spi, &msg);
456 * Figure out the correct setting for the LOWSPEED and HUBPRE mode
457 * bits. The HUBPRE bit needs to be set when MAX3421E operates at
458 * full speed, but it's talking to a low-speed device (i.e., through a
459 * hub). Setting that bit ensures that every low-speed packet is
460 * preceded by a full-speed PRE PID. Possible configurations:
462 * Hub speed: Device speed: => LOWSPEED bit: HUBPRE bit:
463 * FULL FULL => 0 0
464 * FULL LOW => 1 1
465 * LOW LOW => 1 0
466 * LOW FULL => 1 0
468 static void
469 max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev)
471 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
472 u8 mode_lowspeed, mode_hubpre, mode = max3421_hcd->mode;
474 mode_lowspeed = BIT(MAX3421_MODE_LOWSPEED_BIT);
475 mode_hubpre = BIT(MAX3421_MODE_HUBPRE_BIT);
476 if (max3421_hcd->port_status & USB_PORT_STAT_LOW_SPEED) {
477 mode |= mode_lowspeed;
478 mode &= ~mode_hubpre;
479 } else if (dev->speed == USB_SPEED_LOW) {
480 mode |= mode_lowspeed | mode_hubpre;
481 } else {
482 mode &= ~(mode_lowspeed | mode_hubpre);
484 if (mode != max3421_hcd->mode) {
485 max3421_hcd->mode = mode;
486 spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
492 * Caller must NOT hold HCD spinlock.
494 static void
495 max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum,
496 int force_toggles)
498 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
499 int old_epnum, same_ep, rcvtog, sndtog;
500 struct usb_device *old_dev;
501 u8 hctl;
503 old_dev = max3421_hcd->loaded_dev;
504 old_epnum = max3421_hcd->loaded_epnum;
506 same_ep = (dev == old_dev && epnum == old_epnum);
507 if (same_ep && !force_toggles)
508 return;
510 if (old_dev && !same_ep) {
511 /* save the old end-points toggles: */
512 u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
514 rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1;
515 sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
517 /* no locking: HCD (i.e., we) own toggles, don't we? */
518 usb_settoggle(old_dev, old_epnum, 0, rcvtog);
519 usb_settoggle(old_dev, old_epnum, 1, sndtog);
521 /* setup new endpoint's toggle bits: */
522 rcvtog = usb_gettoggle(dev, epnum, 0);
523 sndtog = usb_gettoggle(dev, epnum, 1);
524 hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) |
525 BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
527 max3421_hcd->loaded_epnum = epnum;
528 spi_wr8(hcd, MAX3421_REG_HCTL, hctl);
531 * Note: devnum for one and the same device can change during
532 * address-assignment so it's best to just always load the
533 * address whenever the end-point changed/was forced.
535 max3421_hcd->loaded_dev = dev;
536 spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum);
539 static int
540 max3421_ctrl_setup(struct usb_hcd *hcd, struct urb *urb)
542 spi_wr_buf(hcd, MAX3421_REG_SUDFIFO, urb->setup_packet, 8);
543 return MAX3421_HXFR_SETUP;
546 static int
547 max3421_transfer_in(struct usb_hcd *hcd, struct urb *urb)
549 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
550 int epnum = usb_pipeendpoint(urb->pipe);
552 max3421_hcd->curr_len = 0;
553 max3421_hcd->hien |= BIT(MAX3421_HI_RCVDAV_BIT);
554 return MAX3421_HXFR_BULK_IN(epnum);
557 static int
558 max3421_transfer_out(struct usb_hcd *hcd, struct urb *urb, int fast_retransmit)
560 struct spi_device *spi = to_spi_device(hcd->self.controller);
561 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
562 int epnum = usb_pipeendpoint(urb->pipe);
563 u32 max_packet;
564 void *src;
566 src = urb->transfer_buffer + urb->actual_length;
568 if (fast_retransmit) {
569 if (max3421_hcd->rev == 0x12) {
570 /* work around rev 0x12 bug: */
571 spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
572 spi_wr8(hcd, MAX3421_REG_SNDFIFO, ((u8 *) src)[0]);
573 spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
575 return MAX3421_HXFR_BULK_OUT(epnum);
578 max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
580 if (max_packet > MAX3421_FIFO_SIZE) {
582 * We do not support isochronous transfers at this
583 * time.
585 dev_err(&spi->dev,
586 "%s: packet-size of %u too big (limit is %u bytes)",
587 __func__, max_packet, MAX3421_FIFO_SIZE);
588 max3421_hcd->urb_done = -EMSGSIZE;
589 return -EMSGSIZE;
591 max3421_hcd->curr_len = min((urb->transfer_buffer_length -
592 urb->actual_length), max_packet);
594 spi_wr_buf(hcd, MAX3421_REG_SNDFIFO, src, max3421_hcd->curr_len);
595 spi_wr8(hcd, MAX3421_REG_SNDBC, max3421_hcd->curr_len);
596 return MAX3421_HXFR_BULK_OUT(epnum);
600 * Issue the next host-transfer command.
601 * Caller must NOT hold HCD spinlock.
603 static void
604 max3421_next_transfer(struct usb_hcd *hcd, int fast_retransmit)
606 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
607 struct urb *urb = max3421_hcd->curr_urb;
608 struct max3421_ep *max3421_ep;
609 int cmd = -EINVAL;
611 if (!urb)
612 return; /* nothing to do */
614 max3421_ep = urb->ep->hcpriv;
616 switch (max3421_ep->pkt_state) {
617 case PKT_STATE_SETUP:
618 cmd = max3421_ctrl_setup(hcd, urb);
619 break;
621 case PKT_STATE_TRANSFER:
622 if (usb_urb_dir_in(urb))
623 cmd = max3421_transfer_in(hcd, urb);
624 else
625 cmd = max3421_transfer_out(hcd, urb, fast_retransmit);
626 break;
628 case PKT_STATE_TERMINATE:
630 * IN transfers are terminated with HS_OUT token,
631 * OUT transfers with HS_IN:
633 if (usb_urb_dir_in(urb))
634 cmd = MAX3421_HXFR_HS_OUT;
635 else
636 cmd = MAX3421_HXFR_HS_IN;
637 break;
640 if (cmd < 0)
641 return;
643 /* issue the command and wait for host-xfer-done interrupt: */
645 spi_wr8(hcd, MAX3421_REG_HXFR, cmd);
646 max3421_hcd->hien |= BIT(MAX3421_HI_HXFRDN_BIT);
650 * Find the next URB to process and start its execution.
652 * At this time, we do not anticipate ever connecting a USB hub to the
653 * MAX3421 chip, so at most USB device can be connected and we can use
654 * a simplistic scheduler: at the start of a frame, schedule all
655 * periodic transfers. Once that is done, use the remainder of the
656 * frame to process non-periodic (bulk & control) transfers.
658 * Preconditions:
659 * o Caller must NOT hold HCD spinlock.
660 * o max3421_hcd->curr_urb MUST BE NULL.
661 * o MAX3421E chip must be idle.
663 static int
664 max3421_select_and_start_urb(struct usb_hcd *hcd)
666 struct spi_device *spi = to_spi_device(hcd->self.controller);
667 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
668 struct urb *urb, *curr_urb = NULL;
669 struct max3421_ep *max3421_ep;
670 int epnum, force_toggles = 0;
671 struct usb_host_endpoint *ep;
672 struct list_head *pos;
673 unsigned long flags;
675 spin_lock_irqsave(&max3421_hcd->lock, flags);
677 for (;
678 max3421_hcd->sched_pass < SCHED_PASS_DONE;
679 ++max3421_hcd->sched_pass)
680 list_for_each(pos, &max3421_hcd->ep_list) {
681 urb = NULL;
682 max3421_ep = container_of(pos, struct max3421_ep,
683 ep_list);
684 ep = max3421_ep->ep;
686 switch (usb_endpoint_type(&ep->desc)) {
687 case USB_ENDPOINT_XFER_ISOC:
688 case USB_ENDPOINT_XFER_INT:
689 if (max3421_hcd->sched_pass !=
690 SCHED_PASS_PERIODIC)
691 continue;
692 break;
694 case USB_ENDPOINT_XFER_CONTROL:
695 case USB_ENDPOINT_XFER_BULK:
696 if (max3421_hcd->sched_pass !=
697 SCHED_PASS_NON_PERIODIC)
698 continue;
699 break;
702 if (list_empty(&ep->urb_list))
703 continue; /* nothing to do */
704 urb = list_first_entry(&ep->urb_list, struct urb,
705 urb_list);
706 if (urb->unlinked) {
707 dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
708 __func__, urb, urb->unlinked);
709 max3421_hcd->curr_urb = urb;
710 max3421_hcd->urb_done = 1;
711 spin_unlock_irqrestore(&max3421_hcd->lock,
712 flags);
713 return 1;
716 switch (usb_endpoint_type(&ep->desc)) {
717 case USB_ENDPOINT_XFER_CONTROL:
719 * Allow one control transaction per
720 * frame per endpoint:
722 if (frame_diff(max3421_ep->last_active,
723 max3421_hcd->frame_number) == 0)
724 continue;
725 break;
727 case USB_ENDPOINT_XFER_BULK:
728 if (max3421_ep->retransmit
729 && (frame_diff(max3421_ep->last_active,
730 max3421_hcd->frame_number)
731 == 0))
733 * We already tried this EP
734 * during this frame and got a
735 * NAK or error; wait for next frame
737 continue;
738 break;
740 case USB_ENDPOINT_XFER_ISOC:
741 case USB_ENDPOINT_XFER_INT:
742 if (frame_diff(max3421_hcd->frame_number,
743 max3421_ep->last_active)
744 < urb->interval)
746 * We already processed this
747 * end-point in the current
748 * frame
750 continue;
751 break;
754 /* move current ep to tail: */
755 list_move_tail(pos, &max3421_hcd->ep_list);
756 curr_urb = urb;
757 goto done;
759 done:
760 if (!curr_urb) {
761 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
762 return 0;
765 urb = max3421_hcd->curr_urb = curr_urb;
766 epnum = usb_endpoint_num(&urb->ep->desc);
767 if (max3421_ep->retransmit)
768 /* restart (part of) a USB transaction: */
769 max3421_ep->retransmit = 0;
770 else {
771 /* start USB transaction: */
772 if (usb_endpoint_xfer_control(&ep->desc)) {
774 * See USB 2.0 spec section 8.6.1
775 * Initialization via SETUP Token:
777 usb_settoggle(urb->dev, epnum, 0, 1);
778 usb_settoggle(urb->dev, epnum, 1, 1);
779 max3421_ep->pkt_state = PKT_STATE_SETUP;
780 force_toggles = 1;
781 } else
782 max3421_ep->pkt_state = PKT_STATE_TRANSFER;
785 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
787 max3421_ep->last_active = max3421_hcd->frame_number;
788 max3421_set_address(hcd, urb->dev, epnum, force_toggles);
789 max3421_set_speed(hcd, urb->dev);
790 max3421_next_transfer(hcd, 0);
791 return 1;
795 * Check all endpoints for URBs that got unlinked.
797 * Caller must NOT hold HCD spinlock.
799 static int
800 max3421_check_unlink(struct usb_hcd *hcd)
802 struct spi_device *spi = to_spi_device(hcd->self.controller);
803 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
804 struct max3421_ep *max3421_ep;
805 struct usb_host_endpoint *ep;
806 struct urb *urb, *next;
807 unsigned long flags;
808 int retval = 0;
810 spin_lock_irqsave(&max3421_hcd->lock, flags);
811 list_for_each_entry(max3421_ep, &max3421_hcd->ep_list, ep_list) {
812 ep = max3421_ep->ep;
813 list_for_each_entry_safe(urb, next, &ep->urb_list, urb_list) {
814 if (urb->unlinked) {
815 retval = 1;
816 dev_dbg(&spi->dev, "%s: URB %p unlinked=%d",
817 __func__, urb, urb->unlinked);
818 usb_hcd_unlink_urb_from_ep(hcd, urb);
819 spin_unlock_irqrestore(&max3421_hcd->lock,
820 flags);
821 usb_hcd_giveback_urb(hcd, urb, 0);
822 spin_lock_irqsave(&max3421_hcd->lock, flags);
826 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
827 return retval;
831 * Caller must NOT hold HCD spinlock.
833 static void
834 max3421_slow_retransmit(struct usb_hcd *hcd)
836 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
837 struct urb *urb = max3421_hcd->curr_urb;
838 struct max3421_ep *max3421_ep;
840 max3421_ep = urb->ep->hcpriv;
841 max3421_ep->retransmit = 1;
842 max3421_hcd->curr_urb = NULL;
846 * Caller must NOT hold HCD spinlock.
848 static void
849 max3421_recv_data_available(struct usb_hcd *hcd)
851 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
852 struct urb *urb = max3421_hcd->curr_urb;
853 size_t remaining, transfer_size;
854 u8 rcvbc;
856 rcvbc = spi_rd8(hcd, MAX3421_REG_RCVBC);
858 if (rcvbc > MAX3421_FIFO_SIZE)
859 rcvbc = MAX3421_FIFO_SIZE;
860 if (urb->actual_length >= urb->transfer_buffer_length)
861 remaining = 0;
862 else
863 remaining = urb->transfer_buffer_length - urb->actual_length;
864 transfer_size = rcvbc;
865 if (transfer_size > remaining)
866 transfer_size = remaining;
867 if (transfer_size > 0) {
868 void *dst = urb->transfer_buffer + urb->actual_length;
870 spi_rd_buf(hcd, MAX3421_REG_RCVFIFO, dst, transfer_size);
871 urb->actual_length += transfer_size;
872 max3421_hcd->curr_len = transfer_size;
875 /* ack the RCVDAV irq now that the FIFO has been read: */
876 spi_wr8(hcd, MAX3421_REG_HIRQ, BIT(MAX3421_HI_RCVDAV_BIT));
879 static void
880 max3421_handle_error(struct usb_hcd *hcd, u8 hrsl)
882 struct spi_device *spi = to_spi_device(hcd->self.controller);
883 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
884 u8 result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
885 struct urb *urb = max3421_hcd->curr_urb;
886 struct max3421_ep *max3421_ep = urb->ep->hcpriv;
887 int switch_sndfifo;
890 * If an OUT command results in any response other than OK
891 * (i.e., error or NAK), we have to perform a dummy-write to
892 * SNDBC so the FIFO gets switched back to us. Otherwise, we
893 * get out of sync with the SNDFIFO double buffer.
895 switch_sndfifo = (max3421_ep->pkt_state == PKT_STATE_TRANSFER &&
896 usb_urb_dir_out(urb));
898 switch (result_code) {
899 case MAX3421_HRSL_OK:
900 return; /* this shouldn't happen */
902 case MAX3421_HRSL_WRONGPID: /* received wrong PID */
903 case MAX3421_HRSL_BUSY: /* SIE busy */
904 case MAX3421_HRSL_BADREQ: /* bad val in HXFR */
905 case MAX3421_HRSL_UNDEF: /* reserved */
906 case MAX3421_HRSL_KERR: /* K-state instead of response */
907 case MAX3421_HRSL_JERR: /* J-state instead of response */
909 * packet experienced an error that we cannot recover
910 * from; report error
912 max3421_hcd->urb_done = hrsl_to_error[result_code];
913 dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
914 __func__, hrsl);
915 break;
917 case MAX3421_HRSL_TOGERR:
918 if (usb_urb_dir_in(urb))
919 ; /* don't do anything (device will switch toggle) */
920 else {
921 /* flip the send toggle bit: */
922 int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1;
924 sndtog ^= 1;
925 spi_wr8(hcd, MAX3421_REG_HCTL,
926 BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT));
928 fallthrough;
929 case MAX3421_HRSL_BADBC: /* bad byte count */
930 case MAX3421_HRSL_PIDERR: /* received PID is corrupted */
931 case MAX3421_HRSL_PKTERR: /* packet error (stuff, EOP) */
932 case MAX3421_HRSL_CRCERR: /* CRC error */
933 case MAX3421_HRSL_BABBLE: /* device talked too long */
934 case MAX3421_HRSL_TIMEOUT:
935 if (max3421_ep->retries++ < USB_MAX_RETRIES)
936 /* retry the packet again in the next frame */
937 max3421_slow_retransmit(hcd);
938 else {
939 /* Based on ohci.h cc_to_err[]: */
940 max3421_hcd->urb_done = hrsl_to_error[result_code];
941 dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
942 __func__, hrsl);
944 break;
946 case MAX3421_HRSL_STALL:
947 dev_dbg(&spi->dev, "%s: unexpected error HRSL=0x%02x",
948 __func__, hrsl);
949 max3421_hcd->urb_done = hrsl_to_error[result_code];
950 break;
952 case MAX3421_HRSL_NAK:
954 * Device wasn't ready for data or has no data
955 * available: retry the packet again.
957 if (max3421_ep->naks++ < NAK_MAX_FAST_RETRANSMITS) {
958 max3421_next_transfer(hcd, 1);
959 switch_sndfifo = 0;
960 } else
961 max3421_slow_retransmit(hcd);
962 break;
964 if (switch_sndfifo)
965 spi_wr8(hcd, MAX3421_REG_SNDBC, 0);
969 * Caller must NOT hold HCD spinlock.
971 static int
972 max3421_transfer_in_done(struct usb_hcd *hcd, struct urb *urb)
974 struct spi_device *spi = to_spi_device(hcd->self.controller);
975 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
976 u32 max_packet;
978 if (urb->actual_length >= urb->transfer_buffer_length)
979 return 1; /* read is complete, so we're done */
982 * USB 2.0 Section 5.3.2 Pipes: packets must be full size
983 * except for last one.
985 max_packet = usb_maxpacket(urb->dev, urb->pipe, 0);
986 if (max_packet > MAX3421_FIFO_SIZE) {
988 * We do not support isochronous transfers at this
989 * time...
991 dev_err(&spi->dev,
992 "%s: packet-size of %u too big (limit is %u bytes)",
993 __func__, max_packet, MAX3421_FIFO_SIZE);
994 return -EINVAL;
997 if (max3421_hcd->curr_len < max_packet) {
998 if (urb->transfer_flags & URB_SHORT_NOT_OK) {
1000 * remaining > 0 and received an
1001 * unexpected partial packet ->
1002 * error
1004 return -EREMOTEIO;
1005 } else
1006 /* short read, but it's OK */
1007 return 1;
1009 return 0; /* not done */
1013 * Caller must NOT hold HCD spinlock.
1015 static int
1016 max3421_transfer_out_done(struct usb_hcd *hcd, struct urb *urb)
1018 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1020 urb->actual_length += max3421_hcd->curr_len;
1021 if (urb->actual_length < urb->transfer_buffer_length)
1022 return 0;
1023 if (urb->transfer_flags & URB_ZERO_PACKET) {
1025 * Some hardware needs a zero-size packet at the end
1026 * of a bulk-out transfer if the last transfer was a
1027 * full-sized packet (i.e., such hardware use <
1028 * max_packet as an indicator that the end of the
1029 * packet has been reached).
1031 u32 max_packet = usb_maxpacket(urb->dev, urb->pipe, 1);
1033 if (max3421_hcd->curr_len == max_packet)
1034 return 0;
1036 return 1;
1040 * Caller must NOT hold HCD spinlock.
1042 static void
1043 max3421_host_transfer_done(struct usb_hcd *hcd)
1045 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1046 struct urb *urb = max3421_hcd->curr_urb;
1047 struct max3421_ep *max3421_ep;
1048 u8 result_code, hrsl;
1049 int urb_done = 0;
1051 max3421_hcd->hien &= ~(BIT(MAX3421_HI_HXFRDN_BIT) |
1052 BIT(MAX3421_HI_RCVDAV_BIT));
1054 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1055 result_code = hrsl & MAX3421_HRSL_RESULT_MASK;
1057 #ifdef DEBUG
1058 ++max3421_hcd->err_stat[result_code];
1059 #endif
1061 max3421_ep = urb->ep->hcpriv;
1063 if (unlikely(result_code != MAX3421_HRSL_OK)) {
1064 max3421_handle_error(hcd, hrsl);
1065 return;
1068 max3421_ep->naks = 0;
1069 max3421_ep->retries = 0;
1070 switch (max3421_ep->pkt_state) {
1072 case PKT_STATE_SETUP:
1073 if (urb->transfer_buffer_length > 0)
1074 max3421_ep->pkt_state = PKT_STATE_TRANSFER;
1075 else
1076 max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1077 break;
1079 case PKT_STATE_TRANSFER:
1080 if (usb_urb_dir_in(urb))
1081 urb_done = max3421_transfer_in_done(hcd, urb);
1082 else
1083 urb_done = max3421_transfer_out_done(hcd, urb);
1084 if (urb_done > 0 && usb_pipetype(urb->pipe) == PIPE_CONTROL) {
1086 * We aren't really done - we still need to
1087 * terminate the control transfer:
1089 max3421_hcd->urb_done = urb_done = 0;
1090 max3421_ep->pkt_state = PKT_STATE_TERMINATE;
1092 break;
1094 case PKT_STATE_TERMINATE:
1095 urb_done = 1;
1096 break;
1099 if (urb_done)
1100 max3421_hcd->urb_done = urb_done;
1101 else
1102 max3421_next_transfer(hcd, 0);
1106 * Caller must NOT hold HCD spinlock.
1108 static void
1109 max3421_detect_conn(struct usb_hcd *hcd)
1111 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1112 unsigned int jk, have_conn = 0;
1113 u32 old_port_status, chg;
1114 unsigned long flags;
1115 u8 hrsl, mode;
1117 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL);
1119 jk = ((((hrsl >> MAX3421_HRSL_JSTATUS_BIT) & 1) << 0) |
1120 (((hrsl >> MAX3421_HRSL_KSTATUS_BIT) & 1) << 1));
1122 mode = max3421_hcd->mode;
1124 switch (jk) {
1125 case 0x0: /* SE0: disconnect */
1127 * Turn off SOFKAENAB bit to avoid getting interrupt
1128 * every milli-second:
1130 mode &= ~BIT(MAX3421_MODE_SOFKAENAB_BIT);
1131 break;
1133 case 0x1: /* J=0,K=1: low-speed (in full-speed or vice versa) */
1134 case 0x2: /* J=1,K=0: full-speed (in full-speed or vice versa) */
1135 if (jk == 0x2)
1136 /* need to switch to the other speed: */
1137 mode ^= BIT(MAX3421_MODE_LOWSPEED_BIT);
1138 /* turn on SOFKAENAB bit: */
1139 mode |= BIT(MAX3421_MODE_SOFKAENAB_BIT);
1140 have_conn = 1;
1141 break;
1143 case 0x3: /* illegal */
1144 break;
1147 max3421_hcd->mode = mode;
1148 spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1150 spin_lock_irqsave(&max3421_hcd->lock, flags);
1151 old_port_status = max3421_hcd->port_status;
1152 if (have_conn)
1153 max3421_hcd->port_status |= USB_PORT_STAT_CONNECTION;
1154 else
1155 max3421_hcd->port_status &= ~USB_PORT_STAT_CONNECTION;
1156 if (mode & BIT(MAX3421_MODE_LOWSPEED_BIT))
1157 max3421_hcd->port_status |= USB_PORT_STAT_LOW_SPEED;
1158 else
1159 max3421_hcd->port_status &= ~USB_PORT_STAT_LOW_SPEED;
1160 chg = (old_port_status ^ max3421_hcd->port_status);
1161 max3421_hcd->port_status |= chg << 16;
1162 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1165 static irqreturn_t
1166 max3421_irq_handler(int irq, void *dev_id)
1168 struct usb_hcd *hcd = dev_id;
1169 struct spi_device *spi = to_spi_device(hcd->self.controller);
1170 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1172 if (max3421_hcd->spi_thread &&
1173 max3421_hcd->spi_thread->state != TASK_RUNNING)
1174 wake_up_process(max3421_hcd->spi_thread);
1175 if (!test_and_set_bit(ENABLE_IRQ, &max3421_hcd->todo))
1176 disable_irq_nosync(spi->irq);
1177 return IRQ_HANDLED;
1180 #ifdef DEBUG
1182 static void
1183 dump_eps(struct usb_hcd *hcd)
1185 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1186 struct max3421_ep *max3421_ep;
1187 struct usb_host_endpoint *ep;
1188 char ubuf[512], *dp, *end;
1189 unsigned long flags;
1190 struct urb *urb;
1191 int epnum, ret;
1193 spin_lock_irqsave(&max3421_hcd->lock, flags);
1194 list_for_each_entry(max3421_ep, &max3421_hcd->ep_list, ep_list) {
1195 ep = max3421_ep->ep;
1197 dp = ubuf;
1198 end = dp + sizeof(ubuf);
1199 *dp = '\0';
1200 list_for_each_entry(urb, &ep->urb_list, urb_list) {
1201 ret = snprintf(dp, end - dp, " %p(%d.%s %d/%d)", urb,
1202 usb_pipetype(urb->pipe),
1203 usb_urb_dir_in(urb) ? "IN" : "OUT",
1204 urb->actual_length,
1205 urb->transfer_buffer_length);
1206 if (ret < 0 || ret >= end - dp)
1207 break; /* error or buffer full */
1208 dp += ret;
1211 epnum = usb_endpoint_num(&ep->desc);
1212 pr_info("EP%0u %u lst %04u rtr %u nak %6u rxmt %u: %s\n",
1213 epnum, max3421_ep->pkt_state, max3421_ep->last_active,
1214 max3421_ep->retries, max3421_ep->naks,
1215 max3421_ep->retransmit, ubuf);
1217 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1220 #endif /* DEBUG */
1222 /* Return zero if no work was performed, 1 otherwise. */
1223 static int
1224 max3421_handle_irqs(struct usb_hcd *hcd)
1226 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1227 u32 chg, old_port_status;
1228 unsigned long flags;
1229 u8 hirq;
1232 * Read and ack pending interrupts (CPU must never
1233 * clear SNDBAV directly and RCVDAV must be cleared by
1234 * max3421_recv_data_available()!):
1236 hirq = spi_rd8(hcd, MAX3421_REG_HIRQ);
1237 hirq &= max3421_hcd->hien;
1238 if (!hirq)
1239 return 0;
1241 spi_wr8(hcd, MAX3421_REG_HIRQ,
1242 hirq & ~(BIT(MAX3421_HI_SNDBAV_BIT) |
1243 BIT(MAX3421_HI_RCVDAV_BIT)));
1245 if (hirq & BIT(MAX3421_HI_FRAME_BIT)) {
1246 max3421_hcd->frame_number = ((max3421_hcd->frame_number + 1)
1247 & USB_MAX_FRAME_NUMBER);
1248 max3421_hcd->sched_pass = SCHED_PASS_PERIODIC;
1251 if (hirq & BIT(MAX3421_HI_RCVDAV_BIT))
1252 max3421_recv_data_available(hcd);
1254 if (hirq & BIT(MAX3421_HI_HXFRDN_BIT))
1255 max3421_host_transfer_done(hcd);
1257 if (hirq & BIT(MAX3421_HI_CONDET_BIT))
1258 max3421_detect_conn(hcd);
1261 * Now process interrupts that may affect HCD state
1262 * other than the end-points:
1264 spin_lock_irqsave(&max3421_hcd->lock, flags);
1266 old_port_status = max3421_hcd->port_status;
1267 if (hirq & BIT(MAX3421_HI_BUSEVENT_BIT)) {
1268 if (max3421_hcd->port_status & USB_PORT_STAT_RESET) {
1269 /* BUSEVENT due to completion of Bus Reset */
1270 max3421_hcd->port_status &= ~USB_PORT_STAT_RESET;
1271 max3421_hcd->port_status |= USB_PORT_STAT_ENABLE;
1272 } else {
1273 /* BUSEVENT due to completion of Bus Resume */
1274 pr_info("%s: BUSEVENT Bus Resume Done\n", __func__);
1277 if (hirq & BIT(MAX3421_HI_RWU_BIT))
1278 pr_info("%s: RWU\n", __func__);
1279 if (hirq & BIT(MAX3421_HI_SUSDN_BIT))
1280 pr_info("%s: SUSDN\n", __func__);
1282 chg = (old_port_status ^ max3421_hcd->port_status);
1283 max3421_hcd->port_status |= chg << 16;
1285 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1287 #ifdef DEBUG
1289 static unsigned long last_time;
1290 char sbuf[16 * 16], *dp, *end;
1291 int i;
1293 if (time_after(jiffies, last_time + 5*HZ)) {
1294 dp = sbuf;
1295 end = sbuf + sizeof(sbuf);
1296 *dp = '\0';
1297 for (i = 0; i < 16; ++i) {
1298 int ret = snprintf(dp, end - dp, " %lu",
1299 max3421_hcd->err_stat[i]);
1300 if (ret < 0 || ret >= end - dp)
1301 break; /* error or buffer full */
1302 dp += ret;
1304 pr_info("%s: hrsl_stats %s\n", __func__, sbuf);
1305 memset(max3421_hcd->err_stat, 0,
1306 sizeof(max3421_hcd->err_stat));
1307 last_time = jiffies;
1309 dump_eps(hcd);
1312 #endif
1313 return 1;
1316 static int
1317 max3421_reset_hcd(struct usb_hcd *hcd)
1319 struct spi_device *spi = to_spi_device(hcd->self.controller);
1320 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1321 int timeout;
1323 /* perform a chip reset and wait for OSCIRQ signal to appear: */
1324 spi_wr8(hcd, MAX3421_REG_USBCTL, BIT(MAX3421_USBCTL_CHIPRES_BIT));
1325 /* clear reset: */
1326 spi_wr8(hcd, MAX3421_REG_USBCTL, 0);
1327 timeout = 1000;
1328 while (1) {
1329 if (spi_rd8(hcd, MAX3421_REG_USBIRQ)
1330 & BIT(MAX3421_USBIRQ_OSCOKIRQ_BIT))
1331 break;
1332 if (--timeout < 0) {
1333 dev_err(&spi->dev,
1334 "timed out waiting for oscillator OK signal");
1335 return 1;
1337 cond_resched();
1341 * Turn on host mode, automatic generation of SOF packets, and
1342 * enable pull-down registers on DM/DP:
1344 max3421_hcd->mode = (BIT(MAX3421_MODE_HOST_BIT) |
1345 BIT(MAX3421_MODE_SOFKAENAB_BIT) |
1346 BIT(MAX3421_MODE_DMPULLDN_BIT) |
1347 BIT(MAX3421_MODE_DPPULLDN_BIT));
1348 spi_wr8(hcd, MAX3421_REG_MODE, max3421_hcd->mode);
1350 /* reset frame-number: */
1351 max3421_hcd->frame_number = USB_MAX_FRAME_NUMBER;
1352 spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_FRMRST_BIT));
1354 /* sample the state of the D+ and D- lines */
1355 spi_wr8(hcd, MAX3421_REG_HCTL, BIT(MAX3421_HCTL_SAMPLEBUS_BIT));
1356 max3421_detect_conn(hcd);
1358 /* enable frame, connection-detected, and bus-event interrupts: */
1359 max3421_hcd->hien = (BIT(MAX3421_HI_FRAME_BIT) |
1360 BIT(MAX3421_HI_CONDET_BIT) |
1361 BIT(MAX3421_HI_BUSEVENT_BIT));
1362 spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1364 /* enable interrupts: */
1365 spi_wr8(hcd, MAX3421_REG_CPUCTL, BIT(MAX3421_CPUCTL_IE_BIT));
1366 return 1;
1369 static int
1370 max3421_urb_done(struct usb_hcd *hcd)
1372 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1373 unsigned long flags;
1374 struct urb *urb;
1375 int status;
1377 status = max3421_hcd->urb_done;
1378 max3421_hcd->urb_done = 0;
1379 if (status > 0)
1380 status = 0;
1381 urb = max3421_hcd->curr_urb;
1382 if (urb) {
1383 max3421_hcd->curr_urb = NULL;
1384 spin_lock_irqsave(&max3421_hcd->lock, flags);
1385 usb_hcd_unlink_urb_from_ep(hcd, urb);
1386 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1388 /* must be called without the HCD spinlock: */
1389 usb_hcd_giveback_urb(hcd, urb, status);
1391 return 1;
1394 static int
1395 max3421_spi_thread(void *dev_id)
1397 struct usb_hcd *hcd = dev_id;
1398 struct spi_device *spi = to_spi_device(hcd->self.controller);
1399 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1400 int i, i_worked = 1;
1402 /* set full-duplex SPI mode, low-active interrupt pin: */
1403 spi_wr8(hcd, MAX3421_REG_PINCTL,
1404 (BIT(MAX3421_PINCTL_FDUPSPI_BIT) | /* full-duplex */
1405 BIT(MAX3421_PINCTL_INTLEVEL_BIT))); /* low-active irq */
1407 while (!kthread_should_stop()) {
1408 max3421_hcd->rev = spi_rd8(hcd, MAX3421_REG_REVISION);
1409 if (max3421_hcd->rev == 0x12 || max3421_hcd->rev == 0x13)
1410 break;
1411 dev_err(&spi->dev, "bad rev 0x%02x", max3421_hcd->rev);
1412 msleep(10000);
1414 dev_info(&spi->dev, "rev 0x%x, SPI clk %dHz, bpw %u, irq %d\n",
1415 max3421_hcd->rev, spi->max_speed_hz, spi->bits_per_word,
1416 spi->irq);
1418 while (!kthread_should_stop()) {
1419 if (!i_worked) {
1421 * We'll be waiting for wakeups from the hard
1422 * interrupt handler, so now is a good time to
1423 * sync our hien with the chip:
1425 spi_wr8(hcd, MAX3421_REG_HIEN, max3421_hcd->hien);
1427 set_current_state(TASK_INTERRUPTIBLE);
1428 if (test_and_clear_bit(ENABLE_IRQ, &max3421_hcd->todo))
1429 enable_irq(spi->irq);
1430 schedule();
1431 __set_current_state(TASK_RUNNING);
1434 i_worked = 0;
1436 if (max3421_hcd->urb_done)
1437 i_worked |= max3421_urb_done(hcd);
1438 else if (max3421_handle_irqs(hcd))
1439 i_worked = 1;
1440 else if (!max3421_hcd->curr_urb)
1441 i_worked |= max3421_select_and_start_urb(hcd);
1443 if (test_and_clear_bit(RESET_HCD, &max3421_hcd->todo))
1444 /* reset the HCD: */
1445 i_worked |= max3421_reset_hcd(hcd);
1446 if (test_and_clear_bit(RESET_PORT, &max3421_hcd->todo)) {
1447 /* perform a USB bus reset: */
1448 spi_wr8(hcd, MAX3421_REG_HCTL,
1449 BIT(MAX3421_HCTL_BUSRST_BIT));
1450 i_worked = 1;
1452 if (test_and_clear_bit(CHECK_UNLINK, &max3421_hcd->todo))
1453 i_worked |= max3421_check_unlink(hcd);
1454 if (test_and_clear_bit(IOPIN_UPDATE, &max3421_hcd->todo)) {
1456 * IOPINS1/IOPINS2 do not auto-increment, so we can't
1457 * use spi_wr_buf().
1459 for (i = 0; i < ARRAY_SIZE(max3421_hcd->iopins); ++i) {
1460 u8 val = spi_rd8(hcd, MAX3421_REG_IOPINS1);
1462 val = ((val & 0xf0) |
1463 (max3421_hcd->iopins[i] & 0x0f));
1464 spi_wr8(hcd, MAX3421_REG_IOPINS1 + i, val);
1465 max3421_hcd->iopins[i] = val;
1467 i_worked = 1;
1470 set_current_state(TASK_RUNNING);
1471 dev_info(&spi->dev, "SPI thread exiting");
1472 return 0;
1475 static int
1476 max3421_reset_port(struct usb_hcd *hcd)
1478 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1480 max3421_hcd->port_status &= ~(USB_PORT_STAT_ENABLE |
1481 USB_PORT_STAT_LOW_SPEED);
1482 max3421_hcd->port_status |= USB_PORT_STAT_RESET;
1483 set_bit(RESET_PORT, &max3421_hcd->todo);
1484 wake_up_process(max3421_hcd->spi_thread);
1485 return 0;
1488 static int
1489 max3421_reset(struct usb_hcd *hcd)
1491 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1493 hcd->self.sg_tablesize = 0;
1494 hcd->speed = HCD_USB2;
1495 hcd->self.root_hub->speed = USB_SPEED_FULL;
1496 set_bit(RESET_HCD, &max3421_hcd->todo);
1497 wake_up_process(max3421_hcd->spi_thread);
1498 return 0;
1501 static int
1502 max3421_start(struct usb_hcd *hcd)
1504 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1506 spin_lock_init(&max3421_hcd->lock);
1507 max3421_hcd->rh_state = MAX3421_RH_RUNNING;
1509 INIT_LIST_HEAD(&max3421_hcd->ep_list);
1511 hcd->power_budget = POWER_BUDGET;
1512 hcd->state = HC_STATE_RUNNING;
1513 hcd->uses_new_polling = 1;
1514 return 0;
1517 static void
1518 max3421_stop(struct usb_hcd *hcd)
1522 static int
1523 max3421_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
1525 struct spi_device *spi = to_spi_device(hcd->self.controller);
1526 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1527 struct max3421_ep *max3421_ep;
1528 unsigned long flags;
1529 int retval;
1531 switch (usb_pipetype(urb->pipe)) {
1532 case PIPE_INTERRUPT:
1533 case PIPE_ISOCHRONOUS:
1534 if (urb->interval < 0) {
1535 dev_err(&spi->dev,
1536 "%s: interval=%d for intr-/iso-pipe; expected > 0\n",
1537 __func__, urb->interval);
1538 return -EINVAL;
1540 break;
1541 default:
1542 break;
1545 spin_lock_irqsave(&max3421_hcd->lock, flags);
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;
1555 max3421_ep->ep = urb->ep;
1556 max3421_ep->last_active = max3421_hcd->frame_number;
1557 urb->ep->hcpriv = max3421_ep;
1559 list_add_tail(&max3421_ep->ep_list, &max3421_hcd->ep_list);
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);
1569 out:
1570 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1571 return retval;
1574 static int
1575 max3421_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
1577 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1578 unsigned long flags;
1579 int retval;
1581 spin_lock_irqsave(&max3421_hcd->lock, flags);
1584 * This will set urb->unlinked which in turn causes the entry
1585 * to be dropped at the next opportunity.
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);
1592 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1593 return retval;
1596 static void
1597 max3421_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
1599 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1600 unsigned long flags;
1602 spin_lock_irqsave(&max3421_hcd->lock, flags);
1604 if (ep->hcpriv) {
1605 struct max3421_ep *max3421_ep = ep->hcpriv;
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;
1614 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1617 static int
1618 max3421_get_frame_number(struct usb_hcd *hcd)
1620 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1621 return max3421_hcd->frame_number;
1625 * Should return a non-zero value when any port is undergoing a resume
1626 * transition while the root hub is suspended.
1628 static int
1629 max3421_hub_status_data(struct usb_hcd *hcd, char *buf)
1631 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1632 unsigned long flags;
1633 int retval = 0;
1635 spin_lock_irqsave(&max3421_hcd->lock, flags);
1636 if (!HCD_HW_ACCESSIBLE(hcd))
1637 goto done;
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);
1649 done:
1650 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1651 return retval;
1654 static inline void
1655 hub_descriptor(struct usb_hub_descriptor *desc)
1657 memset(desc, 0, sizeof(*desc));
1659 * See Table 11-13: Hub Descriptor in USB 2.0 spec.
1661 desc->bDescriptorType = USB_DT_HUB; /* hub descriptor */
1662 desc->bDescLength = 9;
1663 desc->wHubCharacteristics = cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM |
1664 HUB_CHAR_COMMON_OCPM);
1665 desc->bNbrPorts = 1;
1669 * Set the MAX3421E general-purpose output with number PIN_NUMBER to
1670 * VALUE (0 or 1). PIN_NUMBER may be in the range from 1-8. For
1671 * any other value, this function acts as a no-op.
1673 static void
1674 max3421_gpout_set_value(struct usb_hcd *hcd, u8 pin_number, u8 value)
1676 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1677 u8 mask, idx;
1679 --pin_number;
1680 if (pin_number >= MAX3421_GPOUT_COUNT)
1681 return;
1683 mask = 1u << (pin_number % 4);
1684 idx = pin_number / 4;
1686 if (value)
1687 max3421_hcd->iopins[idx] |= mask;
1688 else
1689 max3421_hcd->iopins[idx] &= ~mask;
1690 set_bit(IOPIN_UPDATE, &max3421_hcd->todo);
1691 wake_up_process(max3421_hcd->spi_thread);
1694 static int
1695 max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
1696 char *buf, u16 length)
1698 struct spi_device *spi = to_spi_device(hcd->self.controller);
1699 struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);
1700 struct max3421_hcd_platform_data *pdata;
1701 unsigned long flags;
1702 int retval = 0;
1704 pdata = spi->dev.platform_data;
1706 spin_lock_irqsave(&max3421_hcd->lock, flags);
1708 switch (type_req) {
1709 case ClearHubFeature:
1710 break;
1711 case ClearPortFeature:
1712 switch (value) {
1713 case USB_PORT_FEAT_SUSPEND:
1714 break;
1715 case USB_PORT_FEAT_POWER:
1716 dev_dbg(hcd->self.controller, "power-off\n");
1717 max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1718 !pdata->vbus_active_level);
1719 fallthrough;
1720 default:
1721 max3421_hcd->port_status &= ~(1 << value);
1723 break;
1724 case GetHubDescriptor:
1725 hub_descriptor((struct usb_hub_descriptor *) buf);
1726 break;
1728 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
1729 case GetPortErrorCount:
1730 case SetHubDepth:
1731 /* USB3 only */
1732 goto error;
1734 case GetHubStatus:
1735 *(__le32 *) buf = cpu_to_le32(0);
1736 break;
1738 case GetPortStatus:
1739 if (index != 1) {
1740 retval = -EPIPE;
1741 goto error;
1743 ((__le16 *) buf)[0] = cpu_to_le16(max3421_hcd->port_status);
1744 ((__le16 *) buf)[1] =
1745 cpu_to_le16(max3421_hcd->port_status >> 16);
1746 break;
1748 case SetHubFeature:
1749 retval = -EPIPE;
1750 break;
1752 case SetPortFeature:
1753 switch (value) {
1754 case USB_PORT_FEAT_LINK_STATE:
1755 case USB_PORT_FEAT_U1_TIMEOUT:
1756 case USB_PORT_FEAT_U2_TIMEOUT:
1757 case USB_PORT_FEAT_BH_PORT_RESET:
1758 goto error;
1759 case USB_PORT_FEAT_SUSPEND:
1760 if (max3421_hcd->active)
1761 max3421_hcd->port_status |=
1762 USB_PORT_STAT_SUSPEND;
1763 break;
1764 case USB_PORT_FEAT_POWER:
1765 dev_dbg(hcd->self.controller, "power-on\n");
1766 max3421_hcd->port_status |= USB_PORT_STAT_POWER;
1767 max3421_gpout_set_value(hcd, pdata->vbus_gpout,
1768 pdata->vbus_active_level);
1769 break;
1770 case USB_PORT_FEAT_RESET:
1771 max3421_reset_port(hcd);
1772 fallthrough;
1773 default:
1774 if ((max3421_hcd->port_status & USB_PORT_STAT_POWER)
1775 != 0)
1776 max3421_hcd->port_status |= (1 << value);
1778 break;
1780 default:
1781 dev_dbg(hcd->self.controller,
1782 "hub control req%04x v%04x i%04x l%d\n",
1783 type_req, value, index, length);
1784 error: /* "protocol stall" on error */
1785 retval = -EPIPE;
1788 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1789 return retval;
1792 static int
1793 max3421_bus_suspend(struct usb_hcd *hcd)
1795 return -1;
1798 static int
1799 max3421_bus_resume(struct usb_hcd *hcd)
1801 return -1;
1804 static const struct hc_driver max3421_hcd_desc = {
1805 .description = "max3421",
1806 .product_desc = DRIVER_DESC,
1807 .hcd_priv_size = sizeof(struct max3421_hcd),
1808 .flags = HCD_USB11,
1809 .reset = max3421_reset,
1810 .start = max3421_start,
1811 .stop = max3421_stop,
1812 .get_frame_number = max3421_get_frame_number,
1813 .urb_enqueue = max3421_urb_enqueue,
1814 .urb_dequeue = max3421_urb_dequeue,
1815 .endpoint_disable = max3421_endpoint_disable,
1816 .hub_status_data = max3421_hub_status_data,
1817 .hub_control = max3421_hub_control,
1818 .bus_suspend = max3421_bus_suspend,
1819 .bus_resume = max3421_bus_resume,
1822 static int
1823 max3421_of_vbus_en_pin(struct device *dev, struct max3421_hcd_platform_data *pdata)
1825 int retval;
1826 uint32_t value[2];
1828 if (!pdata)
1829 return -EINVAL;
1831 retval = of_property_read_u32_array(dev->of_node, "maxim,vbus-en-pin", value, 2);
1832 if (retval) {
1833 dev_err(dev, "device tree node property 'maxim,vbus-en-pin' is missing\n");
1834 return retval;
1836 dev_info(dev, "property 'maxim,vbus-en-pin' value is <%d %d>\n", value[0], value[1]);
1838 pdata->vbus_gpout = value[0];
1839 pdata->vbus_active_level = value[1];
1841 return 0;
1844 static int
1845 max3421_probe(struct spi_device *spi)
1847 struct device *dev = &spi->dev;
1848 struct max3421_hcd *max3421_hcd;
1849 struct usb_hcd *hcd = NULL;
1850 struct max3421_hcd_platform_data *pdata = NULL;
1851 int retval;
1853 if (spi_setup(spi) < 0) {
1854 dev_err(&spi->dev, "Unable to setup SPI bus");
1855 return -EFAULT;
1858 if (!spi->irq) {
1859 dev_err(dev, "Failed to get SPI IRQ");
1860 return -EFAULT;
1863 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
1864 pdata = devm_kzalloc(&spi->dev, sizeof(*pdata), GFP_KERNEL);
1865 if (!pdata) {
1866 retval = -ENOMEM;
1867 goto error;
1869 retval = max3421_of_vbus_en_pin(dev, pdata);
1870 if (retval)
1871 goto error;
1873 spi->dev.platform_data = pdata;
1876 pdata = spi->dev.platform_data;
1877 if (!pdata) {
1878 dev_err(&spi->dev, "driver configuration data is not provided\n");
1879 retval = -EFAULT;
1880 goto error;
1882 if (pdata->vbus_active_level > 1) {
1883 dev_err(&spi->dev, "vbus active level value %d is out of range (0/1)\n", pdata->vbus_active_level);
1884 retval = -EINVAL;
1885 goto error;
1887 if (pdata->vbus_gpout < 1 || pdata->vbus_gpout > MAX3421_GPOUT_COUNT) {
1888 dev_err(&spi->dev, "vbus gpout value %d is out of range (1..8)\n", pdata->vbus_gpout);
1889 retval = -EINVAL;
1890 goto error;
1893 retval = -ENOMEM;
1894 hcd = usb_create_hcd(&max3421_hcd_desc, &spi->dev,
1895 dev_name(&spi->dev));
1896 if (!hcd) {
1897 dev_err(&spi->dev, "failed to create HCD structure\n");
1898 goto error;
1900 set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
1901 max3421_hcd = hcd_to_max3421(hcd);
1902 max3421_hcd->next = max3421_hcd_list;
1903 max3421_hcd_list = max3421_hcd;
1904 INIT_LIST_HEAD(&max3421_hcd->ep_list);
1906 max3421_hcd->tx = kmalloc(sizeof(*max3421_hcd->tx), GFP_KERNEL);
1907 if (!max3421_hcd->tx)
1908 goto error;
1909 max3421_hcd->rx = kmalloc(sizeof(*max3421_hcd->rx), GFP_KERNEL);
1910 if (!max3421_hcd->rx)
1911 goto error;
1913 max3421_hcd->spi_thread = kthread_run(max3421_spi_thread, hcd,
1914 "max3421_spi_thread");
1915 if (max3421_hcd->spi_thread == ERR_PTR(-ENOMEM)) {
1916 dev_err(&spi->dev,
1917 "failed to create SPI thread (out of memory)\n");
1918 goto error;
1921 retval = usb_add_hcd(hcd, 0, 0);
1922 if (retval) {
1923 dev_err(&spi->dev, "failed to add HCD\n");
1924 goto error;
1927 retval = request_irq(spi->irq, max3421_irq_handler,
1928 IRQF_TRIGGER_LOW, "max3421", hcd);
1929 if (retval < 0) {
1930 dev_err(&spi->dev, "failed to request irq %d\n", spi->irq);
1931 goto error;
1933 return 0;
1935 error:
1936 if (IS_ENABLED(CONFIG_OF) && dev->of_node && pdata) {
1937 devm_kfree(&spi->dev, pdata);
1938 spi->dev.platform_data = NULL;
1941 if (hcd) {
1942 kfree(max3421_hcd->tx);
1943 kfree(max3421_hcd->rx);
1944 if (max3421_hcd->spi_thread)
1945 kthread_stop(max3421_hcd->spi_thread);
1946 usb_put_hcd(hcd);
1948 return retval;
1951 static int
1952 max3421_remove(struct spi_device *spi)
1954 struct max3421_hcd *max3421_hcd = NULL, **prev;
1955 struct usb_hcd *hcd = NULL;
1956 unsigned long flags;
1958 for (prev = &max3421_hcd_list; *prev; prev = &(*prev)->next) {
1959 max3421_hcd = *prev;
1960 hcd = max3421_to_hcd(max3421_hcd);
1961 if (hcd->self.controller == &spi->dev)
1962 break;
1964 if (!max3421_hcd) {
1965 dev_err(&spi->dev, "no MAX3421 HCD found for SPI device %p\n",
1966 spi);
1967 return -ENODEV;
1970 usb_remove_hcd(hcd);
1972 spin_lock_irqsave(&max3421_hcd->lock, flags);
1974 kthread_stop(max3421_hcd->spi_thread);
1975 *prev = max3421_hcd->next;
1977 spin_unlock_irqrestore(&max3421_hcd->lock, flags);
1979 free_irq(spi->irq, hcd);
1981 usb_put_hcd(hcd);
1982 return 0;
1985 static const struct of_device_id max3421_of_match_table[] = {
1986 { .compatible = "maxim,max3421", },
1989 MODULE_DEVICE_TABLE(of, max3421_of_match_table);
1991 static struct spi_driver max3421_driver = {
1992 .probe = max3421_probe,
1993 .remove = max3421_remove,
1994 .driver = {
1995 .name = "max3421-hcd",
1996 .of_match_table = of_match_ptr(max3421_of_match_table),
2000 module_spi_driver(max3421_driver);
2002 MODULE_DESCRIPTION(DRIVER_DESC);
2003 MODULE_AUTHOR("David Mosberger <davidm@egauge.net>");
2004 MODULE_LICENSE("GPL");