2 * Driver for the Diolan DLN-2 USB adapter
4 * Copyright (c) 2014 Intel Corporation
8 * Copyright (c) 2010-2011 Ericsson AB
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation, version 2.
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/slab.h>
19 #include <linux/usb.h>
20 #include <linux/i2c.h>
21 #include <linux/mutex.h>
22 #include <linux/platform_device.h>
23 #include <linux/mfd/core.h>
24 #include <linux/mfd/dln2.h>
25 #include <linux/rculist.h>
34 struct dln2_response {
35 struct dln2_header hdr;
39 #define DLN2_GENERIC_MODULE_ID 0x00
40 #define DLN2_GENERIC_CMD(cmd) DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
41 #define CMD_GET_DEVICE_VER DLN2_GENERIC_CMD(0x30)
42 #define CMD_GET_DEVICE_SN DLN2_GENERIC_CMD(0x31)
44 #define DLN2_HW_ID 0x200
45 #define DLN2_USB_TIMEOUT 200 /* in ms */
46 #define DLN2_MAX_RX_SLOTS 16
47 #define DLN2_MAX_URBS 16
48 #define DLN2_RX_BUF_SIZE 512
51 DLN2_HANDLE_EVENT = 0, /* don't change, hardware defined */
59 * Receive context used between the receive demultiplexer and the transfer
60 * routine. While sending a request the transfer routine will look for a free
61 * receive context and use it to wait for a response and to receive the URB and
62 * thus the response data.
64 struct dln2_rx_context {
65 /* completion used to wait for a response */
66 struct completion done;
68 /* if non-NULL the URB contains the response */
71 /* if true then this context is used to wait for a response */
76 * Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We use the
77 * handle header field to identify the module in dln2_dev.mod_rx_slots and then
78 * the echo header field to index the slots field and find the receive context
79 * for a particular request.
81 struct dln2_mod_rx_slots {
83 DECLARE_BITMAP(bmap, DLN2_MAX_RX_SLOTS);
85 /* used to wait for a free RX slot */
88 /* used to wait for an RX operation to complete */
89 struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS];
91 /* avoid races between alloc/free_rx_slot and dln2_rx_transfer */
96 struct usb_device *usb_dev;
97 struct usb_interface *interface;
101 struct urb *rx_urb[DLN2_MAX_URBS];
102 void *rx_buf[DLN2_MAX_URBS];
104 struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
106 struct list_head event_cb_list;
107 spinlock_t event_cb_lock;
110 int active_transfers;
111 wait_queue_head_t disconnect_wq;
112 spinlock_t disconnect_lock;
115 struct dln2_event_cb_entry {
116 struct list_head list;
118 struct platform_device *pdev;
119 dln2_event_cb_t callback;
122 int dln2_register_event_cb(struct platform_device *pdev, u16 id,
123 dln2_event_cb_t event_cb)
125 struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
126 struct dln2_event_cb_entry *i, *entry;
130 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
135 entry->callback = event_cb;
138 spin_lock_irqsave(&dln2->event_cb_lock, flags);
140 list_for_each_entry(i, &dln2->event_cb_list, list) {
148 list_add_rcu(&entry->list, &dln2->event_cb_list);
150 spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
157 EXPORT_SYMBOL(dln2_register_event_cb);
159 void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
161 struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
162 struct dln2_event_cb_entry *i;
166 spin_lock_irqsave(&dln2->event_cb_lock, flags);
168 list_for_each_entry(i, &dln2->event_cb_list, list) {
170 list_del_rcu(&i->list);
176 spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
183 EXPORT_SYMBOL(dln2_unregister_event_cb);
186 * Returns true if a valid transfer slot is found. In this case the URB must not
187 * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
188 * is woke up. It will be resubmitted there.
190 static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
191 u16 handle, u16 rx_slot)
193 struct device *dev = &dln2->interface->dev;
194 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
195 struct dln2_rx_context *rxc;
196 bool valid_slot = false;
198 rxc = &rxs->slots[rx_slot];
201 * No need to disable interrupts as this lock is not taken in interrupt
202 * context elsewhere in this driver. This function (or its callers) are
203 * also not exported to other modules.
205 spin_lock(&rxs->lock);
206 if (rxc->in_use && !rxc->urb) {
208 complete(&rxc->done);
211 spin_unlock(&rxs->lock);
214 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
219 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
222 struct dln2_event_cb_entry *i;
226 list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
228 i->callback(i->pdev, echo, data, len);
236 static void dln2_rx(struct urb *urb)
238 struct dln2_dev *dln2 = urb->context;
239 struct dln2_header *hdr = urb->transfer_buffer;
240 struct device *dev = &dln2->interface->dev;
241 u16 id, echo, handle, size;
246 switch (urb->status) {
254 /* this urb is terminated, clean up */
255 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
258 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
262 if (urb->actual_length < sizeof(struct dln2_header)) {
263 dev_err(dev, "short response: %d\n", urb->actual_length);
267 handle = le16_to_cpu(hdr->handle);
268 id = le16_to_cpu(hdr->id);
269 echo = le16_to_cpu(hdr->echo);
270 size = le16_to_cpu(hdr->size);
272 if (size != urb->actual_length) {
273 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
274 handle, id, echo, size, urb->actual_length);
278 if (handle >= DLN2_HANDLES) {
279 dev_warn(dev, "invalid handle %d\n", handle);
283 data = urb->transfer_buffer + sizeof(struct dln2_header);
284 len = urb->actual_length - sizeof(struct dln2_header);
286 if (handle == DLN2_HANDLE_EVENT) {
287 dln2_run_event_callbacks(dln2, id, echo, data, len);
289 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
290 if (dln2_transfer_complete(dln2, urb, handle, echo))
295 err = usb_submit_urb(urb, GFP_ATOMIC);
297 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
300 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
301 int *obuf_len, gfp_t gfp)
305 struct dln2_header *hdr;
307 len = *obuf_len + sizeof(*hdr);
308 buf = kmalloc(len, gfp);
312 hdr = (struct dln2_header *)buf;
313 hdr->id = cpu_to_le16(cmd);
314 hdr->size = cpu_to_le16(len);
315 hdr->echo = cpu_to_le16(echo);
316 hdr->handle = cpu_to_le16(handle);
318 memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
325 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
326 const void *obuf, int obuf_len)
333 buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
337 ret = usb_bulk_msg(dln2->usb_dev,
338 usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
339 buf, len, &actual, DLN2_USB_TIMEOUT);
346 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
348 struct dln2_mod_rx_slots *rxs;
351 if (dln2->disconnect) {
356 rxs = &dln2->mod_rx_slots[handle];
358 spin_lock_irqsave(&rxs->lock, flags);
360 *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
362 if (*slot < DLN2_MAX_RX_SLOTS) {
363 struct dln2_rx_context *rxc = &rxs->slots[*slot];
365 set_bit(*slot, rxs->bmap);
369 spin_unlock_irqrestore(&rxs->lock, flags);
371 return *slot < DLN2_MAX_RX_SLOTS;
374 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
380 * No need to timeout here, the wait is bounded by the timeout in
383 ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
384 find_free_slot(dln2, handle, &slot));
391 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
393 struct dln2_mod_rx_slots *rxs;
394 struct urb *urb = NULL;
396 struct dln2_rx_context *rxc;
398 rxs = &dln2->mod_rx_slots[handle];
400 spin_lock_irqsave(&rxs->lock, flags);
402 clear_bit(slot, rxs->bmap);
404 rxc = &rxs->slots[slot];
408 reinit_completion(&rxc->done);
410 spin_unlock_irqrestore(&rxs->lock, flags);
414 struct device *dev = &dln2->interface->dev;
416 err = usb_submit_urb(urb, GFP_KERNEL);
418 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
421 wake_up_interruptible(&rxs->wq);
424 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
425 const void *obuf, unsigned obuf_len,
426 void *ibuf, unsigned *ibuf_len)
430 struct dln2_response *rsp;
431 struct dln2_rx_context *rxc;
432 struct device *dev = &dln2->interface->dev;
433 const unsigned long timeout = DLN2_USB_TIMEOUT * HZ / 1000;
434 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
436 spin_lock(&dln2->disconnect_lock);
437 if (!dln2->disconnect)
438 dln2->active_transfers++;
441 spin_unlock(&dln2->disconnect_lock);
446 rx_slot = alloc_rx_slot(dln2, handle);
452 ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
454 dev_err(dev, "USB write failed: %d\n", ret);
455 goto out_free_rx_slot;
458 rxc = &rxs->slots[rx_slot];
460 ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
464 goto out_free_rx_slot;
469 if (dln2->disconnect) {
471 goto out_free_rx_slot;
474 /* if we got here we know that the response header has been checked */
475 rsp = rxc->urb->transfer_buffer;
477 if (rsp->hdr.size < sizeof(*rsp)) {
479 goto out_free_rx_slot;
482 if (le16_to_cpu(rsp->result) > 0x80) {
483 dev_dbg(dev, "%d received response with error %d\n",
484 handle, le16_to_cpu(rsp->result));
486 goto out_free_rx_slot;
490 goto out_free_rx_slot;
492 if (*ibuf_len > rsp->hdr.size - sizeof(*rsp))
493 *ibuf_len = rsp->hdr.size - sizeof(*rsp);
495 memcpy(ibuf, rsp + 1, *ibuf_len);
498 free_rx_slot(dln2, handle, rx_slot);
500 spin_lock(&dln2->disconnect_lock);
501 dln2->active_transfers--;
502 spin_unlock(&dln2->disconnect_lock);
503 if (dln2->disconnect)
504 wake_up(&dln2->disconnect_wq);
509 int dln2_transfer(struct platform_device *pdev, u16 cmd,
510 const void *obuf, unsigned obuf_len,
511 void *ibuf, unsigned *ibuf_len)
513 struct dln2_platform_data *dln2_pdata;
514 struct dln2_dev *dln2;
517 dln2 = dev_get_drvdata(pdev->dev.parent);
518 dln2_pdata = dev_get_platdata(&pdev->dev);
519 handle = dln2_pdata->handle;
521 return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
524 EXPORT_SYMBOL(dln2_transfer);
526 static int dln2_check_hw(struct dln2_dev *dln2)
530 int len = sizeof(hw_type);
532 ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
533 NULL, 0, &hw_type, &len);
536 if (len < sizeof(hw_type))
539 if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
540 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
541 le32_to_cpu(hw_type));
548 static int dln2_print_serialno(struct dln2_dev *dln2)
552 int len = sizeof(serial_no);
553 struct device *dev = &dln2->interface->dev;
555 ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
559 if (len < sizeof(serial_no))
562 dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
567 static int dln2_hw_init(struct dln2_dev *dln2)
571 ret = dln2_check_hw(dln2);
575 return dln2_print_serialno(dln2);
578 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
582 for (i = 0; i < DLN2_MAX_URBS; i++) {
583 usb_kill_urb(dln2->rx_urb[i]);
584 usb_free_urb(dln2->rx_urb[i]);
585 kfree(dln2->rx_buf[i]);
589 static void dln2_free(struct dln2_dev *dln2)
591 dln2_free_rx_urbs(dln2);
592 usb_put_dev(dln2->usb_dev);
596 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
597 struct usb_host_interface *hostif)
601 const int rx_max_size = DLN2_RX_BUF_SIZE;
602 struct device *dev = &dln2->interface->dev;
604 for (i = 0; i < DLN2_MAX_URBS; i++) {
605 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
606 if (!dln2->rx_buf[i])
609 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
610 if (!dln2->rx_urb[i])
613 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
614 usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
615 dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
617 ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL);
619 dev_err(dev, "failed to submit RX URB: %d\n", ret);
627 static struct dln2_platform_data dln2_pdata_gpio = {
628 .handle = DLN2_HANDLE_GPIO,
631 /* Only one I2C port seems to be supported on current hardware */
632 static struct dln2_platform_data dln2_pdata_i2c = {
633 .handle = DLN2_HANDLE_I2C,
637 static const struct mfd_cell dln2_devs[] = {
640 .platform_data = &dln2_pdata_gpio,
641 .pdata_size = sizeof(struct dln2_platform_data),
645 .platform_data = &dln2_pdata_i2c,
646 .pdata_size = sizeof(struct dln2_platform_data),
650 static void dln2_disconnect(struct usb_interface *interface)
652 struct dln2_dev *dln2 = usb_get_intfdata(interface);
655 /* don't allow starting new transfers */
656 spin_lock(&dln2->disconnect_lock);
657 dln2->disconnect = true;
658 spin_unlock(&dln2->disconnect_lock);
660 /* cancel in progress transfers */
661 for (i = 0; i < DLN2_HANDLES; i++) {
662 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
665 spin_lock_irqsave(&rxs->lock, flags);
667 /* cancel all response waiters */
668 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
669 struct dln2_rx_context *rxc = &rxs->slots[j];
672 complete(&rxc->done);
675 spin_unlock_irqrestore(&rxs->lock, flags);
678 /* wait for transfers to end */
679 wait_event(dln2->disconnect_wq, !dln2->active_transfers);
681 mfd_remove_devices(&interface->dev);
686 static int dln2_probe(struct usb_interface *interface,
687 const struct usb_device_id *usb_id)
689 struct usb_host_interface *hostif = interface->cur_altsetting;
690 struct device *dev = &interface->dev;
691 struct dln2_dev *dln2;
695 if (hostif->desc.bInterfaceNumber != 0 ||
696 hostif->desc.bNumEndpoints < 2)
699 dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
703 dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
704 dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
705 dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
706 dln2->interface = interface;
707 usb_set_intfdata(interface, dln2);
708 init_waitqueue_head(&dln2->disconnect_wq);
710 for (i = 0; i < DLN2_HANDLES; i++) {
711 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
712 spin_lock_init(&dln2->mod_rx_slots[i].lock);
713 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
714 init_completion(&dln2->mod_rx_slots[i].slots[j].done);
717 spin_lock_init(&dln2->event_cb_lock);
718 spin_lock_init(&dln2->disconnect_lock);
719 INIT_LIST_HEAD(&dln2->event_cb_list);
721 ret = dln2_setup_rx_urbs(dln2, hostif);
725 ret = dln2_hw_init(dln2);
727 dev_err(dev, "failed to initialize hardware\n");
731 ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
733 dev_err(dev, "failed to add mfd devices to core\n");
745 static const struct usb_device_id dln2_table[] = {
746 { USB_DEVICE(0xa257, 0x2013) },
750 MODULE_DEVICE_TABLE(usb, dln2_table);
752 static struct usb_driver dln2_driver = {
755 .disconnect = dln2_disconnect,
756 .id_table = dln2_table,
759 module_usb_driver(dln2_driver);
761 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
762 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
763 MODULE_LICENSE("GPL v2");