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 if (rx_slot >= DLN2_MAX_RX_SLOTS)
201 rxc = &rxs->slots[rx_slot];
204 * No need to disable interrupts as this lock is not taken in interrupt
205 * context elsewhere in this driver. This function (or its callers) are
206 * also not exported to other modules.
208 spin_lock(&rxs->lock);
209 if (rxc->in_use && !rxc->urb) {
211 complete(&rxc->done);
214 spin_unlock(&rxs->lock);
218 dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
223 static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
226 struct dln2_event_cb_entry *i;
230 list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
232 i->callback(i->pdev, echo, data, len);
240 static void dln2_rx(struct urb *urb)
242 struct dln2_dev *dln2 = urb->context;
243 struct dln2_header *hdr = urb->transfer_buffer;
244 struct device *dev = &dln2->interface->dev;
245 u16 id, echo, handle, size;
250 switch (urb->status) {
258 /* this urb is terminated, clean up */
259 dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
262 dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
266 if (urb->actual_length < sizeof(struct dln2_header)) {
267 dev_err(dev, "short response: %d\n", urb->actual_length);
271 handle = le16_to_cpu(hdr->handle);
272 id = le16_to_cpu(hdr->id);
273 echo = le16_to_cpu(hdr->echo);
274 size = le16_to_cpu(hdr->size);
276 if (size != urb->actual_length) {
277 dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
278 handle, id, echo, size, urb->actual_length);
282 if (handle >= DLN2_HANDLES) {
283 dev_warn(dev, "invalid handle %d\n", handle);
287 data = urb->transfer_buffer + sizeof(struct dln2_header);
288 len = urb->actual_length - sizeof(struct dln2_header);
290 if (handle == DLN2_HANDLE_EVENT) {
291 dln2_run_event_callbacks(dln2, id, echo, data, len);
293 /* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
294 if (dln2_transfer_complete(dln2, urb, handle, echo))
299 err = usb_submit_urb(urb, GFP_ATOMIC);
301 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
304 static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
305 int *obuf_len, gfp_t gfp)
309 struct dln2_header *hdr;
311 len = *obuf_len + sizeof(*hdr);
312 buf = kmalloc(len, gfp);
316 hdr = (struct dln2_header *)buf;
317 hdr->id = cpu_to_le16(cmd);
318 hdr->size = cpu_to_le16(len);
319 hdr->echo = cpu_to_le16(echo);
320 hdr->handle = cpu_to_le16(handle);
322 memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
329 static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
330 const void *obuf, int obuf_len)
337 buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
341 ret = usb_bulk_msg(dln2->usb_dev,
342 usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
343 buf, len, &actual, DLN2_USB_TIMEOUT);
350 static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
352 struct dln2_mod_rx_slots *rxs;
355 if (dln2->disconnect) {
360 rxs = &dln2->mod_rx_slots[handle];
362 spin_lock_irqsave(&rxs->lock, flags);
364 *slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
366 if (*slot < DLN2_MAX_RX_SLOTS) {
367 struct dln2_rx_context *rxc = &rxs->slots[*slot];
369 set_bit(*slot, rxs->bmap);
373 spin_unlock_irqrestore(&rxs->lock, flags);
375 return *slot < DLN2_MAX_RX_SLOTS;
378 static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
384 * No need to timeout here, the wait is bounded by the timeout in
387 ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
388 find_free_slot(dln2, handle, &slot));
395 static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
397 struct dln2_mod_rx_slots *rxs;
398 struct urb *urb = NULL;
400 struct dln2_rx_context *rxc;
402 rxs = &dln2->mod_rx_slots[handle];
404 spin_lock_irqsave(&rxs->lock, flags);
406 clear_bit(slot, rxs->bmap);
408 rxc = &rxs->slots[slot];
412 reinit_completion(&rxc->done);
414 spin_unlock_irqrestore(&rxs->lock, flags);
418 struct device *dev = &dln2->interface->dev;
420 err = usb_submit_urb(urb, GFP_KERNEL);
422 dev_err(dev, "failed to resubmit RX URB: %d\n", err);
425 wake_up_interruptible(&rxs->wq);
428 static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
429 const void *obuf, unsigned obuf_len,
430 void *ibuf, unsigned *ibuf_len)
434 struct dln2_response *rsp;
435 struct dln2_rx_context *rxc;
436 struct device *dev = &dln2->interface->dev;
437 const unsigned long timeout = DLN2_USB_TIMEOUT * HZ / 1000;
438 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
440 spin_lock(&dln2->disconnect_lock);
441 if (!dln2->disconnect)
442 dln2->active_transfers++;
445 spin_unlock(&dln2->disconnect_lock);
450 rx_slot = alloc_rx_slot(dln2, handle);
456 ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
458 dev_err(dev, "USB write failed: %d\n", ret);
459 goto out_free_rx_slot;
462 rxc = &rxs->slots[rx_slot];
464 ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
468 goto out_free_rx_slot;
473 if (dln2->disconnect) {
475 goto out_free_rx_slot;
478 /* if we got here we know that the response header has been checked */
479 rsp = rxc->urb->transfer_buffer;
481 if (rsp->hdr.size < sizeof(*rsp)) {
483 goto out_free_rx_slot;
486 if (le16_to_cpu(rsp->result) > 0x80) {
487 dev_dbg(dev, "%d received response with error %d\n",
488 handle, le16_to_cpu(rsp->result));
490 goto out_free_rx_slot;
494 goto out_free_rx_slot;
496 if (*ibuf_len > rsp->hdr.size - sizeof(*rsp))
497 *ibuf_len = rsp->hdr.size - sizeof(*rsp);
499 memcpy(ibuf, rsp + 1, *ibuf_len);
502 free_rx_slot(dln2, handle, rx_slot);
504 spin_lock(&dln2->disconnect_lock);
505 dln2->active_transfers--;
506 spin_unlock(&dln2->disconnect_lock);
507 if (dln2->disconnect)
508 wake_up(&dln2->disconnect_wq);
513 int dln2_transfer(struct platform_device *pdev, u16 cmd,
514 const void *obuf, unsigned obuf_len,
515 void *ibuf, unsigned *ibuf_len)
517 struct dln2_platform_data *dln2_pdata;
518 struct dln2_dev *dln2;
521 dln2 = dev_get_drvdata(pdev->dev.parent);
522 dln2_pdata = dev_get_platdata(&pdev->dev);
523 handle = dln2_pdata->handle;
525 return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
528 EXPORT_SYMBOL(dln2_transfer);
530 static int dln2_check_hw(struct dln2_dev *dln2)
534 int len = sizeof(hw_type);
536 ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
537 NULL, 0, &hw_type, &len);
540 if (len < sizeof(hw_type))
543 if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
544 dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
545 le32_to_cpu(hw_type));
552 static int dln2_print_serialno(struct dln2_dev *dln2)
556 int len = sizeof(serial_no);
557 struct device *dev = &dln2->interface->dev;
559 ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
563 if (len < sizeof(serial_no))
566 dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
571 static int dln2_hw_init(struct dln2_dev *dln2)
575 ret = dln2_check_hw(dln2);
579 return dln2_print_serialno(dln2);
582 static void dln2_free_rx_urbs(struct dln2_dev *dln2)
586 for (i = 0; i < DLN2_MAX_URBS; i++) {
587 usb_kill_urb(dln2->rx_urb[i]);
588 usb_free_urb(dln2->rx_urb[i]);
589 kfree(dln2->rx_buf[i]);
593 static void dln2_free(struct dln2_dev *dln2)
595 dln2_free_rx_urbs(dln2);
596 usb_put_dev(dln2->usb_dev);
600 static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
601 struct usb_host_interface *hostif)
605 const int rx_max_size = DLN2_RX_BUF_SIZE;
606 struct device *dev = &dln2->interface->dev;
608 for (i = 0; i < DLN2_MAX_URBS; i++) {
609 dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
610 if (!dln2->rx_buf[i])
613 dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
614 if (!dln2->rx_urb[i])
617 usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
618 usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
619 dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
621 ret = usb_submit_urb(dln2->rx_urb[i], GFP_KERNEL);
623 dev_err(dev, "failed to submit RX URB: %d\n", ret);
631 static struct dln2_platform_data dln2_pdata_gpio = {
632 .handle = DLN2_HANDLE_GPIO,
635 /* Only one I2C port seems to be supported on current hardware */
636 static struct dln2_platform_data dln2_pdata_i2c = {
637 .handle = DLN2_HANDLE_I2C,
641 static const struct mfd_cell dln2_devs[] = {
644 .platform_data = &dln2_pdata_gpio,
645 .pdata_size = sizeof(struct dln2_platform_data),
649 .platform_data = &dln2_pdata_i2c,
650 .pdata_size = sizeof(struct dln2_platform_data),
654 static void dln2_disconnect(struct usb_interface *interface)
656 struct dln2_dev *dln2 = usb_get_intfdata(interface);
659 /* don't allow starting new transfers */
660 spin_lock(&dln2->disconnect_lock);
661 dln2->disconnect = true;
662 spin_unlock(&dln2->disconnect_lock);
664 /* cancel in progress transfers */
665 for (i = 0; i < DLN2_HANDLES; i++) {
666 struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
669 spin_lock_irqsave(&rxs->lock, flags);
671 /* cancel all response waiters */
672 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
673 struct dln2_rx_context *rxc = &rxs->slots[j];
676 complete(&rxc->done);
679 spin_unlock_irqrestore(&rxs->lock, flags);
682 /* wait for transfers to end */
683 wait_event(dln2->disconnect_wq, !dln2->active_transfers);
685 mfd_remove_devices(&interface->dev);
690 static int dln2_probe(struct usb_interface *interface,
691 const struct usb_device_id *usb_id)
693 struct usb_host_interface *hostif = interface->cur_altsetting;
694 struct device *dev = &interface->dev;
695 struct dln2_dev *dln2;
699 if (hostif->desc.bInterfaceNumber != 0 ||
700 hostif->desc.bNumEndpoints < 2)
703 dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
707 dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
708 dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
709 dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
710 dln2->interface = interface;
711 usb_set_intfdata(interface, dln2);
712 init_waitqueue_head(&dln2->disconnect_wq);
714 for (i = 0; i < DLN2_HANDLES; i++) {
715 init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
716 spin_lock_init(&dln2->mod_rx_slots[i].lock);
717 for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
718 init_completion(&dln2->mod_rx_slots[i].slots[j].done);
721 spin_lock_init(&dln2->event_cb_lock);
722 spin_lock_init(&dln2->disconnect_lock);
723 INIT_LIST_HEAD(&dln2->event_cb_list);
725 ret = dln2_setup_rx_urbs(dln2, hostif);
729 ret = dln2_hw_init(dln2);
731 dev_err(dev, "failed to initialize hardware\n");
735 ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
737 dev_err(dev, "failed to add mfd devices to core\n");
749 static const struct usb_device_id dln2_table[] = {
750 { USB_DEVICE(0xa257, 0x2013) },
754 MODULE_DEVICE_TABLE(usb, dln2_table);
756 static struct usb_driver dln2_driver = {
759 .disconnect = dln2_disconnect,
760 .id_table = dln2_table,
763 module_usb_driver(dln2_driver);
765 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
766 MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
767 MODULE_LICENSE("GPL v2");