2 * Greybus "AP" USB driver for "ES2" controller chips
4 * Copyright 2014-2015 Google Inc.
5 * Copyright 2014-2015 Linaro Ltd.
7 * Released under the GPLv2 only.
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/kthread.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/sizes.h>
15 #include <linux/usb.h>
16 #include <linux/kfifo.h>
17 #include <linux/debugfs.h>
18 #include <linux/uaccess.h>
19 #include <asm/unaligned.h>
23 #include "kernel_ver.h"
25 /* Memory sizes for the buffers sent to/from the ES1 controller */
26 #define ES1_SVC_MSG_SIZE (sizeof(struct svc_msg) + SZ_64K)
27 #define ES1_GBUF_MSG_SIZE_MAX 2048
29 static const struct usb_device_id id_table[] = {
30 /* Made up numbers for the SVC USB Bridge in ES2 */
31 { USB_DEVICE(0xffff, 0x0002) },
34 MODULE_DEVICE_TABLE(usb, id_table);
36 #define APB1_LOG_SIZE SZ_16K
37 static struct dentry *apb1_log_dentry;
38 static struct dentry *apb1_log_enable_dentry;
39 static struct task_struct *apb1_log_task;
40 static DEFINE_KFIFO(apb1_log_fifo, char, APB1_LOG_SIZE);
43 * Number of CPort IN urbs in flight at any point in time.
44 * Adjust if we are having stalls in the USB buffer due to not enough urbs in
47 #define NUM_CPORT_IN_URB 4
49 /* Number of CPort OUT urbs in flight at any point in time.
50 * Adjust if we get messages saying we are out of urbs in the system log.
52 #define NUM_CPORT_OUT_URB 8
55 * es1_ap_dev - ES1 USB Bridge to AP structure
56 * @usb_dev: pointer to the USB device we are.
57 * @usb_intf: pointer to the USB interface we are bound to.
58 * @hd: pointer to our greybus_host_device structure
59 * @control_endpoint: endpoint to send data to SVC
60 * @svc_endpoint: endpoint for SVC data in
61 * @cport_in_endpoint: bulk in endpoint for CPort data
62 * @cport-out_endpoint: bulk out endpoint for CPort data
63 * @svc_buffer: buffer for SVC messages coming in on @svc_endpoint
64 * @svc_urb: urb for SVC messages coming in on @svc_endpoint
65 * @cport_in_urb: array of urbs for the CPort in messages
66 * @cport_in_buffer: array of buffers for the @cport_in_urb urbs
67 * @cport_out_urb: array of urbs for the CPort out messages
68 * @cport_out_urb_busy: array of flags to see if the @cport_out_urb is busy or
70 * @cport_out_urb_lock: locks the @cport_out_urb_busy "list"
73 struct usb_device *usb_dev;
74 struct usb_interface *usb_intf;
75 struct greybus_host_device *hd;
77 __u8 control_endpoint;
79 __u8 cport_in_endpoint;
80 __u8 cport_out_endpoint;
85 struct urb *cport_in_urb[NUM_CPORT_IN_URB];
86 u8 *cport_in_buffer[NUM_CPORT_IN_URB];
87 struct urb *cport_out_urb[NUM_CPORT_OUT_URB];
88 bool cport_out_urb_busy[NUM_CPORT_OUT_URB];
89 spinlock_t cport_out_urb_lock;
92 static inline struct es1_ap_dev *hd_to_es1(struct greybus_host_device *hd)
94 return (struct es1_ap_dev *)&hd->hd_priv;
97 static void cport_out_callback(struct urb *urb);
98 static void usb_log_enable(struct es1_ap_dev *es1);
99 static void usb_log_disable(struct es1_ap_dev *es1);
101 #define ES1_TIMEOUT 500 /* 500 ms for the SVC to do something */
102 static int submit_svc(struct svc_msg *svc_msg, struct greybus_host_device *hd)
104 struct es1_ap_dev *es1 = hd_to_es1(hd);
107 /* SVC messages go down our control pipe */
108 retval = usb_control_msg(es1->usb_dev,
109 usb_sndctrlpipe(es1->usb_dev,
110 es1->control_endpoint),
111 0x01, /* vendor request AP message */
112 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
117 if (retval != sizeof(*svc_msg))
123 static struct urb *next_free_urb(struct es1_ap_dev *es1, gfp_t gfp_mask)
125 struct urb *urb = NULL;
129 spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
131 /* Look in our pool of allocated urbs first, as that's the "fastest" */
132 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
133 if (es1->cport_out_urb_busy[i] == false) {
134 es1->cport_out_urb_busy[i] = true;
135 urb = es1->cport_out_urb[i];
139 spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
144 * Crap, pool is empty, complain to the syslog and go allocate one
145 * dynamically as we have to succeed.
147 dev_err(&es1->usb_dev->dev,
148 "No free CPort OUT urbs, having to dynamically allocate one!\n");
149 return usb_alloc_urb(0, gfp_mask);
152 static void free_urb(struct es1_ap_dev *es1, struct urb *urb)
157 * See if this was an urb in our pool, if so mark it "free", otherwise
158 * we need to free it ourselves.
160 spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
161 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
162 if (urb == es1->cport_out_urb[i]) {
163 es1->cport_out_urb_busy[i] = false;
168 spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
170 /* If urb is not NULL, then we need to free this urb */
175 * Returns an opaque cookie value if successful, or a pointer coded
176 * error otherwise. If the caller wishes to cancel the in-flight
177 * buffer, it must supply the returned cookie to the cancel routine.
179 static void *message_send(struct greybus_host_device *hd, u16 cport_id,
180 struct gb_message *message, gfp_t gfp_mask)
182 struct es1_ap_dev *es1 = hd_to_es1(hd);
183 struct usb_device *udev = es1->usb_dev;
189 buffer = message->buffer;
190 buffer_size = sizeof(*message->header) + message->payload_size;
193 * The data actually transferred will include an indication
194 * of where the data should be sent. Do one last check of
195 * the target CPort id before filling it in.
197 if (cport_id == CPORT_ID_BAD) {
198 pr_err("request to send inbound data buffer\n");
199 return ERR_PTR(-EINVAL);
202 /* Find a free urb */
203 urb = next_free_urb(es1, gfp_mask);
205 return ERR_PTR(-ENOMEM);
208 * We (ab)use the operation-message header pad bytes to transfer the
209 * cport id in order to minimise overhead.
211 put_unaligned_le16(cport_id, message->header->pad);
213 usb_fill_bulk_urb(urb, udev,
214 usb_sndbulkpipe(udev, es1->cport_out_endpoint),
216 cport_out_callback, message);
217 retval = usb_submit_urb(urb, gfp_mask);
219 pr_err("error %d submitting URB\n", retval);
221 put_unaligned_le16(0, message->header->pad);
222 return ERR_PTR(retval);
229 * The cookie value supplied is the value that message_send()
230 * returned to its caller. It identifies the message that should be
231 * canceled. This function must also handle (which is to say,
232 * ignore) a null cookie value.
234 static void message_cancel(void *cookie)
238 * We really should be defensive and track all outstanding
239 * (sent) messages rather than trusting the cookie provided
240 * is valid. For the time being, this will do.
243 usb_kill_urb(cookie);
246 static struct greybus_host_driver es1_driver = {
247 .hd_priv_size = sizeof(struct es1_ap_dev),
248 .message_send = message_send,
249 .message_cancel = message_cancel,
250 .submit_svc = submit_svc,
253 /* Common function to report consistent warnings based on URB status */
254 static int check_urb_status(struct urb *urb)
256 struct device *dev = &urb->dev->dev;
257 int status = urb->status;
264 dev_err(dev, "%s: overflow actual length is %d\n",
265 __func__, urb->actual_length);
271 /* device is gone, stop sending */
274 dev_err(dev, "%s: unknown status %d\n", __func__, status);
279 static void ap_disconnect(struct usb_interface *interface)
281 struct es1_ap_dev *es1;
282 struct usb_device *udev;
285 es1 = usb_get_intfdata(interface);
289 usb_log_disable(es1);
291 /* Tear down everything! */
292 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
293 struct urb *urb = es1->cport_out_urb[i];
299 es1->cport_out_urb[i] = NULL;
300 es1->cport_out_urb_busy[i] = false; /* just to be anal */
303 for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
304 struct urb *urb = es1->cport_in_urb[i];
310 kfree(es1->cport_in_buffer[i]);
311 es1->cport_in_buffer[i] = NULL;
314 usb_kill_urb(es1->svc_urb);
315 usb_free_urb(es1->svc_urb);
317 kfree(es1->svc_buffer);
318 es1->svc_buffer = NULL;
320 usb_set_intfdata(interface, NULL);
322 greybus_remove_hd(es1->hd);
327 /* Callback for when we get a SVC message */
328 static void svc_in_callback(struct urb *urb)
330 struct greybus_host_device *hd = urb->context;
331 struct device *dev = &urb->dev->dev;
332 int status = check_urb_status(urb);
336 if ((status == -EAGAIN) || (status == -EPROTO))
338 dev_err(dev, "urb svc in error %d (dropped)\n", status);
342 /* We have a message, create a new message structure, add it to the
343 * list, and wake up our thread that will process the messages.
345 greybus_svc_in(hd, urb->transfer_buffer, urb->actual_length);
348 /* resubmit the urb to get more messages */
349 retval = usb_submit_urb(urb, GFP_ATOMIC);
351 dev_err(dev, "Can not submit urb for AP data: %d\n", retval);
354 static void cport_in_callback(struct urb *urb)
356 struct greybus_host_device *hd = urb->context;
357 struct device *dev = &urb->dev->dev;
358 struct gb_operation_msg_hdr *header;
359 int status = check_urb_status(urb);
364 if ((status == -EAGAIN) || (status == -EPROTO))
366 dev_err(dev, "urb cport in error %d (dropped)\n", status);
370 if (urb->actual_length < sizeof(*header)) {
371 dev_err(dev, "%s: short message received\n", __func__);
375 header = urb->transfer_buffer;
376 cport_id = get_unaligned_le16(header->pad);
377 put_unaligned_le16(0, header->pad);
379 greybus_data_rcvd(hd, cport_id, urb->transfer_buffer,
382 /* put our urb back in the request pool */
383 retval = usb_submit_urb(urb, GFP_ATOMIC);
385 dev_err(dev, "%s: error %d in submitting urb.\n",
389 static void cport_out_callback(struct urb *urb)
391 struct gb_message *message = urb->context;
392 struct greybus_host_device *hd = message->operation->connection->hd;
393 struct es1_ap_dev *es1 = hd_to_es1(hd);
394 int status = check_urb_status(urb);
396 /* Clear the pad bytes used for the cport id */
397 put_unaligned_le16(0, message->header->pad);
400 * Tell the submitter that the message send (attempt) is
401 * complete, and report the status.
403 greybus_message_sent(hd, message, status);
408 #define APB1_LOG_MSG_SIZE 64
409 static void apb1_log_get(struct es1_ap_dev *es1, char *buf)
413 /* SVC messages go down our control pipe */
415 retval = usb_control_msg(es1->usb_dev,
416 usb_rcvctrlpipe(es1->usb_dev,
417 es1->control_endpoint),
418 0x02, /* vendor request APB1 log */
419 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
425 kfifo_in(&apb1_log_fifo, buf, retval);
426 } while (retval > 0);
429 static int apb1_log_poll(void *data)
431 struct es1_ap_dev *es1 = data;
434 buf = kmalloc(APB1_LOG_MSG_SIZE, GFP_KERNEL);
438 while (!kthread_should_stop()) {
440 apb1_log_get(es1, buf);
448 static ssize_t apb1_log_read(struct file *f, char __user *buf,
449 size_t count, loff_t *ppos)
455 if (count > APB1_LOG_SIZE)
456 count = APB1_LOG_SIZE;
458 tmp_buf = kmalloc(count, GFP_KERNEL);
462 copied = kfifo_out(&apb1_log_fifo, tmp_buf, count);
463 ret = simple_read_from_buffer(buf, count, ppos, tmp_buf, copied);
470 static const struct file_operations apb1_log_fops = {
471 .read = apb1_log_read,
474 static void usb_log_enable(struct es1_ap_dev *es1)
476 if (!IS_ERR_OR_NULL(apb1_log_task))
479 /* get log from APB1 */
480 apb1_log_task = kthread_run(apb1_log_poll, es1, "apb1_log");
481 if (IS_ERR(apb1_log_task))
483 apb1_log_dentry = debugfs_create_file("apb1_log", S_IRUGO,
484 gb_debugfs_get(), NULL,
488 static void usb_log_disable(struct es1_ap_dev *es1)
490 if (IS_ERR_OR_NULL(apb1_log_task))
493 debugfs_remove(apb1_log_dentry);
494 apb1_log_dentry = NULL;
496 kthread_stop(apb1_log_task);
497 apb1_log_task = NULL;
500 static ssize_t apb1_log_enable_read(struct file *f, char __user *buf,
501 size_t count, loff_t *ppos)
504 int enable = !IS_ERR_OR_NULL(apb1_log_task);
506 sprintf(tmp_buf, "%d\n", enable);
507 return simple_read_from_buffer(buf, count, ppos, tmp_buf, 3);
510 static ssize_t apb1_log_enable_write(struct file *f, const char __user *buf,
511 size_t count, loff_t *ppos)
515 struct es1_ap_dev *es1 = (struct es1_ap_dev *)f->f_inode->i_private;
517 retval = kstrtoint_from_user(buf, count, 10, &enable);
524 usb_log_disable(es1);
529 static const struct file_operations apb1_log_enable_fops = {
530 .read = apb1_log_enable_read,
531 .write = apb1_log_enable_write,
535 * The ES1 USB Bridge device contains 4 endpoints
536 * 1 Control - usual USB stuff + AP -> SVC messages
537 * 1 Interrupt IN - SVC -> AP messages
538 * 1 Bulk IN - CPort data in
539 * 1 Bulk OUT - CPort data out
541 static int ap_probe(struct usb_interface *interface,
542 const struct usb_device_id *id)
544 struct es1_ap_dev *es1;
545 struct greybus_host_device *hd;
546 struct usb_device *udev;
547 struct usb_host_interface *iface_desc;
548 struct usb_endpoint_descriptor *endpoint;
549 bool int_in_found = false;
550 bool bulk_in_found = false;
551 bool bulk_out_found = false;
552 int retval = -ENOMEM;
554 u16 endo_id = 0x4755; // FIXME - get endo "ID" from the SVC
555 u8 ap_intf_id = 0x01; // FIXME - get endo "ID" from the SVC
558 udev = usb_get_dev(interface_to_usbdev(interface));
560 hd = greybus_create_hd(&es1_driver, &udev->dev, ES1_GBUF_MSG_SIZE_MAX);
568 es1->usb_intf = interface;
570 spin_lock_init(&es1->cport_out_urb_lock);
571 usb_set_intfdata(interface, es1);
573 /* Control endpoint is the pipe to talk to this AP, so save it off */
574 endpoint = &udev->ep0.desc;
575 es1->control_endpoint = endpoint->bEndpointAddress;
577 /* find all 3 of our endpoints */
578 iface_desc = interface->cur_altsetting;
579 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
580 endpoint = &iface_desc->endpoint[i].desc;
582 if (usb_endpoint_is_int_in(endpoint)) {
583 es1->svc_endpoint = endpoint->bEndpointAddress;
584 svc_interval = endpoint->bInterval;
586 } else if (usb_endpoint_is_bulk_in(endpoint)) {
587 es1->cport_in_endpoint = endpoint->bEndpointAddress;
588 bulk_in_found = true;
589 } else if (usb_endpoint_is_bulk_out(endpoint)) {
590 es1->cport_out_endpoint = endpoint->bEndpointAddress;
591 bulk_out_found = true;
594 "Unknown endpoint type found, address %x\n",
595 endpoint->bEndpointAddress);
598 if ((int_in_found == false) ||
599 (bulk_in_found == false) ||
600 (bulk_out_found == false)) {
601 dev_err(&udev->dev, "Not enough endpoints found in device, aborting!\n");
605 /* Create our buffer and URB to get SVC messages, and start it up */
606 es1->svc_buffer = kmalloc(ES1_SVC_MSG_SIZE, GFP_KERNEL);
607 if (!es1->svc_buffer)
610 es1->svc_urb = usb_alloc_urb(0, GFP_KERNEL);
614 usb_fill_int_urb(es1->svc_urb, udev,
615 usb_rcvintpipe(udev, es1->svc_endpoint),
616 es1->svc_buffer, ES1_SVC_MSG_SIZE, svc_in_callback,
619 /* Allocate buffers for our cport in messages and start them up */
620 for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
624 urb = usb_alloc_urb(0, GFP_KERNEL);
627 buffer = kmalloc(ES1_GBUF_MSG_SIZE_MAX, GFP_KERNEL);
631 usb_fill_bulk_urb(urb, udev,
632 usb_rcvbulkpipe(udev, es1->cport_in_endpoint),
633 buffer, ES1_GBUF_MSG_SIZE_MAX,
634 cport_in_callback, hd);
635 es1->cport_in_urb[i] = urb;
636 es1->cport_in_buffer[i] = buffer;
637 retval = usb_submit_urb(urb, GFP_KERNEL);
642 /* Allocate urbs for our CPort OUT messages */
643 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
646 urb = usb_alloc_urb(0, GFP_KERNEL);
650 es1->cport_out_urb[i] = urb;
651 es1->cport_out_urb_busy[i] = false; /* just to be anal */
654 /* Start up our svc urb, which allows events to start flowing */
655 retval = usb_submit_urb(es1->svc_urb, GFP_KERNEL);
659 apb1_log_enable_dentry = debugfs_create_file("apb1_log_enable",
661 gb_debugfs_get(), es1,
662 &apb1_log_enable_fops);
665 * XXX Soon this will be initiated later, with a combination
666 * XXX of a Control protocol probe operation and a
667 * XXX subsequent Control protocol connected operation for
668 * XXX the SVC connection. At that point we know we're
669 * XXX properly connected to an Endo.
671 retval = greybus_endo_setup(hd, endo_id, ap_intf_id);
677 ap_disconnect(interface);
682 static struct usb_driver es1_ap_driver = {
683 .name = "es2_ap_driver",
685 .disconnect = ap_disconnect,
686 .id_table = id_table,
689 module_usb_driver(es1_ap_driver);
691 MODULE_LICENSE("GPL v2");
692 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");