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>
22 #include "kernel_ver.h"
24 /* Memory sizes for the buffers sent to/from the ES1 controller */
25 #define ES1_SVC_MSG_SIZE (sizeof(struct svc_msg) + SZ_64K)
26 #define ES1_GBUF_MSG_SIZE_MAX PAGE_SIZE
28 static const struct usb_device_id id_table[] = {
29 /* Made up numbers for the SVC USB Bridge in ES2 */
30 { USB_DEVICE(0xffff, 0x0002) },
33 MODULE_DEVICE_TABLE(usb, id_table);
35 #define APB1_LOG_SIZE SZ_16K
36 static struct dentry *apb1_log_dentry;
37 static struct dentry *apb1_log_enable_dentry;
38 static struct task_struct *apb1_log_task;
39 static DEFINE_KFIFO(apb1_log_fifo, char, APB1_LOG_SIZE);
42 * Number of CPort IN urbs in flight at any point in time.
43 * Adjust if we are having stalls in the USB buffer due to not enough urbs in
46 #define NUM_CPORT_IN_URB 4
48 /* Number of CPort OUT urbs in flight at any point in time.
49 * Adjust if we get messages saying we are out of urbs in the system log.
51 #define NUM_CPORT_OUT_URB 8
54 * es1_ap_dev - ES1 USB Bridge to AP structure
55 * @usb_dev: pointer to the USB device we are.
56 * @usb_intf: pointer to the USB interface we are bound to.
57 * @hd: pointer to our greybus_host_device structure
58 * @control_endpoint: endpoint to send data to SVC
59 * @svc_endpoint: endpoint for SVC data in
60 * @cport_in_endpoint: bulk in endpoint for CPort data
61 * @cport-out_endpoint: bulk out endpoint for CPort data
62 * @svc_buffer: buffer for SVC messages coming in on @svc_endpoint
63 * @svc_urb: urb for SVC messages coming in on @svc_endpoint
64 * @cport_in_urb: array of urbs for the CPort in messages
65 * @cport_in_buffer: array of buffers for the @cport_in_urb urbs
66 * @cport_out_urb: array of urbs for the CPort out messages
67 * @cport_out_urb_busy: array of flags to see if the @cport_out_urb is busy or
69 * @cport_out_urb_lock: locks the @cport_out_urb_busy "list"
72 struct usb_device *usb_dev;
73 struct usb_interface *usb_intf;
74 struct greybus_host_device *hd;
76 __u8 control_endpoint;
78 __u8 cport_in_endpoint;
79 __u8 cport_out_endpoint;
84 struct urb *cport_in_urb[NUM_CPORT_IN_URB];
85 u8 *cport_in_buffer[NUM_CPORT_IN_URB];
86 struct urb *cport_out_urb[NUM_CPORT_OUT_URB];
87 bool cport_out_urb_busy[NUM_CPORT_OUT_URB];
88 spinlock_t cport_out_urb_lock;
91 static inline struct es1_ap_dev *hd_to_es1(struct greybus_host_device *hd)
93 return (struct es1_ap_dev *)&hd->hd_priv;
96 static void cport_out_callback(struct urb *urb);
97 static void usb_log_enable(struct es1_ap_dev *es1);
98 static void usb_log_disable(struct es1_ap_dev *es1);
101 * Buffer constraints for the host driver.
103 * A "buffer" is used to hold data to be transferred for Greybus by
104 * the host driver. A buffer is represented by a "buffer pointer",
105 * which defines a region of memory used by the host driver for
106 * transferring the data. When Greybus allocates a buffer, it must
107 * do so subject to the constraints associated with the host driver.
108 * These constraints are specified by two parameters: the
109 * headroom; and the maximum buffer size.
111 * +------------------+
113 * | reserved area | }- headroom
115 * buffer pointer ---> +------------------+
116 * | Buffer space for | \
117 * | transferred data | }- buffer size
118 * | . . . | / (limited to size_max)
119 * +------------------+
121 * headroom: Every buffer must have at least this much space
122 * *before* the buffer pointer, reserved for use by the
123 * host driver. I.e., ((char *)buffer - headroom) must
124 * point to valid memory, usable only by the host driver.
125 * size_max: The maximum size of a buffer (not including the
126 * headroom) must not exceed this.
128 static void hd_buffer_constraints(struct greybus_host_device *hd)
131 * Only one byte is required, but this produces a result
132 * that's better aligned for the user.
134 hd->buffer_headroom = sizeof(u32); /* For cport id */
135 hd->buffer_size_max = ES1_GBUF_MSG_SIZE_MAX;
136 BUILD_BUG_ON(hd->buffer_headroom > GB_BUFFER_HEADROOM_MAX);
139 #define ES1_TIMEOUT 500 /* 500 ms for the SVC to do something */
140 static int submit_svc(struct svc_msg *svc_msg, struct greybus_host_device *hd)
142 struct es1_ap_dev *es1 = hd_to_es1(hd);
145 /* SVC messages go down our control pipe */
146 retval = usb_control_msg(es1->usb_dev,
147 usb_sndctrlpipe(es1->usb_dev,
148 es1->control_endpoint),
149 0x01, /* vendor request AP message */
150 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
155 if (retval != sizeof(*svc_msg))
161 static struct urb *next_free_urb(struct es1_ap_dev *es1, gfp_t gfp_mask)
163 struct urb *urb = NULL;
167 spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
169 /* Look in our pool of allocated urbs first, as that's the "fastest" */
170 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
171 if (es1->cport_out_urb_busy[i] == false) {
172 es1->cport_out_urb_busy[i] = true;
173 urb = es1->cport_out_urb[i];
177 spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
182 * Crap, pool is empty, complain to the syslog and go allocate one
183 * dynamically as we have to succeed.
185 dev_err(&es1->usb_dev->dev,
186 "No free CPort OUT urbs, having to dynamically allocate one!\n");
187 return usb_alloc_urb(0, gfp_mask);
190 static void free_urb(struct es1_ap_dev *es1, struct urb *urb)
195 * See if this was an urb in our pool, if so mark it "free", otherwise
196 * we need to free it ourselves.
198 spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
199 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
200 if (urb == es1->cport_out_urb[i]) {
201 es1->cport_out_urb_busy[i] = false;
206 spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
208 /* If urb is not NULL, then we need to free this urb */
213 * Returns an opaque cookie value if successful, or a pointer coded
214 * error otherwise. If the caller wishes to cancel the in-flight
215 * buffer, it must supply the returned cookie to the cancel routine.
217 static void *buffer_send(struct greybus_host_device *hd, u16 cport_id,
218 void *buffer, size_t buffer_size, gfp_t gfp_mask)
220 struct es1_ap_dev *es1 = hd_to_es1(hd);
221 struct usb_device *udev = es1->usb_dev;
222 u8 *transfer_buffer = buffer;
223 int transfer_buffer_size;
228 pr_err("null buffer supplied to send\n");
229 return ERR_PTR(-EINVAL);
231 if (buffer_size > (size_t)INT_MAX) {
232 pr_err("bad buffer size (%zu) supplied to send\n", buffer_size);
233 return ERR_PTR(-EINVAL);
236 transfer_buffer_size = buffer_size + 1;
239 * The data actually transferred will include an indication
240 * of where the data should be sent. Do one last check of
241 * the target CPort id before filling it in.
243 if (cport_id == CPORT_ID_BAD) {
244 pr_err("request to send inbound data buffer\n");
245 return ERR_PTR(-EINVAL);
247 if (cport_id > (u16)U8_MAX) {
248 pr_err("cport_id (%hd) is out of range for ES1\n", cport_id);
249 return ERR_PTR(-EINVAL);
251 /* OK, the destination is fine; record it in the transfer buffer */
252 *transfer_buffer = cport_id;
254 /* Find a free urb */
255 urb = next_free_urb(es1, gfp_mask);
257 return ERR_PTR(-ENOMEM);
259 usb_fill_bulk_urb(urb, udev,
260 usb_sndbulkpipe(udev, es1->cport_out_endpoint),
261 transfer_buffer, transfer_buffer_size,
262 cport_out_callback, hd);
263 retval = usb_submit_urb(urb, gfp_mask);
265 pr_err("error %d submitting URB\n", retval);
267 return ERR_PTR(retval);
274 * The cookie value supplied is the value that buffer_send()
275 * returned to its caller. It identifies the buffer that should be
276 * canceled. This function must also handle (which is to say,
277 * ignore) a null cookie value.
279 static void buffer_cancel(void *cookie)
283 * We really should be defensive and track all outstanding
284 * (sent) buffers rather than trusting the cookie provided
285 * is valid. For the time being, this will do.
288 usb_kill_urb(cookie);
291 static struct greybus_host_driver es1_driver = {
292 .hd_priv_size = sizeof(struct es1_ap_dev),
293 .buffer_send = buffer_send,
294 .buffer_cancel = buffer_cancel,
295 .submit_svc = submit_svc,
298 /* Common function to report consistent warnings based on URB status */
299 static int check_urb_status(struct urb *urb)
301 struct device *dev = &urb->dev->dev;
302 int status = urb->status;
309 dev_err(dev, "%s: overflow actual length is %d\n",
310 __func__, urb->actual_length);
316 /* device is gone, stop sending */
319 dev_err(dev, "%s: unknown status %d\n", __func__, status);
324 static void ap_disconnect(struct usb_interface *interface)
326 struct es1_ap_dev *es1;
327 struct usb_device *udev;
330 es1 = usb_get_intfdata(interface);
334 usb_log_disable(es1);
336 /* Tear down everything! */
337 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
338 struct urb *urb = es1->cport_out_urb[i];
344 es1->cport_out_urb[i] = NULL;
345 es1->cport_out_urb_busy[i] = false; /* just to be anal */
348 for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
349 struct urb *urb = es1->cport_in_urb[i];
355 kfree(es1->cport_in_buffer[i]);
356 es1->cport_in_buffer[i] = NULL;
359 usb_kill_urb(es1->svc_urb);
360 usb_free_urb(es1->svc_urb);
362 kfree(es1->svc_buffer);
363 es1->svc_buffer = NULL;
365 usb_set_intfdata(interface, NULL);
367 greybus_remove_hd(es1->hd);
372 /* Callback for when we get a SVC message */
373 static void svc_in_callback(struct urb *urb)
375 struct greybus_host_device *hd = urb->context;
376 struct device *dev = &urb->dev->dev;
377 int status = check_urb_status(urb);
381 if ((status == -EAGAIN) || (status == -EPROTO))
383 dev_err(dev, "urb svc in error %d (dropped)\n", status);
387 /* We have a message, create a new message structure, add it to the
388 * list, and wake up our thread that will process the messages.
390 greybus_svc_in(hd, urb->transfer_buffer, urb->actual_length);
393 /* resubmit the urb to get more messages */
394 retval = usb_submit_urb(urb, GFP_ATOMIC);
396 dev_err(dev, "Can not submit urb for AP data: %d\n", retval);
399 static void cport_in_callback(struct urb *urb)
401 struct greybus_host_device *hd = urb->context;
402 struct device *dev = &urb->dev->dev;
403 int status = check_urb_status(urb);
409 if ((status == -EAGAIN) || (status == -EPROTO))
411 dev_err(dev, "urb cport in error %d (dropped)\n", status);
415 /* The size has to be at least one, for the cport id */
416 if (!urb->actual_length) {
417 dev_err(dev, "%s: no cport id in input buffer?\n", __func__);
422 * Our CPort number is the first byte of the data stream,
423 * the rest of the stream is "real" data
425 data = urb->transfer_buffer;
426 cport_id = (u16)data[0];
429 /* Pass this data to the greybus core */
430 greybus_data_rcvd(hd, cport_id, data, urb->actual_length - 1);
433 /* put our urb back in the request pool */
434 retval = usb_submit_urb(urb, GFP_ATOMIC);
436 dev_err(dev, "%s: error %d in submitting urb.\n",
440 static void cport_out_callback(struct urb *urb)
442 struct greybus_host_device *hd = urb->context;
443 struct es1_ap_dev *es1 = hd_to_es1(hd);
444 int status = check_urb_status(urb);
445 u8 *data = urb->transfer_buffer + 1;
448 * Tell the submitter that the buffer send (attempt) is
449 * complete, and report the status. The submitter's buffer
450 * starts after the one-byte CPort id we inserted.
452 data = urb->transfer_buffer + 1;
453 greybus_data_sent(hd, data, status);
457 static void apb1_log_get(struct es1_ap_dev *es1)
462 /* SVC messages go down our control pipe */
465 retval = usb_control_msg(es1->usb_dev,
466 usb_rcvctrlpipe(es1->usb_dev,
467 es1->control_endpoint),
468 0x02, /* vendor request APB1 log */
469 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
475 kfifo_in(&apb1_log_fifo, buf, retval);
476 } while (retval > 0);
479 static int apb1_log_poll(void *data)
481 while (!kthread_should_stop()) {
483 apb1_log_get((struct es1_ap_dev *)data);
488 static ssize_t apb1_log_read(struct file *f, char __user *buf,
489 size_t count, loff_t *ppos)
495 if (count > APB1_LOG_SIZE)
496 count = APB1_LOG_SIZE;
498 tmp_buf = kmalloc(count, GFP_KERNEL);
502 copied = kfifo_out(&apb1_log_fifo, tmp_buf, count);
503 ret = simple_read_from_buffer(buf, count, ppos, tmp_buf, copied);
510 static const struct file_operations apb1_log_fops = {
511 .read = apb1_log_read,
514 static void usb_log_enable(struct es1_ap_dev *es1)
516 if (!IS_ERR_OR_NULL(apb1_log_task))
519 /* get log from APB1 */
520 apb1_log_task = kthread_run(apb1_log_poll, es1, "apb1_log");
521 if (IS_ERR(apb1_log_task))
523 apb1_log_dentry = debugfs_create_file("apb1_log", S_IRUGO,
524 gb_debugfs_get(), NULL,
528 static void usb_log_disable(struct es1_ap_dev *es1)
530 if (IS_ERR_OR_NULL(apb1_log_task))
533 debugfs_remove(apb1_log_dentry);
534 apb1_log_dentry = NULL;
536 kthread_stop(apb1_log_task);
537 apb1_log_task = NULL;
540 static ssize_t apb1_log_enable_read(struct file *f, char __user *buf,
541 size_t count, loff_t *ppos)
544 int enable = !IS_ERR_OR_NULL(apb1_log_task);
546 sprintf(tmp_buf, "%d\n", enable);
547 return simple_read_from_buffer(buf, count, ppos, tmp_buf, 3);
550 static ssize_t apb1_log_enable_write(struct file *f, const char __user *buf,
551 size_t count, loff_t *ppos)
555 struct es1_ap_dev *es1 = (struct es1_ap_dev *)f->f_inode->i_private;
557 retval = kstrtoint_from_user(buf, count, 10, &enable);
564 usb_log_disable(es1);
569 static const struct file_operations apb1_log_enable_fops = {
570 .read = apb1_log_enable_read,
571 .write = apb1_log_enable_write,
575 * The ES1 USB Bridge device contains 4 endpoints
576 * 1 Control - usual USB stuff + AP -> SVC messages
577 * 1 Interrupt IN - SVC -> AP messages
578 * 1 Bulk IN - CPort data in
579 * 1 Bulk OUT - CPort data out
581 static int ap_probe(struct usb_interface *interface,
582 const struct usb_device_id *id)
584 struct es1_ap_dev *es1;
585 struct greybus_host_device *hd;
586 struct usb_device *udev;
587 struct usb_host_interface *iface_desc;
588 struct usb_endpoint_descriptor *endpoint;
589 bool int_in_found = false;
590 bool bulk_in_found = false;
591 bool bulk_out_found = false;
592 int retval = -ENOMEM;
596 udev = usb_get_dev(interface_to_usbdev(interface));
598 hd = greybus_create_hd(&es1_driver, &udev->dev);
604 /* Fill in the buffer allocation constraints */
605 hd_buffer_constraints(hd);
609 es1->usb_intf = interface;
611 spin_lock_init(&es1->cport_out_urb_lock);
612 usb_set_intfdata(interface, es1);
614 /* Control endpoint is the pipe to talk to this AP, so save it off */
615 endpoint = &udev->ep0.desc;
616 es1->control_endpoint = endpoint->bEndpointAddress;
618 /* find all 3 of our endpoints */
619 iface_desc = interface->cur_altsetting;
620 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
621 endpoint = &iface_desc->endpoint[i].desc;
623 if (usb_endpoint_is_int_in(endpoint)) {
624 es1->svc_endpoint = endpoint->bEndpointAddress;
625 svc_interval = endpoint->bInterval;
627 } else if (usb_endpoint_is_bulk_in(endpoint)) {
628 es1->cport_in_endpoint = endpoint->bEndpointAddress;
629 bulk_in_found = true;
630 } else if (usb_endpoint_is_bulk_out(endpoint)) {
631 es1->cport_out_endpoint = endpoint->bEndpointAddress;
632 bulk_out_found = true;
635 "Unknown endpoint type found, address %x\n",
636 endpoint->bEndpointAddress);
639 if ((int_in_found == false) ||
640 (bulk_in_found == false) ||
641 (bulk_out_found == false)) {
642 dev_err(&udev->dev, "Not enough endpoints found in device, aborting!\n");
646 /* Create our buffer and URB to get SVC messages, and start it up */
647 es1->svc_buffer = kmalloc(ES1_SVC_MSG_SIZE, GFP_KERNEL);
648 if (!es1->svc_buffer)
651 es1->svc_urb = usb_alloc_urb(0, GFP_KERNEL);
655 usb_fill_int_urb(es1->svc_urb, udev,
656 usb_rcvintpipe(udev, es1->svc_endpoint),
657 es1->svc_buffer, ES1_SVC_MSG_SIZE, svc_in_callback,
660 /* Allocate buffers for our cport in messages and start them up */
661 for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
665 urb = usb_alloc_urb(0, GFP_KERNEL);
668 buffer = kmalloc(ES1_GBUF_MSG_SIZE_MAX, GFP_KERNEL);
672 usb_fill_bulk_urb(urb, udev,
673 usb_rcvbulkpipe(udev, es1->cport_in_endpoint),
674 buffer, ES1_GBUF_MSG_SIZE_MAX,
675 cport_in_callback, hd);
676 es1->cport_in_urb[i] = urb;
677 es1->cport_in_buffer[i] = buffer;
678 retval = usb_submit_urb(urb, GFP_KERNEL);
683 /* Allocate urbs for our CPort OUT messages */
684 for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
687 urb = usb_alloc_urb(0, GFP_KERNEL);
691 es1->cport_out_urb[i] = urb;
692 es1->cport_out_urb_busy[i] = false; /* just to be anal */
695 /* Start up our svc urb, which allows events to start flowing */
696 retval = usb_submit_urb(es1->svc_urb, GFP_KERNEL);
700 apb1_log_enable_dentry = debugfs_create_file("apb1_log_enable",
702 gb_debugfs_get(), es1,
703 &apb1_log_enable_fops);
707 ap_disconnect(interface);
712 static struct usb_driver es1_ap_driver = {
713 .name = "es1_ap_driver",
715 .disconnect = ap_disconnect,
716 .id_table = id_table,
719 module_usb_driver(es1_ap_driver);
721 MODULE_LICENSE("GPL");
722 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");