diff options
Diffstat (limited to 'drivers/usb/wusbcore/wa-nep.c')
| -rw-r--r-- | drivers/usb/wusbcore/wa-nep.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/usb/wusbcore/wa-nep.c b/drivers/usb/wusbcore/wa-nep.c new file mode 100644 index 000000000000..3f542990c73f --- /dev/null +++ b/drivers/usb/wusbcore/wa-nep.c @@ -0,0 +1,310 @@ +/* + * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8]) + * Notification EndPoint support + * + * Copyright (C) 2006 Intel Corporation + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * + * This part takes care of getting the notification from the hw + * only and dispatching through wusbwad into + * wa_notif_dispatch. Handling is done there. + * + * WA notifications are limited in size; most of them are three or + * four bytes long, and the longest is the HWA Device Notification, + * which would not exceed 38 bytes (DNs are limited in payload to 32 + * bytes plus 3 bytes header (WUSB1.0[7.6p2]), plus 3 bytes HWA + * header (WUSB1.0[8.5.4.2]). + * + * It is not clear if more than one Device Notification can be packed + * in a HWA Notification, I assume no because of the wording in + * WUSB1.0[8.5.4.2]. In any case, the bigger any notification could + * get is 256 bytes (as the bLength field is a byte). + * + * So what we do is we have this buffer and read into it; when a + * notification arrives we schedule work to a specific, single thread + * workqueue (so notifications are serialized) and copy the + * notification data. After scheduling the work, we rearm the read from + * the notification endpoint. + * + * Entry points here are: + * + * wa_nep_[create|destroy]() To initialize/release this subsystem + * + * wa_nep_cb() Callback for the notification + * endpoint; when data is ready, this + * does the dispatching. + */ +#include <linux/workqueue.h> +#include <linux/ctype.h> +#include <linux/uwb/debug.h> +#include "wa-hc.h" +#include "wusbhc.h" + +/* Structure for queueing notifications to the workqueue */ +struct wa_notif_work { + struct work_struct work; + struct wahc *wa; + size_t size; + u8 data[]; +}; + +/* + * Process incoming notifications from the WA's Notification EndPoint + * [the wuswad daemon, basically] + * + * @_nw: Pointer to a descriptor which has the pointer to the + * @wa, the size of the buffer and the work queue + * structure (so we can free all when done). + * @returns 0 if ok, < 0 errno code on error. + * + * All notifications follow the same format; they need to start with a + * 'struct wa_notif_hdr' header, so it is easy to parse through + * them. We just break the buffer in individual notifications (the + * standard doesn't say if it can be done or is forbidden, so we are + * cautious) and dispatch each. + * + * So the handling layers are is: + * + * WA specific notification (from NEP) + * Device Notification Received -> wa_handle_notif_dn() + * WUSB Device notification generic handling + * BPST Adjustment -> wa_handle_notif_bpst_adj() + * ... -> ... + * + * @wa has to be referenced + */ +static void wa_notif_dispatch(struct work_struct *ws) +{ + void *itr; + u8 missing = 0; + struct wa_notif_work *nw = container_of(ws, struct wa_notif_work, work); + struct wahc *wa = nw->wa; + struct wa_notif_hdr *notif_hdr; + size_t size; + + struct device *dev = &wa->usb_iface->dev; + +#if 0 + /* FIXME: need to check for this??? */ + if (usb_hcd->state == HC_STATE_QUIESCING) /* Going down? */ + goto out; /* screw it */ +#endif + atomic_dec(&wa->notifs_queued); /* Throttling ctl */ + dev = &wa->usb_iface->dev; + size = nw->size; + itr = nw->data; + + while (size) { + if (size < sizeof(*notif_hdr)) { + missing = sizeof(*notif_hdr) - size; + goto exhausted_buffer; + } + notif_hdr = itr; + if (size < notif_hdr->bLength) + goto exhausted_buffer; + itr += notif_hdr->bLength; + size -= notif_hdr->bLength; + /* Dispatch the notification [don't use itr or size!] */ + switch (notif_hdr->bNotifyType) { + case HWA_NOTIF_DN: { + struct hwa_notif_dn *hwa_dn; + hwa_dn = container_of(notif_hdr, struct hwa_notif_dn, + hdr); + wusbhc_handle_dn(wa->wusb, hwa_dn->bSourceDeviceAddr, + hwa_dn->dndata, + notif_hdr->bLength - sizeof(*hwa_dn)); + break; + } + case WA_NOTIF_TRANSFER: + wa_handle_notif_xfer(wa, notif_hdr); + break; + case DWA_NOTIF_RWAKE: + case DWA_NOTIF_PORTSTATUS: + case HWA_NOTIF_BPST_ADJ: + /* FIXME: unimplemented WA NOTIFs */ + /* fallthru */ + default: + if (printk_ratelimit()) { + dev_err(dev, "HWA: unknown notification 0x%x, " + "%zu bytes; discarding\n", + notif_hdr->bNotifyType, + (size_t)notif_hdr->bLength); + dump_bytes(dev, notif_hdr, 16); + } + break; + } + } +out: + wa_put(wa); + kfree(nw); + return; + + /* THIS SHOULD NOT HAPPEN + * + * Buffer exahusted with partial data remaining; just warn and + * discard the data, as this should not happen. + */ +exhausted_buffer: + if (!printk_ratelimit()) + goto out; + dev_warn(dev, "HWA: device sent short notification, " + "%d bytes missing; discarding %d bytes.\n", + missing, (int)size); + dump_bytes(dev, itr, size); + goto out; +} + +/* + * Deliver incoming WA notifications to the wusbwa workqueue + * + * @wa: Pointer the Wire Adapter Controller Data Streaming + * instance (part of an 'struct usb_hcd'). + * @size: Size of the received buffer + * @returns 0 if ok, < 0 errno code on error. + * + * The input buffer is @wa->nep_buffer, with @size bytes + * (guaranteed to fit in the allocated space, + * @wa->nep_buffer_size). + */ +static int wa_nep_queue(struct wahc *wa, size_t size) +{ + int result = 0; + struct device *dev = &wa->usb_iface->dev; + struct wa_notif_work *nw; + + /* dev_fnstart(dev, "(wa %p, size %zu)\n", wa, size); */ + BUG_ON(size > wa->nep_buffer_size); + if (size == 0) + goto out; + if (atomic_read(&wa->notifs_queued) > 200) { + if (printk_ratelimit()) + dev_err(dev, "Too many notifications queued, " + "throttling back\n"); + goto out; + } + nw = kzalloc(sizeof(*nw) + size, GFP_ATOMIC); + if (nw == NULL) { + if (printk_ratelimit()) + dev_err(dev, "No memory to queue notification\n"); + goto out; + } + INIT_WORK(&nw->work, wa_notif_dispatch); + nw->wa = wa_get(wa); + nw->size = size; + memcpy(nw->data, wa->nep_buffer, size); + atomic_inc(&wa->notifs_queued); /* Throttling ctl */ + queue_work(wusbd, &nw->work); +out: + /* dev_fnend(dev, "(wa %p, size %zu) = result\n", wa, size, result); */ + return result; +} + +/* + * Callback for the notification event endpoint + * + * Check's that everything is fine and then passes the data to be + * queued to the workqueue. + */ +static void wa_nep_cb(struct urb *urb) +{ + int result; + struct wahc *wa = urb->context; + struct device *dev = &wa->usb_iface->dev; + + switch (result = urb->status) { + case 0: + result = wa_nep_queue(wa, urb->actual_length); + if (result < 0) + dev_err(dev, "NEP: unable to process notification(s): " + "%d\n", result); + break; + case -ECONNRESET: /* Not an error, but a controlled situation; */ + case -ENOENT: /* (we killed the URB)...so, no broadcast */ + case -ESHUTDOWN: + dev_dbg(dev, "NEP: going down %d\n", urb->status); + goto out; + default: /* On general errors, we retry unless it gets ugly */ + if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS, + EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "NEP: URB max acceptable errors " + "exceeded, resetting device\n"); + wa_reset_all(wa); + goto out; + } + dev_err(dev, "NEP: URB error %d\n", urb->status); + } + result = wa_nep_arm(wa, GFP_ATOMIC); + if (result < 0) { + dev_err(dev, "NEP: cannot submit URB: %d\n", result); + wa_reset_all(wa); + } +out: + return; +} + +/* + * Initialize @wa's notification and event's endpoint stuff + * + * This includes the allocating the read buffer, the context ID + * allocation bitmap, the URB and submitting the URB. + */ +int wa_nep_create(struct wahc *wa, struct usb_interface *iface) +{ + int result; + struct usb_endpoint_descriptor *epd; + struct usb_device *usb_dev = interface_to_usbdev(iface); + struct device *dev = &iface->dev; + + edc_init(&wa->nep_edc); + epd = &iface->cur_altsetting->endpoint[0].desc; + wa->nep_buffer_size = 1024; + wa->nep_buffer = kmalloc(wa->nep_buffer_size, GFP_KERNEL); + if (wa->nep_buffer == NULL) { + dev_err(dev, "Unable to allocate notification's read buffer\n"); + goto error_nep_buffer; + } + wa->nep_urb = usb_alloc_urb(0, GFP_KERNEL); + if (wa->nep_urb == NULL) { + dev_err(dev, "Unable to allocate notification URB\n"); + goto error_urb_alloc; + } + usb_fill_int_urb(wa->nep_urb, usb_dev, + usb_rcvintpipe(usb_dev, epd->bEndpointAddress), + wa->nep_buffer, wa->nep_buffer_size, + wa_nep_cb, wa, epd->bInterval); + result = wa_nep_arm(wa, GFP_KERNEL); + if (result < 0) { + dev_err(dev, "Cannot submit notification URB: %d\n", result); + goto error_nep_arm; + } + return 0; + +error_nep_arm: + usb_free_urb(wa->nep_urb); +error_urb_alloc: + kfree(wa->nep_buffer); +error_nep_buffer: + return -ENOMEM; +} + +void wa_nep_destroy(struct wahc *wa) +{ + wa_nep_disarm(wa); + usb_free_urb(wa->nep_urb); + kfree(wa->nep_buffer); +} |