diff options
Diffstat (limited to 'drivers/uwb/hwa-rc.c')
| -rw-r--r-- | drivers/uwb/hwa-rc.c | 911 |
1 files changed, 911 insertions, 0 deletions
diff --git a/drivers/uwb/hwa-rc.c b/drivers/uwb/hwa-rc.c new file mode 100644 index 000000000000..f822a1872e49 --- /dev/null +++ b/drivers/uwb/hwa-rc.c @@ -0,0 +1,911 @@ +/* + * WUSB Host Wire Adapter: Radio Control Interface (WUSB[8.6]) + * Radio Control command/event transport + * + * Copyright (C) 2005-2006 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. + * + * + * Initialize the Radio Control interface Driver. + * + * For each device probed, creates an 'struct hwarc' which contains + * just the representation of the UWB Radio Controller, and the logic + * for reading notifications and passing them to the UWB Core. + * + * So we initialize all of those, register the UWB Radio Controller + * and setup the notification/event handle to pipe the notifications + * to the UWB management Daemon. + * + * Command and event filtering. + * + * This is the driver for the Radio Control Interface described in WUSB + * 1.0. The core UWB module assumes that all drivers are compliant to the + * WHCI 0.95 specification. We thus create a filter that parses all + * incoming messages from the (WUSB 1.0) device and manipulate them to + * conform to the WHCI 0.95 specification. Similarly, outgoing messages + * are parsed and manipulated to conform to the WUSB 1.0 compliant messages + * that the device expects. Only a few messages are affected: + * Affected events: + * UWB_RC_EVT_BEACON + * UWB_RC_EVT_BP_SLOT_CHANGE + * UWB_RC_EVT_DRP_AVAIL + * UWB_RC_EVT_DRP + * Affected commands: + * UWB_RC_CMD_SCAN + * UWB_RC_CMD_SET_DRP_IE + * + * + * + */ +#include <linux/version.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/usb.h> +#include <linux/usb/wusb.h> +#include <linux/usb/wusb-wa.h> +#include <linux/uwb.h> +#include "uwb-internal.h" +#define D_LOCAL 1 +#include <linux/uwb/debug.h> + + +/** + * Descriptor for an instance of the UWB Radio Control Driver that + * attaches to the RCI interface of the Host Wired Adapter. + * + * Unless there is a lock specific to the 'data members', all access + * is protected by uwb_rc->mutex. + * + * The NEEP (Notification/Event EndPoint) URB (@neep_urb) writes to + * @rd_buffer. Note there is no locking because it is perfectly (heh!) + * serialized--probe() submits an URB, callback is called, processes + * the data (synchronously), submits another URB, and so on. There is + * no concurrent access to the buffer. + */ +struct hwarc { + struct usb_device *usb_dev; + struct usb_interface *usb_iface; + struct uwb_rc *uwb_rc; /* UWB host controller */ + struct urb *neep_urb; /* Notification endpoint handling */ + struct edc neep_edc; + void *rd_buffer; /* NEEP read buffer */ +}; + + +/* Beacon received notification (WUSB 1.0 [8.6.3.2]) */ +struct uwb_rc_evt_beacon_WUSB_0100 { + struct uwb_rceb rceb; + u8 bChannelNumber; + __le16 wBPSTOffset; + u8 bLQI; + u8 bRSSI; + __le16 wBeaconInfoLength; + u8 BeaconInfo[]; +} __attribute__((packed)); + +/** + * Filter WUSB 1.0 BEACON RCV notification to be WHCI 0.95 + * + * @header: the incoming event + * @buf_size: size of buffer containing incoming event + * @new_size: size of event after filtering completed + * + * The WHCI 0.95 spec has a "Beacon Type" field. This value is unknown at + * the time we receive the beacon from WUSB so we just set it to + * UWB_RC_BEACON_TYPE_NEIGHBOR as a default. + * The solution below allocates memory upon receipt of every beacon from a + * WUSB device. This will deteriorate performance. What is the right way to + * do this? + */ +static +int hwarc_filter_evt_beacon_WUSB_0100(struct uwb_rc *rc, + struct uwb_rceb **header, + const size_t buf_size, + size_t *new_size) +{ + struct uwb_rc_evt_beacon_WUSB_0100 *be; + struct uwb_rc_evt_beacon *newbe; + size_t bytes_left, ielength; + struct device *dev = &rc->uwb_dev.dev; + + be = container_of(*header, struct uwb_rc_evt_beacon_WUSB_0100, rceb); + bytes_left = buf_size; + if (bytes_left < sizeof(*be)) { + dev_err(dev, "Beacon Received Notification: Not enough data " + "to decode for filtering (%zu vs %zu bytes needed)\n", + bytes_left, sizeof(*be)); + return -EINVAL; + } + bytes_left -= sizeof(*be); + ielength = le16_to_cpu(be->wBeaconInfoLength); + if (bytes_left < ielength) { + dev_err(dev, "Beacon Received Notification: Not enough data " + "to decode IEs (%zu vs %zu bytes needed)\n", + bytes_left, ielength); + return -EINVAL; + } + newbe = kzalloc(sizeof(*newbe) + ielength, GFP_ATOMIC); + if (newbe == NULL) + return -ENOMEM; + newbe->rceb = be->rceb; + newbe->bChannelNumber = be->bChannelNumber; + newbe->bBeaconType = UWB_RC_BEACON_TYPE_NEIGHBOR; + newbe->wBPSTOffset = be->wBPSTOffset; + newbe->bLQI = be->bLQI; + newbe->bRSSI = be->bRSSI; + newbe->wBeaconInfoLength = be->wBeaconInfoLength; + memcpy(newbe->BeaconInfo, be->BeaconInfo, ielength); + *header = &newbe->rceb; + *new_size = sizeof(*newbe) + ielength; + return 1; /* calling function will free memory */ +} + + +/* DRP Availability change notification (WUSB 1.0 [8.6.3.8]) */ +struct uwb_rc_evt_drp_avail_WUSB_0100 { + struct uwb_rceb rceb; + __le16 wIELength; + u8 IEData[]; +} __attribute__((packed)); + +/** + * Filter WUSB 1.0 DRP AVAILABILITY CHANGE notification to be WHCI 0.95 + * + * @header: the incoming event + * @buf_size: size of buffer containing incoming event + * @new_size: size of event after filtering completed + */ +static +int hwarc_filter_evt_drp_avail_WUSB_0100(struct uwb_rc *rc, + struct uwb_rceb **header, + const size_t buf_size, + size_t *new_size) +{ + struct uwb_rc_evt_drp_avail_WUSB_0100 *da; + struct uwb_rc_evt_drp_avail *newda; + struct uwb_ie_hdr *ie_hdr; + size_t bytes_left, ielength; + struct device *dev = &rc->uwb_dev.dev; + + + da = container_of(*header, struct uwb_rc_evt_drp_avail_WUSB_0100, rceb); + bytes_left = buf_size; + if (bytes_left < sizeof(*da)) { + dev_err(dev, "Not enough data to decode DRP Avail " + "Notification for filtering. Expected %zu, " + "received %zu.\n", (size_t)sizeof(*da), bytes_left); + return -EINVAL; + } + bytes_left -= sizeof(*da); + ielength = le16_to_cpu(da->wIELength); + if (bytes_left < ielength) { + dev_err(dev, "DRP Avail Notification filter: IE length " + "[%zu bytes] does not match actual length " + "[%zu bytes].\n", ielength, bytes_left); + return -EINVAL; + } + if (ielength < sizeof(*ie_hdr)) { + dev_err(dev, "DRP Avail Notification filter: Not enough " + "data to decode IE [%zu bytes, %zu needed]\n", + ielength, sizeof(*ie_hdr)); + return -EINVAL; + } + ie_hdr = (void *) da->IEData; + if (ie_hdr->length > 32) { + dev_err(dev, "DRP Availability Change event has unexpected " + "length for filtering. Expected < 32 bytes, " + "got %zu bytes.\n", (size_t)ie_hdr->length); + return -EINVAL; + } + newda = kzalloc(sizeof(*newda), GFP_ATOMIC); + if (newda == NULL) + return -ENOMEM; + newda->rceb = da->rceb; + memcpy(newda->bmp, (u8 *) ie_hdr + sizeof(*ie_hdr), ie_hdr->length); + *header = &newda->rceb; + *new_size = sizeof(*newda); + return 1; /* calling function will free memory */ +} + + +/* DRP notification (WUSB 1.0 [8.6.3.9]) */ +struct uwb_rc_evt_drp_WUSB_0100 { + struct uwb_rceb rceb; + struct uwb_dev_addr wSrcAddr; + u8 bExplicit; + __le16 wIELength; + u8 IEData[]; +} __attribute__((packed)); + +/** + * Filter WUSB 1.0 DRP Notification to be WHCI 0.95 + * + * @header: the incoming event + * @buf_size: size of buffer containing incoming event + * @new_size: size of event after filtering completed + * + * It is hard to manage DRP reservations without having a Reason code. + * Unfortunately there is none in the WUSB spec. We just set the default to + * DRP IE RECEIVED. + * We do not currently use the bBeaconSlotNumber value, so we set this to + * zero for now. + */ +static +int hwarc_filter_evt_drp_WUSB_0100(struct uwb_rc *rc, + struct uwb_rceb **header, + const size_t buf_size, + size_t *new_size) +{ + struct uwb_rc_evt_drp_WUSB_0100 *drpev; + struct uwb_rc_evt_drp *newdrpev; + size_t bytes_left, ielength; + struct device *dev = &rc->uwb_dev.dev; + + drpev = container_of(*header, struct uwb_rc_evt_drp_WUSB_0100, rceb); + bytes_left = buf_size; + if (bytes_left < sizeof(*drpev)) { + dev_err(dev, "Not enough data to decode DRP Notification " + "for filtering. Expected %zu, received %zu.\n", + (size_t)sizeof(*drpev), bytes_left); + return -EINVAL; + } + ielength = le16_to_cpu(drpev->wIELength); + bytes_left -= sizeof(*drpev); + if (bytes_left < ielength) { + dev_err(dev, "DRP Notification filter: header length [%zu " + "bytes] does not match actual length [%zu " + "bytes].\n", ielength, bytes_left); + return -EINVAL; + } + newdrpev = kzalloc(sizeof(*newdrpev) + ielength, GFP_ATOMIC); + if (newdrpev == NULL) + return -ENOMEM; + newdrpev->rceb = drpev->rceb; + newdrpev->src_addr = drpev->wSrcAddr; + newdrpev->reason = UWB_DRP_NOTIF_DRP_IE_RCVD; + newdrpev->beacon_slot_number = 0; + newdrpev->ie_length = drpev->wIELength; + memcpy(newdrpev->ie_data, drpev->IEData, ielength); + *header = &newdrpev->rceb; + *new_size = sizeof(*newdrpev) + ielength; + return 1; /* calling function will free memory */ +} + + +/* Scan Command (WUSB 1.0 [8.6.2.5]) */ +struct uwb_rc_cmd_scan_WUSB_0100 { + struct uwb_rccb rccb; + u8 bChannelNumber; + u8 bScanState; +} __attribute__((packed)); + +/** + * Filter WHCI 0.95 SCAN command to be WUSB 1.0 SCAN command + * + * @header: command sent to device (compliant to WHCI 0.95) + * @size: size of command sent to device + * + * We only reduce the size by two bytes because the WUSB 1.0 scan command + * does not have the last field (wStarttime). Also, make sure we don't send + * the device an unexpected scan type. + */ +static +int hwarc_filter_cmd_scan_WUSB_0100(struct uwb_rc *rc, + struct uwb_rccb **header, + size_t *size) +{ + struct uwb_rc_cmd_scan *sc; + + sc = container_of(*header, struct uwb_rc_cmd_scan, rccb); + + if (sc->bScanState == UWB_SCAN_ONLY_STARTTIME) + sc->bScanState = UWB_SCAN_ONLY; + /* Don't send the last two bytes. */ + *size -= 2; + return 0; +} + + +/* SET DRP IE command (WUSB 1.0 [8.6.2.7]) */ +struct uwb_rc_cmd_set_drp_ie_WUSB_0100 { + struct uwb_rccb rccb; + u8 bExplicit; + __le16 wIELength; + struct uwb_ie_drp IEData[]; +} __attribute__((packed)); + +/** + * Filter WHCI 0.95 SET DRP IE command to be WUSB 1.0 SET DRP IE command + * + * @header: command sent to device (compliant to WHCI 0.95) + * @size: size of command sent to device + * + * WUSB has an extra bExplicit field - we assume always explicit + * negotiation so this field is set. The command expected by the device is + * thus larger than the one prepared by the driver so we need to + * reallocate memory to accommodate this. + * We trust the driver to send us the correct data so no checking is done + * on incoming data - evn though it is variable length. + */ +static +int hwarc_filter_cmd_set_drp_ie_WUSB_0100(struct uwb_rc *rc, + struct uwb_rccb **header, + size_t *size) +{ + struct uwb_rc_cmd_set_drp_ie *orgcmd; + struct uwb_rc_cmd_set_drp_ie_WUSB_0100 *cmd; + size_t ielength; + + orgcmd = container_of(*header, struct uwb_rc_cmd_set_drp_ie, rccb); + ielength = le16_to_cpu(orgcmd->wIELength); + cmd = kzalloc(sizeof(*cmd) + ielength, GFP_KERNEL); + if (cmd == NULL) + return -ENOMEM; + cmd->rccb = orgcmd->rccb; + cmd->bExplicit = 0; + cmd->wIELength = orgcmd->wIELength; + memcpy(cmd->IEData, orgcmd->IEData, ielength); + *header = &cmd->rccb; + *size = sizeof(*cmd) + ielength; + return 1; /* calling function will free memory */ +} + + +/** + * Filter data from WHCI driver to WUSB device + * + * @header: WHCI 0.95 compliant command from driver + * @size: length of command + * + * The routine managing commands to the device (uwb_rc_cmd()) will call the + * filtering function pointer (if it exists) before it passes any data to + * the device. At this time the command has been formatted according to + * WHCI 0.95 and is ready to be sent to the device. + * + * The filter function will be provided with the current command and its + * length. The function will manipulate the command if necessary and + * potentially reallocate memory for a command that needed more memory that + * the given command. If new memory was created the function will return 1 + * to indicate to the calling function that the memory need to be freed + * when not needed any more. The size will contain the new length of the + * command. + * If memory has not been allocated we rely on the original mechanisms to + * free the memory of the command - even when we reduce the value of size. + */ +static +int hwarc_filter_cmd_WUSB_0100(struct uwb_rc *rc, struct uwb_rccb **header, + size_t *size) +{ + int result; + struct uwb_rccb *rccb = *header; + int cmd = le16_to_cpu(rccb->wCommand); + switch (cmd) { + case UWB_RC_CMD_SCAN: + result = hwarc_filter_cmd_scan_WUSB_0100(rc, header, size); + break; + case UWB_RC_CMD_SET_DRP_IE: + result = hwarc_filter_cmd_set_drp_ie_WUSB_0100(rc, header, size); + break; + default: + result = -ENOANO; + break; + } + return result; +} + + +/** + * Filter data from WHCI driver to WUSB device + * + * @header: WHCI 0.95 compliant command from driver + * @size: length of command + * + * Filter commands based on which protocol the device supports. The WUSB + * errata should be the same as WHCI 0.95 so we do not filter that here - + * only WUSB 1.0. + */ +static +int hwarc_filter_cmd(struct uwb_rc *rc, struct uwb_rccb **header, + size_t *size) +{ + int result = -ENOANO; + if (rc->version == 0x0100) + result = hwarc_filter_cmd_WUSB_0100(rc, header, size); + return result; +} + + +/** + * Compute return value as sum of incoming value and value at given offset + * + * @rceb: event for which we compute the size, it contains a variable + * length field. + * @core_size: size of the "non variable" part of the event + * @offset: place in event where the length of the variable part is stored + * @buf_size: total length of buffer in which event arrived - we need to make + * sure we read the offset in memory that is still part of the event + */ +static +ssize_t hwarc_get_event_size(struct uwb_rc *rc, const struct uwb_rceb *rceb, + size_t core_size, size_t offset, + const size_t buf_size) +{ + ssize_t size = -ENOSPC; + const void *ptr = rceb; + size_t type_size = sizeof(__le16); + struct device *dev = &rc->uwb_dev.dev; + + if (offset + type_size >= buf_size) { + dev_err(dev, "Not enough data to read extra size of event " + "0x%02x/%04x/%02x, only got %zu bytes.\n", + rceb->bEventType, le16_to_cpu(rceb->wEvent), + rceb->bEventContext, buf_size); + goto out; + } + ptr += offset; + size = core_size + le16_to_cpu(*(__le16 *)ptr); +out: + return size; +} + + +/* Beacon slot change notification (WUSB 1.0 [8.6.3.5]) */ +struct uwb_rc_evt_bp_slot_change_WUSB_0100 { + struct uwb_rceb rceb; + u8 bSlotNumber; +} __attribute__((packed)); + + +/** + * Filter data from WUSB device to WHCI driver + * + * @header: incoming event + * @buf_size: size of buffer in which event arrived + * @_event_size: actual size of event in the buffer + * @new_size: size of event after filtered + * + * We don't know how the buffer is constructed - there may be more than one + * event in it so buffer length does not determine event length. We first + * determine the expected size of the incoming event. This value is passed + * back only if the actual filtering succeeded (so we know the computed + * expected size is correct). This value will be zero if + * the event did not need any filtering. + * + * WHCI interprets the BP Slot Change event's data differently than + * WUSB. The event sizes are exactly the same. The data field + * indicates the new beacon slot in which a RC is transmitting its + * beacon. The maximum value of this is 96 (wMacBPLength ECMA-368 + * 17.16 (Table 117)). We thus know that the WUSB value will not set + * the bit bNoSlot, so we don't really do anything (placeholder). + */ +static +int hwarc_filter_event_WUSB_0100(struct uwb_rc *rc, struct uwb_rceb **header, + const size_t buf_size, size_t *_real_size, + size_t *_new_size) +{ + int result = -ENOANO; + struct uwb_rceb *rceb = *header; + int event = le16_to_cpu(rceb->wEvent); + size_t event_size; + size_t core_size, offset; + + if (rceb->bEventType != UWB_RC_CET_GENERAL) + goto out; + switch (event) { + case UWB_RC_EVT_BEACON: + core_size = sizeof(struct uwb_rc_evt_beacon_WUSB_0100); + offset = offsetof(struct uwb_rc_evt_beacon_WUSB_0100, + wBeaconInfoLength); + event_size = hwarc_get_event_size(rc, rceb, core_size, + offset, buf_size); + if (event_size < 0) + goto out; + *_real_size = event_size; + result = hwarc_filter_evt_beacon_WUSB_0100(rc, header, + buf_size, _new_size); + break; + case UWB_RC_EVT_BP_SLOT_CHANGE: + *_new_size = *_real_size = + sizeof(struct uwb_rc_evt_bp_slot_change_WUSB_0100); + result = 0; + break; + + case UWB_RC_EVT_DRP_AVAIL: + core_size = sizeof(struct uwb_rc_evt_drp_avail_WUSB_0100); + offset = offsetof(struct uwb_rc_evt_drp_avail_WUSB_0100, + wIELength); + event_size = hwarc_get_event_size(rc, rceb, core_size, + offset, buf_size); + if (event_size < 0) + goto out; + *_real_size = event_size; + result = hwarc_filter_evt_drp_avail_WUSB_0100( + rc, header, buf_size, _new_size); + break; + + case UWB_RC_EVT_DRP: + core_size = sizeof(struct uwb_rc_evt_drp_WUSB_0100); + offset = offsetof(struct uwb_rc_evt_drp_WUSB_0100, wIELength); + event_size = hwarc_get_event_size(rc, rceb, core_size, + offset, buf_size); + if (event_size < 0) + goto out; + *_real_size = event_size; + result = hwarc_filter_evt_drp_WUSB_0100(rc, header, + buf_size, _new_size); + break; + + default: + break; + } +out: + return result; +} + +/** + * Filter data from WUSB device to WHCI driver + * + * @header: incoming event + * @buf_size: size of buffer in which event arrived + * @_event_size: actual size of event in the buffer + * @_new_size: size of event after filtered + * + * Filter events based on which protocol the device supports. The WUSB + * errata should be the same as WHCI 0.95 so we do not filter that here - + * only WUSB 1.0. + * + * If we don't handle it, we return -ENOANO (why the weird error code? + * well, so if I get it, I can pinpoint in the code that raised + * it...after all, not too many places use the higher error codes). + */ +static +int hwarc_filter_event(struct uwb_rc *rc, struct uwb_rceb **header, + const size_t buf_size, size_t *_real_size, + size_t *_new_size) +{ + int result = -ENOANO; + if (rc->version == 0x0100) + result = hwarc_filter_event_WUSB_0100( + rc, header, buf_size, _real_size, _new_size); + return result; +} + + +/** + * Execute an UWB RC command on HWA + * + * @rc: Instance of a Radio Controller that is a HWA + * @cmd: Buffer containing the RCCB and payload to execute + * @cmd_size: Size of the command buffer. + * + * NOTE: rc's mutex has to be locked + */ +static +int hwarc_cmd(struct uwb_rc *uwb_rc, const struct uwb_rccb *cmd, size_t cmd_size) +{ + struct hwarc *hwarc = uwb_rc->priv; + return usb_control_msg( + hwarc->usb_dev, usb_sndctrlpipe(hwarc->usb_dev, 0), + WA_EXEC_RC_CMD, USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, + 0, hwarc->usb_iface->cur_altsetting->desc.bInterfaceNumber, + (void *) cmd, cmd_size, 100 /* FIXME: this is totally arbitrary */); +} + +static +int hwarc_reset(struct uwb_rc *uwb_rc) +{ + struct hwarc *hwarc = uwb_rc->priv; + return usb_reset_device(hwarc->usb_dev); +} + +/** + * Callback for the notification and event endpoint + * + * Check's that everything is fine and then passes the read data to + * the notification/event handling mechanism (neh). + */ +static +void hwarc_neep_cb(struct urb *urb) +{ + struct hwarc *hwarc = urb->context; + struct usb_interface *usb_iface = hwarc->usb_iface; + struct device *dev = &usb_iface->dev; + int result; + + switch (result = urb->status) { + case 0: + d_printf(3, dev, "NEEP: receive stat %d, %zu bytes\n", + urb->status, (size_t)urb->actual_length); + uwb_rc_neh_grok(hwarc->uwb_rc, urb->transfer_buffer, + urb->actual_length); + break; + case -ECONNRESET: /* Not an error, but a controlled situation; */ + case -ENOENT: /* (we killed the URB)...so, no broadcast */ + d_printf(2, dev, "NEEP: URB reset/noent %d\n", urb->status); + goto out; + case -ESHUTDOWN: /* going away! */ + d_printf(2, dev, "NEEP: URB down %d\n", urb->status); + goto out; + default: /* On general errors, retry unless it gets ugly */ + if (edc_inc(&hwarc->neep_edc, EDC_MAX_ERRORS, + EDC_ERROR_TIMEFRAME)) + goto error_exceeded; + dev_err(dev, "NEEP: URB error %d\n", urb->status); + } + result = usb_submit_urb(urb, GFP_ATOMIC); + d_printf(3, dev, "NEEP: submit %d\n", result); + if (result < 0) { + dev_err(dev, "NEEP: Can't resubmit URB (%d) resetting device\n", + result); + goto error; + } +out: + return; + +error_exceeded: + dev_err(dev, "NEEP: URB max acceptable errors " + "exceeded, resetting device\n"); +error: + uwb_rc_neh_error(hwarc->uwb_rc, result); + uwb_rc_reset_all(hwarc->uwb_rc); + return; +} + +static void hwarc_init(struct hwarc *hwarc) +{ + edc_init(&hwarc->neep_edc); +} + +/** + * Initialize the notification/event endpoint stuff + * + * Note this is effectively a parallel thread; it knows that + * hwarc->uwb_rc always exists because the existence of a 'hwarc' + * means that there is a reverence on the hwarc->uwb_rc (see + * _probe()), and thus _neep_cb() can execute safely. + */ +static int hwarc_neep_init(struct uwb_rc *rc) +{ + struct hwarc *hwarc = rc->priv; + struct usb_interface *iface = hwarc->usb_iface; + struct usb_device *usb_dev = interface_to_usbdev(iface); + struct device *dev = &iface->dev; + int result; + struct usb_endpoint_descriptor *epd; + + epd = &iface->cur_altsetting->endpoint[0].desc; + hwarc->rd_buffer = (void *) __get_free_page(GFP_KERNEL); + if (hwarc->rd_buffer == NULL) { + dev_err(dev, "Unable to allocate notification's read buffer\n"); + goto error_rd_buffer; + } + hwarc->neep_urb = usb_alloc_urb(0, GFP_KERNEL); + if (hwarc->neep_urb == NULL) { + dev_err(dev, "Unable to allocate notification URB\n"); + goto error_urb_alloc; + } + usb_fill_int_urb(hwarc->neep_urb, usb_dev, + usb_rcvintpipe(usb_dev, epd->bEndpointAddress), + hwarc->rd_buffer, PAGE_SIZE, + hwarc_neep_cb, hwarc, epd->bInterval); + result = usb_submit_urb(hwarc->neep_urb, GFP_ATOMIC); + if (result < 0) { + dev_err(dev, "Cannot submit notification URB: %d\n", result); + goto error_neep_submit; + } + return 0; + +error_neep_submit: + usb_free_urb(hwarc->neep_urb); +error_urb_alloc: + free_page((unsigned long)hwarc->rd_buffer); +error_rd_buffer: + return -ENOMEM; +} + + +/** Clean up all the notification endpoint resources */ +static void hwarc_neep_release(struct uwb_rc *rc) +{ + struct hwarc *hwarc = rc->priv; + + usb_kill_urb(hwarc->neep_urb); + usb_free_urb(hwarc->neep_urb); + free_page((unsigned long)hwarc->rd_buffer); +} + +/** + * Get the version from class-specific descriptor + * + * NOTE: this descriptor comes with the big bundled configuration + * descriptor that includes the interfaces' and endpoints', so + * we just look for it in the cached copy kept by the USB stack. + * + * NOTE2: We convert LE fields to CPU order. + */ +static int hwarc_get_version(struct uwb_rc *rc) +{ + int result; + + struct hwarc *hwarc = rc->priv; + struct uwb_rc_control_intf_class_desc *descr; + struct device *dev = &rc->uwb_dev.dev; + struct usb_device *usb_dev = hwarc->usb_dev; + char *itr; + struct usb_descriptor_header *hdr; + size_t itr_size, actconfig_idx; + u16 version; + + actconfig_idx = (usb_dev->actconfig - usb_dev->config) / + sizeof(usb_dev->config[0]); + itr = usb_dev->rawdescriptors[actconfig_idx]; + itr_size = le16_to_cpu(usb_dev->actconfig->desc.wTotalLength); + while (itr_size >= sizeof(*hdr)) { + hdr = (struct usb_descriptor_header *) itr; + d_printf(3, dev, "Extra device descriptor: " + "type %02x/%u bytes @ %zu (%zu left)\n", + hdr->bDescriptorType, hdr->bLength, + (itr - usb_dev->rawdescriptors[actconfig_idx]), + itr_size); + if (hdr->bDescriptorType == USB_DT_CS_RADIO_CONTROL) + goto found; + itr += hdr->bLength; + itr_size -= hdr->bLength; + } + dev_err(dev, "cannot find Radio Control Interface Class descriptor\n"); + return -ENODEV; + +found: + result = -EINVAL; + if (hdr->bLength > itr_size) { /* is it available? */ + dev_err(dev, "incomplete Radio Control Interface Class " + "descriptor (%zu bytes left, %u needed)\n", + itr_size, hdr->bLength); + goto error; + } + if (hdr->bLength < sizeof(*descr)) { + dev_err(dev, "short Radio Control Interface Class " + "descriptor\n"); + goto error; + } + descr = (struct uwb_rc_control_intf_class_desc *) hdr; + /* Make LE fields CPU order */ + version = __le16_to_cpu(descr->bcdRCIVersion); + if (version != 0x0100) { + dev_err(dev, "Device reports protocol version 0x%04x. We " + "do not support that. \n", version); + result = -EINVAL; + goto error; + } + rc->version = version; + d_printf(3, dev, "Device supports WUSB protocol version 0x%04x \n", + rc->version); + result = 0; +error: + return result; +} + +/* + * By creating a 'uwb_rc', we have a reference on it -- that reference + * is the one we drop when we disconnect. + * + * No need to switch altsettings; according to WUSB1.0[8.6.1.1], there + * is only one altsetting allowed. + */ +static int hwarc_probe(struct usb_interface *iface, + const struct usb_device_id *id) +{ + int result; + struct uwb_rc *uwb_rc; + struct hwarc *hwarc; + struct device *dev = &iface->dev; + + result = -ENOMEM; + uwb_rc = uwb_rc_alloc(); + if (uwb_rc == NULL) { + dev_err(dev, "unable to allocate RC instance\n"); + goto error_rc_alloc; + } + hwarc = kzalloc(sizeof(*hwarc), GFP_KERNEL); + if (hwarc == NULL) { + dev_err(dev, "unable to allocate HWA RC instance\n"); + goto error_alloc; + } + hwarc_init(hwarc); + hwarc->usb_dev = usb_get_dev(interface_to_usbdev(iface)); + hwarc->usb_iface = usb_get_intf(iface); + hwarc->uwb_rc = uwb_rc; + + uwb_rc->owner = THIS_MODULE; + uwb_rc->start = hwarc_neep_init; + uwb_rc->stop = hwarc_neep_release; + uwb_rc->cmd = hwarc_cmd; + uwb_rc->reset = hwarc_reset; + uwb_rc->filter_cmd = hwarc_filter_cmd; + uwb_rc->filter_event = hwarc_filter_event; + + result = uwb_rc_add(uwb_rc, dev, hwarc); + if (result < 0) + goto error_rc_add; + result = hwarc_get_version(uwb_rc); + if (result < 0) { + dev_err(dev, "cannot retrieve version of RC \n"); + goto error_get_version; + } + usb_set_intfdata(iface, hwarc); + return 0; + +error_get_version: + uwb_rc_rm(uwb_rc); +error_rc_add: + usb_put_intf(iface); + usb_put_dev(hwarc->usb_dev); +error_alloc: + uwb_rc_put(uwb_rc); +error_rc_alloc: + return result; +} + +static void hwarc_disconnect(struct usb_interface *iface) +{ + struct hwarc *hwarc = usb_get_intfdata(iface); + struct uwb_rc *uwb_rc = hwarc->uwb_rc; + + usb_set_intfdata(hwarc->usb_iface, NULL); + uwb_rc_rm(uwb_rc); + usb_put_intf(hwarc->usb_iface); + usb_put_dev(hwarc->usb_dev); + d_printf(1, &hwarc->usb_iface->dev, "freed hwarc %p\n", hwarc); + kfree(hwarc); + uwb_rc_put(uwb_rc); /* when creating the device, refcount = 1 */ +} + +/** USB device ID's that we handle */ +static struct usb_device_id hwarc_id_table[] = { + { USB_INTERFACE_INFO(0xe0, 0x01, 0x02), }, + { }, +}; +MODULE_DEVICE_TABLE(usb, hwarc_id_table); + +static struct usb_driver hwarc_driver = { + .name = "hwa-rc", + .probe = hwarc_probe, + .disconnect = hwarc_disconnect, + .id_table = hwarc_id_table, +}; + +static int __init hwarc_driver_init(void) +{ + int result; + result = usb_register(&hwarc_driver); + if (result < 0) + printk(KERN_ERR "HWA-RC: Cannot register USB driver: %d\n", + result); + return result; + +} +module_init(hwarc_driver_init); + +static void __exit hwarc_driver_exit(void) +{ + usb_deregister(&hwarc_driver); +} +module_exit(hwarc_driver_exit); + +MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>"); +MODULE_DESCRIPTION("Host Wireless Adapter Radio Control Driver"); +MODULE_LICENSE("GPL"); |