/* $NetBSD: u3g.c,v 1.37.2.3 2023/02/14 16:10:00 martin Exp $ */ /*- * Copyright (c) 2009 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 2008 AnyWi Technologies * Author: Andrea Guzzo * * based on uark.c 1.1 2006/08/14 08:30:22 jsg * * * parts from ubsa.c 183348 2008-09-25 12:00:56Z phk * * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * $FreeBSD$ */ #include __KERNEL_RCSID(0, "$NetBSD: u3g.c,v 1.37.2.3 2023/02/14 16:10:00 martin Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include "usbdevs.h" /* * We read/write data from/to the device in 4KB chunks to maximise * performance. */ #define U3G_BUFF_SIZE 4096 /* * Some 3G devices (the Huawei E160/E220 springs to mind here) buffer up * data internally even when the USB pipes are closed. So on first open, * we can receive a large chunk of stale data. * * This causes a real problem because the default TTYDEF_LFLAG (applied * on first open) has the ECHO flag set, resulting in all the stale data * being echoed straight back to the device by the tty(4) layer. Some * devices (again, the Huawei E160/E220 for example) react to this spew * by going catatonic. * * All this happens before the application gets a chance to disable ECHO. * * We work around this by ignoring all data received from the device for * a period of two seconds, or until the application starts sending data - * whichever comes first. */ #define U3G_PURGE_SECS 2 /* * Define bits for the virtual modem control pins. * The input pin states are reported via the interrupt pipe on some devices. */ #define U3G_OUTPIN_DTR (1u << 0) #define U3G_OUTPIN_RTS (1u << 1) #define U3G_INPIN_DCD (1u << 0) #define U3G_INPIN_DSR (1u << 1) #define U3G_INPIN_RI (1u << 3) /* * USB request to set the output pin status */ #define U3G_SET_PIN 0x22 struct u3g_softc { device_t sc_dev; struct usbd_device * sc_udev; bool sc_dying; /* We're going away */ int sc_ifaceno; /* Device interface number */ struct usbd_interface *sc_iface; /* Device interface */ struct u3g_com { device_t c_dev; /* Child ucom(4) handle */ bool c_open; /* Device is in use */ bool c_purging; /* Purging stale data */ struct timeval c_purge_start; /* Control duration of purge */ u_char c_msr; /* Emulated 'msr' */ uint16_t c_outpins; /* Output pin state */ } sc_com[10]; size_t sc_ncom; struct usbd_pipe * sc_intr_pipe; /* Interrupt pipe */ u_char *sc_intr_buff; /* Interrupt buffer */ size_t sc_intr_size; /* buffer size */ }; /* * The device driver has two personalities. The first uses the 'usbdevif' * interface attribute so that a match will claim the entire USB device * for itself. This is used for when a device needs to be mode-switched * and ensures any other interfaces present cannot be claimed by other * drivers while the mode-switch is in progress. This is implemented by * the umodeswitch driver. * * The second personality uses the 'usbifif' interface attribute so that * it can claim the 3G modem interfaces for itself, leaving others (such * as the mass storage interfaces on some devices) for other drivers. */ static int u3g_match(device_t, cfdata_t, void *); static void u3g_attach(device_t, device_t, void *); static int u3g_detach(device_t, int); static void u3g_childdet(device_t, device_t); CFATTACH_DECL2_NEW(u3g, sizeof(struct u3g_softc), u3g_match, u3g_attach, u3g_detach, NULL, NULL, u3g_childdet); static void u3g_intr(struct usbd_xfer *, void *, usbd_status); static void u3g_get_status(void *, int, u_char *, u_char *); static void u3g_set(void *, int, int, int); static int u3g_open(void *, int); static void u3g_close(void *, int); static void u3g_read(void *, int, u_char **, uint32_t *); static void u3g_write(void *, int, u_char *, u_char *, uint32_t *); struct ucom_methods u3g_methods = { .ucom_get_status = u3g_get_status, .ucom_set = u3g_set, .ucom_open = u3g_open, .ucom_close = u3g_close, .ucom_read = u3g_read, .ucom_write = u3g_write, }; /* * Allegedly supported devices */ static const struct usb_devno u3g_devs[] = { { USB_VENDOR_DELL, USB_PRODUCT_DELL_W5500 }, { USB_VENDOR_HP, USB_PRODUCT_HP_UN2430 }, /* OEM: Huawei */ { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E1750 }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E1820 }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E220 }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_EM770W }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_K3765 }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_MOBILE }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E171 }, { USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E353 }, /* LG Electronics */ { USB_VENDOR_LG, USB_PRODUCT_LG_NTT_DOCOMO_L02C_MODEM }, /* OEM: Merlin */ { USB_VENDOR_MERLIN, USB_PRODUCT_MERLIN_V620 }, /* OEM: Novatel */ { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_ES620 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_EU8X0D }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MC950D }, #if 0 /* These are matched in u3ginit_match() */ { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MC950D_DRIVER }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U760_DRIVER }, #endif { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MERLINU740 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MERLINV620 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_S720 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U720 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U727 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U740_2 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U760 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U870 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_V740 }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_X950D }, { USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_XU870 }, /* OEM: Option N.V. */ { USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_QUADPLUSUMTS }, { USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_HSDPA }, { USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_GTMAXHSUPA }, /* OEM: Sierra Wireless: */ { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC595U }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC597E }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC875U }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880E }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880U }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881E }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881U }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD580 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD595 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD875 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_C597 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_EM5625 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5720 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5720_2 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5725 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755_2 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755_3 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8765 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8775_2 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8780 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8781 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MINI5725 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_USB305 }, { USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_250U }, /* Toshiba */ { USB_VENDOR_TOSHIBA, USB_PRODUCT_TOSHIBA_HSDPA_MODEM_EU870DT1 }, /* ZTE */ { USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF622 }, { USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF626 }, { USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF628 }, { USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF820D }, { USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF112 }, /* 4G Systems */ { USB_VENDOR_LONGCHEER, USB_PRODUCT_LONGCHEER_XSSTICK_P14 }, { USB_VENDOR_LONGCHEER, USB_PRODUCT_LONGCHEER_XSSTICK_W14 }, /* DLink */ { USB_VENDOR_DLINK, USB_PRODUCT_DLINK_DWM157 }, { USB_VENDOR_DLINK, USB_PRODUCT_DLINK_DWM157E }, { USB_VENDOR_DLINK, USB_PRODUCT_DLINK_DWM222 }, }; /* * Second personality: * * Claim only those interfaces required for 3G modem operation. */ static int u3g_match(device_t parent, cfdata_t match, void *aux) { struct usbif_attach_arg *uiaa = aux; struct usbd_interface *iface = uiaa->uiaa_iface; usb_interface_descriptor_t *id; if (!usb_lookup(u3g_devs, uiaa->uiaa_vendor, uiaa->uiaa_product)) return UMATCH_NONE; id = usbd_get_interface_descriptor(iface); if (id == NULL) { printf("u3g_match: failed to get interface descriptor\n"); return UMATCH_NONE; } /* * Huawei modems use the vendor-specific class for all interfaces, * both tty and CDC NCM, which we should avoid attaching to. */ if (uiaa->uiaa_vendor == USB_VENDOR_HUAWEI && id->bInterfaceSubClass == 2 && (id->bInterfaceProtocol & 0xf) == 6) /* 0x16, 0x46, 0x76 */ return UMATCH_NONE; /* * Sierra Wireless modems use the vendor-specific class also for * Direct IP or QMI interfaces, which we should avoid attaching to. */ if (uiaa->uiaa_vendor == USB_VENDOR_SIERRA && id->bInterfaceClass == UICLASS_VENDOR && uiaa->uiaa_product == USB_PRODUCT_SIERRA_USB305 && uiaa->uiaa_ifaceno >= 7) return UMATCH_NONE; /* * 3G modems generally report vendor-specific class * * XXX: this may be too generalised. */ return id->bInterfaceClass == UICLASS_VENDOR ? UMATCH_VENDOR_PRODUCT : UMATCH_NONE; } static void u3g_attach(device_t parent, device_t self, void *aux) { struct u3g_softc *sc = device_private(self); struct usbif_attach_arg *uiaa = aux; struct usbd_device *dev = uiaa->uiaa_device; struct usbd_interface *iface = uiaa->uiaa_iface; usb_interface_descriptor_t *id; usb_endpoint_descriptor_t *ed; struct ucom_attach_args ucaa; usbd_status error; int n, intr_address, intr_size; aprint_naive("\n"); aprint_normal("\n"); sc->sc_dev = self; sc->sc_dying = false; sc->sc_udev = dev; id = usbd_get_interface_descriptor(iface); ucaa.ucaa_info = "3G Modem"; ucaa.ucaa_ibufsize = U3G_BUFF_SIZE; ucaa.ucaa_obufsize = U3G_BUFF_SIZE; ucaa.ucaa_ibufsizepad = U3G_BUFF_SIZE; ucaa.ucaa_opkthdrlen = 0; ucaa.ucaa_device = dev; ucaa.ucaa_iface = iface; ucaa.ucaa_methods = &u3g_methods; ucaa.ucaa_arg = sc; ucaa.ucaa_portno = -1; ucaa.ucaa_bulkin = ucaa.ucaa_bulkout = -1; sc->sc_ifaceno = uiaa->uiaa_ifaceno; sc->sc_iface = uiaa->uiaa_iface; intr_address = -1; intr_size = 0; for (n = 0; n < id->bNumEndpoints; n++) { ed = usbd_interface2endpoint_descriptor(iface, n); if (ed == NULL) { aprint_error_dev(self, "no endpoint descriptor " "for %d (interface: %d)\n", n, sc->sc_ifaceno); sc->sc_dying = true; return; } if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN && UE_GET_XFERTYPE(ed->bmAttributes) == UE_INTERRUPT) { intr_address = ed->bEndpointAddress; intr_size = UGETW(ed->wMaxPacketSize); } else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN && UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) { ucaa.ucaa_bulkin = ed->bEndpointAddress; } else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT && UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) { ucaa.ucaa_bulkout = ed->bEndpointAddress; } if (ucaa.ucaa_bulkin != -1 && ucaa.ucaa_bulkout != -1) { struct u3g_com *com; if (sc->sc_ncom == __arraycount(sc->sc_com)) { aprint_error_dev(self, "Need to configure " "more than %zu ttys", sc->sc_ncom); continue; } ucaa.ucaa_portno = sc->sc_ncom++; com = &sc->sc_com[ucaa.ucaa_portno]; com->c_outpins = 0; com->c_msr = UMSR_DSR | UMSR_CTS | UMSR_DCD; com->c_open = false; com->c_purging = false; com->c_dev = config_found_sm_loc(self, "ucombus", NULL, &ucaa, ucomprint, ucomsubmatch); ucaa.ucaa_bulkin = -1; ucaa.ucaa_bulkout = -1; } } if (sc->sc_ncom == 0) { aprint_error_dev(self, "Missing bulk in/out for interface %d\n", sc->sc_ifaceno); sc->sc_dying = true; return; } /* * If the interface has an interrupt pipe, open it immediately so * that we can track input pin state changes regardless of whether * the tty(4) device is open or not. */ if (intr_address != -1) { sc->sc_intr_size = intr_size; sc->sc_intr_buff = kmem_alloc(intr_size, KM_SLEEP); error = usbd_open_pipe_intr(iface, intr_address, USBD_SHORT_XFER_OK, &sc->sc_intr_pipe, sc, sc->sc_intr_buff, intr_size, u3g_intr, 100); if (error) { aprint_error_dev(self, "cannot open interrupt pipe " "(addr %d)\n", intr_address); return; } } else { sc->sc_intr_pipe = NULL; sc->sc_intr_buff = NULL; } if (!pmf_device_register(self, NULL, NULL)) aprint_error_dev(self, "couldn't establish power handler\n"); } static int u3g_detach(device_t self, int flags) { struct u3g_softc *sc = device_private(self); int rv = 0; sc->sc_dying = true; if (sc->sc_intr_pipe != NULL) { usbd_abort_pipe(sc->sc_intr_pipe); usbd_close_pipe(sc->sc_intr_pipe); sc->sc_intr_pipe = NULL; } if (sc->sc_intr_buff != NULL) { kmem_free(sc->sc_intr_buff, sc->sc_intr_size); sc->sc_intr_buff = NULL; } for (size_t i = 0; i < sc->sc_ncom; i++) if (sc->sc_com[i].c_dev != NULL) { int port_rv; port_rv = config_detach(sc->sc_com[i].c_dev, flags); if (port_rv != 0) { aprint_verbose_dev(self, "Can't deallocate " "port (%d)", port_rv); } rv |= port_rv; sc->sc_com[i].c_dev = NULL; } pmf_device_deregister(self); return rv; } static void u3g_childdet(device_t self, device_t child) { struct u3g_softc *sc = device_private(self); for (size_t i = 0; i < sc->sc_ncom; i++) if (sc->sc_com[i].c_dev == child) sc->sc_com[i].c_dev = NULL; } static void u3g_intr(struct usbd_xfer *xfer, void *priv, usbd_status status) { struct u3g_softc *sc = (struct u3g_softc *)priv; u_char *buf; int portno = 0; /* XXX */ struct u3g_com *com = &sc->sc_com[portno]; if (sc->sc_dying) return; if (status != USBD_NORMAL_COMPLETION) { if (status == USBD_NOT_STARTED || status == USBD_CANCELLED) return; usbd_clear_endpoint_stall_async(sc->sc_intr_pipe); return; } buf = sc->sc_intr_buff; if (buf[0] == 0xa1 && buf[1] == 0x20) { u_char msr; msr = com->c_msr & ~(UMSR_DCD | UMSR_DSR | UMSR_RI); if (buf[8] & U3G_INPIN_DCD) msr |= UMSR_DCD; if (buf[8] & U3G_INPIN_DSR) msr |= UMSR_DSR; if (buf[8] & U3G_INPIN_RI) msr |= UMSR_RI; if (msr != com->c_msr) { com->c_msr = msr; if (com->c_open) ucom_status_change(device_private(com->c_dev)); } } } /*ARGSUSED*/ static void u3g_get_status(void *arg, int portno, u_char *lsr, u_char *msr) { struct u3g_softc *sc = arg; *lsr = 0; /* LSR isn't supported */ *msr = sc->sc_com[portno].c_msr; } /*ARGSUSED*/ static void u3g_set(void *arg, int portno, int reg, int onoff) { struct u3g_softc *sc = arg; usb_device_request_t req; uint16_t mask, new_state; usbd_status err; struct u3g_com *com = &sc->sc_com[portno]; if (sc->sc_dying) return; switch (reg) { case UCOM_SET_DTR: mask = U3G_OUTPIN_DTR; break; case UCOM_SET_RTS: mask = U3G_OUTPIN_RTS; break; default: return; } new_state = com->c_outpins & ~mask; if (onoff) new_state |= mask; if (new_state == com->c_outpins) return; com->c_outpins = new_state; req.bmRequestType = UT_WRITE_CLASS_INTERFACE; req.bRequest = U3G_SET_PIN; USETW(req.wValue, new_state); USETW(req.wIndex, sc->sc_ifaceno); USETW(req.wLength, 0); err = usbd_do_request(sc->sc_udev, &req, 0); if (err == USBD_STALLED) usbd_clear_endpoint_stall(sc->sc_udev->ud_pipe0); } /*ARGSUSED*/ static int u3g_open(void *arg, int portno) { struct u3g_softc *sc = arg; usb_device_request_t req; usb_endpoint_descriptor_t *ed; usb_interface_descriptor_t *id; usbd_status err; struct u3g_com *com = &sc->sc_com[portno]; int i, nin; if (sc->sc_dying) return EIO; id = usbd_get_interface_descriptor(sc->sc_iface); for (nin = i = 0; i < id->bNumEndpoints; i++) { ed = usbd_interface2endpoint_descriptor(sc->sc_iface, i); if (ed == NULL) return EIO; if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN && UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK && nin++ == portno) { /* Issue ENDPOINT_HALT request */ req.bmRequestType = UT_WRITE_ENDPOINT; req.bRequest = UR_CLEAR_FEATURE; USETW(req.wValue, UF_ENDPOINT_HALT); USETW(req.wIndex, ed->bEndpointAddress); USETW(req.wLength, 0); err = usbd_do_request(sc->sc_udev, &req, 0); if (err) return EIO; } } com->c_open = true; com->c_purging = true; getmicrotime(&com->c_purge_start); return 0; } /*ARGSUSED*/ static void u3g_close(void *arg, int portno) { struct u3g_softc *sc = arg; struct u3g_com *com = &sc->sc_com[portno]; com->c_open = false; } /*ARGSUSED*/ static void u3g_read(void *arg, int portno, u_char **cpp, uint32_t *ccp) { struct u3g_softc *sc = arg; struct timeval curr_tv, diff_tv; struct u3g_com *com = &sc->sc_com[portno]; /* * If we're not purging input data following first open, do nothing. */ if (com->c_purging == false) return; /* * Otherwise check if the purge timeout has expired */ getmicrotime(&curr_tv); timersub(&curr_tv, &com->c_purge_start, &diff_tv); if (diff_tv.tv_sec >= U3G_PURGE_SECS) { /* Timeout expired. */ com->c_purging = false; } else { /* Still purging. Adjust the caller's byte count. */ *ccp = 0; } } /*ARGSUSED*/ static void u3g_write(void *arg, int portno, u_char *to, u_char *from, uint32_t *count) { struct u3g_softc *sc = arg; struct u3g_com *com = &sc->sc_com[portno]; /* * Stop purging as soon as the first data is written to the device. */ com->c_purging = false; memcpy(to, from, *count); }