/*      $NetBSD: uftdi.c,v 1.81 2025/05/11 22:36:13 gutteridge Exp $    */

/*
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Lennart Augustsson ([email protected]).
*
* 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.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uftdi.c,v 1.81 2025/05/11 22:36:13 gutteridge Exp $");

#ifdef _KERNEL_OPT
#include "opt_usb.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/tty.h>

#include <dev/usb/usb.h>

#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbdivar.h>
#include <dev/usb/usbdevs.h>

#include <dev/usb/ucomvar.h>

#include <dev/usb/uftdireg.h>

#ifdef UFTDI_DEBUG
#define DPRINTF(x)      if (uftdidebug) printf x
#define DPRINTFN(n,x)   if (uftdidebug>(n)) printf x
int uftdidebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

#define UFTDI_CONFIG_NO         1

/*
* These are the default number of bytes transferred per frame if the
* endpoint doesn't tell us.  The output buffer size is a hard limit
* for devices that use a 6-bit size encoding.
*/
#define UFTDIIBUFSIZE 64
#define UFTDIOBUFSIZE 64

/*
* Magic constants!  Where do these come from?  They're what Linux uses...
*/
#define UFTDI_MAX_IBUFSIZE      512
#define UFTDI_MAX_OBUFSIZE      256

struct uftdi_softc {
       device_t                sc_dev;         /* base device */
       struct usbd_device *    sc_udev;        /* device */
       struct usbd_interface * sc_iface;       /* interface */
       int                     sc_iface_no;

       enum uftdi_type         sc_type;
       u_int                   sc_flags;
#define FLAGS_BAUDCLK_12M       0x00000001
#define FLAGS_ROUNDOFF_232A     0x00000002
#define FLAGS_BAUDBITS_HINDEX   0x00000004
       u_int                   sc_hdrlen;
       u_int                   sc_chiptype;

       u_char                  sc_msr;
       u_char                  sc_lsr;

       device_t                sc_subdev;

       bool                    sc_dying;

       u_int                   last_lcr;
};

static void     uftdi_get_status(void *, int, u_char *, u_char *);
static void     uftdi_set(void *, int, int, int);
static int      uftdi_param(void *, int, struct termios *);
static int      uftdi_open(void *, int);
static void     uftdi_read(void *, int, u_char **, uint32_t *);
static void     uftdi_write(void *, int, u_char *, u_char *, uint32_t *);
static void     uftdi_break(void *, int, int);

static const struct ucom_methods uftdi_methods = {
       .ucom_get_status = uftdi_get_status,
       .ucom_set = uftdi_set,
       .ucom_param = uftdi_param,
       .ucom_open = uftdi_open,
       .ucom_read = uftdi_read,
       .ucom_write = uftdi_write,
};

/*
* The devices default to UFTDI_TYPE_8U232AM.
* Remember to update uftdi_attach() if it should be UFTDI_TYPE_SIO instead
*/
static const struct usb_devno uftdi_devs[] = {
       { USB_VENDOR_BBELECTRONICS, USB_PRODUCT_BBELECTRONICS_USOTL4 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US101 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US159 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US235 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US257 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US279_12 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US279_34 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US279_56 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US279_78 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US313 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US320 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US324 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US346_12 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US346_34 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US701_12 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US701_34 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US842_12 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US842_34 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US842_56 },
       { USB_VENDOR_BRAINBOXES, USB_PRODUCT_BRAINBOXES_US842_78 },
       { USB_VENDOR_FALCOM, USB_PRODUCT_FALCOM_TWIST },
       { USB_VENDOR_FALCOM, USB_PRODUCT_FALCOM_SAMBA },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_230X },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_232H },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_232RL },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_2232C },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_4232H },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_8U100AX },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SERIAL_8U232AM },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_KW },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_YS },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_Y6 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_Y8 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_IC },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_DB9 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_RS232 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MHAM_Y9 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_COASTAL_TNCX },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_CTI_485_MINI },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_CTI_NANO_485 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_SEMC_DSS20 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_LK202_24_USB },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_LK204_24_USB },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_MX200_USB },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_MX4_MX5_USB },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_CFA_631 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_CFA_632 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_CFA_633 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_CFA_634 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_LCD_CFA_635 },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_OPENRD_JTAGKEY },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_BEAGLEBONE },
       { USB_VENDOR_FTDI, USB_PRODUCT_FTDI_MAXSTREAM_PKG_U },
       { USB_VENDOR_xxFTDI, USB_PRODUCT_xxFTDI_SHEEVAPLUG_JTAG },
       { USB_VENDOR_INTREPIDCS, USB_PRODUCT_INTREPIDCS_VALUECAN },
       { USB_VENDOR_INTREPIDCS, USB_PRODUCT_INTREPIDCS_NEOVI },
       { USB_VENDOR_MELCO, USB_PRODUCT_MELCO_PCOPRS1 },
       { USB_VENDOR_RATOC, USB_PRODUCT_RATOC_REXUSB60F },
       { USB_VENDOR_RTSYS, USB_PRODUCT_RTSYS_CT57A },
       { USB_VENDOR_RTSYS, USB_PRODUCT_RTSYS_RTS03 },
       { USB_VENDOR_SEALEVEL, USB_PRODUCT_SEALEVEL_USBSERIAL },
       { USB_VENDOR_SEALEVEL, USB_PRODUCT_SEALEVEL_SEAPORT4P1 },
       { USB_VENDOR_SEALEVEL, USB_PRODUCT_SEALEVEL_SEAPORT4P2 },
       { USB_VENDOR_SEALEVEL, USB_PRODUCT_SEALEVEL_SEAPORT4P3 },
       { USB_VENDOR_SEALEVEL, USB_PRODUCT_SEALEVEL_SEAPORT4P4 },
       { USB_VENDOR_SIIG2, USB_PRODUCT_SIIG2_US2308 },
       { USB_VENDOR_MISC, USB_PRODUCT_MISC_TELLSTICK },
       { USB_VENDOR_MISC, USB_PRODUCT_MISC_TELLSTICK_DUO },
};
#define uftdi_lookup(v, p) usb_lookup(uftdi_devs, v, p)

static int      uftdi_match(device_t, cfdata_t, void *);
static void     uftdi_attach(device_t, device_t, void *);
static void     uftdi_childdet(device_t, device_t);
static int      uftdi_detach(device_t, int);

CFATTACH_DECL2_NEW(uftdi, sizeof(struct uftdi_softc), uftdi_match,
   uftdi_attach, uftdi_detach, NULL, NULL, uftdi_childdet);

struct uftdi_match_quirk_entry {
       uint16_t        vendor_id;
       uint16_t        product_id;
       int             iface_no;
       const char *    vendor_str;
       const char *    product_str;
       int             match_ret;
};

static const struct uftdi_match_quirk_entry uftdi_match_quirks[] = {
       /*
        * The Tigard board (https://github.com/tigard-tools/tigard)
        * has two interfaces, one of which is meant to act as a
        * regular USB serial port (interface 0), the other of which
        * is meant for other protocols (SWD, JTAG, etc.).  We must
        * reject interface 1 so that ugenif matches, thus allowing
        * full user-space control of that port.
        */
       {
         .vendor_id    = USB_VENDOR_FTDI,
         .product_id   = USB_PRODUCT_FTDI_SERIAL_2232C,
         .iface_no     = 1,
         .vendor_str   = "SecuringHardware.com",
         .product_str  = "Tigard V1.1",
         .match_ret    = UMATCH_NONE,
       },
       /*
        * The SiPEED Tang Nano 9K (and other SiPEED Tang FPGA development
        * boards) have an FT2232 on-board, wired up only for JTAG.
        */
       {
         .vendor_id    = USB_VENDOR_FTDI,
         .product_id   = USB_PRODUCT_FTDI_SERIAL_2232C,
         .iface_no     = -1,
         .vendor_str   = "SIPEED",
         .product_str  = "JTAG Debugger",
         .match_ret    = UMATCH_NONE,
       },
       /*
        * The iCEBreaker board (https://1bitsquared.com/products/icebreaker)
        * has two interfaces, one of which is meant to act as a
        * regular USB serial port (interface 1), the other of which
        * is meant for other protocols.
        */
       {
         .vendor_id    = USB_VENDOR_FTDI,
         .product_id   = USB_PRODUCT_FTDI_SERIAL_2232C,
         .iface_no     = 0,
         .vendor_str   = "1BitSquared",
         .product_str  = "iCEBreaker *",
         .match_ret    = UMATCH_NONE,
       },
};

static int
uftdi_quirk_match(struct usbif_attach_arg *uiaa, int rv)
{
       struct usbd_device *dev = uiaa->uiaa_device;
       const struct uftdi_match_quirk_entry *q;
       int i;

       for (i = 0; i < __arraycount(uftdi_match_quirks); i++) {
               q = &uftdi_match_quirks[i];
               if (uiaa->uiaa_vendor != q->vendor_id ||
                   uiaa->uiaa_product != q->product_id ||
                   (q->iface_no != -1 && uiaa->uiaa_ifaceno != q->iface_no)) {
                       continue;
               }
               if (q->vendor_str != NULL &&
                   (dev->ud_vendor == NULL ||
                    strcmp(dev->ud_vendor, q->vendor_str) != 0)) {
                       continue;
               }
               if (q->product_str != NULL &&
                   (dev->ud_product == NULL ||
                    pmatch(dev->ud_product, q->product_str, NULL) != 2)) {
                       continue;
               }
               /*
                * Got a match!
                */
               rv = q->match_ret;
               break;
       }
       return rv;
}

static int
uftdi_match(device_t parent, cfdata_t match, void *aux)
{
       struct usbif_attach_arg *uiaa = aux;
       int rv;

       DPRINTFN(20,("uftdi: vendor=%#x, product=%#x\n",
                    uiaa->uiaa_vendor, uiaa->uiaa_product));

       if (uiaa->uiaa_configno != UFTDI_CONFIG_NO)
               return UMATCH_NONE;

       rv = uftdi_lookup(uiaa->uiaa_vendor, uiaa->uiaa_product) != NULL ?
               UMATCH_VENDOR_PRODUCT_CONF_IFACE : UMATCH_NONE;
       if (rv != UMATCH_NONE) {
               rv = uftdi_quirk_match(uiaa, rv);
       }
       return rv;
}

static void
uftdi_attach(device_t parent, device_t self, void *aux)
{
       struct uftdi_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_device_descriptor_t *ddesc;
       usb_interface_descriptor_t *id;
       usb_endpoint_descriptor_t *ed;
       char *devinfop;
       int i;
       struct ucom_attach_args ucaa;

       DPRINTFN(10,("\nuftdi_attach: sc=%p\n", sc));

       aprint_naive("\n");
       aprint_normal("\n");

       devinfop = usbd_devinfo_alloc(dev, 0);
       aprint_normal_dev(self, "%s\n", devinfop);
       usbd_devinfo_free(devinfop);

       sc->sc_dev = self;
       sc->sc_udev = dev;
       sc->sc_dying = false;
       sc->sc_iface_no = uiaa->uiaa_ifaceno;
       sc->sc_type = UFTDI_TYPE_8U232AM; /* most devices are post-8U232AM */
       sc->sc_hdrlen = 0;

       ddesc = usbd_get_device_descriptor(dev);
       sc->sc_chiptype = UGETW(ddesc->bcdDevice);

       switch (sc->sc_chiptype) {
       case 0x0200:
               if (ddesc->iSerialNumber != 0)
                       sc->sc_flags |= FLAGS_ROUNDOFF_232A;
               ucaa.ucaa_portno = 0;
               break;
       case 0x0400:
               ucaa.ucaa_portno = 0;
               break;
       case 0x0500:
               sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
               ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
               break;
       case 0x0600:
               ucaa.ucaa_portno = 0;
               break;
       case 0x0700:
       case 0x0800:
       case 0x0900:
               sc->sc_flags |= FLAGS_BAUDCLK_12M;
               sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
               ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
               break;
       case 0x1000:
               sc->sc_flags |= FLAGS_BAUDBITS_HINDEX;
               ucaa.ucaa_portno = FTDI_PIT_SIOA + sc->sc_iface_no;
               break;
       default:
               if (sc->sc_chiptype < 0x0200) {
                       sc->sc_type = UFTDI_TYPE_SIO;
                       sc->sc_hdrlen = 1;
               }
               ucaa.ucaa_portno = 0;
               break;
       }

       id = usbd_get_interface_descriptor(iface);

       sc->sc_iface = iface;

       ucaa.ucaa_bulkin = ucaa.ucaa_bulkout = -1;
       ucaa.ucaa_ibufsize = ucaa.ucaa_obufsize = 0;
       for (i = 0; i < id->bNumEndpoints; i++) {
               int addr, dir, attr;
               ed = usbd_interface2endpoint_descriptor(iface, i);
               if (ed == NULL) {
                       aprint_error_dev(self,
                           "could not read endpoint descriptor\n");
                       goto bad;
               }

               addr = ed->bEndpointAddress;
               dir = UE_GET_DIR(ed->bEndpointAddress);
               attr = ed->bmAttributes & UE_XFERTYPE;
               if (dir == UE_DIR_IN && attr == UE_BULK) {
                       ucaa.ucaa_bulkin = addr;
                       ucaa.ucaa_ibufsize = UGETW(ed->wMaxPacketSize);
                       if (ucaa.ucaa_ibufsize >= UFTDI_MAX_IBUFSIZE)
                               ucaa.ucaa_ibufsize = UFTDI_MAX_IBUFSIZE;
               } else if (dir == UE_DIR_OUT && attr == UE_BULK) {
                       ucaa.ucaa_bulkout = addr;
                       ucaa.ucaa_obufsize = UGETW(ed->wMaxPacketSize)
                           - sc->sc_hdrlen;
                       if (ucaa.ucaa_obufsize >= UFTDI_MAX_OBUFSIZE)
                               ucaa.ucaa_obufsize = UFTDI_MAX_OBUFSIZE;
                       /* Limit length if we have a 6-bit header.  */
                       if ((sc->sc_hdrlen > 0) &&
                           (ucaa.ucaa_obufsize > UFTDIOBUFSIZE))
                               ucaa.ucaa_obufsize = UFTDIOBUFSIZE;
               } else {
                       aprint_error_dev(self, "unexpected endpoint\n");
                       goto bad;
               }
       }
       if (ucaa.ucaa_bulkin == -1) {
               aprint_error_dev(self, "Could not find data bulk in\n");
               goto bad;
       }
       if (ucaa.ucaa_bulkout == -1) {
               aprint_error_dev(self, "Could not find data bulk out\n");
               goto bad;
       }

       /* ucaa_bulkin, ucaa_bulkout set above */
       if (ucaa.ucaa_ibufsize == 0)
               ucaa.ucaa_ibufsize = UFTDIIBUFSIZE;
       ucaa.ucaa_ibufsizepad = ucaa.ucaa_ibufsize;
       if (ucaa.ucaa_obufsize == 0)
               ucaa.ucaa_obufsize = UFTDIOBUFSIZE - sc->sc_hdrlen;
       ucaa.ucaa_opkthdrlen = sc->sc_hdrlen;
       ucaa.ucaa_device = dev;
       ucaa.ucaa_iface = iface;
       ucaa.ucaa_methods = &uftdi_methods;
       ucaa.ucaa_arg = sc;
       ucaa.ucaa_info = NULL;

       DPRINTF(("uftdi: in=%#x out=%#x isize=%#x osize=%#x\n",
               ucaa.ucaa_bulkin, ucaa.ucaa_bulkout,
               ucaa.ucaa_ibufsize, ucaa.ucaa_obufsize));
       sc->sc_subdev = config_found(self, &ucaa, ucomprint,
           CFARGS(.submatch = ucomsubmatch));

       usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev, sc->sc_dev);

       if (!pmf_device_register(self, NULL, NULL))
               aprint_error_dev(self, "couldn't establish power handler\n");

       return;

bad:
       DPRINTF(("uftdi_attach: ATTACH ERROR\n"));
       sc->sc_dying = true;
       return;
}

static void
uftdi_childdet(device_t self, device_t child)
{
       struct uftdi_softc *sc = device_private(self);

       KASSERT(child == sc->sc_subdev);
       sc->sc_subdev = NULL;
}

static int
uftdi_detach(device_t self, int flags)
{
       struct uftdi_softc *sc = device_private(self);
       int rv = 0;

       DPRINTF(("uftdi_detach: sc=%p flags=%d\n", sc, flags));

       sc->sc_dying = true;

       if (sc->sc_subdev != NULL) {
               rv = config_detach(sc->sc_subdev, flags);
               sc->sc_subdev = NULL;
       }

       usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev, sc->sc_dev);

       return rv;
}

static int
uftdi_open(void *vsc, int portno)
{
       struct uftdi_softc *sc = vsc;
       usb_device_request_t req;
       usbd_status err;
       struct termios t;

       DPRINTF(("uftdi_open: sc=%p\n", sc));

       if (sc->sc_dying)
               return EIO;

       /* Perform a full reset on the device */
       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_RESET;
       USETW(req.wValue, FTDI_SIO_RESET_SIO);
       USETW(req.wIndex, portno);
       USETW(req.wLength, 0);
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       /* Set 9600 baud, 2 stop bits, no parity, 8 bits */
       t.c_ospeed = 9600;
       t.c_cflag = CSTOPB | CS8;
       (void)uftdi_param(sc, portno, &t);

       /* Turn on RTS/CTS flow control */
       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_FLOW_CTRL;
       USETW(req.wValue, 0);
       USETW2(req.wIndex, FTDI_SIO_RTS_CTS_HS, portno);
       USETW(req.wLength, 0);
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       return 0;
}

static void
uftdi_read(void *vsc, int portno, u_char **ptr, uint32_t *count)
{
       struct uftdi_softc *sc = vsc;
       u_char msr, lsr;

       DPRINTFN(15,("uftdi_read: sc=%p, port=%d count=%d\n", sc, portno,
                    *count));

       msr = FTDI_GET_MSR(*ptr);
       lsr = FTDI_GET_LSR(*ptr);

#ifdef UFTDI_DEBUG
       if (*count != 2)
               DPRINTFN(10,("uftdi_read: sc=%p, port=%d count=%d data[0]="
                           "0x%02x\n", sc, portno, *count, (*ptr)[2]));
#endif

       if (sc->sc_msr != msr ||
           (sc->sc_lsr & FTDI_LSR_MASK) != (lsr & FTDI_LSR_MASK)) {
               DPRINTF(("uftdi_read: status change msr=0x%02x(0x%02x) "
                        "lsr=0x%02x(0x%02x)\n", msr, sc->sc_msr,
                        lsr, sc->sc_lsr));
               sc->sc_msr = msr;
               sc->sc_lsr = lsr;
               ucom_status_change(device_private(sc->sc_subdev));
       }

       /* Adjust buffer pointer to skip status prefix */
       *ptr += 2;
}

static void
uftdi_write(void *vsc, int portno, u_char *to, u_char *from, uint32_t *count)
{
       struct uftdi_softc *sc = vsc;

       DPRINTFN(10,("uftdi_write: sc=%p, port=%d count=%u data[0]=0x%02x\n",
                    vsc, portno, *count, from[0]));

       /* Make length tag and copy data */
       if (sc->sc_hdrlen > 0)
               *to = FTDI_OUT_TAG(*count, portno);

       memcpy(to + sc->sc_hdrlen, from, *count);
       *count += sc->sc_hdrlen;
}

static void
uftdi_set(void *vsc, int portno, int reg, int onoff)
{
       struct uftdi_softc *sc = vsc;
       usb_device_request_t req;
       int ctl;

       DPRINTF(("uftdi_set: sc=%p, port=%d reg=%d onoff=%d\n", vsc, portno,
                reg, onoff));

       if (sc->sc_dying)
               return;

       switch (reg) {
       case UCOM_SET_DTR:
               ctl = onoff ? FTDI_SIO_SET_DTR_HIGH : FTDI_SIO_SET_DTR_LOW;
               break;
       case UCOM_SET_RTS:
               ctl = onoff ? FTDI_SIO_SET_RTS_HIGH : FTDI_SIO_SET_RTS_LOW;
               break;
       case UCOM_SET_BREAK:
               uftdi_break(sc, portno, onoff);
               return;
       default:
               return;
       }
       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_MODEM_CTRL;
       USETW(req.wValue, ctl);
       USETW(req.wIndex, portno);
       USETW(req.wLength, 0);
       DPRINTFN(2,("uftdi_set: reqtype=0x%02x req=0x%02x value=0x%04x "
                   "index=0x%04x len=%d\n", req.bmRequestType, req.bRequest,
                   UGETW(req.wValue), UGETW(req.wIndex), UGETW(req.wLength)));
       (void)usbd_do_request(sc->sc_udev, &req, NULL);
}

/*
* Return true if the given speed is within operational tolerance of the target
* speed.  FTDI recommends that the hardware speed be within 3% of nominal.
*/
static inline bool
uftdi_baud_within_tolerance(uint64_t speed, uint64_t target)
{
       return ((speed >= (target * 100) / 103) &&
           (speed <= (target * 100) / 97));
}

static int
uftdi_encode_baudrate(struct uftdi_softc *sc, int speed, int *rate, int *ratehi)
{
       static const uint8_t encoded_fraction[8] = {
           0, 3, 2, 4, 1, 5, 6, 7
       };
       static const uint8_t roundoff_232a[16] = {
           0,  1,  0,  1,  0, -1,  2,  1,
           0, -1, -2, -3,  4,  3,  2,  1,
       };
       uint32_t clk, divisor, fastclk_flag, frac, hwspeed;

       /*
        * If this chip has the fast clock capability and the speed is within
        * range, use the 12MHz clock, otherwise the standard clock is 3MHz.
        */
       if ((sc->sc_flags & FLAGS_BAUDCLK_12M) && speed >= 1200) {
               clk = 12000000;
               fastclk_flag = (1 << 17);
       } else {
               clk = 3000000;
               fastclk_flag = 0;
       }

       /*
        * Make sure the requested speed is reachable with the available clock
        * and a 14-bit divisor.
        */
       if (speed < (clk >> 14) || speed > clk)
               return -1;

       /*
        * Calculate the divisor, initially yielding a fixed point number with a
        * 4-bit (1/16ths) fraction, then round it to the nearest fraction the
        * hardware can handle.  When the integral part of the divisor is
        * greater than one, the fractional part is in 1/8ths of the base clock.
        * The FT8U232AM chips can handle only 0.125, 0.250, and 0.5 fractions.
        * Later chips can handle all 1/8th fractions.
        *
        * If the integral part of the divisor is 1, a special rule applies: the
        * fractional part can only be .0 or .5 (this is a limitation of the
        * hardware).  We handle this by truncating the fraction rather than
        * rounding, because this only applies to the two fastest speeds the
        * chip can achieve and rounding doesn't matter, either you've asked for
        * that exact speed or you've asked for something the chip can't do.
        *
        * For the FT8U232AM chips, use a roundoff table to adjust the result
        * to the nearest 1/8th fraction that is supported by the hardware,
        * leaving a fixed-point number with a 3-bit fraction which exactly
        * represents the math the hardware divider will do.  For later-series
        * chips that support all 8 fractional divisors, just round 16ths to
        * 8ths by adding 1 and dividing by 2.
        */
       divisor = (clk << 4) / speed;
       if ((divisor & 0xf) == 1)
               divisor &= 0xfffffff8;
       else if (sc->sc_flags & FLAGS_ROUNDOFF_232A)
               divisor += roundoff_232a[divisor & 0x0f];
       else
               divisor += 1;  /* Rounds odd 16ths up to next 8th. */
       divisor >>= 1;

       /*
        * Ensure the resulting hardware speed will be within operational
        * tolerance (within 3% of nominal).
        */
       hwspeed = (clk << 3) / divisor;
       if (!uftdi_baud_within_tolerance(hwspeed, speed))
               return -1;

       /*
        * Re-pack the divisor into hardware format. The lower 14-bits hold the
        * integral part, while the upper bits specify the fraction by indexing
        * a table of fractions within the hardware which is laid out as:
        *    {0.0, 0.5, 0.25, 0.125, 0.325, 0.625, 0.725, 0.875}
        * The A-series chips only have the first four table entries; the
        * roundoff table logic above ensures that the fractional part for those
        * chips will be one of the first four values.
        *
        * When the divisor is 1 a special encoding applies:  1.0 is encoded as
        * 0.0, and 1.5 is encoded as 1.0.  The rounding logic above has already
        * ensured that the fraction is either .0 or .5 if the integral is 1.
        */
       frac = divisor & 0x07;
       divisor >>= 3;
       if (divisor == 1) {
               if (frac == 0)
                       divisor = 0;    /* 1.0 becomes 0.0 */
               else
                       frac = 0;       /* 1.5 becomes 1.0 */
       }
       divisor |= (encoded_fraction[frac] << 14) | fastclk_flag;

       *rate = (uint16_t)divisor;
       *ratehi = (uint16_t)(divisor >> 16);

       /*
        * If this chip requires the baud bits to be in the high byte of the
        * index word, move the bits up to that location.
        */
       if (sc->sc_flags & FLAGS_BAUDBITS_HINDEX)
               *ratehi <<= 8;

       return 0;
}

static int
uftdi_param(void *vsc, int portno, struct termios *t)
{
       struct uftdi_softc *sc = vsc;
       usb_device_request_t req;
       usbd_status err;
       int rate, ratehi, rerr, data, flow;

       DPRINTF(("uftdi_param: sc=%p\n", sc));

       if (sc->sc_dying)
               return EIO;

       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_BITMODE;
       USETW(req.wValue, FTDI_BITMODE_RESET << 8 | 0x00);
       USETW(req.wIndex, portno);
       USETW(req.wLength, 0);
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       switch (sc->sc_type) {
       case UFTDI_TYPE_SIO:
               switch (t->c_ospeed) {
               case 300: rate = ftdi_sio_b300; break;
               case 600: rate = ftdi_sio_b600; break;
               case 1200: rate = ftdi_sio_b1200; break;
               case 2400: rate = ftdi_sio_b2400; break;
               case 4800: rate = ftdi_sio_b4800; break;
               case 9600: rate = ftdi_sio_b9600; break;
               case 19200: rate = ftdi_sio_b19200; break;
               case 38400: rate = ftdi_sio_b38400; break;
               case 57600: rate = ftdi_sio_b57600; break;
               case 115200: rate = ftdi_sio_b115200; break;
               default:
                       return EINVAL;
               }
               ratehi = 0;
               break;
       case UFTDI_TYPE_8U232AM:
               rerr = uftdi_encode_baudrate(sc, t->c_ospeed, &rate, &ratehi);
               if (rerr != 0)
                       return EINVAL;
               break;
       default:
               return EINVAL;
       }
       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_BAUD_RATE;
       USETW(req.wValue, rate);
       USETW(req.wIndex, portno | ratehi);
       USETW(req.wLength, 0);
       DPRINTFN(2,("uftdi_param: reqtype=0x%02x req=0x%02x value=0x%04x "
                   "index=0x%04x len=%d\n", req.bmRequestType, req.bRequest,
                   UGETW(req.wValue), UGETW(req.wIndex), UGETW(req.wLength)));
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       if (ISSET(t->c_cflag, CSTOPB))
               data = FTDI_SIO_SET_DATA_STOP_BITS_2;
       else
               data = FTDI_SIO_SET_DATA_STOP_BITS_1;
       if (ISSET(t->c_cflag, PARENB)) {
               if (ISSET(t->c_cflag, PARODD))
                       data |= FTDI_SIO_SET_DATA_PARITY_ODD;
               else
                       data |= FTDI_SIO_SET_DATA_PARITY_EVEN;
       } else
               data |= FTDI_SIO_SET_DATA_PARITY_NONE;
       switch (ISSET(t->c_cflag, CSIZE)) {
       case CS5:
               data |= FTDI_SIO_SET_DATA_BITS(5);
               break;
       case CS6:
               data |= FTDI_SIO_SET_DATA_BITS(6);
               break;
       case CS7:
               data |= FTDI_SIO_SET_DATA_BITS(7);
               break;
       case CS8:
               data |= FTDI_SIO_SET_DATA_BITS(8);
               break;
       }
       sc->last_lcr = data;

       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_DATA;
       USETW(req.wValue, data);
       USETW(req.wIndex, portno);
       USETW(req.wLength, 0);
       DPRINTFN(2,("uftdi_param: reqtype=0x%02x req=0x%02x value=0x%04x "
                   "index=0x%04x len=%d\n", req.bmRequestType, req.bRequest,
                   UGETW(req.wValue), UGETW(req.wIndex), UGETW(req.wLength)));
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       if (ISSET(t->c_cflag, CRTSCTS)) {
               flow = FTDI_SIO_RTS_CTS_HS;
               USETW(req.wValue, 0);
       } else if (ISSET(t->c_iflag, IXON) && ISSET(t->c_iflag, IXOFF)) {
               flow = FTDI_SIO_XON_XOFF_HS;
               USETW2(req.wValue, t->c_cc[VSTOP], t->c_cc[VSTART]);
       } else {
               flow = FTDI_SIO_DISABLE_FLOW_CTRL;
               USETW(req.wValue, 0);
       }
       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_FLOW_CTRL;
       USETW2(req.wIndex, flow, portno);
       USETW(req.wLength, 0);
       err = usbd_do_request(sc->sc_udev, &req, NULL);
       if (err)
               return EIO;

       return 0;
}

static void
uftdi_get_status(void *vsc, int portno, u_char *lsr, u_char *msr)
{
       struct uftdi_softc *sc = vsc;

       DPRINTF(("uftdi_status: msr=0x%02x lsr=0x%02x\n",
                sc->sc_msr, sc->sc_lsr));

       if (sc->sc_dying)
               return;

       *msr = sc->sc_msr;
       *lsr = sc->sc_lsr;
}

static void
uftdi_break(void *vsc, int portno, int onoff)
{
       struct uftdi_softc *sc = vsc;
       usb_device_request_t req;
       int data;

       DPRINTF(("uftdi_break: sc=%p, port=%d onoff=%d\n", vsc, portno,
                 onoff));

       if (onoff) {
               data = sc->last_lcr | FTDI_SIO_SET_BREAK;
       } else {
               data = sc->last_lcr;
       }

       req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
       req.bRequest = FTDI_SIO_SET_DATA;
       USETW(req.wValue, data);
       USETW(req.wIndex, portno);
       USETW(req.wLength, 0);
       (void)usbd_do_request(sc->sc_udev, &req, NULL);
}