Modern chromebooks expose a debugging interface on one of their USB
Type-C connectors. Part of this interface are *three* USB serial
devices that connect to microcontrollers and a serial port on the SoC.
It all works nicely with ucom(4) but we need a bit of glue to actually
make that attach. What I ended up is pretty close to uscom(4) but the
discovery of the descriptors is different and I don't immediately see
a way to fold this into that driver.
Should this be enabled on more architectures than amd64?
ok?
Index: arch/amd64/conf/GENERIC
===================================================================
RCS file: /cvs/src/sys/arch/amd64/conf/GENERIC,v
retrieving revision 1.470
diff -u -p -r1.470 GENERIC
--- arch/amd64/conf/GENERIC 4 May 2019 17:59:40 -0000 1.470
+++ arch/amd64/conf/GENERIC 8 May 2019 22:03:21 -0000
@@ -234,6 +234,8 @@ uslcom* at uhub? # Silicon Laboratories
ucom* at uslcom?
uscom* at uhub? # Simple USB serial adapters
ucom* at uscom?
+ucrcom* at uhub? # Chromebook serial
+ucom* at ucrcom?
uark* at uhub? # Arkmicro ARK3116 serial
ucom* at uark?
moscom* at uhub? # MosChip MCS7703 serial
Index: dev/usb/files.usb
===================================================================
RCS file: /cvs/src/sys/dev/usb/files.usb,v
retrieving revision 1.137
diff -u -p -r1.137 files.usb
--- dev/usb/files.usb 27 Mar 2019 22:08:51 -0000 1.137
+++ dev/usb/files.usb 8 May 2019 22:02:02 -0000
@@ -342,6 +342,11 @@ device uscom: ucombus
attach uscom at uhub
file dev/usb/uscom.c uscom
+# Chromebook serial
+device ucrcom: ucombus
+attach ucrcom at uhub
+file dev/usb/ucrcom.c ucrcom
+
# Exar XR21V1410
device uxrcom: ucombus
attach uxrcom at uhub
Index: dev/usb/ucrcom.c
===================================================================
RCS file: dev/usb/ucrcom.c
diff -N dev/usb/ucrcom.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ dev/usb/ucrcom.c 8 May 2019 22:49:57 -0000
@@ -0,0 +1,136 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2019 Mark Kettenis <kette...@openbsd.org>
+ *
+ * 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.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/tty.h>
+#include <sys/device.h>
+
+#include <dev/usb/usb.h>
+#include <dev/usb/usbdi.h>
+#include <dev/usb/usbdi_util.h>
+#include <dev/usb/usbdevs.h>
+
+#include <dev/usb/ucomvar.h>
+
+#define UCRCOMBUFSZ 64
+
+struct ucrcom_softc {
+ struct device sc_dev;
+ struct device *sc_subdev;
+};
+
+struct ucom_methods ucrcom_methods = { NULL };
+
+int ucrcom_match(struct device *, void *, void *);
+void ucrcom_attach(struct device *, struct device *, void *);
+int ucrcom_detach(struct device *, int);
+
+struct cfdriver ucrcom_cd = {
+ NULL, "ucrcom", DV_DULL
+};
+
+const struct cfattach ucrcom_ca = {
+ sizeof(struct ucrcom_softc), ucrcom_match, ucrcom_attach, ucrcom_detach
+};
+
+int
+ucrcom_match(struct device *parent, void *match, void *aux)
+{
+ struct usb_attach_arg *uaa = aux;
+ usb_interface_descriptor_t *id;
+ usb_device_descriptor_t *dd;
+
+ if (uaa->iface == NULL)
+ return UMATCH_NONE;
+
+ id = usbd_get_interface_descriptor(uaa->iface);
+ dd = usbd_get_device_descriptor(uaa->device);
+ if (id == NULL || dd == NULL)
+ return UMATCH_NONE;
+
+ if (UGETW(dd->idVendor) == USB_VENDOR_GOOGLE &&
+ id->bInterfaceClass == UICLASS_VENDOR &&
+ id->bInterfaceSubClass == 0x50 &&
+ id->bInterfaceProtocol == 1)
+ return UMATCH_VENDOR_IFACESUBCLASS_IFACEPROTO;
+
+ return UMATCH_NONE;
+}
+
+void
+ucrcom_attach(struct device *parent, struct device *self, void *aux)
+{
+ struct ucrcom_softc *sc = (struct ucrcom_softc *)self;
+ struct usb_attach_arg *uaa = aux;
+ struct ucom_attach_args uca;
+ usb_interface_descriptor_t *id;
+ usb_endpoint_descriptor_t *ed;
+ int i;
+
+ id = usbd_get_interface_descriptor(uaa->iface);
+
+ memset(&uca, 0, sizeof(uca));
+ uca.bulkin = uca.bulkout = -1;
+ for (i = 0; i < id->bNumEndpoints; i++) {
+ ed = usbd_interface2endpoint_descriptor(uaa->iface, i);
+ if (ed == NULL) {
+ printf("%s: no endpoint descriptor for %d\n",
+ sc->sc_dev.dv_xname, i);
+ usbd_deactivate(uaa->device);
+ return;
+ }
+
+ if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
+ UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK)
+ uca.bulkin = ed->bEndpointAddress;
+ else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
+ UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK)
+ uca.bulkout = ed->bEndpointAddress;
+ }
+
+ if (uca.bulkin == -1 || uca.bulkout == -1) {
+ printf("%s: missing endpoint\n", sc->sc_dev.dv_xname);
+ usbd_deactivate(uaa->device);
+ return;
+ }
+
+ uca.ibufsize = UCRCOMBUFSZ;
+ uca.ibufsizepad = UCRCOMBUFSZ;
+ uca.obufsize = UCRCOMBUFSZ;
+ uca.opkthdrlen = 0;
+ uca.device = uaa->device;
+ uca.iface = uaa->iface;
+ uca.methods = &ucrcom_methods;
+ uca.arg = sc;
+
+ sc->sc_subdev = config_found_sm(self, &uca, ucomprint, ucomsubmatch);
+}
+
+int
+ucrcom_detach(struct device *self, int flags)
+{
+ struct ucrcom_softc *sc = (struct ucrcom_softc *)self;
+ int rv = 0;
+
+ if (sc->sc_subdev != NULL)
+ rv = config_detach(sc->sc_subdev, flags);
+
+ return rv;
+}
Index: dev/usb/usbdevs
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdevs,v
retrieving revision 1.698
diff -u -p -r1.698 usbdevs
--- dev/usb/usbdevs 24 Apr 2019 20:28:31 -0000 1.698
+++ dev/usb/usbdevs 8 May 2019 22:46:00 -0000
@@ -576,6 +576,7 @@ vendor LENOVO 0x17ef Lenovo
vendor WAVESENSE 0x17f4 WaveSense
vendor VAISALA 0x1843 VAISALA
vendor AMIT 0x18c5 AMIT
+vendor GOOGLE 0x18d1 Google
vendor QCOM 0x18e8 Qcom
vendor ELV 0x18ef ELV
vendor LINKSYS3 0x1915 Linksys
Index: dev/usb/usbdevs.h
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdevs.h,v
retrieving revision 1.710
diff -u -p -r1.710 usbdevs.h
--- dev/usb/usbdevs.h 24 Apr 2019 20:32:23 -0000 1.710
+++ dev/usb/usbdevs.h 8 May 2019 22:46:51 -0000
@@ -1,4 +1,4 @@
-/* $OpenBSD: usbdevs.h,v 1.710 2019/04/24 20:32:23 remi Exp $ */
+/* $OpenBSD$ */
/*
* THIS FILE IS AUTOMATICALLY GENERATED. DO NOT EDIT.
@@ -583,6 +583,7 @@
#define USB_VENDOR_WAVESENSE 0x17f4 /* WaveSense */
#define USB_VENDOR_VAISALA 0x1843 /* VAISALA */
#define USB_VENDOR_AMIT 0x18c5 /* AMIT */
+#define USB_VENDOR_GOOGLE 0x18d1 /* Google */
#define USB_VENDOR_QCOM 0x18e8 /* Qcom */
#define USB_VENDOR_ELV 0x18ef /* ELV */
#define USB_VENDOR_LINKSYS3 0x1915 /* Linksys */
Index: dev/usb/usbdevs_data.h
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdevs_data.h,v
retrieving revision 1.704
diff -u -p -r1.704 usbdevs_data.h
--- dev/usb/usbdevs_data.h 24 Apr 2019 20:32:23 -0000 1.704
+++ dev/usb/usbdevs_data.h 8 May 2019 22:46:51 -0000
@@ -1,4 +1,4 @@
-/* $OpenBSD: usbdevs_data.h,v 1.704 2019/04/24 20:32:23 remi Exp $ */
+/* $OpenBSD$ */
/*
* THIS FILE IS AUTOMATICALLY GENERATED. DO NOT EDIT.
@@ -13812,6 +13812,10 @@ const struct usb_known_vendor usb_known_
{
USB_VENDOR_AMIT,
"AMIT",
+ },
+ {
+ USB_VENDOR_GOOGLE,
+ "Google",
},
{
USB_VENDOR_QCOM,
