Add wctablet device

Add QEMU Wacom Penpartner serial tablet emulation.
GSoC 2016 project.

Signed-off-by: Anatoli Huseu1 <avg.tolik@gmail.com>

Various cleanups.
Add line speed tracking.
Implement ST and SP commands.
Adapted to chardev QOMification.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1486391007-10116-1-git-send-email-kraxel@redhat.com

7 files changed, 385 insertions, 3 deletions

diff --git a/Makefile.objs b/Makefile.objs
index 431fc59264..e4bfc160bd 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -125,6 +125,7 @@ trace-events-subdirs += crypto
 trace-events-subdirs += io
 trace-events-subdirs += migration
 trace-events-subdirs += block
+trace-events-subdirs += backends
 trace-events-subdirs += hw/block
 trace-events-subdirs += hw/block/dataplane
 trace-events-subdirs += hw/char
diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index 18469980e6..0e0f1567b2 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -1,7 +1,7 @@
 common-obj-y += rng.o rng-egd.o
 common-obj-$(CONFIG_POSIX) += rng-random.o
 
-common-obj-y += msmouse.o testdev.o
+common-obj-y += msmouse.o wctablet.o testdev.o
 common-obj-$(CONFIG_BRLAPI) += baum.o
 baum.o-cflags := $(SDL_CFLAGS)
 
diff --git a/backends/trace-events b/backends/trace-events
new file mode 100644
index 0000000000..8c3289a3f9
--- /dev/null
+++ b/backends/trace-events
@@ -0,0 +1,10 @@
+# See docs/tracing.txt for syntax documentation.
+
+# backends/wctablet.c
+wct_init(void) ""
+wct_cmd_re(void) ""
+wct_cmd_st(void) ""
+wct_cmd_sp(void) ""
+wct_cmd_ts(int input) "0x%02x"
+wct_cmd_other(const char *cmd) "%s"
+wct_speed(int speed) "%d"
diff --git a/backends/wctablet.c b/backends/wctablet.c
new file mode 100644
index 0000000000..a4d3ae098a
--- /dev/null
+++ b/backends/wctablet.c
@@ -0,0 +1,369 @@
+/*
+ * QEMU Wacom Penpartner serial tablet emulation
+ *
+ * some protocol details:
+ *   http://linuxwacom.sourceforge.net/wiki/index.php/Serial_Protocol_IV
+ *
+ * Copyright (c) 2016 Anatoli Huseu1
+ * Copyright (c) 2016,17 Gerd Hoffmann
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "sysemu/char.h"
+#include "ui/console.h"
+#include "ui/input.h"
+#include "trace.h"
+
+
+#define WC_OUTPUT_BUF_MAX_LEN 512
+#define WC_COMMAND_MAX_LEN 60
+
+#define WC_L7(n) ((n) & 127)
+#define WC_M7(n) (((n) >> 7) & 127)
+#define WC_H2(n) ((n) >> 14)
+
+#define WC_L4(n) ((n) & 15)
+#define WC_H4(n) (((n) >> 4) & 15)
+
+/* Model string and config string */
+#define WC_MODEL_STRING_LENGTH 18
+uint8_t WC_MODEL_STRING[WC_MODEL_STRING_LENGTH + 1] = "~#CT-0045R,V1.3-5,";
+
+#define WC_CONFIG_STRING_LENGTH 8
+uint8_t WC_CONFIG_STRING[WC_CONFIG_STRING_LENGTH + 1] = "96,N,8,0";
+
+#define WC_FULL_CONFIG_STRING_LENGTH 61
+uint8_t WC_FULL_CONFIG_STRING[WC_FULL_CONFIG_STRING_LENGTH + 1] = {
+    0x5c, 0x39, 0x36, 0x2c, 0x4e, 0x2c, 0x38, 0x2c,
+    0x31, 0x28, 0x01, 0x24, 0x57, 0x41, 0x43, 0x30,
+    0x30, 0x34, 0x35, 0x5c, 0x5c, 0x50, 0x45, 0x4e, 0x5c,
+    0x57, 0x41, 0x43, 0x30, 0x30, 0x30, 0x30, 0x5c,
+    0x54, 0x61, 0x62, 0x6c, 0x65, 0x74, 0x0d, 0x0a,
+    0x43, 0x54, 0x2d, 0x30, 0x30, 0x34, 0x35, 0x52,
+    0x2c, 0x56, 0x31, 0x2e, 0x33, 0x2d, 0x35, 0x0d,
+    0x0a, 0x45, 0x37, 0x29
+};
+
+/* This structure is used to save private info for Wacom Tablet. */
+typedef struct {
+    Chardev parent;
+    QemuInputHandlerState *hs;
+
+    /* Query string from serial */
+    uint8_t query[100];
+    int query_index;
+
+    /* Command to be sent to serial port */
+    uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
+    int outlen;
+
+    int line_speed;
+    bool send_events;
+    int axis[INPUT_AXIS__MAX];
+    bool btns[INPUT_BUTTON__MAX];
+
+} TabletChardev;
+
+#define TYPE_CHARDEV_WCTABLET "chardev-wctablet"
+#define WCTABLET_CHARDEV(obj)                                      \
+    OBJECT_CHECK(TabletChardev, (obj), TYPE_CHARDEV_WCTABLET)
+
+
+static void wctablet_chr_accept_input(Chardev *chr);
+
+static void wctablet_shift_input(TabletChardev *tablet, int count)
+{
+    tablet->query_index -= count;
+    memmove(tablet->query, tablet->query + count, tablet->query_index);
+    tablet->query[tablet->query_index] = 0;
+}
+
+static void wctablet_queue_output(TabletChardev *tablet, uint8_t *buf, int count)
+{
+    if (tablet->outlen + count > sizeof(tablet->outbuf)) {
+        return;
+    }
+
+    memcpy(tablet->outbuf + tablet->outlen, buf, count);
+    tablet->outlen += count;
+    wctablet_chr_accept_input(CHARDEV(tablet));
+}
+
+static void wctablet_reset(TabletChardev *tablet)
+{
+    /* clear buffers */
+    tablet->query_index = 0;
+    tablet->outlen = 0;
+    /* reset state */
+    tablet->send_events = false;
+}
+
+static void wctablet_queue_event(TabletChardev *tablet)
+{
+    uint8_t codes[8] = { 0xe0, 0, 0, 0, 0, 0, 0 };
+
+    if (tablet->line_speed != 9600) {
+        return;
+    }
+
+    int newX = tablet->axis[INPUT_AXIS_X] * 0.1537;
+    int nexY = tablet->axis[INPUT_AXIS_Y] * 0.1152;
+
+    codes[0] = codes[0] | WC_H2(newX);
+    codes[1] = codes[1] | WC_M7(newX);
+    codes[2] = codes[2] | WC_L7(newX);
+
+    codes[3] = codes[3] | WC_H2(nexY);
+    codes[4] = codes[4] | WC_M7(nexY);
+    codes[5] = codes[5] | WC_L7(nexY);
+
+    if (tablet->btns[INPUT_BUTTON_LEFT]) {
+        codes[0] = 0xa0;
+    }
+
+    wctablet_queue_output(tablet, codes, 7);
+}
+
+static void wctablet_input_event(DeviceState *dev, QemuConsole *src,
+                                InputEvent *evt)
+{
+    TabletChardev *tablet = (TabletChardev *)dev;
+    InputMoveEvent *move;
+    InputBtnEvent *btn;
+
+    switch (evt->type) {
+    case INPUT_EVENT_KIND_ABS:
+        move = evt->u.abs.data;
+        tablet->axis[move->axis] = move->value;
+        break;
+
+    case INPUT_EVENT_KIND_BTN:
+        btn = evt->u.btn.data;
+        tablet->btns[btn->button] = btn->down;
+        break;
+
+    default:
+        /* keep gcc happy */
+        break;
+    }
+}
+
+static void wctablet_input_sync(DeviceState *dev)
+{
+    TabletChardev *tablet = (TabletChardev *)dev;
+
+    if (tablet->send_events) {
+        wctablet_queue_event(tablet);
+    }
+}
+
+static QemuInputHandler wctablet_handler = {
+    .name  = "QEMU Wacome Pen Tablet",
+    .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
+    .event = wctablet_input_event,
+    .sync  = wctablet_input_sync,
+};
+
+static void wctablet_chr_accept_input(Chardev *chr)
+{
+    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
+    int len, canWrite;
+
+    canWrite = qemu_chr_be_can_write(chr);
+    len = canWrite;
+    if (len > tablet->outlen) {
+        len = tablet->outlen;
+    }
+
+    if (len) {
+        qemu_chr_be_write(chr, tablet->outbuf, len);
+        tablet->outlen -= len;
+        if (tablet->outlen) {
+            memmove(tablet->outbuf, tablet->outbuf + len, tablet->outlen);
+        }
+    }
+}
+
+static int wctablet_chr_write(struct Chardev *chr,
+                              const uint8_t *buf, int len)
+{
+    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
+    unsigned int i, clen;
+    char *pos;
+
+    if (tablet->line_speed != 9600) {
+        return len;
+    }
+    for (i = 0; i < len && tablet->query_index < sizeof(tablet->query) - 1; i++) {
+        tablet->query[tablet->query_index++] = buf[i];
+    }
+    tablet->query[tablet->query_index] = 0;
+
+    while (tablet->query_index > 0 && (tablet->query[0] == '@'  ||
+                                       tablet->query[0] == '\r' ||
+                                       tablet->query[0] == '\n')) {
+        wctablet_shift_input(tablet, 1);
+    }
+    if (!tablet->query_index) {
+        return len;
+    }
+
+    if (strncmp((char *)tablet->query, "~#", 2) == 0) {
+        /* init / detect sequence */
+        trace_wct_init();
+        wctablet_shift_input(tablet, 2);
+        wctablet_queue_output(tablet, WC_MODEL_STRING,
+                              WC_MODEL_STRING_LENGTH);
+        return len;
+    }
+
+    /* detect line */
+    pos = strchr((char *)tablet->query, '\r');
+    if (!pos) {
+        pos = strchr((char *)tablet->query, '\n');
+    }
+    if (!pos) {
+        return len;
+    }
+    clen = pos - (char *)tablet->query;
+
+    /* process commands */
+    if (strncmp((char *)tablet->query, "RE", 2) == 0 &&
+        clen == 2) {
+        trace_wct_cmd_re();
+        wctablet_shift_input(tablet, 3);
+        wctablet_queue_output(tablet, WC_CONFIG_STRING,
+                              WC_CONFIG_STRING_LENGTH);
+
+    } else if (strncmp((char *)tablet->query, "ST", 2) == 0 &&
+               clen == 2) {
+        trace_wct_cmd_st();
+        wctablet_shift_input(tablet, 3);
+        tablet->send_events = true;
+        wctablet_queue_event(tablet);
+
+    } else if (strncmp((char *)tablet->query, "SP", 2) == 0 &&
+               clen == 2) {
+        trace_wct_cmd_sp();
+        wctablet_shift_input(tablet, 3);
+        tablet->send_events = false;
+
+    } else if (strncmp((char *)tablet->query, "TS", 2) == 0 &&
+               clen == 3) {
+        unsigned int input = tablet->query[2];
+        uint8_t codes[7] = {
+            0xa3,
+            ((input & 0x80) == 0) ? 0x7e : 0x7f,
+            (((WC_H4(input) & 0x7) ^ 0x5) << 4) | (WC_L4(input) ^ 0x7),
+            0x03,
+            0x7f,
+            0x7f,
+            0x00,
+        };
+        trace_wct_cmd_ts(input);
+        wctablet_shift_input(tablet, 4);
+        wctablet_queue_output(tablet, codes, 7);
+
+    } else {
+        tablet->query[clen] = 0; /* terminate line for printing */
+        trace_wct_cmd_other((char *)tablet->query);
+        wctablet_shift_input(tablet, clen + 1);
+
+    }
+
+    return len;
+}
+
+static int wctablet_chr_ioctl(Chardev *chr, int cmd, void *arg)
+{
+    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
+    QEMUSerialSetParams *ssp;
+
+    switch (cmd) {
+    case CHR_IOCTL_SERIAL_SET_PARAMS:
+        ssp = arg;
+        if (tablet->line_speed != ssp->speed) {
+            trace_wct_speed(ssp->speed);
+            wctablet_reset(tablet);
+            tablet->line_speed = ssp->speed;
+        }
+        break;
+    default:
+        return -ENOTSUP;
+    }
+    return 0;
+}
+
+static void wctablet_chr_finalize(Object *obj)
+{
+    TabletChardev *tablet = WCTABLET_CHARDEV(obj);
+
+    qemu_input_handler_unregister(tablet->hs);
+    g_free(tablet);
+}
+
+static void wctablet_chr_open(Chardev *chr,
+                              ChardevBackend *backend,
+                              bool *be_opened,
+                              Error **errp)
+{
+    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
+
+    *be_opened = true;
+
+    /* init state machine */
+    memcpy(tablet->outbuf, WC_FULL_CONFIG_STRING, WC_FULL_CONFIG_STRING_LENGTH);
+    tablet->outlen = WC_FULL_CONFIG_STRING_LENGTH;
+    tablet->query_index = 0;
+
+    tablet->hs = qemu_input_handler_register((DeviceState *)tablet,
+                                             &wctablet_handler);
+}
+
+static void wctablet_chr_class_init(ObjectClass *oc, void *data)
+{
+    ChardevClass *cc = CHARDEV_CLASS(oc);
+
+    cc->open = wctablet_chr_open;
+    cc->chr_write = wctablet_chr_write;
+    cc->chr_ioctl = wctablet_chr_ioctl;
+    cc->chr_accept_input = wctablet_chr_accept_input;
+}
+
+static const TypeInfo wctablet_type_info = {
+    .name = TYPE_CHARDEV_WCTABLET,
+    .parent = TYPE_CHARDEV,
+    .instance_size = sizeof(TabletChardev),
+    .instance_finalize = wctablet_chr_finalize,
+    .class_init = wctablet_chr_class_init,
+};
+
+static void register_types(void)
+{
+     type_register_static(&wctablet_type_info);
+}
+
+type_init(register_types);
diff --git a/chardev/char.c b/chardev/char.c
index abd525f75e..54cd5f4081 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -652,6 +652,7 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
     if (strcmp(filename, "null")    == 0 ||
         strcmp(filename, "pty")     == 0 ||
         strcmp(filename, "msmouse") == 0 ||
+        strcmp(filename, "wctablet") == 0 ||
         strcmp(filename, "braille") == 0 ||
         strcmp(filename, "testdev") == 0 ||
         strcmp(filename, "stdio")   == 0) {
diff --git a/docs/qdev-device-use.txt b/docs/qdev-device-use.txt
index 136d271120..b059405e0e 100644
--- a/docs/qdev-device-use.txt
+++ b/docs/qdev-device-use.txt
@@ -200,7 +200,7 @@ LEGACY-CHARDEV translates to -chardev HOST-OPTS... as follows:
 
 * null becomes -chardev null
 
-* pty, msmouse, braille, stdio likewise
+* pty, msmouse, wctablet, braille, stdio likewise
 
 * vc:WIDTHxHEIGHT becomes -chardev vc,width=WIDTH,height=HEIGHT
 
diff --git a/qapi-schema.json b/qapi-schema.json
index baa0d263d6..e9a6364b7d 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4890,7 +4890,7 @@
 #
 # Configuration info for the new chardev backend.
 #
-# Since: 1.4 (testdev since 2.2)
+# Since: 1.4 (testdev since 2.2, wctablet since 2.9)
 ##
 { 'union': 'ChardevBackend', 'data': { 'file'   : 'ChardevFile',
                                        'serial' : 'ChardevHostdev',
@@ -4902,6 +4902,7 @@
                                        'null'   : 'ChardevCommon',
                                        'mux'    : 'ChardevMux',
                                        'msmouse': 'ChardevCommon',
+                                       'wctablet' : 'ChardevCommon',
                                        'braille': 'ChardevCommon',
                                        'testdev': 'ChardevCommon',
                                        'stdio'  : 'ChardevStdio',