[Qemu-devel] [PATCH 02/14] GPIO matrix keyboard implementation

[Filip Navara]

This patch introduces an emulation of the standard 4x4 matrix keyboard that
could be connected to GPIO controller.

It doesn't emulate any pull-up resistors connected to the wires and depends on
the GPIO controller for their emulation. This requires the GPIO controller to
support the notion of special -1 value on the GPIO pins, which signals that
the wire is currently disconnected.

The emulation of keys is implemented through standard QEMU keyboard emulation
capabilities. An individual key mapping is specified using a device property
"keys", which should be set to array of 16 bytes where each byte corresponds
to scan code of the key.

Signed-off-by: Filip Navara <address@hidden>
---
 Makefile.target  |    2 +-
 hw/gpio_keypad.c |  174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 175 insertions(+), 1 deletions(-)
 create mode 100644 hw/gpio_keypad.c

diff --git a/Makefile.target b/Makefile.target
index 0e66139..5c1bd4a 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -666,7 +666,7 @@ obj-y += framebuffer.o
 obj-y += syborg.o syborg_fb.o syborg_interrupt.o syborg_keyboard.o
 obj-y += syborg_serial.o syborg_timer.o syborg_pointer.o syborg_rtc.o
 obj-y += syborg_virtio.o
-obj-y += gpio_rotary.o
+obj-y += gpio_rotary.o gpio_keypad.o
 CPPFLAGS += -DHAS_AUDIO
 endif
 ifeq ($(TARGET_BASE_ARCH), sh4)
diff --git a/hw/gpio_keypad.c b/hw/gpio_keypad.c
new file mode 100644
index 0000000..7977d03
--- /dev/null
+++ b/hw/gpio_keypad.c
@@ -0,0 +1,174 @@
+/*
+ * GPIO 4x4 Matrix Keyboard
+ *
+ * Copyright (c) 2009 Filip Navara
+ *
+ * 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 "sysbus.h"
+#include "console.h"
+
+typedef struct KeyPadState {
+    SysBusDevice busdev;
+    qemu_irq out[8];
+    uint32_t in[8];
+    uint16_t keymask;
+    uint16_t keymap[256];
+    uint8_t extension;
+} KeyPadState;
+
+static void keypad_update(KeyPadState *s)
+{
+    int pin;
+    int keymask;
+
+    for (pin = 0; pin < 4; pin++) {
+        if (s->keymask & (0xf << (pin * 4))) {
+            keymask = s->keymask >> (pin * 4);
+            qemu_set_irq(
+                s->out[pin + 4],
+                (s->in[0] && (keymask & 0x1)) ||
+                (s->in[1] && (keymask & 0x2)) ||
+                (s->in[2] && (keymask & 0x4)) ||
+                (s->in[3] && (keymask & 0x8)));
+        } else {
+            qemu_set_irq(s->out[pin + 4], -1);
+        }
+
+        if (s->keymask & (0x1111 << pin)) {
+            keymask = s->keymask >> pin;
+            qemu_set_irq(
+                s->out[pin],
+                (s->in[4] && (keymask & 0x1)) ||
+                (s->in[5] && (keymask & 0x10)) ||
+                (s->in[6] && (keymask & 0x100)) ||
+                (s->in[7] && (keymask & 0x1000)));
+        } else {
+            qemu_set_irq(s->out[pin], -1);
+        }
+    }
+}
+
+static void keypad_set_pin(void *opaque, int pin, int level)
+{
+    KeyPadState *s = opaque;
+
+    s->in[pin] = level;
+    keypad_update(s);
+}
+
+static void keypad_keyboard_event(void *opaque, int keycode)
+{
+    KeyPadState *s = opaque;
+    int index;
+
+    if (keycode == 0xe0 && !s->extension) {
+        s->extension = 0x80;
+        return;
+    }
+
+    index = (keycode & 0x7f) | s->extension;
+    s->extension = 0;
+    if (keycode & 0x80)
+        s->keymask &= ~s->keymap[index];
+    else if (keycode)
+        s->keymask |= s->keymap[index];
+
+    keypad_update(s);
+}
+
+static void keypad_save(QEMUFile *f, void *opaque)
+{
+    KeyPadState *s = opaque;
+    int i;
+
+    for (i = 0; i < 8; i++) {
+        qemu_put_be32(f, s->in[i]);
+    }
+    qemu_put_be16(f, s->keymask);
+    qemu_put_byte(f, s->extension);
+}
+
+static int keypad_load(QEMUFile *f, void *opaque, int version_id)
+{
+    KeyPadState *s = opaque;
+    int i;
+
+    if (version_id != 1)
+        return -EINVAL;
+
+    for (i = 0; i < 8; i++) {
+        s->in[i] = qemu_get_be32(f);
+    }
+    s->keymask = qemu_get_be16(f);
+    s->extension = qemu_get_byte(f);
+
+    return 0;
+}
+
+
+/*
+static void keypad_late_init(DeviceState *dev)
+{
+    KeyPadState *s = FROM_SYSBUS(KeyPadState, sysbus_from_qdev(dev));
+
+    keypad_update(s);
+}
+*/
+
+static void keypad_init(SysBusDevice *dev)
+{
+    KeyPadState *s = FROM_SYSBUS(KeyPadState, dev);
+    const uint32_t *keys;
+    int i;
+
+    /* if (qdev_get_prop_array(&dev->qdev, "keys", &keys) == 16) { */
+    if ((keys = qdev_get_prop_ptr(&dev->qdev, "keys")) != NULL) {
+        for (i = 0; i < 16; i++) {
+            s->keymap[keys[i] & 0xff] = 1 << i;
+        }
+    }
+
+    qdev_init_gpio_in(&dev->qdev, keypad_set_pin, 8);
+    qdev_init_gpio_out(&dev->qdev, s->out, 8);
+
+    qemu_add_kbd_event_handler(keypad_keyboard_event, s);
+
+    register_savevm("gpio_keypad", -1, 1, keypad_save, keypad_load, s);
+}
+
+static SysBusDeviceInfo keypad_info = {
+    .init = keypad_init,
+    /* .qdev.late_init = keypad_late_init, */
+    .qdev.name  = "gpio,keypad",
+    .qdev.size  = sizeof(KeyPadState),
+    .qdev.props = (DevicePropList[]) {
+        /* {.name = "keys", .type = PROP_TYPE_ARRAY}, */
+        {.name = "keys", .type = PROP_TYPE_PTR},
+        {.name = NULL}
+    }
+};
+
+static void keypad_register(void)
+{
+    sysbus_register_withprop(&keypad_info);
+}
+
+device_init(keypad_register)
-- 
1.6.3.msysgit.0