[Qemu-devel] [PATCH] ps2: add support of auto-repeat

[Amos Kong <akong@redhat.com>]

Guest driver sets repeat rate and delay time by KBD_CMD_SET_RATE,
but ps2 backend doesn't process it and no auto-repeat implementation.
This patch adds support of auto-repeat feature.

Guest ps2 driver sets autorepeat to fastest possible in reset,
period: 250ms, delay: 33ms

Tested by 'sendkey' monitor command.

referenced: http://www.computer-engineering.org/ps2keyboard/

Signed-off-by: Amos Kong <akong@redhat.com>
---
 hw/input/ps2.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 3412079..1cfe055 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -94,6 +94,9 @@ typedef struct {
     int translate;
     int scancode_set; /* 1=XT, 2=AT, 3=PS/2 */
     int ledstate;
+    int repeat_period; /* typematic period, ms */
+    int repeat_delay; /* typematic delay, ms */
+    int repeat_key; /* keycode to repeat */
 } PS2KbdState;
 
 typedef struct {
@@ -146,6 +149,22 @@ void ps2_queue(void *opaque, int b)
     s->update_irq(s->update_arg, 1);
 }
 
+static QEMUTimer *repeat_timer;
+static bool auto_repeat;
+
+static void repeat_ps2_queue(void *opaque)
+{
+    PS2KbdState *s = opaque;
+
+    if (auto_repeat) {
+        qemu_mod_timer(repeat_timer, qemu_get_clock_ns(vm_clock) +
+                       muldiv64(get_ticks_per_sec(), s->repeat_period,
+                       1000));
+        ps2_queue(&s->common, s->repeat_key);
+    }
+}
+
+
 /*
    keycode is expressed as follow:
    bit 7    - 0 key pressed, 1 = key released
@@ -167,7 +186,17 @@ static void ps2_put_keycode(void *opaque, int keycode)
             keycode = ps2_raw_keycode_set3[keycode & 0x7f];
         }
       }
+
+    /* only auto-repeat press event */
+    auto_repeat = ~keycode & 0x80;
     ps2_queue(&s->common, keycode);
+
+    if (auto_repeat) {
+        s->repeat_key = keycode;
+        /* delay a while before first repeat */
+        qemu_mod_timer(repeat_timer, qemu_get_clock_ns(vm_clock) +
+                       muldiv64(get_ticks_per_sec(), s->repeat_delay, 1000));
+    }
 }
 
 uint32_t ps2_read_data(void *opaque)
@@ -213,6 +242,11 @@ static void ps2_reset_keyboard(PS2KbdState *s)
 
 void ps2_write_keyboard(void *opaque, int val)
 {
+    /* repeat period/delay table from kernel (drivers/input/keyboard/atkbd.c) */
+    const short period[32] = { 33,  37,  42,  46,  50,  54,  58,  63,  67,  75,
+                83,  92, 100, 109, 116, 125, 133, 149, 167, 182, 200, 217, 232,
+                250, 270, 303, 333, 370, 400, 435, 470, 500 };
+    const short delay[4] = { 250, 500, 750, 1000 };
     PS2KbdState *s = (PS2KbdState *)opaque;
 
     switch(s->common.write_cmd) {
@@ -288,6 +322,11 @@ void ps2_write_keyboard(void *opaque, int val)
         s->common.write_cmd = -1;
         break;
     case KBD_CMD_SET_RATE:
+       /* Bit0-4 specifies the repeat rate */
+        s->repeat_period = period[val & 0x1f];
+       /* Bit5-6 bit specifies the delay time */
+        s->repeat_delay = delay[(val & 0x60) >> 5];
+
         ps2_queue(&s->common, KBD_REPLY_ACK);
         s->common.write_cmd = -1;
         break;
@@ -536,6 +575,8 @@ static void ps2_kbd_reset(void *opaque)
     s->scan_enabled = 0;
     s->translate = 0;
     s->scancode_set = 0;
+    s->repeat_period = 92;
+    s->repeat_delay = 500;
 }
 
 static void ps2_mouse_reset(void *opaque)
@@ -660,6 +701,7 @@ void *ps2_kbd_init(void (*update_irq)(void *, int), void *update_arg)
     vmstate_register(NULL, 0, &vmstate_ps2_keyboard, s);
     qemu_add_kbd_event_handler(ps2_put_keycode, s);
     qemu_register_reset(ps2_kbd_reset, s);
+    repeat_timer = qemu_new_timer_ns(vm_clock, repeat_ps2_queue, s);
     return s;
 }
 
-- 
1.8.1.4