[Qemu-devel] [PATCH] musicpal: Improve button handling

[Jan Kiszka <jan.kiszka@web.de>]

Looking at the hold-button-on-powerup thing, I came across some
improvable parts in the MusicPal's button handling. This patch allows
for repeated wheel events by keying the arrow keys pressed, corrects
some constant name, and introduces an explicitly maintained GPIO_ISR
state.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
---
 hw/musicpal.c |   27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

Index: b/hw/musicpal.c
===================================================================
--- a/hw/musicpal.c
+++ b/hw/musicpal.c
@@ -59,6 +59,7 @@
 #define MP_AUDIO_IRQ            30
 
 static uint32_t gpio_in_state = 0xffffffff;
+static uint32_t gpio_isr;
 static uint32_t gpio_out_state;
 static ram_addr_t sram_off;
 
@@ -1280,11 +1281,10 @@ static uint32_t musicpal_read(void *opaq
                         (i2c_get_data(mixer_i2c) << MP_GPIO_I2C_DATA_BIT);
         return gpio_in_state >> 16;
 
-    /* This is a simplification of reality */
     case MP_GPIO_ISR_LO:
-        return ~gpio_in_state & 0xFFFF;
+        return gpio_isr & 0xFFFF;
     case MP_GPIO_ISR_HI:
-        return ~gpio_in_state >> 16;
+        return gpio_isr >> 16;
 
     /* Workaround to allow loading the binary-only wlandrv.ko crap
      * from the original Freecom firmware. */
@@ -1324,7 +1324,7 @@ static void musicpal_write(void *opaque,
 }
 
 /* Keyboard codes & masks */
-#define KEY_PRESSED             0x80
+#define KEY_RELEASED            0x80
 #define KEY_CODE                0x7f
 
 #define KEYCODE_TAB             0x0f
@@ -1367,7 +1367,7 @@ static void musicpal_key_event(void *opa
             event = MP_GPIO_WHEEL_VOL;
             break;
         }
-    else
+    else {
         switch (keycode & KEY_CODE) {
         case KEYCODE_F:
             event = MP_GPIO_BTN_FAVORITS;
@@ -1385,12 +1385,19 @@ static void musicpal_key_event(void *opa
             event = MP_GPIO_BTN_MENU;
             break;
         }
+        /* Do not repeat already pressed buttons */
+        if (!(keycode & KEY_RELEASED) && !(gpio_in_state & event))
+            event = 0;
+    }
 
-    if (keycode & KEY_PRESSED)
-        gpio_in_state |= event;
-    else if (gpio_in_state & event) {
-        gpio_in_state &= ~event;
-        qemu_irq_raise(irq);
+    if (event) {
+        if (keycode & KEY_RELEASED) {
+            gpio_in_state |= event;
+        } else {
+            gpio_in_state &= ~event;
+            gpio_isr = event;
+            qemu_irq_raise(irq);
+        }
     }
 
     kbd_extended = 0;