musicpal: Rework GPIO input events

The qdev_gpio conversion of 343ec8e caused come polarity mismatch of key
event pins and left an overly complex solution behind. Take this chance
and refactor the GPIO input system of the Musicpal, moving it closer to
reality:
 - Instantiate all 32 GPIO input pins and do the routing only via
   qdev_connect_gpio_out.
 - Implement IMR and IER registers. They manage the GPIO pin IRQ. IMR
   seems to enable IRQs on rising edges, IER on falling ones. At least
   this matches what the Musicpal fireware require.
 - Move key pin logic inversion from the GPIO layer to musicpal_key.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 75 insertions, 75 deletions

diff --git a/hw/musicpal.c b/hw/musicpal.c
index c8f0235981..f92c442dd2 100644
--- a/hw/musicpal.c
+++ b/hw/musicpal.c
@@ -935,16 +935,19 @@ static int mv88w8618_wlan_init(SysBusDevice *dev)
 #define MP_GPIO_OE_LO           0x008
 #define MP_GPIO_OUT_LO          0x00c
 #define MP_GPIO_IN_LO           0x010
+#define MP_GPIO_IER_LO          0x014
+#define MP_GPIO_IMR_LO          0x018
 #define MP_GPIO_ISR_LO          0x020
 #define MP_GPIO_OE_HI           0x508
 #define MP_GPIO_OUT_HI          0x50c
 #define MP_GPIO_IN_HI           0x510
+#define MP_GPIO_IER_HI          0x514
+#define MP_GPIO_IMR_HI          0x518
 #define MP_GPIO_ISR_HI          0x520
 
 /* GPIO bits & masks */
 #define MP_GPIO_LCD_BRIGHTNESS  0x00070000
 #define MP_GPIO_I2C_DATA_BIT    29
-#define MP_GPIO_I2C_DATA        (1 << MP_GPIO_I2C_DATA_BIT)
 #define MP_GPIO_I2C_CLOCK_BIT   30
 
 /* LCD brightness bits in GPIO_OE_HI */
@@ -955,12 +958,11 @@ typedef struct musicpal_gpio_state {
     uint32_t lcd_brightness;
     uint32_t out_state;
     uint32_t in_state;
+    uint32_t ier;
+    uint32_t imr;
     uint32_t isr;
-    uint32_t i2c_read_data;
-    uint32_t key_released;
-    uint32_t keys_event;    /* store the received key event */
     qemu_irq irq;
-    qemu_irq out[5];
+    qemu_irq out[5]; /* 3 brightness out + 2 lcd (data and clock ) */
 } musicpal_gpio_state;
 
 static void musicpal_gpio_brightness_update(musicpal_gpio_state *s) {
@@ -1007,48 +1009,21 @@ static void musicpal_gpio_brightness_update(musicpal_gpio_state *s) {
         qemu_set_irq(s->out[i], (brightness >> i) & 1);
 }
 
-static void musicpal_gpio_keys_update(musicpal_gpio_state *s)
-{
-        int gpio_mask = 0;
-
-        /* transform the key state for GPIO usage */
-        gpio_mask |= (s->keys_event & 15) << 8;
-        gpio_mask |= ((s->keys_event >> 4) & 15) << 19;
-
-        /* update GPIO state */
-        if (s->key_released) {
-            s->in_state |= gpio_mask;
-        } else {
-            s->in_state &= ~gpio_mask;
-            s->isr = gpio_mask;
-            qemu_irq_raise(s->irq);
-        }
-}
-
-static void musicpal_gpio_irq(void *opaque, int irq, int level)
+static void musicpal_gpio_pin_event(void *opaque, int pin, int level)
 {
     musicpal_gpio_state *s = (musicpal_gpio_state *) opaque;
+    uint32_t mask = 1 << pin;
+    uint32_t delta = level << pin;
+    uint32_t old = s->in_state & mask;
 
-    if (irq == 10) {
-        s->i2c_read_data = level;
-    }
-
-    /* receives keys bits */
-    if (irq <= 7) {
-        s->keys_event &= ~(1 << irq);
-        s->keys_event |= level << irq;
-        return;
-    }
+    s->in_state &= ~mask;
+    s->in_state |= delta;
 
-    /* receives key press/release */
-    if (irq == 8) {
-        s->key_released = level;
-        return;
+    if ((old ^ delta) &&
+        ((level && (s->imr & mask)) || (!level && (s->ier & mask)))) {
+        s->isr = mask;
+        qemu_irq_raise(s->irq);
     }
-
-    /* a key has been transmited */
-    if (irq == 9 && level == 1)
-        musicpal_gpio_keys_update(s);
 }
 
 static uint32_t musicpal_gpio_read(void *opaque, target_phys_addr_t offset)
@@ -1067,11 +1042,18 @@ static uint32_t musicpal_gpio_read(void *opaque, target_phys_addr_t offset)
     case MP_GPIO_IN_LO:
         return s->in_state & 0xFFFF;
     case MP_GPIO_IN_HI:
-        /* Update received I2C data */
-        s->in_state = (s->in_state & ~MP_GPIO_I2C_DATA) |
-                        (s->i2c_read_data << MP_GPIO_I2C_DATA_BIT);
         return s->in_state >> 16;
 
+    case MP_GPIO_IER_LO:
+        return s->ier & 0xFFFF;
+    case MP_GPIO_IER_HI:
+        return s->ier >> 16;
+
+    case MP_GPIO_IMR_LO:
+        return s->imr & 0xFFFF;
+    case MP_GPIO_IMR_HI:
+        return s->imr >> 16;
+
     case MP_GPIO_ISR_LO:
         return s->isr & 0xFFFF;
     case MP_GPIO_ISR_HI:
@@ -1105,6 +1087,19 @@ static void musicpal_gpio_write(void *opaque, target_phys_addr_t offset,
         qemu_set_irq(s->out[4], (s->out_state >> MP_GPIO_I2C_CLOCK_BIT) & 1);
         break;
 
+    case MP_GPIO_IER_LO:
+        s->ier = (s->ier & 0xFFFF0000) | (value & 0xFFFF);
+        break;
+    case MP_GPIO_IER_HI:
+        s->ier = (s->ier & 0xFFFF) | (value << 16);
+        break;
+
+    case MP_GPIO_IMR_LO:
+        s->imr = (s->imr & 0xFFFF0000) | (value & 0xFFFF);
+        break;
+    case MP_GPIO_IMR_HI:
+        s->imr = (s->imr & 0xFFFF) | (value << 16);
+        break;
     }
 }
 
@@ -1123,9 +1118,8 @@ static CPUWriteMemoryFunc * const musicpal_gpio_writefn[] = {
 static void musicpal_gpio_reset(musicpal_gpio_state *s)
 {
     s->in_state = 0xffffffff;
-    s->i2c_read_data = 1;
-    s->key_released = 0;
-    s->keys_event = 0;
+    s->ier = 0;
+    s->imr = 0;
     s->isr = 0;
 }
 
@@ -1142,10 +1136,9 @@ static int musicpal_gpio_init(SysBusDevice *dev)
 
     musicpal_gpio_reset(s);
 
-    /* 3 brightness out + 2 lcd (data and clock ) */
-    qdev_init_gpio_out(&dev->qdev, s->out, 5);
-    /* 10 gpio button input + 1 I2C data input */
-    qdev_init_gpio_in(&dev->qdev, musicpal_gpio_irq, 11);
+    qdev_init_gpio_out(&dev->qdev, s->out, ARRAY_SIZE(s->out));
+
+    qdev_init_gpio_in(&dev->qdev, musicpal_gpio_pin_event, 32);
 
     return 0;
 }
@@ -1165,7 +1158,7 @@ static int musicpal_gpio_init(SysBusDevice *dev)
 #define KEYCODE_LEFT            0x4b
 #define KEYCODE_RIGHT           0x4d
 
-#define MP_KEY_WHEEL_VOL       (1)
+#define MP_KEY_WHEEL_VOL       (1 << 0)
 #define MP_KEY_WHEEL_VOL_INV   (1 << 1)
 #define MP_KEY_WHEEL_NAV       (1 << 2)
 #define MP_KEY_WHEEL_NAV_INV   (1 << 3)
@@ -1177,8 +1170,8 @@ static int musicpal_gpio_init(SysBusDevice *dev)
 typedef struct musicpal_key_state {
     SysBusDevice busdev;
     uint32_t kbd_extended;
-    uint32_t keys_state;
-    qemu_irq out[10];
+    uint32_t pressed_keys;
+    qemu_irq out[8];
 } musicpal_key_state;
 
 static void musicpal_key_event(void *opaque, int keycode)
@@ -1229,27 +1222,30 @@ static void musicpal_key_event(void *opaque, int keycode)
             break;
         }
         /* Do not repeat already pressed buttons */
-        if (!(keycode & KEY_RELEASED) && !(s->keys_state & event))
+        if (!(keycode & KEY_RELEASED) && (s->pressed_keys & event)) {
             event = 0;
+        }
     }
 
     if (event) {
-
-        /* transmit key event on GPIOS */
-        for (i = 0; i <= 7; i++)
-            qemu_set_irq(s->out[i], (event >> i) & 1);
-
-        /* handle key press/release */
+        /* Raise GPIO pin first if repeating a key */
+        if (!(keycode & KEY_RELEASED) && (s->pressed_keys & event)) {
+            for (i = 0; i <= 7; i++) {
+                if (event & (1 << i)) {
+                    qemu_set_irq(s->out[i], 1);
+                }
+            }
+        }
+        for (i = 0; i <= 7; i++) {
+            if (event & (1 << i)) {
+                qemu_set_irq(s->out[i], !!(keycode & KEY_RELEASED));
+            }
+        }
         if (keycode & KEY_RELEASED) {
-            s->keys_state |= event;
-            qemu_irq_raise(s->out[8]);
+            s->pressed_keys &= ~event;
         } else {
-            s->keys_state &= ~event;
-            qemu_irq_lower(s->out[8]);
+            s->pressed_keys |= event;
         }
-
-        /* signal that a key event occured */
-        qemu_irq_pulse(s->out[9]);
     }
 
     s->kbd_extended = 0;
@@ -1262,10 +1258,9 @@ static int musicpal_key_init(SysBusDevice *dev)
     sysbus_init_mmio(dev, 0x0, 0);
 
     s->kbd_extended = 0;
-    s->keys_state = 0;
+    s->pressed_keys = 0;
 
-    /* 8 key event GPIO + 1 key press/release + 1 strobe */
-    qdev_init_gpio_out(&dev->qdev, s->out, 10);
+    qdev_init_gpio_out(&dev->qdev, s->out, ARRAY_SIZE(s->out));
 
     qemu_add_kbd_event_handler(musicpal_key_event, s);
 
@@ -1375,7 +1370,8 @@ static void musicpal_init(ram_addr_t ram_size,
     key_dev = sysbus_create_simple("musicpal_key", 0, NULL);
 
     /* I2C read data */
-    qdev_connect_gpio_out(i2c_dev, 0, qdev_get_gpio_in(dev, 10));
+    qdev_connect_gpio_out(i2c_dev, 0,
+                          qdev_get_gpio_in(dev, MP_GPIO_I2C_DATA_BIT));
     /* I2C data */
     qdev_connect_gpio_out(dev, 3, qdev_get_gpio_in(i2c_dev, 0));
     /* I2C clock */
@@ -1384,8 +1380,12 @@ static void musicpal_init(ram_addr_t ram_size,
     for (i = 0; i < 3; i++)
         qdev_connect_gpio_out(dev, i, qdev_get_gpio_in(lcd_dev, i));
 
-    for (i = 0; i < 10; i++)
-        qdev_connect_gpio_out(key_dev, i, qdev_get_gpio_in(dev, i));
+    for (i = 0; i < 4; i++) {
+        qdev_connect_gpio_out(key_dev, i, qdev_get_gpio_in(dev, i + 8));
+    }
+    for (i = 4; i < 8; i++) {
+        qdev_connect_gpio_out(key_dev, i, qdev_get_gpio_in(dev, i + 15));
+    }
 
 #ifdef HAS_AUDIO
     wm8750_dev = i2c_create_slave(i2c, "wm8750", MP_WM_ADDR);