1 files changed, 51 insertions, 7 deletions

diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
index 72b653463f..2ae13af35e 100644
--- a/hw/misc/pca9552.c
+++ b/hw/misc/pca9552.c
@@ -36,11 +36,16 @@ typedef struct PCA955xClass PCA955xClass;
 
 DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X,
                        TYPE_PCA955X)
-
+/*
+ * Note:  The LED_ON and LED_OFF configuration values for the PCA955X
+ *        chips are the reverse of the PCA953X family of chips.
+ */
 #define PCA9552_LED_ON   0x0
 #define PCA9552_LED_OFF  0x1
 #define PCA9552_LED_PWM0 0x2
 #define PCA9552_LED_PWM1 0x3
+#define PCA9552_PIN_LOW  0x0
+#define PCA9552_PIN_HIZ  0x1
 
 static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
 
@@ -107,17 +112,27 @@ static void pca955x_update_pin_input(PCA955xState *s)
 
     for (i = 0; i < k->pin_count; i++) {
         uint8_t input_reg = PCA9552_INPUT0 + (i / 8);
-        uint8_t input_shift = (i % 8);
+        uint8_t bit_mask = 1 << (i % 8);
         uint8_t config = pca955x_pin_get_config(s, i);
+        uint8_t old_value = s->regs[input_reg] & bit_mask;
+        uint8_t new_value;
 
         switch (config) {
         case PCA9552_LED_ON:
-            qemu_set_irq(s->gpio[i], 1);
-            s->regs[input_reg] |= 1 << input_shift;
+            /* Pin is set to 0V to turn on LED */
+            s->regs[input_reg] &= ~bit_mask;
             break;
         case PCA9552_LED_OFF:
-            qemu_set_irq(s->gpio[i], 0);
-            s->regs[input_reg] &= ~(1 << input_shift);
+            /*
+             * Pin is set to Hi-Z to turn off LED and
+             * pullup sets it to a logical 1 unless
+             * external device drives it low.
+             */
+            if (s->ext_state[i] == PCA9552_PIN_LOW) {
+                s->regs[input_reg] &= ~bit_mask;
+            } else {
+                s->regs[input_reg] |=  bit_mask;
+            }
             break;
         case PCA9552_LED_PWM0:
         case PCA9552_LED_PWM1:
@@ -125,6 +140,12 @@ static void pca955x_update_pin_input(PCA955xState *s)
         default:
             break;
         }
+
+        /* update irq state only if pin state changed */
+        new_value = s->regs[input_reg] & bit_mask;
+        if (new_value != old_value) {
+            qemu_set_irq(s->gpio_out[i], !!new_value);
+        }
     }
 }
 
@@ -332,6 +353,7 @@ static const VMStateDescription pca9552_vmstate = {
         VMSTATE_UINT8(len, PCA955xState),
         VMSTATE_UINT8(pointer, PCA955xState),
         VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS),
+        VMSTATE_UINT8_ARRAY(ext_state, PCA955xState, PCA955X_PIN_COUNT_MAX),
         VMSTATE_I2C_SLAVE(i2c, PCA955xState),
         VMSTATE_END_OF_LIST()
     }
@@ -350,6 +372,7 @@ static void pca9552_reset(DeviceState *dev)
     s->regs[PCA9552_LS2] = 0x55;
     s->regs[PCA9552_LS3] = 0x55;
 
+    memset(s->ext_state, PCA9552_PIN_HIZ, PCA955X_PIN_COUNT_MAX);
     pca955x_update_pin_input(s);
 
     s->pointer = 0xFF;
@@ -372,6 +395,26 @@ static void pca955x_initfn(Object *obj)
     }
 }
 
+static void pca955x_set_ext_state(PCA955xState *s, int pin, int level)
+{
+    if (s->ext_state[pin] != level) {
+        uint16_t pins_status = pca955x_pins_get_status(s);
+        s->ext_state[pin] = level;
+        pca955x_update_pin_input(s);
+        pca955x_display_pins_status(s, pins_status);
+    }
+}
+
+static void pca955x_gpio_in_handler(void *opaque, int pin, int level)
+{
+
+    PCA955xState *s = PCA955X(opaque);
+    PCA955xClass *k = PCA955X_GET_CLASS(s);
+
+    assert((pin >= 0) && (pin < k->pin_count));
+    pca955x_set_ext_state(s, pin, level);
+}
+
 static void pca955x_realize(DeviceState *dev, Error **errp)
 {
     PCA955xClass *k = PCA955X_GET_CLASS(dev);
@@ -381,7 +424,8 @@ static void pca955x_realize(DeviceState *dev, Error **errp)
         s->description = g_strdup("pca-unspecified");
     }
 
-    qdev_init_gpio_out(dev, s->gpio, k->pin_count);
+    qdev_init_gpio_out(dev, s->gpio_out, k->pin_count);
+    qdev_init_gpio_in(dev, pca955x_gpio_in_handler, k->pin_count);
 }
 
 static Property pca955x_properties[] = {