i2c: pm_smbus: Add interrupt handling

Add the necessary code so that interrupts actually work from
the pm_smbus device.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1534796770-10295-7-git-send-email-minyard@acm.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/i2c/pm_smbus.c

@@ -214,6 +214,12 @@ static void smb_transaction_start(PMSMBus *s)
     s->smb_stat |= STS_HOST_BUSY;
 }
 
+static bool
+smb_irq_value(PMSMBus *s)
+{
+    return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN);
+}
+
 static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
                               unsigned width)
 {
@@ -309,7 +315,9 @@ static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
     }
 
  out:
-    return;
+    if (s->set_irq) {
+        s->set_irq(s, smb_irq_value(s));
+    }
 }
 
 static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
@@ -365,6 +373,10 @@ static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
     SMBUS_DPRINTF("SMB readb port=0x%04" HWADDR_PRIx " val=0x%02x\n",
                   addr, val);
 
+    if (s->set_irq) {
+        s->set_irq(s, smb_irq_value(s));
+    }
+
     return val;
 }
 

hw/i2c/smbus_ich9.c

@@ -40,6 +40,8 @@
 typedef struct ICH9SMBState {
     PCIDevice dev;
 
+    bool irq_enabled;
+
     PMSMBus smb;
 } ICH9SMBState;
 
@@ -109,11 +111,25 @@ static void ich9_smb_class_init(ObjectClass *klass, void *data)
     dc->user_creatable = false;
 }
 
+static void ich9_smb_set_irq(PMSMBus *pmsmb, bool enabled)
+{
+    ICH9SMBState *s = pmsmb->opaque;
+
+    if (enabled == s->irq_enabled) {
+        return;
+    }
+
+    s->irq_enabled = enabled;
+    pci_set_irq(&s->dev, enabled);
+}
+
 I2CBus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
 {
     PCIDevice *d =
         pci_create_simple_multifunction(bus, devfn, true, TYPE_ICH9_SMB_DEVICE);
     ICH9SMBState *s = ICH9_SMB_DEVICE(d);
+    s->smb.set_irq = ich9_smb_set_irq;
+    s->smb.opaque = s;
     return s->smb.smbus;
 }
 

include/hw/i2c/pm_smbus.h

@@ -23,6 +23,8 @@ typedef struct PMSMBus {
 
     /* Set by the user. */
     bool i2c_enable;
+    void (*set_irq)(struct PMSMBus *s, bool enabled);
+    void *opaque;
 
     /* Internally used by pm_smbus. */