hw/char/pl011: Support all interrupt lines

The PL011 UART has six interrupt lines:
 * RX (receive data)
 * TX (transmit data)
 * RT (receive timeout)
 * MS (modem status)
 * E (errors)
 * combined (logical OR of all the above)

So far we have only emulated the combined interrupt line;
add support for the others, so that boards that wire them
up to different interrupt controller inputs can do so.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 44 insertions, 2 deletions

diff --git a/hw/char/pl011.c b/hw/char/pl011.c
index 0c4711e402..29f4e5eb22 100644
--- a/hw/char/pl011.c
+++ b/hw/char/pl011.c
@@ -7,6 +7,17 @@
  * This code is licensed under the GPL.
  */
 
+/*
+ * QEMU interface:
+ *  + sysbus MMIO region 0: device registers
+ *  + sysbus IRQ 0: UARTINTR (combined interrupt line)
+ *  + sysbus IRQ 1: UARTRXINTR (receive FIFO interrupt line)
+ *  + sysbus IRQ 2: UARTTXINTR (transmit FIFO interrupt line)
+ *  + sysbus IRQ 3: UARTRTINTR (receive timeout interrupt line)
+ *  + sysbus IRQ 4: UARTMSINTR (momem status interrupt line)
+ *  + sysbus IRQ 5: UARTEINTR (error interrupt line)
+ */
+
 #include "qemu/osdep.h"
 #include "hw/char/pl011.h"
 #include "hw/sysbus.h"
@@ -22,18 +33,46 @@
 #define PL011_FLAG_TXFF 0x20
 #define PL011_FLAG_RXFE 0x10
 
+/* Interrupt status bits in UARTRIS, UARTMIS, UARTIMSC */
+#define INT_OE (1 << 10)
+#define INT_BE (1 << 9)
+#define INT_PE (1 << 8)
+#define INT_FE (1 << 7)
+#define INT_RT (1 << 6)
+#define INT_TX (1 << 5)
+#define INT_RX (1 << 4)
+#define INT_DSR (1 << 3)
+#define INT_DCD (1 << 2)
+#define INT_CTS (1 << 1)
+#define INT_RI (1 << 0)
+#define INT_E (INT_OE | INT_BE | INT_PE | INT_FE)
+#define INT_MS (INT_RI | INT_DSR | INT_DCD | INT_CTS)
+
 static const unsigned char pl011_id_arm[8] =
   { 0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
 static const unsigned char pl011_id_luminary[8] =
   { 0x11, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1 };
 
+/* Which bits in the interrupt status matter for each outbound IRQ line ? */
+static const uint32_t irqmask[] = {
+    INT_E | INT_MS | INT_RT | INT_TX | INT_RX, /* combined IRQ */
+    INT_RX,
+    INT_TX,
+    INT_RT,
+    INT_MS,
+    INT_E,
+};
+
 static void pl011_update(PL011State *s)
 {
     uint32_t flags;
+    int i;
 
     flags = s->int_level & s->int_enabled;
     trace_pl011_irq_state(flags != 0);
-    qemu_set_irq(s->irq, flags != 0);
+    for (i = 0; i < ARRAY_SIZE(s->irq); i++) {
+        qemu_set_irq(s->irq[i], (flags & irqmask[i]) != 0);
+    }
 }
 
 static uint64_t pl011_read(void *opaque, hwaddr offset,
@@ -284,10 +323,13 @@ static void pl011_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     PL011State *s = PL011(obj);
+    int i;
 
     memory_region_init_io(&s->iomem, OBJECT(s), &pl011_ops, s, "pl011", 0x1000);
     sysbus_init_mmio(sbd, &s->iomem);
-    sysbus_init_irq(sbd, &s->irq);
+    for (i = 0; i < ARRAY_SIZE(s->irq); i++) {
+        sysbus_init_irq(sbd, &s->irq[i]);
+    }
 
     s->read_trigger = 1;
     s->ifl = 0x12;