integrator/cp: Implement CARDIN and WPROT signals

This allows to use the SD card emulation of the board: Forward the
signals from the pl181 top the CP control register emulation, report the
current state via CP_INTREG, deliver CARDIN IRQ to the secondary
interrupt controller and also support clearing that line via CP_INTREG.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Message-id: c55d9fb28d19ec83625cb0074b3b6f2e5958caf6.1426004843.git.jan.kiszka@siemens.com
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/integratorcp.c

@@ -416,18 +416,29 @@ typedef struct ICPCtrlRegsState {
     /*< public >*/
 
     MemoryRegion iomem;
+
+    qemu_irq mmc_irq;
+    uint32_t intreg_state;
 } ICPCtrlRegsState;
 
+#define ICP_GPIO_MMC_WPROT      "mmc-wprot"
+#define ICP_GPIO_MMC_CARDIN     "mmc-cardin"
+
+#define ICP_INTREG_WPROT        (1 << 0)
+#define ICP_INTREG_CARDIN       (1 << 3)
+
 static uint64_t icp_control_read(void *opaque, hwaddr offset,
                                  unsigned size)
 {
+    ICPCtrlRegsState *s = opaque;
+
     switch (offset >> 2) {
     case 0: /* CP_IDFIELD */
         return 0x41034003;
     case 1: /* CP_FLASHPROG */
         return 0;
     case 2: /* CP_INTREG */
-        return 0;
+        return s->intreg_state;
     case 3: /* CP_DECODE */
         return 0x11;
     default:
@@ -439,9 +450,14 @@ static uint64_t icp_control_read(void *opaque, hwaddr offset,
 static void icp_control_write(void *opaque, hwaddr offset,
                           uint64_t value, unsigned size)
 {
+    ICPCtrlRegsState *s = opaque;
+
     switch (offset >> 2) {
-    case 1: /* CP_FLASHPROG */
     case 2: /* CP_INTREG */
+        s->intreg_state &= ~(value & ICP_INTREG_CARDIN);
+        qemu_set_irq(s->mmc_irq, !!(s->intreg_state & ICP_INTREG_CARDIN));
+        break;
+    case 1: /* CP_FLASHPROG */
     case 3: /* CP_DECODE */
         /* Nothing interesting implemented yet.  */
         break;
@@ -456,14 +472,41 @@ static const MemoryRegionOps icp_control_ops = {
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
+static void icp_control_mmc_wprot(void *opaque, int line, int level)
+{
+    ICPCtrlRegsState *s = opaque;
+
+    s->intreg_state &= ~ICP_INTREG_WPROT;
+    if (level) {
+        s->intreg_state |= ICP_INTREG_WPROT;
+    }
+}
+
+static void icp_control_mmc_cardin(void *opaque, int line, int level)
+{
+    ICPCtrlRegsState *s = opaque;
+
+    /* line is released by writing to CP_INTREG */
+    if (level) {
+        s->intreg_state |= ICP_INTREG_CARDIN;
+        qemu_set_irq(s->mmc_irq, 1);
+    }
+}
+
 static void icp_control_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     ICPCtrlRegsState *s = ICP_CONTROL_REGS(obj);
+    DeviceState *dev = DEVICE(obj);
 
     memory_region_init_io(&s->iomem, OBJECT(s), &icp_control_ops, s,
                           "icp_ctrl_regs", 0x00800000);
     sysbus_init_mmio(sbd, &s->iomem);
+
+    qdev_init_gpio_in_named(dev, icp_control_mmc_wprot, ICP_GPIO_MMC_WPROT, 1);
+    qdev_init_gpio_in_named(dev, icp_control_mmc_cardin,
+                            ICP_GPIO_MMC_CARDIN, 1);
+    sysbus_init_irq(sbd, &s->mmc_irq);
 }
 
 
@@ -488,7 +531,7 @@ static void integratorcp_init(MachineState *machine)
     MemoryRegion *ram = g_new(MemoryRegion, 1);
     MemoryRegion *ram_alias = g_new(MemoryRegion, 1);
     qemu_irq pic[32];
-    DeviceState *dev;
+    DeviceState *dev, *sic, *icp;
     int i;
     Error *err = NULL;
 
@@ -546,17 +589,24 @@ static void integratorcp_init(MachineState *machine)
     for (i = 0; i < 32; i++) {
         pic[i] = qdev_get_gpio_in(dev, i);
     }
-    sysbus_create_simple(TYPE_INTEGRATOR_PIC, 0xca000000, pic[26]);
+    sic = sysbus_create_simple(TYPE_INTEGRATOR_PIC, 0xca000000, pic[26]);
     sysbus_create_varargs("integrator_pit", 0x13000000,
                           pic[5], pic[6], pic[7], NULL);
     sysbus_create_simple("pl031", 0x15000000, pic[8]);
     sysbus_create_simple("pl011", 0x16000000, pic[1]);
     sysbus_create_simple("pl011", 0x17000000, pic[2]);
-    sysbus_create_simple(TYPE_ICP_CONTROL_REGS, 0xcb000000, NULL);
+    icp = sysbus_create_simple(TYPE_ICP_CONTROL_REGS, 0xcb000000,
+                               qdev_get_gpio_in(sic, 3));
     sysbus_create_simple("pl050_keyboard", 0x18000000, pic[3]);
     sysbus_create_simple("pl050_mouse", 0x19000000, pic[4]);
     sysbus_create_simple(TYPE_INTEGRATOR_DEBUG, 0x1a000000, 0);
-    sysbus_create_varargs("pl181", 0x1c000000, pic[23], pic[24], NULL);
+
+    dev = sysbus_create_varargs("pl181", 0x1c000000, pic[23], pic[24], NULL);
+    qdev_connect_gpio_out(dev, 0,
+                          qdev_get_gpio_in_named(icp, ICP_GPIO_MMC_WPROT, 0));
+    qdev_connect_gpio_out(dev, 1,
+                          qdev_get_gpio_in_named(icp, ICP_GPIO_MMC_CARDIN, 0));
+
     if (nd_table[0].used)
         smc91c111_init(&nd_table[0], 0xc8000000, pic[27]);