hw/arm/stellaris: Implement watchdog timer

Implement the watchdog timer for the stellaris boards.
This device is a close variant of the CMSDK APB watchdog
device, so we can model it by subclassing that device and
tweaking the behaviour of some of its registers.

Signed-off-by: Michel Heily <michelheily@gmail.com>
Reviewed-by: Peter Maydell <petser.maydell@linaro.org>
[PMM: rewrote commit message, fixed a few checkpatch nits,
 added comment giving the URL of the spec for the Stellaris
 variant of the watchdog device]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 20 insertions, 2 deletions

diff --git a/hw/arm/stellaris.c b/hw/arm/stellaris.c
index 7b45fe3ccf..05f86749f4 100644
--- a/hw/arm/stellaris.c
+++ b/hw/arm/stellaris.c
@@ -22,6 +22,7 @@
 #include "sysemu/sysemu.h"
 #include "hw/arm/armv7m.h"
 #include "hw/char/pl011.h"
+#include "hw/watchdog/cmsdk-apb-watchdog.h"
 #include "hw/misc/unimp.h"
 #include "cpu.h"
 
@@ -1243,7 +1244,7 @@ static void stellaris_init(MachineState *ms, stellaris_board_info *board)
      * Stellaris LM3S6965 Microcontroller Data Sheet (rev I)
      * http://www.ti.com/lit/ds/symlink/lm3s6965.pdf
      *
-     * 40000000 wdtimer (unimplemented)
+     * 40000000 wdtimer
      * 40002000 i2c (unimplemented)
      * 40004000 GPIO
      * 40005000 GPIO
@@ -1338,6 +1339,24 @@ static void stellaris_init(MachineState *ms, stellaris_board_info *board)
     stellaris_sys_init(0x400fe000, qdev_get_gpio_in(nvic, 28),
                        board, nd_table[0].macaddr.a);
 
+
+    if (board->dc1 & (1 << 3)) { /* watchdog present */
+        dev = qdev_create(NULL, TYPE_LUMINARY_WATCHDOG);
+
+        /* system_clock_scale is valid now */
+        uint32_t mainclk = NANOSECONDS_PER_SECOND / system_clock_scale;
+        qdev_prop_set_uint32(dev, "wdogclk-frq", mainclk);
+
+        qdev_init_nofail(dev);
+        sysbus_mmio_map(SYS_BUS_DEVICE(dev),
+                        0,
+                        0x40000000u);
+        sysbus_connect_irq(SYS_BUS_DEVICE(dev),
+                           0,
+                           qdev_get_gpio_in(nvic, 18));
+    }
+
+
     for (i = 0; i < 7; i++) {
         if (board->dc4 & (1 << i)) {
             gpio_dev[i] = sysbus_create_simple("pl061_luminary", gpio_addr[i],
@@ -1431,7 +1450,6 @@ static void stellaris_init(MachineState *ms, stellaris_board_info *board)
     /* Add dummy regions for the devices we don't implement yet,
      * so guest accesses don't cause unlogged crashes.
      */
-    create_unimplemented_device("wdtimer", 0x40000000, 0x1000);
     create_unimplemented_device("i2c-0", 0x40002000, 0x1000);
     create_unimplemented_device("i2c-2", 0x40021000, 0x1000);
     create_unimplemented_device("PWM", 0x40028000, 0x1000);