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Diffstat (limited to 'hw/timer/imx_gpt.c')
-rw-r--r--hw/timer/imx_gpt.c33
1 files changed, 25 insertions, 8 deletions
diff --git a/hw/timer/imx_gpt.c b/hw/timer/imx_gpt.c
index 010ccbf207..4b9b54bf2e 100644
--- a/hw/timer/imx_gpt.c
+++ b/hw/timer/imx_gpt.c
@@ -296,18 +296,23 @@ static uint64_t imx_gpt_read(void *opaque, hwaddr offset, unsigned size)
     return reg_value;
 }
 
-static void imx_gpt_reset(DeviceState *dev)
-{
-    IMXGPTState *s = IMX_GPT(dev);
 
+static void imx_gpt_reset_common(IMXGPTState *s, bool is_soft_reset)
+{
     /* stop timer */
     ptimer_stop(s->timer);
 
-    /*
-     * Soft reset doesn't touch some bits; hard reset clears them
+    /* Soft reset and hard reset differ only in their handling of the CR
+     * register -- soft reset preserves the values of some bits there.
      */
-    s->cr &= ~(GPT_CR_EN|GPT_CR_ENMOD|GPT_CR_STOPEN|GPT_CR_DOZEN|
-               GPT_CR_WAITEN|GPT_CR_DBGEN);
+    if (is_soft_reset) {
+        /* Clear all CR bits except those that are preserved by soft reset. */
+        s->cr &= GPT_CR_EN | GPT_CR_ENMOD | GPT_CR_STOPEN | GPT_CR_DOZEN |
+            GPT_CR_WAITEN | GPT_CR_DBGEN |
+            (GPT_CR_CLKSRC_MASK << GPT_CR_CLKSRC_SHIFT);
+    } else {
+        s->cr = 0;
+    }
     s->sr = 0;
     s->pr = 0;
     s->ir = 0;
@@ -333,6 +338,18 @@ static void imx_gpt_reset(DeviceState *dev)
     }
 }
 
+static void imx_gpt_soft_reset(DeviceState *dev)
+{
+    IMXGPTState *s = IMX_GPT(dev);
+    imx_gpt_reset_common(s, true);
+}
+
+static void imx_gpt_reset(DeviceState *dev)
+{
+    IMXGPTState *s = IMX_GPT(dev);
+    imx_gpt_reset_common(s, false);
+}
+
 static void imx_gpt_write(void *opaque, hwaddr offset, uint64_t value,
                           unsigned size)
 {
@@ -348,7 +365,7 @@ static void imx_gpt_write(void *opaque, hwaddr offset, uint64_t value,
         s->cr = value & ~0x7c14;
         if (s->cr & GPT_CR_SWR) { /* force reset */
             /* handle the reset */
-            imx_gpt_reset(DEVICE(s));
+            imx_gpt_soft_reset(DEVICE(s));
         } else {
             /* set our freq, as the source might have changed */
             imx_gpt_set_freq(s);