ARM: OMAP: change get_context_loss_count ret value to int

get_context_loss_count functions return context loss count as u32, and
zero means an error. However, zero is also returned when context has
never been lost and could also be returned when the context loss count
has wrapped and goes to zero.

Change the functions to return an int, with negative value meaning an
error.

OMAP HSMMC code uses omap_pm_get_dev_context_loss_count(), but as the
hsmmc code handles the returned value as an int, with negative value
meaning an error, this patch actually fixes hsmmc code also.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
[tony@atomide.com: updated to fix a warning with recent dmtimer changes]
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/powerdomain.c

@@ -1002,16 +1002,16 @@ int pwrdm_post_transition(void)
  * @pwrdm: struct powerdomain * to wait for
  *
  * Context loss count is the sum of powerdomain off-mode counter, the
- * logic off counter and the per-bank memory off counter.  Returns 0
+ * logic off counter and the per-bank memory off counter.  Returns negative
  * (and WARNs) upon error, otherwise, returns the context loss count.
  */
-u32 pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
+int pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
 {
 	int i, count;
 
 	if (!pwrdm) {
 		WARN(1, "powerdomain: %s: pwrdm is null\n", __func__);
-		return 0;
+		return -ENODEV;
 	}
 
 	count = pwrdm->state_counter[PWRDM_POWER_OFF];
@@ -1020,7 +1020,13 @@ u32 pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
 	for (i = 0; i < pwrdm->banks; i++)
 		count += pwrdm->ret_mem_off_counter[i];
 
-	pr_debug("powerdomain: %s: context loss count = %u\n",
+	/*
+	 * Context loss count has to be a non-negative value. Clear the sign
+	 * bit to get a value range from 0 to INT_MAX.
+	 */
+	count &= INT_MAX;
+
+	pr_debug("powerdomain: %s: context loss count = %d\n",
 		 pwrdm->name, count);
 
 	return count;