soc: rockchip: power-domain: allow domains only handling idle requests

On some Rockchip SoC there exist child-domains only handling their
idle state with the actual power-state handled by a (shared) parent-
domain.

So allow such types of domains. For them, we can determine their
state (on/off) by checking the inverse idle-state instead.

There exist one special case if both idle as well power handling
were set as not present, but as the domain-data is defined in the
code itself, we can expect the reasonable developer to define them
in a correct way, without adding more checks.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

drivers/soc/rockchip/pm_domains.c

@@ -66,8 +66,8 @@ struct rockchip_pmu {
 
 #define DOMAIN(pwr, status, req, idle, ack)	\
 {						\
-	.pwr_mask = BIT(pwr),			\
-	.status_mask = BIT(status),		\
+	.pwr_mask = (pwr >= 0) ? BIT(pwr) : 0,		\
+	.status_mask = (status >= 0) ? BIT(status) : 0,	\
 	.req_mask = (req >= 0) ? BIT(req) : 0,		\
 	.idle_mask = (idle >= 0) ? BIT(idle) : 0,	\
 	.ack_mask = (ack >= 0) ? BIT(ack) : 0,		\
@@ -119,6 +119,10 @@ static bool rockchip_pmu_domain_is_on(struct rockchip_pm_domain *pd)
 	struct rockchip_pmu *pmu = pd->pmu;
 	unsigned int val;
 
+	/* check idle status for idle-only domains */
+	if (pd->info->status_mask == 0)
+		return !rockchip_pmu_domain_is_idle(pd);
+
 	regmap_read(pmu->regmap, pmu->info->status_offset, &val);
 
 	/* 1'b0: power on, 1'b1: power off */
@@ -130,6 +134,9 @@ static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
 {
 	struct rockchip_pmu *pmu = pd->pmu;
 
+	if (pd->info->pwr_mask == 0)
+		return;
+
 	regmap_update_bits(pmu->regmap, pmu->info->pwr_offset,
 			   pd->info->pwr_mask, on ? 0 : -1U);