allwinner: psci: Drop .get_node_hw_state callback

This optional PSCI function was only implemented when SCPI was
available. However, the underlying SCPI function is not able to fulfill
the necessary contract. First, the SCPI protocol has no way to represent
HW_STANDBY at the CPU power level. Second, the SCPI implementation
maintains its own logical view of power states, and its implementation
of SCPI_CMD_GET_CSS_POWER_STATE does not actually query the hardware.
Thus it cannot provide "the physical view of power state", as required
for this function by the PSCI specification.

Since the function is optional, drop it.

Change-Id: I5f3a0810ac19ddeb3c0c5d35aeb09f09a0b80c1d
Signed-off-by: Samuel Holland <samuel@sholland.org>

plat/allwinner/common/sunxi_pm.c

@@ -226,29 +226,6 @@ static void sunxi_get_sys_suspend_power_state(psci_power_state_t *req_state)
 		req_state->pwr_domain_state[i] = PLAT_MAX_OFF_STATE;
 }
 
-static int sunxi_get_node_hw_state(u_register_t mpidr,
-				   unsigned int power_level)
-{
-	unsigned int cluster_state, cpu_state;
-	unsigned int cpu = MPIDR_AFFLVL0_VAL(mpidr);
-
-	/* SoC power level (always on if PSCI works). */
-	if (power_level == SYSTEM_PWR_LVL)
-		return HW_ON;
-	if (scpi_get_css_power_state(mpidr, &cpu_state, &cluster_state))
-		return PSCI_E_NOT_SUPPORTED;
-	/* Cluster power level (full power state available). */
-	if (power_level == CLUSTER_PWR_LVL) {
-		if (cluster_state == scpi_power_on)
-			return HW_ON;
-		if (cluster_state == scpi_power_retention)
-			return HW_STANDBY;
-		return HW_OFF;
-	}
-	/* CPU power level (one bit boolean for on or off). */
-	return ((cpu_state & BIT(cpu)) != 0) ? HW_ON : HW_OFF;
-}
-
 static plat_psci_ops_t sunxi_psci_ops = {
 	.cpu_standby			= sunxi_cpu_standby,
 	.pwr_domain_on			= sunxi_pwr_domain_on,
@@ -297,7 +274,6 @@ int plat_setup_psci_ops(uintptr_t sec_entrypoint,
 		sunxi_psci_ops.pwr_domain_suspend = sunxi_pwr_domain_off;
 		sunxi_psci_ops.pwr_domain_suspend_finish = sunxi_pwr_domain_on_finish;
 		sunxi_psci_ops.get_sys_suspend_power_state = sunxi_get_sys_suspend_power_state;
-		sunxi_psci_ops.get_node_hw_state = sunxi_get_node_hw_state;
 	} else {
 		/* This is only needed when SCPI is unavailable. */
 		sunxi_psci_ops.pwr_domain_pwr_down_wfi = sunxi_pwr_down_wfi;