imx: power optimization for i.mx8qx

Current implementation of i.MX8QX power management related
features does NOT optimize power number, all system resources
like CCI, DDR, and A cluster etc. are kept in STBY mode (powered
ON) when system suspend or CPU hotplug.

To lower the power number, OFF mode should be adopted for those
system resources whenever they can be OFF, A cluster will be OFF
if the CPUs in the cluster are all off line, DDR/MU/DB can be OFF
if system suspend, IRQ steer can be OFF if the wakeup source is
belonged to system controller partition, so wakeup source runtime
check is used to determine if IRQ steer can be OFF before system
suspend.

If resources are powered off for suspend, they should be restored
properly after system resume.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

1 files changed, 140 insertions, 18 deletions

diff --git a/plat/imx/imx8qx/imx8qx_psci.c b/plat/imx/imx8qx/imx8qx_psci.c
index 94c2e2b1..aab3a2da 100644
--- a/plat/imx/imx8qx/imx8qx_psci.c
+++ b/plat/imx/imx8qx/imx8qx_psci.c
@@ -16,10 +16,52 @@
 #include <plat_imx8.h>
 #include <sci/sci.h>
 
+#include "../../common/sci/imx8_mu.h"
+
 const static int ap_core_index[PLATFORM_CORE_COUNT] = {
 	SC_R_A35_0, SC_R_A35_1, SC_R_A35_2, SC_R_A35_3
 };
 
+/* save gic dist/redist context when GIC is power down */
+static struct plat_gic_ctx imx_gicv3_ctx;
+static unsigned int gpt_lpcg, gpt_reg[2];
+
+static void imx_enable_irqstr_wakeup(void)
+{
+	uint32_t irq_mask;
+	gicv3_dist_ctx_t *dist_ctx = &imx_gicv3_ctx.dist_ctx;
+
+	/* put IRQSTR into ON mode */
+	sc_pm_set_resource_power_mode(ipc_handle, SC_R_IRQSTR_SCU2, SC_PM_PW_MODE_ON);
+
+	/* enable the irqsteer to handle wakeup irq */
+	mmio_write_32(IMX_WUP_IRQSTR_BASE, 0x1);
+	for (int i = 0; i < 15; i++) {
+		irq_mask = dist_ctx->gicd_isenabler[i];
+		mmio_write_32(IMX_WUP_IRQSTR_BASE + 0x3c - 0x4 * i, irq_mask);
+	}
+
+	/* set IRQSTR low power mode */
+	if (imx_is_wakeup_src_irqsteer())
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_IRQSTR_SCU2, SC_PM_PW_MODE_STBY);
+	else
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_IRQSTR_SCU2, SC_PM_PW_MODE_OFF);
+}
+
+static void imx_disable_irqstr_wakeup(void)
+{
+	/* Put IRQSTEER back to ON mode */
+	sc_pm_set_resource_power_mode(ipc_handle, SC_R_IRQSTR_SCU2, SC_PM_PW_MODE_ON);
+
+	/* disable the irqsteer */
+	mmio_write_32(IMX_WUP_IRQSTR_BASE, 0x0);
+	for (int i = 0; i < 16; i++)
+		mmio_write_32(IMX_WUP_IRQSTR_BASE + 0x4 + 0x4 * i, 0x0);
+
+	/* Put IRQSTEER into OFF mode */
+	sc_pm_set_resource_power_mode(ipc_handle, SC_R_IRQSTR_SCU2, SC_PM_PW_MODE_OFF);
+}
+
 int imx_pwr_domain_on(u_register_t mpidr)
 {
 	int ret = PSCI_E_SUCCESS;
@@ -71,11 +113,52 @@ void imx_domain_suspend(const psci_power_state_t *target_state)
 	u_register_t mpidr = read_mpidr_el1();
 	unsigned int cpu_id = MPIDR_AFFLVL0_VAL(mpidr);
 
-	plat_gic_cpuif_disable();
+	if (is_local_state_off(target_state->pwr_domain_state[MPIDR_AFFLVL0])) {
+		plat_gic_cpuif_disable();
+		sc_pm_set_cpu_resume(ipc_handle, ap_core_index[cpu_id], true, BL31_BASE);
+		sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
+			SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_GIC);
+	} else {
+		dsb();
+		write_scr_el3(read_scr_el3() | SCR_FIQ_BIT);
+		isb();
+	}
 
-	sc_pm_set_cpu_resume_addr(ipc_handle, ap_core_index[cpu_id], BL31_BASE);
-	sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
-		SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_GIC);
+	if (is_local_state_off(target_state->pwr_domain_state[MPIDR_AFFLVL1]))
+		sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_OFF);
+
+	if (is_local_state_retn(target_state->pwr_domain_state[PLAT_MAX_PWR_LVL])) {
+		plat_gic_cpuif_disable();
+
+		/* save gic context */
+		plat_gic_save(cpu_id, &imx_gicv3_ctx);
+		/* enable the irqsteer for wakeup */
+		imx_enable_irqstr_wakeup();
+
+		/* Save GPT clock and registers, then turn off its power */
+		gpt_lpcg = mmio_read_32(IMX_GPT0_LPCG_BASE);
+		gpt_reg[0] = mmio_read_32(IMX_GPT0_BASE);
+		gpt_reg[1] = mmio_read_32(IMX_GPT0_BASE + 0x4);
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_GPT_0, SC_PM_PW_MODE_OFF);
+
+		sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_OFF);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_DDR,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_OFF);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_MU,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_OFF);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_INTERCONNECT,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_OFF);
+
+		/* Put GIC in OFF mode. */
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_GIC, SC_PM_PW_MODE_OFF);
+		sc_pm_set_cpu_resume(ipc_handle, ap_core_index[cpu_id], true, BL31_BASE);
+		if (imx_is_wakeup_src_irqsteer())
+			sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
+				SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_IRQSTEER);
+		else
+			sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
+				SC_PM_PW_MODE_OFF, SC_PM_WAKE_SRC_SCU);
+	}
 }
 
 void imx_domain_suspend_finish(const psci_power_state_t *target_state)
@@ -83,10 +166,51 @@ void imx_domain_suspend_finish(const psci_power_state_t *target_state)
 	u_register_t mpidr = read_mpidr_el1();
 	unsigned int cpu_id = MPIDR_AFFLVL0_VAL(mpidr);
 
-	sc_pm_req_low_power_mode(ipc_handle, ap_core_index[cpu_id],
-		SC_PM_PW_MODE_ON);
+	if (is_local_state_retn(target_state->pwr_domain_state[PLAT_MAX_PWR_LVL])) {
+		MU_Resume(SC_IPC_BASE);
 
-	plat_gic_cpuif_enable();
+		sc_pm_req_low_power_mode(ipc_handle, ap_core_index[cpu_id], SC_PM_PW_MODE_ON);
+		sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
+			SC_PM_PW_MODE_ON, SC_PM_WAKE_SRC_GIC);
+
+		/* Put GIC back to high power mode. */
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_GIC, SC_PM_PW_MODE_ON);
+
+		/* restore gic context */
+		plat_gic_restore(cpu_id, &imx_gicv3_ctx);
+
+		/* Turn on GPT power and restore its clock and registers */
+		sc_pm_set_resource_power_mode(ipc_handle, SC_R_GPT_0, SC_PM_PW_MODE_ON);
+		sc_pm_clock_enable(ipc_handle, SC_R_GPT_0, SC_PM_CLK_PER, true, 0);
+		mmio_write_32(IMX_GPT0_BASE, gpt_reg[0]);
+		mmio_write_32(IMX_GPT0_BASE + 0x4, gpt_reg[1]);
+		mmio_write_32(IMX_GPT0_LPCG_BASE, gpt_lpcg);
+
+		sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_ON);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_DDR,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_MU,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
+		sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_INTERCONNECT,
+			SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
+
+		/* disable the irqsteer wakeup */
+		imx_disable_irqstr_wakeup();
+
+		plat_gic_cpuif_enable();
+	}
+
+	if (is_local_state_off(target_state->pwr_domain_state[MPIDR_AFFLVL1]))
+		sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_ON);
+
+	if (is_local_state_off(target_state->pwr_domain_state[MPIDR_AFFLVL0])) {
+		sc_pm_req_cpu_low_power_mode(ipc_handle, ap_core_index[cpu_id],
+			SC_PM_PW_MODE_ON, SC_PM_WAKE_SRC_GIC);
+		plat_gic_cpuif_enable();
+	} else {
+		write_scr_el3(read_scr_el3() & (~SCR_FIQ_BIT));
+		isb();
+	}
 }
 
 static const plat_psci_ops_t imx_plat_psci_ops = {
@@ -108,17 +232,15 @@ int plat_setup_psci_ops(uintptr_t sec_entrypoint,
 	imx_mailbox_init(sec_entrypoint);
 	*psci_ops = &imx_plat_psci_ops;
 
-	/* Request low power mode for A35 cluster, only need to do once */
-	sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_OFF);
-
-	/* Request RUN and LP modes for DDR, system interconnect etc. */
-	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35,
-		SC_PM_SYS_IF_DDR, SC_PM_PW_MODE_ON, SC_PM_PW_MODE_STBY);
-	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35,
-		SC_PM_SYS_IF_MU, SC_PM_PW_MODE_ON, SC_PM_PW_MODE_STBY);
-	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35,
-		SC_PM_SYS_IF_INTERCONNECT, SC_PM_PW_MODE_ON,
-		SC_PM_PW_MODE_STBY);
+	/* make sure system sources power ON in low power mode by default */
+	sc_pm_req_low_power_mode(ipc_handle, SC_R_A35, SC_PM_PW_MODE_ON);
+
+	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_DDR,
+		SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
+	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_MU,
+		SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
+	sc_pm_req_sys_if_power_mode(ipc_handle, SC_R_A35, SC_PM_SYS_IF_INTERCONNECT,
+		SC_PM_PW_MODE_ON, SC_PM_PW_MODE_ON);
 
 	return 0;
 }